Merge pull request #81939 from YuriSizov/gui-flat-and-depressed

Replace flat buttons with flat-styled buttons with a visible pressed state

editor/debugger/script_editor_debugger.cpp

@@ -1814,7 +1814,7 @@ ScriptEditorDebugger::ScriptEditorDebugger() {
 		hbc->add_child(memnew(VSeparator));
 
 		skip_breakpoints = memnew(Button);
-		skip_breakpoints->set_flat(true);
+		skip_breakpoints->set_theme_type_variation("FlatButton");
 		hbc->add_child(skip_breakpoints);
 		skip_breakpoints->set_tooltip_text(TTR("Skip Breakpoints"));
 		skip_breakpoints->connect("pressed", callable_mp(this, &ScriptEditorDebugger::debug_skip_breakpoints));
@@ -1822,7 +1822,7 @@ ScriptEditorDebugger::ScriptEditorDebugger() {
 		hbc->add_child(memnew(VSeparator));
 
 		copy = memnew(Button);
-		copy->set_flat(true);
+		copy->set_theme_type_variation("FlatButton");
 		hbc->add_child(copy);
 		copy->set_tooltip_text(TTR("Copy Error"));
 		copy->connect("pressed", callable_mp(this, &ScriptEditorDebugger::debug_copy));
@@ -1830,14 +1830,14 @@ ScriptEditorDebugger::ScriptEditorDebugger() {
 		hbc->add_child(memnew(VSeparator));
 
 		step = memnew(Button);
-		step->set_flat(true);
+		step->set_theme_type_variation("FlatButton");
 		hbc->add_child(step);
 		step->set_tooltip_text(TTR("Step Into"));
 		step->set_shortcut(ED_GET_SHORTCUT("debugger/step_into"));
 		step->connect("pressed", callable_mp(this, &ScriptEditorDebugger::debug_step));
 
 		next = memnew(Button);
-		next->set_flat(true);
+		next->set_theme_type_variation("FlatButton");
 		hbc->add_child(next);
 		next->set_tooltip_text(TTR("Step Over"));
 		next->set_shortcut(ED_GET_SHORTCUT("debugger/step_over"));
@@ -1846,14 +1846,14 @@ ScriptEditorDebugger::ScriptEditorDebugger() {
 		hbc->add_child(memnew(VSeparator));
 
 		dobreak = memnew(Button);
-		dobreak->set_flat(true);
+		dobreak->set_theme_type_variation("FlatButton");
 		hbc->add_child(dobreak);
 		dobreak->set_tooltip_text(TTR("Break"));
 		dobreak->set_shortcut(ED_GET_SHORTCUT("debugger/break"));
 		dobreak->connect("pressed", callable_mp(this, &ScriptEditorDebugger::debug_break));
 
 		docontinue = memnew(Button);
-		docontinue->set_flat(true);
+		docontinue->set_theme_type_variation("FlatButton");
 		hbc->add_child(docontinue);
 		docontinue->set_tooltip_text(TTR("Continue"));
 		docontinue->set_shortcut(ED_GET_SHORTCUT("debugger/continue"));
@@ -2028,10 +2028,10 @@ ScriptEditorDebugger::ScriptEditorDebugger() {
 		vmem_total->set_custom_minimum_size(Size2(100, 0) * EDSCALE);
 		vmem_hb->add_child(vmem_total);
 		vmem_refresh = memnew(Button);
-		vmem_refresh->set_flat(true);
+		vmem_refresh->set_theme_type_variation("FlatButton");
 		vmem_hb->add_child(vmem_refresh);
 		vmem_export = memnew(Button);
-		vmem_export->set_flat(true);
+		vmem_export->set_theme_type_variation("FlatButton");
 		vmem_export->set_tooltip_text(TTR("Export list to a CSV file"));
 		vmem_hb->add_child(vmem_export);
 		vmem_vb->add_child(vmem_hb);

editor/editor_audio_buses.cpp

@@ -803,21 +803,21 @@ EditorAudioBus::EditorAudioBus(EditorAudioBuses *p_buses, bool p_is_master) {
 	HBoxContainer *hbc = memnew(HBoxContainer);
 	vb->add_child(hbc);
 	solo = memnew(Button);
-	solo->set_flat(true);
+	solo->set_theme_type_variation("FlatButton");
 	solo->set_toggle_mode(true);
 	solo->set_tooltip_text(TTR("Solo"));
 	solo->set_focus_mode(FOCUS_NONE);
 	solo->connect("pressed", callable_mp(this, &EditorAudioBus::_solo_toggled));
 	hbc->add_child(solo);
 	mute = memnew(Button);
-	mute->set_flat(true);
+	mute->set_theme_type_variation("FlatButton");
 	mute->set_toggle_mode(true);
 	mute->set_tooltip_text(TTR("Mute"));
 	mute->set_focus_mode(FOCUS_NONE);
 	mute->connect("pressed", callable_mp(this, &EditorAudioBus::_mute_toggled));
 	hbc->add_child(mute);
 	bypass = memnew(Button);
-	bypass->set_flat(true);
+	bypass->set_theme_type_variation("FlatButton");
 	bypass->set_toggle_mode(true);
 	bypass->set_tooltip_text(TTR("Bypass"));
 	bypass->set_focus_mode(FOCUS_NONE);

editor/editor_help_search.cpp

@@ -210,7 +210,7 @@ EditorHelpSearch::EditorHelpSearch() {
 	hbox->add_child(search_box);
 
 	case_sensitive_button = memnew(Button);
-	case_sensitive_button->set_flat(true);
+	case_sensitive_button->set_theme_type_variation("FlatButton");
 	case_sensitive_button->set_tooltip_text(TTR("Case Sensitive"));
 	case_sensitive_button->connect("pressed", callable_mp(this, &EditorHelpSearch::_update_results));
 	case_sensitive_button->set_toggle_mode(true);
@@ -218,7 +218,7 @@ EditorHelpSearch::EditorHelpSearch() {
 	hbox->add_child(case_sensitive_button);
 
 	hierarchy_button = memnew(Button);
-	hierarchy_button->set_flat(true);
+	hierarchy_button->set_theme_type_variation("FlatButton");
 	hierarchy_button->set_tooltip_text(TTR("Show Hierarchy"));
 	hierarchy_button->connect("pressed", callable_mp(this, &EditorHelpSearch::_update_results));
 	hierarchy_button->set_toggle_mode(true);

editor/editor_log.cpp

@@ -426,7 +426,7 @@ EditorLog::EditorLog() {
 
 	// Clear.
 	clear_button = memnew(Button);
-	clear_button->set_flat(true);
+	clear_button->set_theme_type_variation("FlatButton");
 	clear_button->set_focus_mode(FOCUS_NONE);
 	clear_button->set_shortcut(ED_SHORTCUT("editor/clear_output", TTR("Clear Output"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::K));
 	clear_button->set_shortcut_context(this);
@@ -435,7 +435,7 @@ EditorLog::EditorLog() {
 
 	// Copy.
 	copy_button = memnew(Button);
-	copy_button->set_flat(true);
+	copy_button->set_theme_type_variation("FlatButton");
 	copy_button->set_focus_mode(FOCUS_NONE);
 	copy_button->set_shortcut(ED_SHORTCUT("editor/copy_output", TTR("Copy Selection"), KeyModifierMask::CMD_OR_CTRL | Key::C));
 	copy_button->set_shortcut_context(this);
@@ -449,7 +449,7 @@ EditorLog::EditorLog() {
 
 	// Collapse.
 	collapse_button = memnew(Button);
-	collapse_button->set_flat(true);
+	collapse_button->set_theme_type_variation("FlatButton");
 	collapse_button->set_focus_mode(FOCUS_NONE);
 	collapse_button->set_tooltip_text(TTR("Collapse duplicate messages into one log entry. Shows number of occurrences."));
 	collapse_button->set_toggle_mode(true);
@@ -459,7 +459,7 @@ EditorLog::EditorLog() {
 
 	// Show Search.
 	show_search_button = memnew(Button);
-	show_search_button->set_flat(true);
+	show_search_button->set_theme_type_variation("FlatButton");
 	show_search_button->set_focus_mode(FOCUS_NONE);
 	show_search_button->set_toggle_mode(true);
 	show_search_button->set_pressed(true);

editor/editor_themes.cpp

@@ -951,7 +951,7 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	toolbar_stylebox->set_border_color(accent_color);
 	toolbar_stylebox->set_border_width(SIDE_BOTTOM, Math::round(2 * EDSCALE));
 	toolbar_stylebox->set_content_margin(SIDE_BOTTOM, 0);
-	toolbar_stylebox->set_expand_margin_all(2 * EDSCALE);
+	toolbar_stylebox->set_expand_margin_individual(4 * EDSCALE, 2 * EDSCALE, 4 * EDSCALE, 4 * EDSCALE);
 	theme->set_stylebox("ContextualToolbar", EditorStringName(EditorStyles), toolbar_stylebox);
 
 	// Script Editor
@@ -1022,6 +1022,30 @@ Ref<Theme> create_editor_theme(const Ref<Theme> p_theme) {
 	theme->set_constant("h_separation", "Button", 4 * EDSCALE);
 	theme->set_constant("outline_size", "Button", 0);
 
+	// Flat button variations.
+
+	Ref<StyleBoxEmpty> style_flat_button = make_empty_stylebox();
+	for (int i = 0; i < 4; i++) {
+		style_flat_button->set_content_margin((Side)i, style_widget->get_margin((Side)i) + style_widget->get_border_width((Side)i));
+	}
+
+	Ref<StyleBoxFlat> style_flat_button_pressed = style_widget_pressed->duplicate();
+	Color flat_pressed_color = dark_color_1.lerp(accent_color, 0.2) * Color(0.8, 0.8, 0.8, 0.85);
+	if (dark_theme) {
+		flat_pressed_color = dark_color_1.lerp(accent_color, 0.2) * Color(0.6, 0.6, 0.6, 0.85);
+	}
+	style_flat_button_pressed->set_bg_color(flat_pressed_color);
+
+	theme->set_stylebox("normal", "FlatButton", style_flat_button);
+	theme->set_stylebox("hover", "FlatButton", style_flat_button);
+	theme->set_stylebox("pressed", "FlatButton", style_flat_button_pressed);
+	theme->set_stylebox("disabled", "FlatButton", style_flat_button);
+
+	theme->set_stylebox("normal", "FlatMenuButton", style_flat_button);
+	theme->set_stylebox("hover", "FlatMenuButton", style_flat_button);
+	theme->set_stylebox("pressed", "FlatMenuButton", style_flat_button_pressed);
+	theme->set_stylebox("disabled", "FlatMenuButton", style_flat_button);
+
 	const float ACTION_BUTTON_EXTRA_MARGIN = 32 * EDSCALE;
 
 	theme->set_type_variation("InspectorActionButton", "Button");

editor/gui/editor_file_dialog.cpp

@@ -1741,13 +1741,13 @@ EditorFileDialog::EditorFileDialog() {
 	HBoxContainer *pathhb = memnew(HBoxContainer);
 
 	dir_prev = memnew(Button);
-	dir_prev->set_flat(true);
+	dir_prev->set_theme_type_variation("FlatButton");
 	dir_prev->set_tooltip_text(TTR("Go to previous folder."));
 	dir_next = memnew(Button);
-	dir_next->set_flat(true);
+	dir_next->set_theme_type_variation("FlatButton");
 	dir_next->set_tooltip_text(TTR("Go to next folder."));
 	dir_up = memnew(Button);
-	dir_up->set_flat(true);
+	dir_up->set_theme_type_variation("FlatButton");
 	dir_up->set_tooltip_text(TTR("Go to parent folder."));
 
 	pathhb->add_child(dir_prev);
@@ -1771,20 +1771,20 @@ EditorFileDialog::EditorFileDialog() {
 	dir->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 
 	refresh = memnew(Button);
-	refresh->set_flat(true);
+	refresh->set_theme_type_variation("FlatButton");
 	refresh->set_tooltip_text(TTR("Refresh files."));
 	refresh->connect("pressed", callable_mp(this, &EditorFileDialog::update_file_list));
 	pathhb->add_child(refresh);
 
 	favorite = memnew(Button);
-	favorite->set_flat(true);
+	favorite->set_theme_type_variation("FlatButton");
 	favorite->set_toggle_mode(true);
 	favorite->set_tooltip_text(TTR("(Un)favorite current folder."));
 	favorite->connect("pressed", callable_mp(this, &EditorFileDialog::_favorite_pressed));
 	pathhb->add_child(favorite);
 
 	show_hidden = memnew(Button);
-	show_hidden->set_flat(true);
+	show_hidden->set_theme_type_variation("FlatButton");
 	show_hidden->set_toggle_mode(true);
 	show_hidden->set_pressed(is_showing_hidden_files());
 	show_hidden->set_tooltip_text(TTR("Toggle the visibility of hidden files."));
@@ -1797,7 +1797,7 @@ EditorFileDialog::EditorFileDialog() {
 	view_mode_group.instantiate();
 
 	mode_thumbnails = memnew(Button);
-	mode_thumbnails->set_flat(true);
+	mode_thumbnails->set_theme_type_variation("FlatButton");
 	mode_thumbnails->connect("pressed", callable_mp(this, &EditorFileDialog::set_display_mode).bind(DISPLAY_THUMBNAILS));
 	mode_thumbnails->set_toggle_mode(true);
 	mode_thumbnails->set_pressed(display_mode == DISPLAY_THUMBNAILS);
@@ -1806,7 +1806,7 @@ EditorFileDialog::EditorFileDialog() {
 	pathhb->add_child(mode_thumbnails);
 
 	mode_list = memnew(Button);
-	mode_list->set_flat(true);
+	mode_list->set_theme_type_variation("FlatButton");
 	mode_list->connect("pressed", callable_mp(this, &EditorFileDialog::set_display_mode).bind(DISPLAY_LIST));
 	mode_list->set_toggle_mode(true);
 	mode_list->set_pressed(display_mode == DISPLAY_LIST);
@@ -1848,11 +1848,11 @@ EditorFileDialog::EditorFileDialog() {
 
 	fav_hb->add_spacer();
 	fav_up = memnew(Button);
-	fav_up->set_flat(true);
+	fav_up->set_theme_type_variation("FlatButton");
 	fav_hb->add_child(fav_up);
 	fav_up->connect("pressed", callable_mp(this, &EditorFileDialog::_favorite_move_up));
 	fav_down = memnew(Button);
-	fav_down->set_flat(true);
+	fav_down->set_theme_type_variation("FlatButton");
 	fav_hb->add_child(fav_down);
 	fav_down->connect("pressed", callable_mp(this, &EditorFileDialog::_favorite_move_down));
 

editor/plugins/abstract_polygon_2d_editor.cpp

@@ -726,19 +726,19 @@ AbstractPolygon2DEditor::AbstractPolygon2DEditor(bool p_wip_destructive) {
 	edge_point = PosVertex();
 
 	button_create = memnew(Button);
-	button_create->set_flat(true);
+	button_create->set_theme_type_variation("FlatButton");
 	add_child(button_create);
 	button_create->connect("pressed", callable_mp(this, &AbstractPolygon2DEditor::_menu_option).bind(MODE_CREATE));
 	button_create->set_toggle_mode(true);
 
 	button_edit = memnew(Button);
-	button_edit->set_flat(true);
+	button_edit->set_theme_type_variation("FlatButton");
 	add_child(button_edit);
 	button_edit->connect("pressed", callable_mp(this, &AbstractPolygon2DEditor::_menu_option).bind(MODE_EDIT));
 	button_edit->set_toggle_mode(true);
 
 	button_delete = memnew(Button);
-	button_delete->set_flat(true);
+	button_delete->set_theme_type_variation("FlatButton");
 	add_child(button_delete);
 	button_delete->connect("pressed", callable_mp(this, &AbstractPolygon2DEditor::_menu_option).bind(MODE_DELETE));
 	button_delete->set_toggle_mode(true);

editor/plugins/animation_blend_space_1d_editor.cpp

@@ -663,7 +663,7 @@ AnimationNodeBlendSpace1DEditor::AnimationNodeBlendSpace1DEditor() {
 	bg.instantiate();
 
 	tool_blend = memnew(Button);
-	tool_blend->set_flat(true);
+	tool_blend->set_theme_type_variation("FlatButton");
 	tool_blend->set_toggle_mode(true);
 	tool_blend->set_button_group(bg);
 	top_hb->add_child(tool_blend);
@@ -672,7 +672,7 @@ AnimationNodeBlendSpace1DEditor::AnimationNodeBlendSpace1DEditor() {
 	tool_blend->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace1DEditor::_tool_switch).bind(3));
 
 	tool_select = memnew(Button);
-	tool_select->set_flat(true);
+	tool_select->set_theme_type_variation("FlatButton");
 	tool_select->set_toggle_mode(true);
 	tool_select->set_button_group(bg);
 	top_hb->add_child(tool_select);
@@ -680,7 +680,7 @@ AnimationNodeBlendSpace1DEditor::AnimationNodeBlendSpace1DEditor() {
 	tool_select->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace1DEditor::_tool_switch).bind(0));
 
 	tool_create = memnew(Button);
-	tool_create->set_flat(true);
+	tool_create->set_theme_type_variation("FlatButton");
 	tool_create->set_toggle_mode(true);
 	tool_create->set_button_group(bg);
 	top_hb->add_child(tool_create);
@@ -690,7 +690,7 @@ AnimationNodeBlendSpace1DEditor::AnimationNodeBlendSpace1DEditor() {
 	tool_erase_sep = memnew(VSeparator);
 	top_hb->add_child(tool_erase_sep);
 	tool_erase = memnew(Button);
-	tool_erase->set_flat(true);
+	tool_erase->set_theme_type_variation("FlatButton");
 	top_hb->add_child(tool_erase);
 	tool_erase->set_tooltip_text(TTR("Erase points."));
 	tool_erase->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace1DEditor::_erase_selected));
@@ -698,7 +698,7 @@ AnimationNodeBlendSpace1DEditor::AnimationNodeBlendSpace1DEditor() {
 	top_hb->add_child(memnew(VSeparator));
 
 	snap = memnew(Button);
-	snap->set_flat(true);
+	snap->set_theme_type_variation("FlatButton");
 	snap->set_toggle_mode(true);
 	top_hb->add_child(snap);
 	snap->set_pressed(true);

editor/plugins/animation_blend_space_2d_editor.cpp

@@ -883,7 +883,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	bg.instantiate();
 
 	tool_blend = memnew(Button);
-	tool_blend->set_flat(true);
+	tool_blend->set_theme_type_variation("FlatButton");
 	tool_blend->set_toggle_mode(true);
 	tool_blend->set_button_group(bg);
 	top_hb->add_child(tool_blend);
@@ -892,7 +892,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	tool_blend->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace2DEditor::_tool_switch).bind(3));
 
 	tool_select = memnew(Button);
-	tool_select->set_flat(true);
+	tool_select->set_theme_type_variation("FlatButton");
 	tool_select->set_toggle_mode(true);
 	tool_select->set_button_group(bg);
 	top_hb->add_child(tool_select);
@@ -900,7 +900,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	tool_select->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace2DEditor::_tool_switch).bind(0));
 
 	tool_create = memnew(Button);
-	tool_create->set_flat(true);
+	tool_create->set_theme_type_variation("FlatButton");
 	tool_create->set_toggle_mode(true);
 	tool_create->set_button_group(bg);
 	top_hb->add_child(tool_create);
@@ -908,7 +908,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	tool_create->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace2DEditor::_tool_switch).bind(1));
 
 	tool_triangle = memnew(Button);
-	tool_triangle->set_flat(true);
+	tool_triangle->set_theme_type_variation("FlatButton");
 	tool_triangle->set_toggle_mode(true);
 	tool_triangle->set_button_group(bg);
 	top_hb->add_child(tool_triangle);
@@ -918,7 +918,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	tool_erase_sep = memnew(VSeparator);
 	top_hb->add_child(tool_erase_sep);
 	tool_erase = memnew(Button);
-	tool_erase->set_flat(true);
+	tool_erase->set_theme_type_variation("FlatButton");
 	top_hb->add_child(tool_erase);
 	tool_erase->set_tooltip_text(TTR("Erase points and triangles."));
 	tool_erase->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace2DEditor::_erase_selected));
@@ -927,7 +927,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	top_hb->add_child(memnew(VSeparator));
 
 	auto_triangles = memnew(Button);
-	auto_triangles->set_flat(true);
+	auto_triangles->set_theme_type_variation("FlatButton");
 	top_hb->add_child(auto_triangles);
 	auto_triangles->connect("pressed", callable_mp(this, &AnimationNodeBlendSpace2DEditor::_auto_triangles_toggled));
 	auto_triangles->set_toggle_mode(true);
@@ -936,7 +936,7 @@ AnimationNodeBlendSpace2DEditor::AnimationNodeBlendSpace2DEditor() {
 	top_hb->add_child(memnew(VSeparator));
 
 	snap = memnew(Button);
-	snap->set_flat(true);
+	snap->set_theme_type_variation("FlatButton");
 	snap->set_toggle_mode(true);
 	top_hb->add_child(snap);
 	snap->set_pressed(true);

editor/plugins/animation_player_editor_plugin.cpp

@@ -1682,27 +1682,27 @@ AnimationPlayerEditor::AnimationPlayerEditor(AnimationPlayerEditorPlugin *p_plug
 	add_child(hb);
 
 	play_bw_from = memnew(Button);
-	play_bw_from->set_flat(true);
+	play_bw_from->set_theme_type_variation("FlatButton");
 	play_bw_from->set_tooltip_text(TTR("Play selected animation backwards from current pos. (A)"));
 	hb->add_child(play_bw_from);
 
 	play_bw = memnew(Button);
-	play_bw->set_flat(true);
+	play_bw->set_theme_type_variation("FlatButton");
 	play_bw->set_tooltip_text(TTR("Play selected animation backwards from end. (Shift+A)"));
 	hb->add_child(play_bw);
 
 	stop = memnew(Button);
-	stop->set_flat(true);
+	stop->set_theme_type_variation("FlatButton");
 	hb->add_child(stop);
 	stop->set_tooltip_text(TTR("Pause/stop animation playback. (S)"));
 
 	play = memnew(Button);
-	play->set_flat(true);
+	play->set_theme_type_variation("FlatButton");
 	play->set_tooltip_text(TTR("Play selected animation from start. (Shift+D)"));
 	hb->add_child(play);
 
 	play_from = memnew(Button);
-	play_from->set_flat(true);
+	play_from->set_theme_type_variation("FlatButton");
 	play_from->set_tooltip_text(TTR("Play selected animation from current pos. (D)"));
 	hb->add_child(play_from);
 
@@ -1753,7 +1753,7 @@ AnimationPlayerEditor::AnimationPlayerEditor(AnimationPlayerEditorPlugin *p_plug
 	animation->set_auto_translate(false);
 
 	autoplay = memnew(Button);
-	autoplay->set_flat(true);
+	autoplay->set_theme_type_variation("FlatButton");
 	hb->add_child(autoplay);
 	autoplay->set_tooltip_text(TTR("Autoplay on Load"));
 
@@ -1766,7 +1766,7 @@ AnimationPlayerEditor::AnimationPlayerEditor(AnimationPlayerEditorPlugin *p_plug
 	hb->add_child(memnew(VSeparator));
 
 	onion_toggle = memnew(Button);
-	onion_toggle->set_flat(true);
+	onion_toggle->set_theme_type_variation("FlatButton");
 	onion_toggle->set_toggle_mode(true);
 	onion_toggle->set_tooltip_text(TTR("Enable Onion Skinning"));
 	onion_toggle->connect("pressed", callable_mp(this, &AnimationPlayerEditor::_onion_skinning_menu).bind(ONION_SKINNING_ENABLE));
@@ -1804,7 +1804,7 @@ AnimationPlayerEditor::AnimationPlayerEditor(AnimationPlayerEditorPlugin *p_plug
 	hb->add_child(memnew(VSeparator));
 
 	pin = memnew(Button);
-	pin->set_flat(true);
+	pin->set_theme_type_variation("FlatButton");
 	pin->set_toggle_mode(true);
 	pin->set_tooltip_text(TTR("Pin AnimationPlayer"));
 	hb->add_child(pin);

editor/plugins/animation_state_machine_editor.cpp

@@ -1676,7 +1676,7 @@ AnimationNodeStateMachineEditor::AnimationNodeStateMachineEditor() {
 	bg.instantiate();
 
 	tool_select = memnew(Button);
-	tool_select->set_flat(true);
+	tool_select->set_theme_type_variation("FlatButton");
 	top_hb->add_child(tool_select);
 	tool_select->set_toggle_mode(true);
 	tool_select->set_button_group(bg);
@@ -1685,7 +1685,7 @@ AnimationNodeStateMachineEditor::AnimationNodeStateMachineEditor() {
 	tool_select->connect("pressed", callable_mp(this, &AnimationNodeStateMachineEditor::_update_mode), CONNECT_DEFERRED);
 
 	tool_create = memnew(Button);
-	tool_create->set_flat(true);
+	tool_create->set_theme_type_variation("FlatButton");
 	top_hb->add_child(tool_create);
 	tool_create->set_toggle_mode(true);
 	tool_create->set_button_group(bg);
@@ -1693,7 +1693,7 @@ AnimationNodeStateMachineEditor::AnimationNodeStateMachineEditor() {
 	tool_create->connect("pressed", callable_mp(this, &AnimationNodeStateMachineEditor::_update_mode), CONNECT_DEFERRED);
 
 	tool_connect = memnew(Button);
-	tool_connect->set_flat(true);
+	tool_connect->set_theme_type_variation("FlatButton");
 	top_hb->add_child(tool_connect);
 	tool_connect->set_toggle_mode(true);
 	tool_connect->set_button_group(bg);
@@ -1706,7 +1706,7 @@ AnimationNodeStateMachineEditor::AnimationNodeStateMachineEditor() {
 	selection_tools_hb->add_child(memnew(VSeparator));
 
 	tool_erase = memnew(Button);
-	tool_erase->set_flat(true);
+	tool_erase->set_theme_type_variation("FlatButton");
 	tool_erase->set_tooltip_text(TTR("Remove selected node or transition."));
 	tool_erase->connect("pressed", callable_mp(this, &AnimationNodeStateMachineEditor::_erase_selected).bind(false));
 	tool_erase->set_disabled(true);
@@ -1721,7 +1721,7 @@ AnimationNodeStateMachineEditor::AnimationNodeStateMachineEditor() {
 	transition_tools_hb->add_child(switch_mode);
 
 	auto_advance = memnew(Button);
-	auto_advance->set_flat(true);
+	auto_advance->set_theme_type_variation("FlatButton");
 	auto_advance->set_tooltip_text(TTR("New Transitions Should Auto Advance"));
 	auto_advance->set_toggle_mode(true);
 	auto_advance->set_pressed(true);

editor/plugins/canvas_item_editor_plugin.cpp

@@ -5175,7 +5175,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	viewport->add_child(controls_vb);
 
 	select_button = memnew(Button);
-	select_button->set_flat(true);
+	select_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(select_button);
 	select_button->set_toggle_mode(true);
 	select_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_SELECT));
@@ -5187,7 +5187,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	move_button = memnew(Button);
-	move_button->set_flat(true);
+	move_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(move_button);
 	move_button->set_toggle_mode(true);
 	move_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_MOVE));
@@ -5196,7 +5196,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	move_button->set_tooltip_text(TTR("Move Mode"));
 
 	rotate_button = memnew(Button);
-	rotate_button->set_flat(true);
+	rotate_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(rotate_button);
 	rotate_button->set_toggle_mode(true);
 	rotate_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_ROTATE));
@@ -5205,7 +5205,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	rotate_button->set_tooltip_text(TTR("Rotate Mode"));
 
 	scale_button = memnew(Button);
-	scale_button->set_flat(true);
+	scale_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(scale_button);
 	scale_button->set_toggle_mode(true);
 	scale_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_SCALE));
@@ -5216,21 +5216,21 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	list_select_button = memnew(Button);
-	list_select_button->set_flat(true);
+	list_select_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(list_select_button);
 	list_select_button->set_toggle_mode(true);
 	list_select_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_LIST_SELECT));
 	list_select_button->set_tooltip_text(TTR("Show list of selectable nodes at position clicked."));
 
 	pivot_button = memnew(Button);
-	pivot_button->set_flat(true);
+	pivot_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(pivot_button);
 	pivot_button->set_toggle_mode(true);
 	pivot_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_EDIT_PIVOT));
 	pivot_button->set_tooltip_text(TTR("Click to change object's rotation pivot."));
 
 	pan_button = memnew(Button);
-	pan_button->set_flat(true);
+	pan_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(pan_button);
 	pan_button->set_toggle_mode(true);
 	pan_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_PAN));
@@ -5239,7 +5239,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	pan_button->set_tooltip_text(TTR("You can also use Pan View shortcut (Space by default) to pan in any mode."));
 
 	ruler_button = memnew(Button);
-	ruler_button->set_flat(true);
+	ruler_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(ruler_button);
 	ruler_button->set_toggle_mode(true);
 	ruler_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_button_tool_select).bind(TOOL_RULER));
@@ -5250,7 +5250,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	smart_snap_button = memnew(Button);
-	smart_snap_button->set_flat(true);
+	smart_snap_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(smart_snap_button);
 	smart_snap_button->set_toggle_mode(true);
 	smart_snap_button->connect("toggled", callable_mp(this, &CanvasItemEditor::_button_toggle_smart_snap));
@@ -5259,7 +5259,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	smart_snap_button->set_shortcut_context(this);
 
 	grid_snap_button = memnew(Button);
-	grid_snap_button->set_flat(true);
+	grid_snap_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(grid_snap_button);
 	grid_snap_button->set_toggle_mode(true);
 	grid_snap_button->connect("toggled", callable_mp(this, &CanvasItemEditor::_button_toggle_grid_snap));
@@ -5268,6 +5268,8 @@ CanvasItemEditor::CanvasItemEditor() {
 	grid_snap_button->set_shortcut_context(this);
 
 	snap_config_menu = memnew(MenuButton);
+	snap_config_menu->set_flat(false);
+	snap_config_menu->set_theme_type_variation("FlatMenuButton");
 	snap_config_menu->set_shortcut_context(this);
 	main_menu_hbox->add_child(snap_config_menu);
 	snap_config_menu->set_h_size_flags(SIZE_SHRINK_END);
@@ -5301,7 +5303,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	lock_button = memnew(Button);
-	lock_button->set_flat(true);
+	lock_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(lock_button);
 
 	lock_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_popup_callback).bind(LOCK_SELECTED));
@@ -5310,7 +5312,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	lock_button->set_shortcut(ED_SHORTCUT("editor/lock_selected_nodes", TTR("Lock Selected Node(s)"), KeyModifierMask::CMD_OR_CTRL | Key::L));
 
 	unlock_button = memnew(Button);
-	unlock_button->set_flat(true);
+	unlock_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(unlock_button);
 	unlock_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_popup_callback).bind(UNLOCK_SELECTED));
 	unlock_button->set_tooltip_text(TTR("Unlock selected node, allowing selection and movement."));
@@ -5318,7 +5320,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	unlock_button->set_shortcut(ED_SHORTCUT("editor/unlock_selected_nodes", TTR("Unlock Selected Node(s)"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::L));
 
 	group_button = memnew(Button);
-	group_button->set_flat(true);
+	group_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(group_button);
 	group_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_popup_callback).bind(GROUP_SELECTED));
 	group_button->set_tooltip_text(TTR("Make selected node's children not selectable."));
@@ -5326,7 +5328,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	group_button->set_shortcut(ED_SHORTCUT("editor/group_selected_nodes", TTR("Group Selected Node(s)"), KeyModifierMask::CMD_OR_CTRL | Key::G));
 
 	ungroup_button = memnew(Button);
-	ungroup_button->set_flat(true);
+	ungroup_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(ungroup_button);
 	ungroup_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_popup_callback).bind(UNGROUP_SELECTED));
 	ungroup_button->set_tooltip_text(TTR("Make selected node's children selectable."));
@@ -5336,6 +5338,8 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	skeleton_menu = memnew(MenuButton);
+	skeleton_menu->set_flat(false);
+	skeleton_menu->set_theme_type_variation("FlatMenuButton");
 	skeleton_menu->set_shortcut_context(this);
 	main_menu_hbox->add_child(skeleton_menu);
 	skeleton_menu->set_tooltip_text(TTR("Skeleton Options"));
@@ -5351,7 +5355,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	override_camera_button = memnew(Button);
-	override_camera_button->set_flat(true);
+	override_camera_button->set_theme_type_variation("FlatButton");
 	main_menu_hbox->add_child(override_camera_button);
 	override_camera_button->connect("toggled", callable_mp(this, &CanvasItemEditor::_button_override_camera));
 	override_camera_button->set_toggle_mode(true);
@@ -5361,6 +5365,8 @@ CanvasItemEditor::CanvasItemEditor() {
 	main_menu_hbox->add_child(memnew(VSeparator));
 
 	view_menu = memnew(MenuButton);
+	view_menu->set_flat(false);
+	view_menu->set_theme_type_variation("FlatMenuButton");
 	// TRANSLATORS: Noun, name of the 2D/3D View menus.
 	view_menu->set_text(TTR("View"));
 	view_menu->set_switch_on_hover(true);
@@ -5426,7 +5432,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	animation_hb->hide();
 
 	key_loc_button = memnew(Button);
-	key_loc_button->set_flat(true);
+	key_loc_button->set_theme_type_variation("FlatButton");
 	key_loc_button->set_toggle_mode(true);
 	key_loc_button->set_pressed(true);
 	key_loc_button->set_focus_mode(FOCUS_NONE);
@@ -5435,7 +5441,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	animation_hb->add_child(key_loc_button);
 
 	key_rot_button = memnew(Button);
-	key_rot_button->set_flat(true);
+	key_rot_button->set_theme_type_variation("FlatButton");
 	key_rot_button->set_toggle_mode(true);
 	key_rot_button->set_pressed(true);
 	key_rot_button->set_focus_mode(FOCUS_NONE);
@@ -5444,7 +5450,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	animation_hb->add_child(key_rot_button);
 
 	key_scale_button = memnew(Button);
-	key_scale_button->set_flat(true);
+	key_scale_button->set_theme_type_variation("FlatButton");
 	key_scale_button->set_toggle_mode(true);
 	key_scale_button->set_focus_mode(FOCUS_NONE);
 	key_scale_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_popup_callback).bind(ANIM_INSERT_SCALE));
@@ -5452,7 +5458,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	animation_hb->add_child(key_scale_button);
 
 	key_insert_button = memnew(Button);
-	key_insert_button->set_flat(true);
+	key_insert_button->set_theme_type_variation("FlatButton");
 	key_insert_button->set_focus_mode(FOCUS_NONE);
 	key_insert_button->connect("pressed", callable_mp(this, &CanvasItemEditor::_popup_callback).bind(ANIM_INSERT_KEY));
 	key_insert_button->set_tooltip_text(TTR("Insert keys (based on mask)."));
@@ -5461,7 +5467,7 @@ CanvasItemEditor::CanvasItemEditor() {
 	animation_hb->add_child(key_insert_button);
 
 	key_auto_insert_button = memnew(Button);
-	key_auto_insert_button->set_flat(true);
+	key_auto_insert_button->set_theme_type_variation("FlatButton");
 	key_auto_insert_button->set_toggle_mode(true);
 	key_auto_insert_button->set_focus_mode(FOCUS_NONE);
 	key_auto_insert_button->set_tooltip_text(TTR("Auto insert keys when objects are translated, rotated or scaled (based on mask).\nKeys are only added to existing tracks, no new tracks will be created.\nKeys must be inserted manually for the first time."));
@@ -5470,6 +5476,8 @@ CanvasItemEditor::CanvasItemEditor() {
 	animation_hb->add_child(key_auto_insert_button);
 
 	animation_menu = memnew(MenuButton);
+	animation_menu->set_flat(false);
+	animation_menu->set_theme_type_variation("FlatMenuButton");
 	animation_menu->set_shortcut_context(this);
 	animation_menu->set_tooltip_text(TTR("Animation Key and Pose Options"));
 	animation_hb->add_child(animation_menu);

editor/plugins/control_editor_plugin.cpp

@@ -520,7 +520,7 @@ void ControlEditorPopupButton::_notification(int p_what) {
 }
 
 ControlEditorPopupButton::ControlEditorPopupButton() {
-	set_flat(true);
+	set_theme_type_variation("FlatButton");
 	set_toggle_mode(true);
 	set_focus_mode(FOCUS_NONE);
 
@@ -1000,7 +1000,7 @@ ControlEditorToolbar::ControlEditorToolbar() {
 	keep_ratio_button->connect("pressed", callable_mp(this, &ControlEditorToolbar::_anchors_to_current_ratio));
 
 	anchor_mode_button = memnew(Button);
-	anchor_mode_button->set_flat(true);
+	anchor_mode_button->set_theme_type_variation("FlatButton");
 	anchor_mode_button->set_toggle_mode(true);
 	anchor_mode_button->set_tooltip_text(TTR("When active, moving Control nodes changes their anchors instead of their offsets."));
 	add_child(anchor_mode_button);

editor/plugins/gpu_particles_collision_sdf_editor_plugin.cpp

@@ -183,7 +183,7 @@ GPUParticlesCollisionSDF3DEditorPlugin::GPUParticlesCollisionSDF3DEditorPlugin()
 	bake_hb->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 	bake_hb->hide();
 	bake = memnew(Button);
-	bake->set_flat(true);
+	bake->set_theme_type_variation("FlatButton");
 	bake->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Bake"), EditorStringName(EditorIcons)));
 	bake->set_text(TTR("Bake SDF"));
 	bake->connect("pressed", callable_mp(this, &GPUParticlesCollisionSDF3DEditorPlugin::_bake));

editor/plugins/lightmap_gi_editor_plugin.cpp

@@ -168,7 +168,7 @@ void LightmapGIEditorPlugin::_bind_methods() {
 
 LightmapGIEditorPlugin::LightmapGIEditorPlugin() {
 	bake = memnew(Button);
-	bake->set_flat(true);
+	bake->set_theme_type_variation("FlatButton");
 	// TODO: Rework this as a dedicated toolbar control so we can hook into theme changes and update it
 	// when the editor theme updates.
 	bake->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Bake"), EditorStringName(EditorIcons)));

editor/plugins/navigation_obstacle_3d_editor_plugin.cpp

@@ -523,13 +523,13 @@ NavigationObstacle3DEditor::NavigationObstacle3DEditor() {
 	obstacle_node = nullptr;
 
 	button_create = memnew(Button);
-	button_create->set_flat(true);
+	button_create->set_theme_type_variation("FlatButton");
 	add_child(button_create);
 	button_create->connect("pressed", callable_mp(this, &NavigationObstacle3DEditor::_menu_option).bind(MODE_CREATE));
 	button_create->set_toggle_mode(true);
 
 	button_edit = memnew(Button);
-	button_edit->set_flat(true);
+	button_edit->set_theme_type_variation("FlatButton");
 	add_child(button_edit);
 	button_edit->connect("pressed", callable_mp(this, &NavigationObstacle3DEditor::_menu_option).bind(MODE_EDIT));
 	button_edit->set_toggle_mode(true);

editor/plugins/node_3d_editor_plugin.cpp

@@ -8225,7 +8225,7 @@ Node3DEditor::Node3DEditor() {
 	tool_button[TOOL_MODE_SELECT] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_MODE_SELECT]);
 	tool_button[TOOL_MODE_SELECT]->set_toggle_mode(true);
-	tool_button[TOOL_MODE_SELECT]->set_flat(true);
+	tool_button[TOOL_MODE_SELECT]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_MODE_SELECT]->set_pressed(true);
 	tool_button[TOOL_MODE_SELECT]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_TOOL_SELECT));
 	tool_button[TOOL_MODE_SELECT]->set_shortcut(ED_SHORTCUT("spatial_editor/tool_select", TTR("Select Mode"), Key::Q));
@@ -8236,7 +8236,7 @@ Node3DEditor::Node3DEditor() {
 	tool_button[TOOL_MODE_MOVE] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_MODE_MOVE]);
 	tool_button[TOOL_MODE_MOVE]->set_toggle_mode(true);
-	tool_button[TOOL_MODE_MOVE]->set_flat(true);
+	tool_button[TOOL_MODE_MOVE]->set_theme_type_variation("FlatButton");
 
 	tool_button[TOOL_MODE_MOVE]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_TOOL_MOVE));
 	tool_button[TOOL_MODE_MOVE]->set_shortcut(ED_SHORTCUT("spatial_editor/tool_move", TTR("Move Mode"), Key::W));
@@ -8245,7 +8245,7 @@ Node3DEditor::Node3DEditor() {
 	tool_button[TOOL_MODE_ROTATE] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_MODE_ROTATE]);
 	tool_button[TOOL_MODE_ROTATE]->set_toggle_mode(true);
-	tool_button[TOOL_MODE_ROTATE]->set_flat(true);
+	tool_button[TOOL_MODE_ROTATE]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_MODE_ROTATE]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_TOOL_ROTATE));
 	tool_button[TOOL_MODE_ROTATE]->set_shortcut(ED_SHORTCUT("spatial_editor/tool_rotate", TTR("Rotate Mode"), Key::E));
 	tool_button[TOOL_MODE_ROTATE]->set_shortcut_context(this);
@@ -8253,7 +8253,7 @@ Node3DEditor::Node3DEditor() {
 	tool_button[TOOL_MODE_SCALE] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_MODE_SCALE]);
 	tool_button[TOOL_MODE_SCALE]->set_toggle_mode(true);
-	tool_button[TOOL_MODE_SCALE]->set_flat(true);
+	tool_button[TOOL_MODE_SCALE]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_MODE_SCALE]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_TOOL_SCALE));
 	tool_button[TOOL_MODE_SCALE]->set_shortcut(ED_SHORTCUT("spatial_editor/tool_scale", TTR("Scale Mode"), Key::R));
 	tool_button[TOOL_MODE_SCALE]->set_shortcut_context(this);
@@ -8263,13 +8263,13 @@ Node3DEditor::Node3DEditor() {
 	tool_button[TOOL_MODE_LIST_SELECT] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_MODE_LIST_SELECT]);
 	tool_button[TOOL_MODE_LIST_SELECT]->set_toggle_mode(true);
-	tool_button[TOOL_MODE_LIST_SELECT]->set_flat(true);
+	tool_button[TOOL_MODE_LIST_SELECT]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_MODE_LIST_SELECT]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_TOOL_LIST_SELECT));
 	tool_button[TOOL_MODE_LIST_SELECT]->set_tooltip_text(TTR("Show list of selectable nodes at position clicked."));
 
 	tool_button[TOOL_LOCK_SELECTED] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_LOCK_SELECTED]);
-	tool_button[TOOL_LOCK_SELECTED]->set_flat(true);
+	tool_button[TOOL_LOCK_SELECTED]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_LOCK_SELECTED]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_LOCK_SELECTED));
 	tool_button[TOOL_LOCK_SELECTED]->set_tooltip_text(TTR("Lock selected node, preventing selection and movement."));
 	// Define the shortcut globally (without a context) so that it works if the Scene tree dock is currently focused.
@@ -8277,7 +8277,7 @@ Node3DEditor::Node3DEditor() {
 
 	tool_button[TOOL_UNLOCK_SELECTED] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_UNLOCK_SELECTED]);
-	tool_button[TOOL_UNLOCK_SELECTED]->set_flat(true);
+	tool_button[TOOL_UNLOCK_SELECTED]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_UNLOCK_SELECTED]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_UNLOCK_SELECTED));
 	tool_button[TOOL_UNLOCK_SELECTED]->set_tooltip_text(TTR("Unlock selected node, allowing selection and movement."));
 	// Define the shortcut globally (without a context) so that it works if the Scene tree dock is currently focused.
@@ -8285,7 +8285,7 @@ Node3DEditor::Node3DEditor() {
 
 	tool_button[TOOL_GROUP_SELECTED] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_GROUP_SELECTED]);
-	tool_button[TOOL_GROUP_SELECTED]->set_flat(true);
+	tool_button[TOOL_GROUP_SELECTED]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_GROUP_SELECTED]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_GROUP_SELECTED));
 	tool_button[TOOL_GROUP_SELECTED]->set_tooltip_text(TTR("Make selected node's children not selectable."));
 	// Define the shortcut globally (without a context) so that it works if the Scene tree dock is currently focused.
@@ -8293,7 +8293,7 @@ Node3DEditor::Node3DEditor() {
 
 	tool_button[TOOL_UNGROUP_SELECTED] = memnew(Button);
 	main_menu_hbox->add_child(tool_button[TOOL_UNGROUP_SELECTED]);
-	tool_button[TOOL_UNGROUP_SELECTED]->set_flat(true);
+	tool_button[TOOL_UNGROUP_SELECTED]->set_theme_type_variation("FlatButton");
 	tool_button[TOOL_UNGROUP_SELECTED]->connect("pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed).bind(MENU_UNGROUP_SELECTED));
 	tool_button[TOOL_UNGROUP_SELECTED]->set_tooltip_text(TTR("Make selected node's children selectable."));
 	// Define the shortcut globally (without a context) so that it works if the Scene tree dock is currently focused.
@@ -8304,7 +8304,7 @@ Node3DEditor::Node3DEditor() {
 	tool_option_button[TOOL_OPT_LOCAL_COORDS] = memnew(Button);
 	main_menu_hbox->add_child(tool_option_button[TOOL_OPT_LOCAL_COORDS]);
 	tool_option_button[TOOL_OPT_LOCAL_COORDS]->set_toggle_mode(true);
-	tool_option_button[TOOL_OPT_LOCAL_COORDS]->set_flat(true);
+	tool_option_button[TOOL_OPT_LOCAL_COORDS]->set_theme_type_variation("FlatButton");
 	tool_option_button[TOOL_OPT_LOCAL_COORDS]->connect("toggled", callable_mp(this, &Node3DEditor::_menu_item_toggled).bind(MENU_TOOL_LOCAL_COORDS));
 	tool_option_button[TOOL_OPT_LOCAL_COORDS]->set_shortcut(ED_SHORTCUT("spatial_editor/local_coords", TTR("Use Local Space"), Key::T));
 	tool_option_button[TOOL_OPT_LOCAL_COORDS]->set_shortcut_context(this);
@@ -8312,7 +8312,7 @@ Node3DEditor::Node3DEditor() {
 	tool_option_button[TOOL_OPT_USE_SNAP] = memnew(Button);
 	main_menu_hbox->add_child(tool_option_button[TOOL_OPT_USE_SNAP]);
 	tool_option_button[TOOL_OPT_USE_SNAP]->set_toggle_mode(true);
-	tool_option_button[TOOL_OPT_USE_SNAP]->set_flat(true);
+	tool_option_button[TOOL_OPT_USE_SNAP]->set_theme_type_variation("FlatButton");
 	tool_option_button[TOOL_OPT_USE_SNAP]->connect("toggled", callable_mp(this, &Node3DEditor::_menu_item_toggled).bind(MENU_TOOL_USE_SNAP));
 	tool_option_button[TOOL_OPT_USE_SNAP]->set_shortcut(ED_SHORTCUT("spatial_editor/snap", TTR("Use Snap"), Key::Y));
 	tool_option_button[TOOL_OPT_USE_SNAP]->set_shortcut_context(this);
@@ -8322,7 +8322,7 @@ Node3DEditor::Node3DEditor() {
 	tool_option_button[TOOL_OPT_OVERRIDE_CAMERA] = memnew(Button);
 	main_menu_hbox->add_child(tool_option_button[TOOL_OPT_OVERRIDE_CAMERA]);
 	tool_option_button[TOOL_OPT_OVERRIDE_CAMERA]->set_toggle_mode(true);
-	tool_option_button[TOOL_OPT_OVERRIDE_CAMERA]->set_flat(true);
+	tool_option_button[TOOL_OPT_OVERRIDE_CAMERA]->set_theme_type_variation("FlatButton");
 	tool_option_button[TOOL_OPT_OVERRIDE_CAMERA]->set_disabled(true);
 	tool_option_button[TOOL_OPT_OVERRIDE_CAMERA]->connect("toggled", callable_mp(this, &Node3DEditor::_menu_item_toggled).bind(MENU_TOOL_OVERRIDE_CAMERA));
 	_update_camera_override_button(false);
@@ -8331,7 +8331,7 @@ Node3DEditor::Node3DEditor() {
 	sun_button = memnew(Button);
 	sun_button->set_tooltip_text(TTR("Toggle preview sunlight.\nIf a DirectionalLight3D node is added to the scene, preview sunlight is disabled."));
 	sun_button->set_toggle_mode(true);
-	sun_button->set_flat(true);
+	sun_button->set_theme_type_variation("FlatButton");
 	sun_button->connect("pressed", callable_mp(this, &Node3DEditor::_update_preview_environment), CONNECT_DEFERRED);
 	// Preview is enabled by default - ensure this applies on editor startup when there is no state yet.
 	sun_button->set_pressed(true);
@@ -8341,7 +8341,7 @@ Node3DEditor::Node3DEditor() {
 	environ_button = memnew(Button);
 	environ_button->set_tooltip_text(TTR("Toggle preview environment.\nIf a WorldEnvironment node is added to the scene, preview environment is disabled."));
 	environ_button->set_toggle_mode(true);
-	environ_button->set_flat(true);
+	environ_button->set_theme_type_variation("FlatButton");
 	environ_button->connect("pressed", callable_mp(this, &Node3DEditor::_update_preview_environment), CONNECT_DEFERRED);
 	// Preview is enabled by default - ensure this applies on editor startup when there is no state yet.
 	environ_button->set_pressed(true);
@@ -8350,7 +8350,7 @@ Node3DEditor::Node3DEditor() {
 
 	sun_environ_settings = memnew(Button);
 	sun_environ_settings->set_tooltip_text(TTR("Edit Sun and Environment settings."));
-	sun_environ_settings->set_flat(true);
+	sun_environ_settings->set_theme_type_variation("FlatButton");
 	sun_environ_settings->connect("pressed", callable_mp(this, &Node3DEditor::_sun_environ_settings_pressed));
 
 	main_menu_hbox->add_child(sun_environ_settings);
@@ -8386,6 +8386,8 @@ Node3DEditor::Node3DEditor() {
 	PopupMenu *p;
 
 	transform_menu = memnew(MenuButton);
+	transform_menu->set_flat(false);
+	transform_menu->set_theme_type_variation("FlatMenuButton");
 	transform_menu->set_text(TTR("Transform"));
 	transform_menu->set_switch_on_hover(true);
 	transform_menu->set_shortcut_context(this);
@@ -8401,6 +8403,8 @@ Node3DEditor::Node3DEditor() {
 	p->connect("id_pressed", callable_mp(this, &Node3DEditor::_menu_item_pressed));
 
 	view_menu = memnew(MenuButton);
+	view_menu->set_flat(false);
+	view_menu->set_theme_type_variation("FlatMenuButton");
 	// TRANSLATORS: Noun, name of the 2D/3D View menus.
 	view_menu->set_text(TTR("View"));
 	view_menu->set_switch_on_hover(true);

editor/plugins/occluder_instance_3d_editor_plugin.cpp

@@ -104,7 +104,7 @@ void OccluderInstance3DEditorPlugin::_bind_methods() {
 
 OccluderInstance3DEditorPlugin::OccluderInstance3DEditorPlugin() {
 	bake = memnew(Button);
-	bake->set_flat(true);
+	bake->set_theme_type_variation("FlatButton");
 	bake->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Bake"), EditorStringName(EditorIcons)));
 	bake->set_text(TTR("Bake Occluders"));
 	bake->hide();

editor/plugins/path_2d_editor_plugin.cpp

@@ -533,7 +533,7 @@ Path2DEditor::Path2DEditor() {
 	action = ACTION_NONE;
 
 	curve_edit = memnew(Button);
-	curve_edit->set_flat(true);
+	curve_edit->set_theme_type_variation("FlatButton");
 	curve_edit->set_toggle_mode(true);
 	curve_edit->set_pressed(true);
 	curve_edit->set_focus_mode(Control::FOCUS_NONE);
@@ -542,7 +542,7 @@ Path2DEditor::Path2DEditor() {
 	add_child(curve_edit);
 
 	curve_edit_curve = memnew(Button);
-	curve_edit_curve->set_flat(true);
+	curve_edit_curve->set_theme_type_variation("FlatButton");
 	curve_edit_curve->set_toggle_mode(true);
 	curve_edit_curve->set_focus_mode(Control::FOCUS_NONE);
 	curve_edit_curve->set_tooltip_text(TTR("Select Control Points (Shift+Drag)"));
@@ -550,7 +550,7 @@ Path2DEditor::Path2DEditor() {
 	add_child(curve_edit_curve);
 
 	curve_create = memnew(Button);
-	curve_create->set_flat(true);
+	curve_create->set_theme_type_variation("FlatButton");
 	curve_create->set_toggle_mode(true);
 	curve_create->set_focus_mode(Control::FOCUS_NONE);
 	curve_create->set_tooltip_text(TTR("Add Point (in empty space)"));
@@ -558,7 +558,7 @@ Path2DEditor::Path2DEditor() {
 	add_child(curve_create);
 
 	curve_del = memnew(Button);
-	curve_del->set_flat(true);
+	curve_del->set_theme_type_variation("FlatButton");
 	curve_del->set_toggle_mode(true);
 	curve_del->set_focus_mode(Control::FOCUS_NONE);
 	curve_del->set_tooltip_text(TTR("Delete Point"));
@@ -566,7 +566,7 @@ Path2DEditor::Path2DEditor() {
 	add_child(curve_del);
 
 	curve_close = memnew(Button);
-	curve_close->set_flat(true);
+	curve_close->set_theme_type_variation("FlatButton");
 	curve_close->set_focus_mode(Control::FOCUS_NONE);
 	curve_close->set_tooltip_text(TTR("Close Curve"));
 	curve_close->connect("pressed", callable_mp(this, &Path2DEditor::_mode_selected).bind(ACTION_CLOSE));
@@ -575,6 +575,8 @@ Path2DEditor::Path2DEditor() {
 	PopupMenu *menu;
 
 	handle_menu = memnew(MenuButton);
+	handle_menu->set_flat(false);
+	handle_menu->set_theme_type_variation("FlatMenuButton");
 	handle_menu->set_text(TTR("Options"));
 	add_child(handle_menu);
 

editor/plugins/path_3d_editor_plugin.cpp

@@ -730,35 +730,35 @@ Path3DEditorPlugin::Path3DEditorPlugin() {
 	Node3DEditor::get_singleton()->add_control_to_menu_panel(topmenu_bar);
 
 	curve_edit = memnew(Button);
-	curve_edit->set_flat(true);
+	curve_edit->set_theme_type_variation("FlatButton");
 	curve_edit->set_toggle_mode(true);
 	curve_edit->set_focus_mode(Control::FOCUS_NONE);
 	curve_edit->set_tooltip_text(TTR("Select Points") + "\n" + TTR("Shift+Drag: Select Control Points") + "\n" + keycode_get_string((Key)KeyModifierMask::CMD_OR_CTRL) + TTR("Click: Add Point") + "\n" + TTR("Right Click: Delete Point"));
 	topmenu_bar->add_child(curve_edit);
 
 	curve_edit_curve = memnew(Button);
-	curve_edit_curve->set_flat(true);
+	curve_edit_curve->set_theme_type_variation("FlatButton");
 	curve_edit_curve->set_toggle_mode(true);
 	curve_edit_curve->set_focus_mode(Control::FOCUS_NONE);
 	curve_edit_curve->set_tooltip_text(TTR("Select Control Points (Shift+Drag)"));
 	topmenu_bar->add_child(curve_edit_curve);
 
 	curve_create = memnew(Button);
-	curve_create->set_flat(true);
+	curve_create->set_theme_type_variation("FlatButton");
 	curve_create->set_toggle_mode(true);
 	curve_create->set_focus_mode(Control::FOCUS_NONE);
 	curve_create->set_tooltip_text(TTR("Add Point (in empty space)") + "\n" + TTR("Split Segment (in curve)"));
 	topmenu_bar->add_child(curve_create);
 
 	curve_del = memnew(Button);
-	curve_del->set_flat(true);
+	curve_del->set_theme_type_variation("FlatButton");
 	curve_del->set_toggle_mode(true);
 	curve_del->set_focus_mode(Control::FOCUS_NONE);
 	curve_del->set_tooltip_text(TTR("Delete Point"));
 	topmenu_bar->add_child(curve_del);
 
 	curve_close = memnew(Button);
-	curve_close->set_flat(true);
+	curve_close->set_theme_type_variation("FlatButton");
 	curve_close->set_focus_mode(Control::FOCUS_NONE);
 	curve_close->set_tooltip_text(TTR("Close Curve"));
 	topmenu_bar->add_child(curve_close);
@@ -766,6 +766,8 @@ Path3DEditorPlugin::Path3DEditorPlugin() {
 	PopupMenu *menu;
 
 	handle_menu = memnew(MenuButton);
+	handle_menu->set_flat(false);
+	handle_menu->set_theme_type_variation("FlatMenuButton");
 	handle_menu->set_text(TTR("Options"));
 	topmenu_bar->add_child(handle_menu);
 

editor/plugins/physical_bone_3d_editor_plugin.cpp

@@ -56,7 +56,7 @@ PhysicalBone3DEditor::PhysicalBone3DEditor() {
 	Node3DEditor::get_singleton()->add_control_to_menu_panel(spatial_editor_hb);
 
 	button_transform_joint = memnew(Button);
-	button_transform_joint->set_flat(true);
+	button_transform_joint->set_theme_type_variation("FlatButton");
 	spatial_editor_hb->add_child(button_transform_joint);
 
 	button_transform_joint->set_text(TTR("Move Joint"));

editor/plugins/polygon_2d_editor_plugin.cpp

@@ -1243,7 +1243,7 @@ Polygon2DEditor::Polygon2DEditor() {
 	snap_show_grid = EditorSettings::get_singleton()->get_project_metadata("polygon_2d_uv_editor", "show_grid", false);
 
 	button_uv = memnew(Button);
-	button_uv->set_flat(true);
+	button_uv->set_theme_type_variation("FlatButton");
 	add_child(button_uv);
 	button_uv->set_tooltip_text(TTR("Open Polygon 2D UV editor."));
 	button_uv->connect("pressed", callable_mp(this, &Polygon2DEditor::_menu_option).bind(MODE_EDIT_UV));
@@ -1294,7 +1294,7 @@ Polygon2DEditor::Polygon2DEditor() {
 	uv_main_vb->add_child(uv_mode_hb);
 	for (int i = 0; i < UV_MODE_MAX; i++) {
 		uv_button[i] = memnew(Button);
-		uv_button[i]->set_flat(true);
+		uv_button[i]->set_theme_type_variation("FlatButton");
 		uv_button[i]->set_toggle_mode(true);
 		uv_mode_hb->add_child(uv_button[i]);
 		uv_button[i]->connect("pressed", callable_mp(this, &Polygon2DEditor::_uv_mode).bind(i));
@@ -1359,6 +1359,8 @@ Polygon2DEditor::Polygon2DEditor() {
 
 	uv_menu = memnew(MenuButton);
 	uv_mode_hb->add_child(uv_menu);
+	uv_menu->set_flat(false);
+	uv_menu->set_theme_type_variation("FlatMenuButton");
 	uv_menu->set_text(TTR("Edit"));
 	uv_menu->get_popup()->add_item(TTR("Copy Polygon to UV"), UVEDIT_POLYGON_TO_UV);
 	uv_menu->get_popup()->add_item(TTR("Copy UV to Polygon"), UVEDIT_UV_TO_POLYGON);
@@ -1371,7 +1373,7 @@ Polygon2DEditor::Polygon2DEditor() {
 	uv_mode_hb->add_child(memnew(VSeparator));
 
 	b_snap_enable = memnew(Button);
-	b_snap_enable->set_flat(true);
+	b_snap_enable->set_theme_type_variation("FlatButton");
 	uv_mode_hb->add_child(b_snap_enable);
 	b_snap_enable->set_text(TTR("Snap"));
 	b_snap_enable->set_focus_mode(FOCUS_NONE);
@@ -1381,7 +1383,7 @@ Polygon2DEditor::Polygon2DEditor() {
 	b_snap_enable->connect("toggled", callable_mp(this, &Polygon2DEditor::_set_use_snap));
 
 	b_snap_grid = memnew(Button);
-	b_snap_grid->set_flat(true);
+	b_snap_grid->set_theme_type_variation("FlatButton");
 	uv_mode_hb->add_child(b_snap_grid);
 	b_snap_grid->set_text(TTR("Grid"));
 	b_snap_grid->set_focus_mode(FOCUS_NONE);

editor/plugins/polygon_3d_editor_plugin.cpp

@@ -538,13 +538,13 @@ Polygon3DEditor::Polygon3DEditor() {
 	node = nullptr;
 
 	button_create = memnew(Button);
-	button_create->set_flat(true);
+	button_create->set_theme_type_variation("FlatButton");
 	add_child(button_create);
 	button_create->connect("pressed", callable_mp(this, &Polygon3DEditor::_menu_option).bind(MODE_CREATE));
 	button_create->set_toggle_mode(true);
 
 	button_edit = memnew(Button);
-	button_edit->set_flat(true);
+	button_edit->set_theme_type_variation("FlatButton");
 	add_child(button_edit);
 	button_edit->connect("pressed", callable_mp(this, &Polygon3DEditor::_menu_option).bind(MODE_EDIT));
 	button_edit->set_toggle_mode(true);

editor/plugins/skeleton_3d_editor_plugin.cpp

@@ -717,6 +717,8 @@ void Skeleton3DEditor::create_editors() {
 
 	// Create Skeleton Option in Top Menu Bar.
 	skeleton_options = memnew(MenuButton);
+	skeleton_options->set_flat(false);
+	skeleton_options->set_theme_type_variation("FlatMenuButton");
 	topmenu_bar->add_child(skeleton_options);
 
 	skeleton_options->set_text(TTR("Skeleton3D"));
@@ -738,7 +740,7 @@ void Skeleton3DEditor::create_editors() {
 
 	edit_mode_button = memnew(Button);
 	topmenu_bar->add_child(edit_mode_button);
-	edit_mode_button->set_flat(true);
+	edit_mode_button->set_theme_type_variation("FlatButton");
 	edit_mode_button->set_toggle_mode(true);
 	edit_mode_button->set_focus_mode(FOCUS_NONE);
 	edit_mode_button->set_tooltip_text(TTR("Edit Mode\nShow buttons on joints."));
@@ -758,7 +760,7 @@ void Skeleton3DEditor::create_editors() {
 	animation_hb->hide();
 
 	key_loc_button = memnew(Button);
-	key_loc_button->set_flat(true);
+	key_loc_button->set_theme_type_variation("FlatButton");
 	key_loc_button->set_toggle_mode(true);
 	key_loc_button->set_pressed(false);
 	key_loc_button->set_focus_mode(FOCUS_NONE);
@@ -766,7 +768,7 @@ void Skeleton3DEditor::create_editors() {
 	animation_hb->add_child(key_loc_button);
 
 	key_rot_button = memnew(Button);
-	key_rot_button->set_flat(true);
+	key_rot_button->set_theme_type_variation("FlatButton");
 	key_rot_button->set_toggle_mode(true);
 	key_rot_button->set_pressed(true);
 	key_rot_button->set_focus_mode(FOCUS_NONE);
@@ -774,7 +776,7 @@ void Skeleton3DEditor::create_editors() {
 	animation_hb->add_child(key_rot_button);
 
 	key_scale_button = memnew(Button);
-	key_scale_button->set_flat(true);
+	key_scale_button->set_theme_type_variation("FlatButton");
 	key_scale_button->set_toggle_mode(true);
 	key_scale_button->set_pressed(false);
 	key_scale_button->set_focus_mode(FOCUS_NONE);
@@ -782,7 +784,7 @@ void Skeleton3DEditor::create_editors() {
 	animation_hb->add_child(key_scale_button);
 
 	key_insert_button = memnew(Button);
-	key_insert_button->set_flat(true);
+	key_insert_button->set_theme_type_variation("FlatButton");
 	key_insert_button->set_focus_mode(FOCUS_NONE);
 	key_insert_button->connect("pressed", callable_mp(this, &Skeleton3DEditor::insert_keys).bind(false));
 	key_insert_button->set_tooltip_text(TTR("Insert key of bone poses already exist track."));
@@ -790,7 +792,7 @@ void Skeleton3DEditor::create_editors() {
 	animation_hb->add_child(key_insert_button);
 
 	key_insert_all_button = memnew(Button);
-	key_insert_all_button->set_flat(true);
+	key_insert_all_button->set_theme_type_variation("FlatButton");
 	key_insert_all_button->set_focus_mode(FOCUS_NONE);
 	key_insert_all_button->connect("pressed", callable_mp(this, &Skeleton3DEditor::insert_keys).bind(true));
 	key_insert_all_button->set_tooltip_text(TTR("Insert key of all bone poses."));

editor/plugins/sprite_frames_editor_plugin.cpp

@@ -1657,12 +1657,12 @@ SpriteFramesEditor::SpriteFramesEditor() {
 	sub_vb->add_child(hbc_animlist);
 
 	add_anim = memnew(Button);
-	add_anim->set_flat(true);
+	add_anim->set_theme_type_variation("FlatButton");
 	hbc_animlist->add_child(add_anim);
 	add_anim->connect("pressed", callable_mp(this, &SpriteFramesEditor::_animation_add));
 
 	delete_anim = memnew(Button);
-	delete_anim->set_flat(true);
+	delete_anim->set_theme_type_variation("FlatButton");
 	hbc_animlist->add_child(delete_anim);
 	delete_anim->set_disabled(true);
 	delete_anim->connect("pressed", callable_mp(this, &SpriteFramesEditor::_animation_remove));
@@ -1673,7 +1673,7 @@ SpriteFramesEditor::SpriteFramesEditor() {
 	autoplay_container->add_child(memnew(VSeparator));
 
 	autoplay = memnew(Button);
-	autoplay->set_flat(true);
+	autoplay->set_theme_type_variation("FlatButton");
 	autoplay->set_tooltip_text(TTR("Autoplay on Load"));
 	autoplay_container->add_child(autoplay);
 
@@ -1681,7 +1681,7 @@ SpriteFramesEditor::SpriteFramesEditor() {
 
 	anim_loop = memnew(Button);
 	anim_loop->set_toggle_mode(true);
-	anim_loop->set_flat(true);
+	anim_loop->set_theme_type_variation("FlatButton");
 	anim_loop->set_tooltip_text(TTR("Animation Looping"));
 	anim_loop->connect("pressed", callable_mp(this, &SpriteFramesEditor::_animation_loop_changed));
 	hbc_animlist->add_child(anim_loop);
@@ -1740,27 +1740,27 @@ SpriteFramesEditor::SpriteFramesEditor() {
 	hfc->add_child(playback_container);
 
 	play_bw_from = memnew(Button);
-	play_bw_from->set_flat(true);
+	play_bw_from->set_theme_type_variation("FlatButton");
 	play_bw_from->set_tooltip_text(TTR("Play selected animation backwards from current pos. (A)"));
 	playback_container->add_child(play_bw_from);
 
 	play_bw = memnew(Button);
-	play_bw->set_flat(true);
+	play_bw->set_theme_type_variation("FlatButton");
 	play_bw->set_tooltip_text(TTR("Play selected animation backwards from end. (Shift+A)"));
 	playback_container->add_child(play_bw);
 
 	stop = memnew(Button);
-	stop->set_flat(true);
+	stop->set_theme_type_variation("FlatButton");
 	stop->set_tooltip_text(TTR("Pause/stop animation playback. (S)"));
 	playback_container->add_child(stop);
 
 	play = memnew(Button);
-	play->set_flat(true);
+	play->set_theme_type_variation("FlatButton");
 	play->set_tooltip_text(TTR("Play selected animation from start. (Shift+D)"));
 	playback_container->add_child(play);
 
 	play_from = memnew(Button);
-	play_from->set_flat(true);
+	play_from->set_theme_type_variation("FlatButton");
 	play_from->set_tooltip_text(TTR("Play selected animation from current pos. (D)"));
 	playback_container->add_child(play_from);
 
@@ -1778,45 +1778,45 @@ SpriteFramesEditor::SpriteFramesEditor() {
 	hfc->add_child(hbc_actions);
 
 	load = memnew(Button);
-	load->set_flat(true);
+	load->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(load);
 
 	load_sheet = memnew(Button);
-	load_sheet->set_flat(true);
+	load_sheet->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(load_sheet);
 
 	hbc_actions->add_child(memnew(VSeparator));
 
 	copy = memnew(Button);
-	copy->set_flat(true);
+	copy->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(copy);
 
 	paste = memnew(Button);
-	paste->set_flat(true);
+	paste->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(paste);
 
 	hbc_actions->add_child(memnew(VSeparator));
 
 	empty_before = memnew(Button);
-	empty_before->set_flat(true);
+	empty_before->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(empty_before);
 
 	empty_after = memnew(Button);
-	empty_after->set_flat(true);
+	empty_after->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(empty_after);
 
 	hbc_actions->add_child(memnew(VSeparator));
 
 	move_up = memnew(Button);
-	move_up->set_flat(true);
+	move_up->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(move_up);
 
 	move_down = memnew(Button);
-	move_down->set_flat(true);
+	move_down->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(move_down);
 
 	delete_frame = memnew(Button);
-	delete_frame->set_flat(true);
+	delete_frame->set_theme_type_variation("FlatButton");
 	hbc_actions->add_child(delete_frame);
 
 	hbc_actions->add_child(memnew(VSeparator));
@@ -1982,7 +1982,7 @@ SpriteFramesEditor::SpriteFramesEditor() {
 
 	toggle_settings_button = memnew(Button);
 	toggle_settings_button->set_h_size_flags(SIZE_SHRINK_END);
-	toggle_settings_button->set_flat(true);
+	toggle_settings_button->set_theme_type_variation("FlatButton");
 	toggle_settings_button->connect("pressed", callable_mp(this, &SpriteFramesEditor::_toggle_show_settings));
 	toggle_settings_button->set_tooltip_text(TTR("Toggle Settings Panel"));
 	split_sheet_menu_hb->add_child(toggle_settings_button);
@@ -2020,21 +2020,21 @@ SpriteFramesEditor::SpriteFramesEditor() {
 	split_sheet_zoom_margin->add_child(split_sheet_zoom_hb);
 
 	split_sheet_zoom_out = memnew(Button);
-	split_sheet_zoom_out->set_flat(true);
+	split_sheet_zoom_out->set_theme_type_variation("FlatButton");
 	split_sheet_zoom_out->set_focus_mode(FOCUS_NONE);
 	split_sheet_zoom_out->set_tooltip_text(TTR("Zoom Out"));
 	split_sheet_zoom_out->connect("pressed", callable_mp(this, &SpriteFramesEditor::_sheet_zoom_out));
 	split_sheet_zoom_hb->add_child(split_sheet_zoom_out);
 
 	split_sheet_zoom_reset = memnew(Button);
-	split_sheet_zoom_reset->set_flat(true);
+	split_sheet_zoom_reset->set_theme_type_variation("FlatButton");
 	split_sheet_zoom_reset->set_focus_mode(FOCUS_NONE);
 	split_sheet_zoom_reset->set_tooltip_text(TTR("Zoom Reset"));
 	split_sheet_zoom_reset->connect("pressed", callable_mp(this, &SpriteFramesEditor::_sheet_zoom_reset));
 	split_sheet_zoom_hb->add_child(split_sheet_zoom_reset);
 
 	split_sheet_zoom_in = memnew(Button);
-	split_sheet_zoom_in->set_flat(true);
+	split_sheet_zoom_in->set_theme_type_variation("FlatButton");
 	split_sheet_zoom_in->set_focus_mode(FOCUS_NONE);
 	split_sheet_zoom_in->set_tooltip_text(TTR("Zoom In"));
 	split_sheet_zoom_in->connect("pressed", callable_mp(this, &SpriteFramesEditor::_sheet_zoom_in));

editor/plugins/theme_editor_preview.cpp

@@ -240,7 +240,7 @@ ThemeEditorPreview::ThemeEditorPreview() {
 
 	picker_button = memnew(Button);
 	preview_toolbar->add_child(picker_button);
-	picker_button->set_flat(true);
+	picker_button->set_theme_type_variation("FlatButton");
 	picker_button->set_toggle_mode(true);
 	picker_button->set_tooltip_text(TTR("Toggle the control picker, allowing to visually select control types for edit."));
 	picker_button->connect("pressed", callable_mp(this, &ThemeEditorPreview::_picker_button_cbk));

editor/plugins/tiles/tile_data_editors.cpp

@@ -846,7 +846,7 @@ GenericTilePolygonEditor::GenericTilePolygonEditor() {
 	tools_button_group.instantiate();
 
 	button_expand = memnew(Button);
-	button_expand->set_flat(true);
+	button_expand->set_theme_type_variation("FlatButton");
 	button_expand->set_toggle_mode(true);
 	button_expand->set_pressed(false);
 	button_expand->set_tooltip_text(TTR("Expand editor"));
@@ -856,7 +856,7 @@ GenericTilePolygonEditor::GenericTilePolygonEditor() {
 	toolbar->add_child(memnew(VSeparator));
 
 	button_create = memnew(Button);
-	button_create->set_flat(true);
+	button_create->set_theme_type_variation("FlatButton");
 	button_create->set_toggle_mode(true);
 	button_create->set_button_group(tools_button_group);
 	button_create->set_pressed(true);
@@ -864,21 +864,22 @@ GenericTilePolygonEditor::GenericTilePolygonEditor() {
 	toolbar->add_child(button_create);
 
 	button_edit = memnew(Button);
-	button_edit->set_flat(true);
+	button_edit->set_theme_type_variation("FlatButton");
 	button_edit->set_toggle_mode(true);
 	button_edit->set_button_group(tools_button_group);
 	button_edit->set_tooltip_text(TTR("Edit points tool"));
 	toolbar->add_child(button_edit);
 
 	button_delete = memnew(Button);
-	button_delete->set_flat(true);
+	button_delete->set_theme_type_variation("FlatButton");
 	button_delete->set_toggle_mode(true);
 	button_delete->set_button_group(tools_button_group);
 	button_delete->set_tooltip_text(TTR("Delete points tool"));
 	toolbar->add_child(button_delete);
 
 	button_advanced_menu = memnew(MenuButton);
-	button_advanced_menu->set_flat(true);
+	button_advanced_menu->set_flat(false);
+	button_advanced_menu->set_theme_type_variation("FlatMenuButton");
 	button_advanced_menu->set_toggle_mode(true);
 	button_advanced_menu->get_popup()->add_item(TTR("Reset to default tile shape"), RESET_TO_DEFAULT_TILE, Key::F);
 	button_advanced_menu->get_popup()->add_item(TTR("Clear"), CLEAR_TILE, Key::C);
@@ -895,7 +896,8 @@ GenericTilePolygonEditor::GenericTilePolygonEditor() {
 
 	button_pixel_snap = memnew(MenuButton);
 	toolbar->add_child(button_pixel_snap);
-	button_pixel_snap->set_flat(true);
+	button_pixel_snap->set_flat(false);
+	button_pixel_snap->set_theme_type_variation("FlatMenuButton");
 	button_pixel_snap->set_tooltip_text(TTR("Toggle Grid Snap"));
 	button_pixel_snap->get_popup()->add_item(TTR("Disable Snap"), SNAP_NONE);
 	button_pixel_snap->get_popup()->add_item(TTR("Half-Pixel Snap"), SNAP_HALF_PIXEL);
@@ -939,7 +941,7 @@ GenericTilePolygonEditor::GenericTilePolygonEditor() {
 	button_center_view = memnew(Button);
 	button_center_view->set_anchors_and_offsets_preset(Control::PRESET_TOP_RIGHT, Control::PRESET_MODE_MINSIZE, 5);
 	button_center_view->connect("pressed", callable_mp(this, &GenericTilePolygonEditor::_center_view));
-	button_center_view->set_flat(true);
+	button_center_view->set_theme_type_variation("FlatButton");
 	button_center_view->set_disabled(true);
 	root->add_child(button_center_view);
 
@@ -1302,7 +1304,7 @@ TileDataDefaultEditor::TileDataDefaultEditor() {
 	add_child(label);
 
 	picker_button = memnew(Button);
-	picker_button->set_flat(true);
+	picker_button->set_theme_type_variation("FlatButton");
 	picker_button->set_toggle_mode(true);
 	picker_button->set_shortcut(ED_SHORTCUT("tiles_editor/picker", TTR("Picker"), Key::P));
 	toolbar->add_child(picker_button);
@@ -2789,7 +2791,7 @@ TileDataTerrainsEditor::TileDataTerrainsEditor() {
 
 	// Toolbar
 	picker_button = memnew(Button);
-	picker_button->set_flat(true);
+	picker_button->set_theme_type_variation("FlatButton");
 	picker_button->set_toggle_mode(true);
 	picker_button->set_shortcut(ED_SHORTCUT("tiles_editor/picker", TTR("Picker"), Key::P));
 	toolbar->add_child(picker_button);

editor/plugins/tiles/tile_map_editor.cpp

@@ -2220,7 +2220,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	tool_buttons_group.instantiate();
 
 	select_tool_button = memnew(Button);
-	select_tool_button->set_flat(true);
+	select_tool_button->set_theme_type_variation("FlatButton");
 	select_tool_button->set_toggle_mode(true);
 	select_tool_button->set_button_group(tool_buttons_group);
 	select_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/selection_tool", TTR("Selection"), Key::S));
@@ -2229,7 +2229,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	viewport_shortcut_buttons.push_back(select_tool_button);
 
 	paint_tool_button = memnew(Button);
-	paint_tool_button->set_flat(true);
+	paint_tool_button->set_theme_type_variation("FlatButton");
 	paint_tool_button->set_toggle_mode(true);
 	paint_tool_button->set_button_group(tool_buttons_group);
 	paint_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/paint_tool", TTR("Paint"), Key::D));
@@ -2239,7 +2239,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	viewport_shortcut_buttons.push_back(paint_tool_button);
 
 	line_tool_button = memnew(Button);
-	line_tool_button->set_flat(true);
+	line_tool_button->set_theme_type_variation("FlatButton");
 	line_tool_button->set_toggle_mode(true);
 	line_tool_button->set_button_group(tool_buttons_group);
 	// TRANSLATORS: This refers to the line tool in the tilemap editor.
@@ -2249,7 +2249,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	viewport_shortcut_buttons.push_back(line_tool_button);
 
 	rect_tool_button = memnew(Button);
-	rect_tool_button->set_flat(true);
+	rect_tool_button->set_theme_type_variation("FlatButton");
 	rect_tool_button->set_toggle_mode(true);
 	rect_tool_button->set_button_group(tool_buttons_group);
 	rect_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/rect_tool", TTR("Rect"), Key::R));
@@ -2258,7 +2258,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	viewport_shortcut_buttons.push_back(rect_tool_button);
 
 	bucket_tool_button = memnew(Button);
-	bucket_tool_button->set_flat(true);
+	bucket_tool_button->set_theme_type_variation("FlatButton");
 	bucket_tool_button->set_toggle_mode(true);
 	bucket_tool_button->set_button_group(tool_buttons_group);
 	bucket_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/bucket_tool", TTR("Bucket"), Key::B));
@@ -2276,7 +2276,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 
 	// Picker
 	picker_button = memnew(Button);
-	picker_button->set_flat(true);
+	picker_button->set_theme_type_variation("FlatButton");
 	picker_button->set_toggle_mode(true);
 	picker_button->set_shortcut(ED_SHORTCUT("tiles_editor/picker", TTR("Picker"), Key::P));
 	Key key = (OS::get_singleton()->has_feature("macos") || OS::get_singleton()->has_feature("web_macos") || OS::get_singleton()->has_feature("web_ios")) ? Key::META : Key::CTRL;
@@ -2287,7 +2287,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 
 	// Erase button.
 	erase_button = memnew(Button);
-	erase_button->set_flat(true);
+	erase_button->set_theme_type_variation("FlatButton");
 	erase_button->set_toggle_mode(true);
 	erase_button->set_shortcut(ED_SHORTCUT("tiles_editor/eraser", TTR("Eraser"), Key::E));
 	erase_button->set_tooltip_text(TTR("Alternatively use RMB to erase tiles."));
@@ -2301,28 +2301,28 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	transform_toolbar->add_child(memnew(VSeparator));
 
 	transform_button_rotate_left = memnew(Button);
-	transform_button_rotate_left->set_flat(true);
+	transform_button_rotate_left->set_theme_type_variation("FlatButton");
 	transform_button_rotate_left->set_shortcut(ED_SHORTCUT("tiles_editor/rotate_tile_left", TTR("Rotate Tile Left"), Key::Z));
 	transform_toolbar->add_child(transform_button_rotate_left);
 	transform_button_rotate_left->connect("pressed", callable_mp(this, &TileMapEditorTilesPlugin::_apply_transform).bind(TRANSFORM_ROTATE_LEFT));
 	viewport_shortcut_buttons.push_back(transform_button_rotate_left);
 
 	transform_button_rotate_right = memnew(Button);
-	transform_button_rotate_right->set_flat(true);
+	transform_button_rotate_right->set_theme_type_variation("FlatButton");
 	transform_button_rotate_right->set_shortcut(ED_SHORTCUT("tiles_editor/rotate_tile_right", TTR("Rotate Tile Right"), Key::X));
 	transform_toolbar->add_child(transform_button_rotate_right);
 	transform_button_rotate_right->connect("pressed", callable_mp(this, &TileMapEditorTilesPlugin::_apply_transform).bind(TRANSFORM_ROTATE_RIGHT));
 	viewport_shortcut_buttons.push_back(transform_button_rotate_right);
 
 	transform_button_flip_h = memnew(Button);
-	transform_button_flip_h->set_flat(true);
+	transform_button_flip_h->set_theme_type_variation("FlatButton");
 	transform_button_flip_h->set_shortcut(ED_SHORTCUT("tiles_editor/flip_tile_horizontal", TTR("Flip Tile Horizontally"), Key::C));
 	transform_toolbar->add_child(transform_button_flip_h);
 	transform_button_flip_h->connect("pressed", callable_mp(this, &TileMapEditorTilesPlugin::_apply_transform).bind(TRANSFORM_FLIP_H));
 	viewport_shortcut_buttons.push_back(transform_button_flip_h);
 
 	transform_button_flip_v = memnew(Button);
-	transform_button_flip_v->set_flat(true);
+	transform_button_flip_v->set_theme_type_variation("FlatButton");
 	transform_button_flip_v->set_shortcut(ED_SHORTCUT("tiles_editor/flip_tile_vertical", TTR("Flip Tile Vertically"), Key::V));
 	transform_toolbar->add_child(transform_button_flip_v);
 	transform_button_flip_v->connect("pressed", callable_mp(this, &TileMapEditorTilesPlugin::_apply_transform).bind(TRANSFORM_FLIP_V));
@@ -2341,7 +2341,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 
 	// Random tile checkbox.
 	random_tile_toggle = memnew(Button);
-	random_tile_toggle->set_flat(true);
+	random_tile_toggle->set_theme_type_variation("FlatButton");
 	random_tile_toggle->set_toggle_mode(true);
 	random_tile_toggle->set_tooltip_text(TTR("Place Random Tile"));
 	random_tile_toggle->connect("toggled", callable_mp(this, &TileMapEditorTilesPlugin::_on_random_tile_checkbox_toggled));
@@ -2404,7 +2404,8 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	sources_bottom_actions->set_alignment(HBoxContainer::ALIGNMENT_END);
 
 	source_sort_button = memnew(MenuButton);
-	source_sort_button->set_flat(true);
+	source_sort_button->set_flat(false);
+	source_sort_button->set_theme_type_variation("FlatMenuButton");
 	source_sort_button->set_tooltip_text(TTR("Sort sources"));
 
 	PopupMenu *p = source_sort_button->get_popup();
@@ -3569,7 +3570,7 @@ TileMapEditorTerrainsPlugin::TileMapEditorTerrainsPlugin() {
 	tool_buttons_group.instantiate();
 
 	paint_tool_button = memnew(Button);
-	paint_tool_button->set_flat(true);
+	paint_tool_button->set_theme_type_variation("FlatButton");
 	paint_tool_button->set_toggle_mode(true);
 	paint_tool_button->set_button_group(tool_buttons_group);
 	paint_tool_button->set_pressed(true);
@@ -3579,7 +3580,7 @@ TileMapEditorTerrainsPlugin::TileMapEditorTerrainsPlugin() {
 	viewport_shortcut_buttons.push_back(paint_tool_button);
 
 	line_tool_button = memnew(Button);
-	line_tool_button->set_flat(true);
+	line_tool_button->set_theme_type_variation("FlatButton");
 	line_tool_button->set_toggle_mode(true);
 	line_tool_button->set_button_group(tool_buttons_group);
 	line_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/line_tool", TTR("Line"), Key::L));
@@ -3588,7 +3589,7 @@ TileMapEditorTerrainsPlugin::TileMapEditorTerrainsPlugin() {
 	viewport_shortcut_buttons.push_back(line_tool_button);
 
 	rect_tool_button = memnew(Button);
-	rect_tool_button->set_flat(true);
+	rect_tool_button->set_theme_type_variation("FlatButton");
 	rect_tool_button->set_toggle_mode(true);
 	rect_tool_button->set_button_group(tool_buttons_group);
 	rect_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/rect_tool", TTR("Rect"), Key::R));
@@ -3597,7 +3598,7 @@ TileMapEditorTerrainsPlugin::TileMapEditorTerrainsPlugin() {
 	viewport_shortcut_buttons.push_back(rect_tool_button);
 
 	bucket_tool_button = memnew(Button);
-	bucket_tool_button->set_flat(true);
+	bucket_tool_button->set_theme_type_variation("FlatButton");
 	bucket_tool_button->set_toggle_mode(true);
 	bucket_tool_button->set_button_group(tool_buttons_group);
 	bucket_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/bucket_tool", TTR("Bucket"), Key::B));
@@ -3616,7 +3617,7 @@ TileMapEditorTerrainsPlugin::TileMapEditorTerrainsPlugin() {
 
 	// Picker
 	picker_button = memnew(Button);
-	picker_button->set_flat(true);
+	picker_button->set_theme_type_variation("FlatButton");
 	picker_button->set_toggle_mode(true);
 	picker_button->set_shortcut(ED_SHORTCUT("tiles_editor/picker", TTR("Picker"), Key::P));
 	picker_button->connect("pressed", callable_mp(CanvasItemEditor::get_singleton(), &CanvasItemEditor::update_viewport));
@@ -3625,7 +3626,7 @@ TileMapEditorTerrainsPlugin::TileMapEditorTerrainsPlugin() {
 
 	// Erase button.
 	erase_button = memnew(Button);
-	erase_button->set_flat(true);
+	erase_button->set_theme_type_variation("FlatButton");
 	erase_button->set_toggle_mode(true);
 	erase_button->set_shortcut(ED_SHORTCUT("tiles_editor/eraser", TTR("Eraser"), Key::E));
 	erase_button->connect("pressed", callable_mp(CanvasItemEditor::get_singleton(), &CanvasItemEditor::update_viewport));
@@ -4240,7 +4241,7 @@ TileMapEditor::TileMapEditor() {
 	tile_map_toolbar->add_child(layers_selection_button);
 
 	toggle_highlight_selected_layer_button = memnew(Button);
-	toggle_highlight_selected_layer_button->set_flat(true);
+	toggle_highlight_selected_layer_button->set_theme_type_variation("FlatButton");
 	toggle_highlight_selected_layer_button->set_toggle_mode(true);
 	toggle_highlight_selected_layer_button->set_pressed(true);
 	toggle_highlight_selected_layer_button->connect("pressed", callable_mp(this, &TileMapEditor::_update_layers_selection));
@@ -4251,7 +4252,7 @@ TileMapEditor::TileMapEditor() {
 
 	// Grid toggle.
 	toggle_grid_button = memnew(Button);
-	toggle_grid_button->set_flat(true);
+	toggle_grid_button->set_theme_type_variation("FlatButton");
 	toggle_grid_button->set_toggle_mode(true);
 	toggle_grid_button->set_tooltip_text(TTR("Toggle grid visibility."));
 	toggle_grid_button->connect("toggled", callable_mp(this, &TileMapEditor::_on_grid_toggled));
@@ -4259,7 +4260,8 @@ TileMapEditor::TileMapEditor() {
 
 	// Advanced settings menu button.
 	advanced_menu_button = memnew(MenuButton);
-	advanced_menu_button->set_flat(true);
+	advanced_menu_button->set_flat(false);
+	advanced_menu_button->set_theme_type_variation("FlatButton");
 	advanced_menu_button->get_popup()->add_item(TTR("Automatically Replace Tiles with Proxies"));
 	advanced_menu_button->get_popup()->connect("id_pressed", callable_mp(this, &TileMapEditor::_advanced_menu_button_id_pressed));
 	tile_map_toolbar->add_child(advanced_menu_button);

editor/plugins/tiles/tile_set_atlas_source_editor.cpp

@@ -2491,7 +2491,7 @@ TileSetAtlasSourceEditor::TileSetAtlasSourceEditor() {
 
 	tool_setup_atlas_source_button = memnew(Button);
 	tool_setup_atlas_source_button->set_text(TTR("Setup"));
-	tool_setup_atlas_source_button->set_flat(true);
+	tool_setup_atlas_source_button->set_theme_type_variation("FlatButton");
 	tool_setup_atlas_source_button->set_toggle_mode(true);
 	tool_setup_atlas_source_button->set_pressed(true);
 	tool_setup_atlas_source_button->set_button_group(tools_button_group);
@@ -2500,7 +2500,7 @@ TileSetAtlasSourceEditor::TileSetAtlasSourceEditor() {
 
 	tool_select_button = memnew(Button);
 	tool_select_button->set_text(TTR("Select"));
-	tool_select_button->set_flat(true);
+	tool_select_button->set_theme_type_variation("FlatButton");
 	tool_select_button->set_toggle_mode(true);
 	tool_select_button->set_pressed(false);
 	tool_select_button->set_button_group(tools_button_group);
@@ -2509,7 +2509,7 @@ TileSetAtlasSourceEditor::TileSetAtlasSourceEditor() {
 
 	tool_paint_button = memnew(Button);
 	tool_paint_button->set_text(TTR("Paint"));
-	tool_paint_button->set_flat(true);
+	tool_paint_button->set_theme_type_variation("FlatButton");
 	tool_paint_button->set_toggle_mode(true);
 	tool_paint_button->set_button_group(tools_button_group);
 	tool_paint_button->set_tooltip_text(TTR("Paint properties."));
@@ -2592,14 +2592,15 @@ TileSetAtlasSourceEditor::TileSetAtlasSourceEditor() {
 	tool_settings->add_child(tool_settings_tile_data_toolbar_container);
 
 	tools_settings_erase_button = memnew(Button);
-	tools_settings_erase_button->set_flat(true);
+	tools_settings_erase_button->set_theme_type_variation("FlatButton");
 	tools_settings_erase_button->set_toggle_mode(true);
 	tools_settings_erase_button->set_shortcut(ED_SHORTCUT("tiles_editor/eraser", TTR("Eraser"), Key::E));
 	tools_settings_erase_button->set_shortcut_context(this);
 	tool_settings->add_child(tools_settings_erase_button);
 
 	tool_advanced_menu_button = memnew(MenuButton);
-	tool_advanced_menu_button->set_flat(true);
+	tool_advanced_menu_button->set_flat(false);
+	tool_advanced_menu_button->set_theme_type_variation("FlatMenuButton");
 	tool_advanced_menu_button->get_popup()->add_item(TTR("Create Tiles in Non-Transparent Texture Regions"), ADVANCED_AUTO_CREATE_TILES);
 	tool_advanced_menu_button->get_popup()->add_item(TTR("Remove Tiles in Fully Transparent Texture Regions"), ADVANCED_AUTO_REMOVE_TILES);
 	tool_advanced_menu_button->get_popup()->add_item(TTR("Remove Tiles Outside the Texture"), ADVANCED_CLEANUP_TILES);

editor/plugins/tiles/tile_set_editor.cpp

@@ -842,7 +842,8 @@ TileSetEditor::TileSetEditor() {
 	split_container->add_child(split_container_left_side);
 
 	source_sort_button = memnew(MenuButton);
-	source_sort_button->set_flat(true);
+	source_sort_button->set_flat(false);
+	source_sort_button->set_theme_type_variation("FlatButton");
 	source_sort_button->set_tooltip_text(TTR("Sort Sources"));
 
 	PopupMenu *p = source_sort_button->get_popup();
@@ -871,20 +872,22 @@ TileSetEditor::TileSetEditor() {
 	split_container_left_side->add_child(sources_bottom_actions);
 
 	sources_delete_button = memnew(Button);
-	sources_delete_button->set_flat(true);
+	sources_delete_button->set_theme_type_variation("FlatButton");
 	sources_delete_button->set_disabled(true);
 	sources_delete_button->connect("pressed", callable_mp(this, &TileSetEditor::_source_delete_pressed));
 	sources_bottom_actions->add_child(sources_delete_button);
 
 	sources_add_button = memnew(MenuButton);
-	sources_add_button->set_flat(true);
+	sources_add_button->set_flat(false);
+	sources_add_button->set_theme_type_variation("FlatButton");
 	sources_add_button->get_popup()->add_item(TTR("Atlas"));
 	sources_add_button->get_popup()->add_item(TTR("Scenes Collection"));
 	sources_add_button->get_popup()->connect("id_pressed", callable_mp(this, &TileSetEditor::_source_add_id_pressed));
 	sources_bottom_actions->add_child(sources_add_button);
 
 	sources_advanced_menu_button = memnew(MenuButton);
-	sources_advanced_menu_button->set_flat(true);
+	sources_advanced_menu_button->set_flat(false);
+	sources_advanced_menu_button->set_theme_type_variation("FlatButton");
 	sources_advanced_menu_button->get_popup()->add_item(TTR("Open Atlas Merging Tool"));
 	sources_advanced_menu_button->get_popup()->add_item(TTR("Manage Tile Proxies"));
 	sources_advanced_menu_button->get_popup()->connect("id_pressed", callable_mp(this, &TileSetEditor::_sources_advanced_menu_id_pressed));

editor/plugins/tiles/tile_set_scenes_collection_source_editor.cpp

@@ -563,12 +563,12 @@ TileSetScenesCollectionSourceEditor::TileSetScenesCollectionSourceEditor() {
 	right_vbox_container->add_child(scenes_bottom_actions);
 
 	scene_tile_add_button = memnew(Button);
-	scene_tile_add_button->set_flat(true);
+	scene_tile_add_button->set_theme_type_variation("FlatButton");
 	scene_tile_add_button->connect("pressed", callable_mp(this, &TileSetScenesCollectionSourceEditor::_source_add_pressed));
 	scenes_bottom_actions->add_child(scene_tile_add_button);
 
 	scene_tile_delete_button = memnew(Button);
-	scene_tile_delete_button->set_flat(true);
+	scene_tile_delete_button->set_theme_type_variation("FlatButton");
 	scene_tile_delete_button->set_disabled(true);
 	scene_tile_delete_button->connect("pressed", callable_mp(this, &TileSetScenesCollectionSourceEditor::_source_delete_pressed));
 	scenes_bottom_actions->add_child(scene_tile_delete_button);

editor/plugins/version_control_editor_plugin.cpp

@@ -1160,7 +1160,7 @@ VersionControlEditorPlugin::VersionControlEditorPlugin() {
 
 	refresh_button = memnew(Button);
 	refresh_button->set_tooltip_text(TTR("Detect new changes"));
-	refresh_button->set_flat(true);
+	refresh_button->set_theme_type_variation("FlatButton");
 	refresh_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Reload"), EditorStringName(EditorIcons)));
 	refresh_button->connect(SNAME("pressed"), callable_mp(this, &VersionControlEditorPlugin::_refresh_stage_area));
 	refresh_button->connect(SNAME("pressed"), callable_mp(this, &VersionControlEditorPlugin::_refresh_commit_list));
@@ -1183,11 +1183,11 @@ VersionControlEditorPlugin::VersionControlEditorPlugin() {
 	discard_all_button->set_tooltip_text(TTR("Discard all changes"));
 	discard_all_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Close"), EditorStringName(EditorIcons)));
 	discard_all_button->connect(SNAME("pressed"), callable_mp(this, &VersionControlEditorPlugin::_confirm_discard_all));
-	discard_all_button->set_flat(true);
+	discard_all_button->set_theme_type_variation("FlatButton");
 	unstage_title->add_child(discard_all_button);
 
 	stage_all_button = memnew(Button);
-	stage_all_button->set_flat(true);
+	stage_all_button->set_theme_type_variation("FlatButton");
 	stage_all_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("MoveDown"), EditorStringName(EditorIcons)));
 	stage_all_button->set_tooltip_text(TTR("Stage all changes"));
 	unstage_title->add_child(stage_all_button);
@@ -1217,7 +1217,7 @@ VersionControlEditorPlugin::VersionControlEditorPlugin() {
 	stage_title->add_child(stage_label);
 
 	unstage_all_button = memnew(Button);
-	unstage_all_button->set_flat(true);
+	unstage_all_button->set_theme_type_variation("FlatButton");
 	unstage_all_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("MoveUp"), EditorStringName(EditorIcons)));
 	unstage_all_button->set_tooltip_text(TTR("Unstage all changes"));
 	stage_title->add_child(unstage_all_button);
@@ -1411,21 +1411,21 @@ VersionControlEditorPlugin::VersionControlEditorPlugin() {
 	remote_create_hbc->add_child(remote_create_url_input);
 
 	fetch_button = memnew(Button);
-	fetch_button->set_flat(true);
+	fetch_button->set_theme_type_variation("FlatButton");
 	fetch_button->set_tooltip_text(TTR("Fetch"));
 	fetch_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Reload"), EditorStringName(EditorIcons)));
 	fetch_button->connect(SNAME("pressed"), callable_mp(this, &VersionControlEditorPlugin::_fetch));
 	menu_bar->add_child(fetch_button);
 
 	pull_button = memnew(Button);
-	pull_button->set_flat(true);
+	pull_button->set_theme_type_variation("FlatButton");
 	pull_button->set_tooltip_text(TTR("Pull"));
 	pull_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("MoveDown"), EditorStringName(EditorIcons)));
 	pull_button->connect(SNAME("pressed"), callable_mp(this, &VersionControlEditorPlugin::_pull));
 	menu_bar->add_child(pull_button);
 
 	push_button = memnew(Button);
-	push_button->set_flat(true);
+	push_button->set_theme_type_variation("FlatButton");
 	push_button->set_tooltip_text(TTR("Push"));
 	push_button->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("MoveUp"), EditorStringName(EditorIcons)));
 	push_button->connect(SNAME("pressed"), callable_mp(this, &VersionControlEditorPlugin::_push));

editor/plugins/visual_shader_editor_plugin.cpp

@@ -5268,7 +5268,7 @@ VisualShaderEditor::VisualShaderEditor() {
 	varying_menu->connect("id_pressed", callable_mp(this, &VisualShaderEditor::_varying_menu_id_pressed));
 
 	preview_shader = memnew(Button);
-	preview_shader->set_flat(true);
+	preview_shader->set_theme_type_variation("FlatButton");
 	preview_shader->set_toggle_mode(true);
 	preview_shader->set_tooltip_text(TTR("Show generated shader code."));
 	graph->get_menu_hbox()->add_child(preview_shader);

editor/plugins/voxel_gi_editor_plugin.cpp

@@ -185,7 +185,7 @@ VoxelGIEditorPlugin::VoxelGIEditorPlugin() {
 	bake_hb->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 	bake_hb->hide();
 	bake = memnew(Button);
-	bake->set_flat(true);
+	bake->set_theme_type_variation("FlatButton");
 	// TODO: Rework this as a dedicated toolbar control so we can hook into theme changes and update it
 	// when the editor theme updates.
 	bake->set_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Bake"), EditorStringName(EditorIcons)));

modules/gridmap/editor/grid_map_editor_plugin.cpp

@@ -1291,14 +1291,14 @@ GridMapEditor::GridMapEditor() {
 	search_box->connect("gui_input", callable_mp(this, &GridMapEditor::_sbox_input));
 
 	mode_thumbnail = memnew(Button);
-	mode_thumbnail->set_flat(true);
+	mode_thumbnail->set_theme_type_variation("FlatButton");
 	mode_thumbnail->set_toggle_mode(true);
 	mode_thumbnail->set_pressed(true);
 	hb->add_child(mode_thumbnail);
 	mode_thumbnail->connect("pressed", callable_mp(this, &GridMapEditor::_set_display_mode).bind(DISPLAY_THUMBNAIL));
 
 	mode_list = memnew(Button);
-	mode_list->set_flat(true);
+	mode_list->set_theme_type_variation("FlatButton");
 	mode_list->set_toggle_mode(true);
 	mode_list->set_pressed(false);
 	hb->add_child(mode_list);

modules/multiplayer/editor/replication_editor.cpp

@@ -245,24 +245,29 @@ ReplicationEditor::ReplicationEditor() {
 	add_pick_button->connect("pressed", callable_mp(this, &ReplicationEditor::_pick_new_property));
 	add_pick_button->set_text(TTR("Add property to sync..."));
 	hb->add_child(add_pick_button);
+
 	VSeparator *vs = memnew(VSeparator);
 	vs->set_custom_minimum_size(Size2(30 * EDSCALE, 0));
 	hb->add_child(vs);
 	hb->add_child(memnew(Label(TTR("Path:"))));
+
 	np_line_edit = memnew(LineEdit);
 	np_line_edit->set_placeholder(":property");
 	np_line_edit->set_h_size_flags(SIZE_EXPAND_FILL);
 	np_line_edit->connect("text_submitted", callable_mp(this, &ReplicationEditor::_np_text_submitted));
 	hb->add_child(np_line_edit);
+
 	add_from_path_button = memnew(Button);
 	add_from_path_button->connect("pressed", callable_mp(this, &ReplicationEditor::_add_pressed));
 	add_from_path_button->set_text(TTR("Add from path"));
 	hb->add_child(add_from_path_button);
+
 	vs = memnew(VSeparator);
 	vs->set_custom_minimum_size(Size2(30 * EDSCALE, 0));
 	hb->add_child(vs);
+
 	pin = memnew(Button);
-	pin->set_flat(true);
+	pin->set_theme_type_variation("FlatButton");
 	pin->set_toggle_mode(true);
 	hb->add_child(pin);
 

modules/navigation/editor/navigation_mesh_editor_plugin.cpp

@@ -134,7 +134,7 @@ NavigationMeshEditor::NavigationMeshEditor() {
 	bake_hbox = memnew(HBoxContainer);
 
 	button_bake = memnew(Button);
-	button_bake->set_flat(true);
+	button_bake->set_theme_type_variation("FlatButton");
 	bake_hbox->add_child(button_bake);
 	button_bake->set_toggle_mode(true);
 	button_bake->set_text(TTR("Bake NavigationMesh"));
@@ -142,7 +142,7 @@ NavigationMeshEditor::NavigationMeshEditor() {
 	button_bake->connect("pressed", callable_mp(this, &NavigationMeshEditor::_bake_pressed));
 
 	button_reset = memnew(Button);
-	button_reset->set_flat(true);
+	button_reset->set_theme_type_variation("FlatButton");
 	bake_hbox->add_child(button_reset);
 	button_reset->set_text(TTR("Clear NavigationMesh"));
 	button_reset->set_tooltip_text(TTR("Clears the internal NavigationMesh vertices and polygons."));

scene/gui/file_dialog.cpp

@@ -1084,13 +1084,13 @@ FileDialog::FileDialog() {
 	HBoxContainer *hbc = memnew(HBoxContainer);
 
 	dir_prev = memnew(Button);
-	dir_prev->set_flat(true);
+	dir_prev->set_theme_type_variation("FlatButton");
 	dir_prev->set_tooltip_text(RTR("Go to previous folder."));
 	dir_next = memnew(Button);
-	dir_next->set_flat(true);
+	dir_next->set_theme_type_variation("FlatButton");
 	dir_next->set_tooltip_text(RTR("Go to next folder."));
 	dir_up = memnew(Button);
-	dir_up->set_flat(true);
+	dir_up->set_theme_type_variation("FlatButton");
 	dir_up->set_tooltip_text(RTR("Go to parent folder."));
 	hbc->add_child(dir_prev);
 	hbc->add_child(dir_next);
@@ -1114,13 +1114,13 @@ FileDialog::FileDialog() {
 	dir->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 
 	refresh = memnew(Button);
-	refresh->set_flat(true);
+	refresh->set_theme_type_variation("FlatButton");
 	refresh->set_tooltip_text(RTR("Refresh files."));
 	refresh->connect("pressed", callable_mp(this, &FileDialog::update_file_list));
 	hbc->add_child(refresh);
 
 	show_hidden = memnew(Button);
-	show_hidden->set_flat(true);
+	show_hidden->set_theme_type_variation("FlatButton");
 	show_hidden->set_toggle_mode(true);
 	show_hidden->set_pressed(is_showing_hidden_files());
 	show_hidden->set_tooltip_text(RTR("Toggle the visibility of hidden files."));

scene/gui/graph_edit.cpp

@@ -1988,28 +1988,28 @@ GraphEdit::GraphEdit() {
 	_update_zoom_label();
 
 	zoom_minus_button = memnew(Button);
-	zoom_minus_button->set_flat(true);
+	zoom_minus_button->set_theme_type_variation("FlatButton");
 	menu_hbox->add_child(zoom_minus_button);
 	zoom_minus_button->set_tooltip_text(RTR("Zoom Out"));
 	zoom_minus_button->connect("pressed", callable_mp(this, &GraphEdit::_zoom_minus));
 	zoom_minus_button->set_focus_mode(FOCUS_NONE);
 
 	zoom_reset_button = memnew(Button);
-	zoom_reset_button->set_flat(true);
+	zoom_reset_button->set_theme_type_variation("FlatButton");
 	menu_hbox->add_child(zoom_reset_button);
 	zoom_reset_button->set_tooltip_text(RTR("Zoom Reset"));
 	zoom_reset_button->connect("pressed", callable_mp(this, &GraphEdit::_zoom_reset));
 	zoom_reset_button->set_focus_mode(FOCUS_NONE);
 
 	zoom_plus_button = memnew(Button);
-	zoom_plus_button->set_flat(true);
+	zoom_plus_button->set_theme_type_variation("FlatButton");
 	menu_hbox->add_child(zoom_plus_button);
 	zoom_plus_button->set_tooltip_text(RTR("Zoom In"));
 	zoom_plus_button->connect("pressed", callable_mp(this, &GraphEdit::_zoom_plus));
 	zoom_plus_button->set_focus_mode(FOCUS_NONE);
 
 	show_grid_button = memnew(Button);
-	show_grid_button->set_flat(true);
+	show_grid_button->set_theme_type_variation("FlatButton");
 	show_grid_button->set_toggle_mode(true);
 	show_grid_button->set_tooltip_text(RTR("Toggle the visual grid."));
 	show_grid_button->connect("pressed", callable_mp(this, &GraphEdit::_show_grid_toggled));
@@ -2018,7 +2018,7 @@ GraphEdit::GraphEdit() {
 	menu_hbox->add_child(show_grid_button);
 
 	toggle_snapping_button = memnew(Button);
-	toggle_snapping_button->set_flat(true);
+	toggle_snapping_button->set_theme_type_variation("FlatButton");
 	toggle_snapping_button->set_toggle_mode(true);
 	toggle_snapping_button->set_tooltip_text(RTR("Toggle snapping to the grid."));
 	toggle_snapping_button->connect("pressed", callable_mp(this, &GraphEdit::_snapping_toggled));
@@ -2036,7 +2036,7 @@ GraphEdit::GraphEdit() {
 	menu_hbox->add_child(snapping_distance_spinbox);
 
 	minimap_button = memnew(Button);
-	minimap_button->set_flat(true);
+	minimap_button->set_theme_type_variation("FlatButton");
 	minimap_button->set_toggle_mode(true);
 	minimap_button->set_tooltip_text(RTR("Toggle the graph minimap."));
 	minimap_button->connect("pressed", callable_mp(this, &GraphEdit::_minimap_toggled));
@@ -2045,7 +2045,7 @@ GraphEdit::GraphEdit() {
 	menu_hbox->add_child(minimap_button);
 
 	layout_button = memnew(Button);
-	layout_button->set_flat(true);
+	layout_button->set_theme_type_variation("FlatButton");
 	menu_hbox->add_child(layout_button);
 	layout_button->set_tooltip_text(RTR("Automatically arrange selected nodes."));
 	layout_button->connect("pressed", callable_mp(this, &GraphEdit::arrange_nodes));

scene/theme/default_theme.cpp

@@ -360,6 +360,28 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	theme->set_constant("check_v_offset", "CheckButton", 0);
 	theme->set_constant("outline_size", "CheckButton", 0);
 
+	// Button variations
+
+	theme->set_type_variation("FlatButton", "Button");
+	theme->set_type_variation("FlatMenuButton", "MenuButton");
+
+	Ref<StyleBoxEmpty> flat_button_normal = make_empty_stylebox();
+	for (int i = 0; i < 4; i++) {
+		flat_button_normal->set_content_margin((Side)i, button_normal->get_margin((Side)i) + button_normal->get_border_width((Side)i));
+	}
+	Ref<StyleBoxFlat> flat_button_pressed = button_pressed->duplicate();
+	flat_button_pressed->set_bg_color(style_pressed_color * Color(1, 1, 1, 0.85));
+
+	theme->set_stylebox("normal", "FlatButton", flat_button_normal);
+	theme->set_stylebox("hover", "FlatButton", flat_button_normal);
+	theme->set_stylebox("pressed", "FlatButton", flat_button_pressed);
+	theme->set_stylebox("disabled", "FlatButton", flat_button_normal);
+
+	theme->set_stylebox("normal", "FlatMenuButton", flat_button_normal);
+	theme->set_stylebox("hover", "FlatMenuButton", flat_button_normal);
+	theme->set_stylebox("pressed", "FlatMenuButton", flat_button_pressed);
+	theme->set_stylebox("disabled", "FlatMenuButton", flat_button_normal);
+
 	// Label
 
 	theme->set_stylebox("normal", "Label", memnew(StyleBoxEmpty));