Added code preview to visual shader

editor/plugins/visual_shader_editor_plugin.cpp

@@ -69,8 +69,16 @@ void VisualShaderEditor::edit(VisualShader *p_visual_shader) {
 			}
 		}
 		visual_shader = Ref<VisualShader>(p_visual_shader);
+		if (!visual_shader->is_connected("changed", this, "_update_preview")) {
+			visual_shader->connect("changed", this, "_update_preview");
+		}
 		visual_shader->set_graph_offset(graph->get_scroll_ofs() / EDSCALE);
 	} else {
+		if (visual_shader.is_valid()) {
+			if (visual_shader->is_connected("changed", this, "")) {
+				visual_shader->disconnect("changed", this, "_update_preview");
+			}
+		}
 		visual_shader.unref();
 	}
 
@@ -81,6 +89,7 @@ void VisualShaderEditor::edit(VisualShader *p_visual_shader) {
 			_clear_buffer();
 			_update_custom_nodes();
 			_update_options_menu();
+			_update_preview();
 		}
 		_update_graph();
 	}
@@ -1566,6 +1575,29 @@ void VisualShaderEditor::_notification(int p_what) {
 
 		node_filter->set_right_icon(Control::get_icon("Search", "EditorIcons"));
 
+		preview_shader->set_icon(Control::get_icon("Shader", "EditorIcons"));
+
+		{
+			Color background_color = EDITOR_GET("text_editor/highlighting/background_color");
+			Color text_color = EDITOR_GET("text_editor/highlighting/text_color");
+			Color keyword_color = EDITOR_GET("text_editor/highlighting/keyword_color");
+			Color comment_color = EDITOR_GET("text_editor/highlighting/comment_color");
+			Color symbol_color = EDITOR_GET("text_editor/highlighting/symbol_color");
+
+			preview_text->add_color_override("background_color", background_color);
+
+			for (List<String>::Element *E = keyword_list.front(); E; E = E->next()) {
+
+				preview_text->add_keyword_color(E->get(), keyword_color);
+			}
+
+			preview_text->add_font_override("font", get_font("expression", "EditorFonts"));
+			preview_text->add_color_override("font_color", text_color);
+			preview_text->add_color_override("symbol_color", symbol_color);
+			preview_text->add_color_region("/*", "*/", comment_color, false);
+			preview_text->add_color_region("//", "", comment_color, false);
+		}
+
 		tools->set_icon(EditorNode::get_singleton()->get_gui_base()->get_icon("Tools", "EditorIcons"));
 
 		if (p_what == NOTIFICATION_THEME_CHANGED && is_visible_in_tree())
@@ -2016,6 +2048,15 @@ void VisualShaderEditor::drop_data_fw(const Point2 &p_point, const Variant &p_da
 	}
 }
 
+void VisualShaderEditor::_show_preview_panel() {
+	preview_showed = !preview_showed;
+	preview_panel->set_visible(preview_showed);
+}
+
+void VisualShaderEditor::_update_preview() {
+	preview_text->set_text(visual_shader->get_code());
+}
+
 void VisualShaderEditor::_bind_methods() {
 	ClassDB::bind_method("_rebuild", &VisualShaderEditor::_rebuild);
 	ClassDB::bind_method("_update_graph", &VisualShaderEditor::_update_graph);
@@ -2055,6 +2096,8 @@ void VisualShaderEditor::_bind_methods() {
 	ClassDB::bind_method("_node_resized", &VisualShaderEditor::_node_resized);
 	ClassDB::bind_method("_set_node_size", &VisualShaderEditor::_set_node_size);
 	ClassDB::bind_method("_clear_buffer", &VisualShaderEditor::_clear_buffer);
+	ClassDB::bind_method("_show_preview_panel", &VisualShaderEditor::_show_preview_panel);
+	ClassDB::bind_method("_update_preview", &VisualShaderEditor::_update_preview);
 
 	ClassDB::bind_method(D_METHOD("get_drag_data_fw"), &VisualShaderEditor::get_drag_data_fw);
 	ClassDB::bind_method(D_METHOD("can_drop_data_fw"), &VisualShaderEditor::can_drop_data_fw);
@@ -2081,13 +2124,23 @@ VisualShaderEditor::VisualShaderEditor() {
 	saved_node_pos = Point2(0, 0);
 	ShaderLanguage::get_keyword_list(&keyword_list);
 
+	preview_showed = false;
+
 	to_node = -1;
 	to_slot = -1;
 	from_node = -1;
 	from_slot = -1;
 
+	main_box = memnew(HSplitContainer);
+	main_box->set_v_size_flags(SIZE_EXPAND_FILL);
+	main_box->set_h_size_flags(SIZE_EXPAND_FILL);
+	add_child(main_box);
+
 	graph = memnew(GraphEdit);
-	add_child(graph);
+	graph->get_zoom_hbox()->set_h_size_flags(SIZE_EXPAND_FILL);
+	graph->set_v_size_flags(SIZE_EXPAND_FILL);
+	graph->set_h_size_flags(SIZE_EXPAND_FILL);
+	main_box->add_child(graph);
 	graph->set_drag_forwarding(this);
 	graph->add_valid_right_disconnect_type(VisualShaderNode::PORT_TYPE_SCALAR);
 	graph->add_valid_right_disconnect_type(VisualShaderNode::PORT_TYPE_BOOLEAN);
@@ -2136,6 +2189,33 @@ VisualShaderEditor::VisualShaderEditor() {
 	graph->get_zoom_hbox()->move_child(add_node, 0);
 	add_node->connect("pressed", this, "_show_members_dialog", varray(false));
 
+	preview_shader = memnew(ToolButton);
+	preview_shader->set_toggle_mode(true);
+	preview_shader->set_tooltip(TTR("Show resulted shader code."));
+	graph->get_zoom_hbox()->add_child(preview_shader);
+	preview_shader->connect("pressed", this, "_show_preview_panel");
+
+	///////////////////////////////////////
+	// PREVIEW PANEL
+	///////////////////////////////////////
+
+	preview_panel = memnew(PanelContainer);
+	main_box->add_child(preview_panel);
+
+	VBoxContainer *preview_vb = memnew(VBoxContainer);
+	preview_panel->add_child(preview_vb);
+	preview_vb->set_h_size_flags(SIZE_EXPAND_FILL);
+	preview_vb->set_v_size_flags(SIZE_EXPAND_FILL);
+	preview_text = memnew(TextEdit);
+	preview_text->set_h_size_flags(SIZE_EXPAND_FILL);
+	preview_text->set_v_size_flags(SIZE_EXPAND_FILL);
+	preview_text->set_syntax_coloring(true);
+	preview_text->set_readonly(true);
+	preview_vb->add_child(preview_text);
+
+	preview_panel->set_visible(preview_showed);
+	preview_panel->set_custom_minimum_size(Size2(400 * EDSCALE, 0));
+
 	///////////////////////////////////////
 	// SHADER NODES TREE
 	///////////////////////////////////////

editor/plugins/visual_shader_editor_plugin.h

@@ -60,14 +60,19 @@ class VisualShaderEditor : public VBoxContainer {
 	int editing_port;
 
 	Ref<VisualShader> visual_shader;
+	HSplitContainer *main_box;
 	GraphEdit *graph;
 	ToolButton *add_node;
+	ToolButton *preview_shader;
 
 	OptionButton *edit_type;
 
 	PanelContainer *error_panel;
 	Label *error_label;
 
+	PanelContainer *preview_panel;
+	TextEdit *preview_text;
+
 	UndoRedo *undo_redo;
 	Point2 saved_node_pos;
 	bool saved_node_pos_dirty;
@@ -75,6 +80,8 @@ class VisualShaderEditor : public VBoxContainer {
 	ConfirmationDialog *members_dialog;
 	MenuButton *tools;
 
+	bool preview_showed;
+
 	enum ToolsMenuOptions {
 		EXPAND_ALL,
 		COLLAPSE_ALL
@@ -146,6 +153,9 @@ class VisualShaderEditor : public VBoxContainer {
 	void _update_custom_nodes();
 	void _update_options_menu();
 
+	void _show_preview_panel();
+	void _update_preview();
+
 	static VisualShaderEditor *singleton;
 
 	void _node_dragged(const Vector2 &p_from, const Vector2 &p_to, int p_node);

scene/resources/visual_shader.cpp

@@ -1249,6 +1249,10 @@ void VisualShader::_update_shader() const {
 	for (int i = 0; i < default_tex_params.size(); i++) {
 		const_cast<VisualShader *>(this)->set_default_texture_param(default_tex_params[i].name, default_tex_params[i].param);
 	}
+	if (previous_code != final_code) {
+		const_cast<VisualShader *>(this)->emit_signal("changed");
+	}
+	previous_code = final_code;
 }
 
 void VisualShader::_queue_update() {

scene/resources/visual_shader.h

@@ -73,6 +73,7 @@ private:
 	} graph[TYPE_MAX];
 
 	Shader::Mode shader_mode;
+	mutable String previous_code;
 
 	Array _get_node_connections(Type p_type) const;