Make the drawing logic clearer in `Button`

The drawing logic follows the calculation logic in `Button::get_minimum_size`.

According to the order of `stylebox`, `icon`, and `text`, and follow properties
such as alignment mode, to fill the display space of the button.

Add a `Button::_set_h_separation_is_valid_when_no_text` for Button derived
classes (like `OptionButton`) that expects a `h_separation` between `icon`
and theme icon even if the `text` is empty.

scene/gui/button.cpp

@@ -50,6 +50,63 @@ void Button::_set_internal_margin(Side p_side, float p_value) {
 void Button::_queue_update_size_cache() {
 }
 
+void Button::_set_h_separation_is_valid_when_no_text(bool p_h_separation_is_valid_when_no_text) {
+	h_separation_is_valid_when_no_text = p_h_separation_is_valid_when_no_text;
+}
+
+Ref<StyleBox> Button::_get_current_stylebox() const {
+	Ref<StyleBox> stylebox = theme_cache.normal;
+	const bool rtl = is_layout_rtl();
+
+	switch (get_draw_mode()) {
+		case DRAW_NORMAL: {
+			if (rtl && has_theme_stylebox(SNAME("normal_mirrored"))) {
+				stylebox = theme_cache.normal_mirrored;
+			} else {
+				stylebox = theme_cache.normal;
+			}
+		} break;
+
+		case DRAW_HOVER_PRESSED: {
+			// Edge case for CheckButton and CheckBox.
+			if (has_theme_stylebox("hover_pressed")) {
+				if (rtl && has_theme_stylebox(SNAME("hover_pressed_mirrored"))) {
+					stylebox = theme_cache.hover_pressed_mirrored;
+				} else {
+					stylebox = theme_cache.hover_pressed;
+				}
+				break;
+			}
+		}
+			[[fallthrough]];
+		case DRAW_PRESSED: {
+			if (rtl && has_theme_stylebox(SNAME("pressed_mirrored"))) {
+				stylebox = theme_cache.pressed_mirrored;
+			} else {
+				stylebox = theme_cache.pressed;
+			}
+		} break;
+
+		case DRAW_HOVER: {
+			if (rtl && has_theme_stylebox(SNAME("hover_mirrored"))) {
+				stylebox = theme_cache.hover_mirrored;
+			} else {
+				stylebox = theme_cache.hover;
+			}
+		} break;
+
+		case DRAW_DISABLED: {
+			if (rtl && has_theme_stylebox(SNAME("disabled_mirrored"))) {
+				stylebox = theme_cache.disabled_mirrored;
+			} else {
+				stylebox = theme_cache.disabled;
+			}
+		} break;
+	}
+
+	return stylebox;
+}
+
 void Button::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED: {
@@ -72,287 +129,265 @@ void Button::_notification(int p_what) {
 		} break;
 
 		case NOTIFICATION_DRAW: {
-			RID ci = get_canvas_item();
-			Size2 size = get_size();
-			Color color;
-			Color color_icon(1, 1, 1, 1);
+			const RID ci = get_canvas_item();
+			const Size2 size = get_size();
 
-			Ref<StyleBox> style = theme_cache.normal;
-			bool rtl = is_layout_rtl();
-			const bool is_clipped = clip_text || overrun_behavior != TextServer::OVERRUN_NO_TRIMMING;
+			const Ref<StyleBox> style = _get_current_stylebox();
+			{ // Draws the stylebox in the current state.
+				if (!flat) {
+					style->draw(ci, Rect2(Point2(), size));
+				}
 
-			switch (get_draw_mode()) {
-				case DRAW_NORMAL: {
-					if (rtl && has_theme_stylebox(SNAME("normal_mirrored"))) {
-						style = theme_cache.normal_mirrored;
-					} else {
-						style = theme_cache.normal;
+				if (has_focus()) {
+					Ref<StyleBox> style2 = theme_cache.focus;
+					style2->draw(ci, Rect2(Point2(), size));
+				}
+			}
+
+			Ref<Texture2D> _icon = icon;
+			if (_icon.is_null() && has_theme_icon(SNAME("icon"))) {
+				_icon = theme_cache.icon;
+			}
+
+			if (xl_text.is_empty() && _icon.is_null()) {
+				break;
+			}
+
+			const float style_margin_left = style->get_margin(SIDE_LEFT);
+			const float style_margin_right = style->get_margin(SIDE_RIGHT);
+			const float style_margin_top = style->get_margin(SIDE_TOP);
+			const float style_margin_bottom = style->get_margin(SIDE_BOTTOM);
+
+			Size2 drawable_size_remained = size;
+
+			{ // The size after the stelybox is stripped.
+				drawable_size_remained.width -= style_margin_left + style_margin_right;
+				drawable_size_remained.height -= style_margin_top + style_margin_bottom;
+			}
+
+			const int h_separation = MAX(0, theme_cache.h_separation);
+
+			{ // The width reserved for internal element in derived classes (and h_separation if need).
+				float internal_margin = _internal_margin[SIDE_LEFT] + _internal_margin[SIDE_RIGHT];
+
+				if (!xl_text.is_empty() || h_separation_is_valid_when_no_text) {
+					if (_internal_margin[SIDE_LEFT] > 0.0f) {
+						internal_margin += h_separation;
 					}
 
-					if (!flat) {
-						style->draw(ci, Rect2(Point2(0, 0), size));
+					if (_internal_margin[SIDE_RIGHT] > 0.0f) {
+						internal_margin += h_separation;
 					}
+				}
+
+				drawable_size_remained.width -= internal_margin; // The size after the internal element is stripped.
+			}
+
+			HorizontalAlignment icon_align_rtl_checked = horizontal_icon_alignment;
+			HorizontalAlignment align_rtl_checked = alignment;
+			// Swap icon and text alignment sides if right-to-left layout is set.
+			if (is_layout_rtl()) {
+				if (horizontal_icon_alignment == HORIZONTAL_ALIGNMENT_RIGHT) {
+					icon_align_rtl_checked = HORIZONTAL_ALIGNMENT_LEFT;
+				} else if (horizontal_icon_alignment == HORIZONTAL_ALIGNMENT_LEFT) {
+					icon_align_rtl_checked = HORIZONTAL_ALIGNMENT_RIGHT;
+				}
+				if (alignment == HORIZONTAL_ALIGNMENT_RIGHT) {
+					align_rtl_checked = HORIZONTAL_ALIGNMENT_LEFT;
+				} else if (alignment == HORIZONTAL_ALIGNMENT_LEFT) {
+					align_rtl_checked = HORIZONTAL_ALIGNMENT_RIGHT;
+				}
+			}
 
+			Color font_color;
+			Color icon_modulate_color(1, 1, 1, 1);
+			// Get the font color and icon modulate color in the current state.
+			switch (get_draw_mode()) {
+				case DRAW_NORMAL: {
 					// Focus colors only take precedence over normal state.
 					if (has_focus()) {
-						color = theme_cache.font_focus_color;
+						font_color = theme_cache.font_focus_color;
 						if (has_theme_color(SNAME("icon_focus_color"))) {
-							color_icon = theme_cache.icon_focus_color;
+							icon_modulate_color = theme_cache.icon_focus_color;
 						}
 					} else {
-						color = theme_cache.font_color;
+						font_color = theme_cache.font_color;
 						if (has_theme_color(SNAME("icon_normal_color"))) {
-							color_icon = theme_cache.icon_normal_color;
+							icon_modulate_color = theme_cache.icon_normal_color;
 						}
 					}
 				} break;
 				case DRAW_HOVER_PRESSED: {
 					// Edge case for CheckButton and CheckBox.
 					if (has_theme_stylebox("hover_pressed")) {
-						if (rtl && has_theme_stylebox(SNAME("hover_pressed_mirrored"))) {
-							style = theme_cache.hover_pressed_mirrored;
-						} else {
-							style = theme_cache.hover_pressed;
-						}
-
-						if (!flat) {
-							style->draw(ci, Rect2(Point2(0, 0), size));
-						}
 						if (has_theme_color(SNAME("font_hover_pressed_color"))) {
-							color = theme_cache.font_hover_pressed_color;
+							font_color = theme_cache.font_hover_pressed_color;
 						}
 						if (has_theme_color(SNAME("icon_hover_pressed_color"))) {
-							color_icon = theme_cache.icon_hover_pressed_color;
+							icon_modulate_color = theme_cache.icon_hover_pressed_color;
 						}
 
 						break;
 					}
-					[[fallthrough]];
 				}
+					[[fallthrough]];
 				case DRAW_PRESSED: {
-					if (rtl && has_theme_stylebox(SNAME("pressed_mirrored"))) {
-						style = theme_cache.pressed_mirrored;
-					} else {
-						style = theme_cache.pressed;
-					}
-
-					if (!flat) {
-						style->draw(ci, Rect2(Point2(0, 0), size));
-					}
 					if (has_theme_color(SNAME("font_pressed_color"))) {
-						color = theme_cache.font_pressed_color;
+						font_color = theme_cache.font_pressed_color;
 					} else {
-						color = theme_cache.font_color;
+						font_color = theme_cache.font_color;
 					}
 					if (has_theme_color(SNAME("icon_pressed_color"))) {
-						color_icon = theme_cache.icon_pressed_color;
+						icon_modulate_color = theme_cache.icon_pressed_color;
 					}
 
 				} break;
 				case DRAW_HOVER: {
-					if (rtl && has_theme_stylebox(SNAME("hover_mirrored"))) {
-						style = theme_cache.hover_mirrored;
-					} else {
-						style = theme_cache.hover;
-					}
-
-					if (!flat) {
-						style->draw(ci, Rect2(Point2(0, 0), size));
-					}
-					color = theme_cache.font_hover_color;
+					font_color = theme_cache.font_hover_color;
 					if (has_theme_color(SNAME("icon_hover_color"))) {
-						color_icon = theme_cache.icon_hover_color;
+						icon_modulate_color = theme_cache.icon_hover_color;
 					}
 
 				} break;
 				case DRAW_DISABLED: {
-					if (rtl && has_theme_stylebox(SNAME("disabled_mirrored"))) {
-						style = theme_cache.disabled_mirrored;
-					} else {
-						style = theme_cache.disabled;
-					}
-
-					if (!flat) {
-						style->draw(ci, Rect2(Point2(0, 0), size));
-					}
-					color = theme_cache.font_disabled_color;
+					font_color = theme_cache.font_disabled_color;
 					if (has_theme_color(SNAME("icon_disabled_color"))) {
-						color_icon = theme_cache.icon_disabled_color;
+						icon_modulate_color = theme_cache.icon_disabled_color;
 					} else {
-						color_icon.a = 0.4;
+						icon_modulate_color.a = 0.4;
 					}
 
 				} break;
 			}
 
-			if (has_focus()) {
-				Ref<StyleBox> style2 = theme_cache.focus;
-				style2->draw(ci, Rect2(Point2(), size));
-			}
-
-			Ref<Texture2D> _icon;
-			if (icon.is_null() && has_theme_icon(SNAME("icon"))) {
-				_icon = theme_cache.icon;
-			} else {
-				_icon = icon;
-			}
-
-			Rect2 icon_region;
-			HorizontalAlignment icon_align_rtl_checked = horizontal_icon_alignment;
-			HorizontalAlignment align_rtl_checked = alignment;
-			// Swap icon and text alignment sides if right-to-left layout is set.
-			if (rtl) {
-				if (horizontal_icon_alignment == HORIZONTAL_ALIGNMENT_RIGHT) {
-					icon_align_rtl_checked = HORIZONTAL_ALIGNMENT_LEFT;
-				} else if (horizontal_icon_alignment == HORIZONTAL_ALIGNMENT_LEFT) {
-					icon_align_rtl_checked = HORIZONTAL_ALIGNMENT_RIGHT;
-				}
-				if (alignment == HORIZONTAL_ALIGNMENT_RIGHT) {
-					align_rtl_checked = HORIZONTAL_ALIGNMENT_LEFT;
-				} else if (alignment == HORIZONTAL_ALIGNMENT_LEFT) {
-					align_rtl_checked = HORIZONTAL_ALIGNMENT_RIGHT;
-				}
-			}
-			if (!_icon.is_null()) {
-				int valign = size.height - style->get_minimum_size().y;
+			const bool is_clipped = clip_text || overrun_behavior != TextServer::OVERRUN_NO_TRIMMING;
+			const Size2 custom_element_size = drawable_size_remained;
+
+			// Draw the icon.
+			if (_icon.is_valid()) {
+				Size2 icon_size;
+
+				{ // Calculate the drawing size of the icon.
+					icon_size = _icon->get_size();
+
+					if (expand_icon) {
+						const Size2 text_buf_size = text_buf->get_size();
+						Size2 _size = custom_element_size;
+						if (!is_clipped && icon_align_rtl_checked != HORIZONTAL_ALIGNMENT_CENTER && text_buf_size.width > 0.0f) {
+							// If there is not enough space for icon and h_separation, h_separation will occupy the space first,
+							// so the icon's width may be negative. Keep it negative to make it easier to calculate the space
+							// reserved for text later.
+							_size.width -= text_buf_size.width + h_separation;
+						}
+						if (vertical_icon_alignment != VERTICAL_ALIGNMENT_CENTER) {
+							_size.height -= text_buf_size.height;
+						}
 
-				int voffset = 0;
-				Size2 icon_size = _icon->get_size();
+						float icon_width = icon_size.width * _size.height / icon_size.height;
+						float icon_height = _size.height;
 
-				// Fix vertical size.
-				if (vertical_icon_alignment != VERTICAL_ALIGNMENT_CENTER) {
-					valign -= text_buf->get_size().height;
-				}
+						if (icon_width > _size.width) {
+							icon_width = _size.width;
+							icon_height = icon_size.height * icon_width / icon_size.width;
+						}
 
-				float icon_ofs_region = 0.0;
-				Point2 style_offset;
-				if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_LEFT) {
-					style_offset.x = style->get_margin(SIDE_LEFT);
-					if (_internal_margin[SIDE_LEFT] > 0) {
-						icon_ofs_region = _internal_margin[SIDE_LEFT] + theme_cache.h_separation;
-					}
-				} else if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_CENTER) {
-					style_offset.x = 0.0;
-				} else if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_RIGHT) {
-					style_offset.x = -style->get_margin(SIDE_RIGHT);
-					if (_internal_margin[SIDE_RIGHT] > 0) {
-						icon_ofs_region = -_internal_margin[SIDE_RIGHT] - theme_cache.h_separation;
+						icon_size = Size2(icon_width, icon_height);
 					}
+					icon_size = _fit_icon_size(icon_size);
 				}
-				style_offset.y = style->get_margin(SIDE_TOP);
-
-				if (expand_icon) {
-					Size2 _size = get_size() - style->get_offset() * 2;
-					int icon_text_separation = text.is_empty() ? 0 : theme_cache.h_separation;
-					_size.width -= icon_text_separation + icon_ofs_region;
-					if (!is_clipped && icon_align_rtl_checked != HORIZONTAL_ALIGNMENT_CENTER) {
-						_size.width -= text_buf->get_size().width;
-					}
-					if (vertical_icon_alignment != VERTICAL_ALIGNMENT_CENTER) {
-						_size.height -= text_buf->get_size().height;
-					}
-					float icon_width = _icon->get_width() * _size.height / _icon->get_height();
-					float icon_height = _size.height;
 
-					if (icon_width > _size.width) {
-						icon_width = _size.width;
-						icon_height = _icon->get_height() * icon_width / _icon->get_width();
+				if (icon_size.width > 0.0f) {
+					// Calculate the drawing position of the icon.
+					Point2 icon_ofs;
+
+					switch (icon_align_rtl_checked) {
+						case HORIZONTAL_ALIGNMENT_CENTER: {
+							icon_ofs.x = (custom_element_size.width - icon_size.width) / 2.0f;
+						}
+							[[fallthrough]];
+						case HORIZONTAL_ALIGNMENT_FILL:
+						case HORIZONTAL_ALIGNMENT_LEFT: {
+							icon_ofs.x += style_margin_left;
+							icon_ofs.x += _internal_margin[SIDE_LEFT];
+						} break;
+
+						case HORIZONTAL_ALIGNMENT_RIGHT: {
+							icon_ofs.x = size.x - style_margin_right;
+							icon_ofs.x -= _internal_margin[SIDE_RIGHT];
+							icon_ofs.x -= icon_size.width;
+						} break;
 					}
 
-					icon_size = Size2(icon_width, icon_height);
-				}
-				icon_size = _fit_icon_size(icon_size);
+					switch (vertical_icon_alignment) {
+						case VERTICAL_ALIGNMENT_CENTER: {
+							icon_ofs.y = (custom_element_size.height - icon_size.height) / 2.0f;
+						}
+							[[fallthrough]];
+						case VERTICAL_ALIGNMENT_FILL:
+						case VERTICAL_ALIGNMENT_TOP: {
+							icon_ofs.y += style_margin_top;
+						} break;
+
+						case VERTICAL_ALIGNMENT_BOTTOM: {
+							icon_ofs.y = size.y - style_margin_bottom - icon_size.height;
+						} break;
+					}
 
-				if (vertical_icon_alignment == VERTICAL_ALIGNMENT_TOP) {
-					voffset = -(valign - icon_size.y) / 2;
-				}
-				if (vertical_icon_alignment == VERTICAL_ALIGNMENT_BOTTOM) {
-					voffset = (valign - icon_size.y) / 2 + text_buf->get_size().y;
+					Rect2 icon_region = Rect2(icon_ofs, icon_size);
+					draw_texture_rect(_icon, icon_region, false, icon_modulate_color);
 				}
 
-				if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_LEFT) {
-					icon_region = Rect2(style_offset + Point2(icon_ofs_region, voffset + Math::floor((valign - icon_size.y) * 0.5)), icon_size);
-				} else if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_CENTER) {
-					icon_region = Rect2(style_offset + Point2(icon_ofs_region + Math::floor((size.x - icon_size.x) * 0.5), voffset + Math::floor((valign - icon_size.y) * 0.5)), icon_size);
-				} else {
-					icon_region = Rect2(style_offset + Point2(icon_ofs_region + size.x - icon_size.x, voffset + Math::floor((valign - icon_size.y) * 0.5)), icon_size);
-				}
+				if (!xl_text.is_empty()) {
+					// Update the size after the icon is stripped. Stripping only when the icon alignments are not center.
+					if (icon_align_rtl_checked != HORIZONTAL_ALIGNMENT_CENTER) {
+						// Subtract the space's width occupied by icon and h_separation together.
+						drawable_size_remained.width -= icon_size.width + h_separation;
+					}
 
-				if (icon_region.size.width > 0) {
-					Rect2 icon_region_rounded = Rect2(icon_region.position.round(), icon_region.size.round());
-					draw_texture_rect(_icon, icon_region_rounded, false, color_icon);
+					if (vertical_icon_alignment != VERTICAL_ALIGNMENT_CENTER) {
+						drawable_size_remained.height -= icon_size.height;
+					}
 				}
 			}
 
-			Point2 icon_ofs = !_icon.is_null() ? Point2(icon_region.size.width + theme_cache.h_separation, 0) : Point2();
-			if (align_rtl_checked == HORIZONTAL_ALIGNMENT_CENTER && icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_CENTER) {
-				icon_ofs.x = 0.0;
-			}
-
-			int text_clip = size.width - style->get_minimum_size().width - icon_ofs.width;
-			if (_internal_margin[SIDE_LEFT] > 0) {
-				text_clip -= _internal_margin[SIDE_LEFT] + theme_cache.h_separation;
-			}
-			if (_internal_margin[SIDE_RIGHT] > 0) {
-				text_clip -= _internal_margin[SIDE_RIGHT] + theme_cache.h_separation;
-			}
-
-			text_buf->set_width(is_clipped ? text_clip : -1);
+			// Draw the text.
+			if (!xl_text.is_empty()) {
+				text_buf->set_alignment(align_rtl_checked);
 
-			int text_width = MAX(1, is_clipped ? MIN(text_clip, text_buf->get_size().x) : text_buf->get_size().x);
+				float text_buf_width = MAX(1.0f, drawable_size_remained.width); // The space's width filled by the text_buf.
+				text_buf->set_width(text_buf_width);
 
-			Point2 text_ofs = (size - style->get_minimum_size() - icon_ofs - text_buf->get_size() - Point2(_internal_margin[SIDE_RIGHT] - _internal_margin[SIDE_LEFT], 0)) / 2.0;
-
-			if (vertical_icon_alignment == VERTICAL_ALIGNMENT_TOP) {
-				text_ofs.y += icon_region.size.height / 2;
-			}
-			if (vertical_icon_alignment == VERTICAL_ALIGNMENT_BOTTOM) {
-				text_ofs.y -= icon_region.size.height / 2;
-			}
+				Point2 text_ofs;
 
-			text_buf->set_alignment(align_rtl_checked);
-			text_buf->set_width(text_width);
-			switch (align_rtl_checked) {
-				case HORIZONTAL_ALIGNMENT_FILL:
-				case HORIZONTAL_ALIGNMENT_LEFT: {
-					if (icon_align_rtl_checked != HORIZONTAL_ALIGNMENT_LEFT) {
-						icon_ofs.x = 0.0;
-					}
-					if (_internal_margin[SIDE_LEFT] > 0) {
-						text_ofs.x = style->get_margin(SIDE_LEFT) + icon_ofs.x + _internal_margin[SIDE_LEFT] + theme_cache.h_separation;
-					} else {
-						text_ofs.x = style->get_margin(SIDE_LEFT) + icon_ofs.x;
-					}
-					text_ofs.y += style->get_offset().y;
-				} break;
-				case HORIZONTAL_ALIGNMENT_CENTER: {
-					if (text_ofs.x < 0) {
-						text_ofs.x = 0;
-					}
-					if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_LEFT) {
-						text_ofs += icon_ofs;
-					}
-					text_ofs += style->get_offset();
-				} break;
-				case HORIZONTAL_ALIGNMENT_RIGHT: {
-					if (_internal_margin[SIDE_RIGHT] > 0) {
-						text_ofs.x = size.x - style->get_margin(SIDE_RIGHT) - text_width - _internal_margin[SIDE_RIGHT] - theme_cache.h_separation;
-					} else {
-						text_ofs.x = size.x - style->get_margin(SIDE_RIGHT) - text_width;
-					}
-					text_ofs.y += style->get_offset().y;
-					if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_RIGHT) {
-						text_ofs.x -= icon_ofs.x;
+				switch (align_rtl_checked) {
+					case HORIZONTAL_ALIGNMENT_CENTER: {
+						text_ofs.x = (drawable_size_remained.width - text_buf_width) / 2.0f;
 					}
-				} break;
-			}
+						[[fallthrough]];
+					case HORIZONTAL_ALIGNMENT_FILL:
+					case HORIZONTAL_ALIGNMENT_LEFT:
+					case HORIZONTAL_ALIGNMENT_RIGHT: {
+						text_ofs.x += style_margin_left;
+						text_ofs.x += _internal_margin[SIDE_LEFT];
+						if (icon_align_rtl_checked == HORIZONTAL_ALIGNMENT_LEFT) {
+							// Offset by the space's width that occupied by icon and h_separation together.
+							text_ofs.x += custom_element_size.width - drawable_size_remained.width;
+						}
+					} break;
+				}
+
+				text_ofs.y = (drawable_size_remained.height - text_buf->get_size().height) / 2.0f + style_margin_top;
+				if (vertical_icon_alignment == VERTICAL_ALIGNMENT_TOP) {
+					text_ofs.y += custom_element_size.height - drawable_size_remained.height; // Offset by the icon's height.
+				}
 
-			Color font_outline_color = theme_cache.font_outline_color;
-			int outline_size = theme_cache.outline_size;
-			if (outline_size > 0 && font_outline_color.a > 0) {
-				text_buf->draw_outline(ci, text_ofs, outline_size, font_outline_color);
+				Color font_outline_color = theme_cache.font_outline_color;
+				int outline_size = theme_cache.outline_size;
+				if (outline_size > 0 && font_outline_color.a > 0.0f) {
+					text_buf->draw_outline(ci, text_ofs, outline_size, font_outline_color);
+				}
+				text_buf->draw(ci, text_ofs, font_color);
 			}
-			text_buf->draw(ci, text_ofs, color);
 		} break;
 	}
 }
@@ -411,7 +446,7 @@ Size2 Button::get_minimum_size_for_text_and_icon(const String &p_text, Ref<Textu
 		}
 	}
 
-	return theme_cache.normal->get_minimum_size() + minsize;
+	return _get_current_stylebox()->get_minimum_size() + minsize;
 }
 
 void Button::_shape(Ref<TextParagraph> p_paragraph, String p_text) {
@@ -443,9 +478,13 @@ void Button::_shape(Ref<TextParagraph> p_paragraph, String p_text) {
 
 void Button::set_text_overrun_behavior(TextServer::OverrunBehavior p_behavior) {
 	if (overrun_behavior != p_behavior) {
+		bool need_update_cache = overrun_behavior == TextServer::OVERRUN_NO_TRIMMING || p_behavior == TextServer::OVERRUN_NO_TRIMMING;
 		overrun_behavior = p_behavior;
 		_shape();
 
+		if (need_update_cache) {
+			_queue_update_size_cache();
+		}
 		queue_redraw();
 		update_minimum_size();
 	}
@@ -550,6 +589,8 @@ bool Button::is_flat() const {
 void Button::set_clip_text(bool p_enabled) {
 	if (clip_text != p_enabled) {
 		clip_text = p_enabled;
+
+		_queue_update_size_cache();
 		queue_redraw();
 		update_minimum_size();
 	}
@@ -571,13 +612,25 @@ HorizontalAlignment Button::get_text_alignment() const {
 }
 
 void Button::set_icon_alignment(HorizontalAlignment p_alignment) {
+	if (horizontal_icon_alignment == p_alignment) {
+		return;
+	}
+
 	horizontal_icon_alignment = p_alignment;
 	update_minimum_size();
 	queue_redraw();
 }
 
 void Button::set_vertical_icon_alignment(VerticalAlignment p_alignment) {
+	if (vertical_icon_alignment == p_alignment) {
+		return;
+	}
+	bool need_update_cache = vertical_icon_alignment == VERTICAL_ALIGNMENT_CENTER || p_alignment == VERTICAL_ALIGNMENT_CENTER;
 	vertical_icon_alignment = p_alignment;
+
+	if (need_update_cache) {
+		_queue_update_size_cache();
+	}
 	update_minimum_size();
 	queue_redraw();
 }

scene/gui/button.h

@@ -55,6 +55,8 @@ private:
 	VerticalAlignment vertical_icon_alignment = VERTICAL_ALIGNMENT_CENTER;
 	float _internal_margin[4] = {};
 
+	bool h_separation_is_valid_when_no_text = false;
+
 	struct ThemeCache {
 		Ref<StyleBox> normal;
 		Ref<StyleBox> normal_mirrored;
@@ -102,6 +104,8 @@ protected:
 	void _set_internal_margin(Side p_side, float p_value);
 	virtual void _queue_update_size_cache();
 
+	void _set_h_separation_is_valid_when_no_text(bool p_h_separation_is_valid_when_no_text);
+	Ref<StyleBox> _get_current_stylebox() const;
 	void _notification(int p_what);
 	static void _bind_methods();
 

scene/gui/option_button.cpp

@@ -60,7 +60,7 @@ Size2 OptionButton::get_minimum_size() const {
 	}
 
 	if (has_theme_icon(SNAME("arrow"))) {
-		const Size2 padding = theme_cache.normal->get_minimum_size();
+		const Size2 padding = _get_current_stylebox()->get_minimum_size();
 		const Size2 arrow_size = theme_cache.arrow_icon->get_size();
 
 		Size2 content_size = minsize - padding;
@@ -605,6 +605,8 @@ void OptionButton::set_disable_shortcuts(bool p_disabled) {
 
 OptionButton::OptionButton(const String &p_text) :
 		Button(p_text) {
+	_set_h_separation_is_valid_when_no_text(true);
+
 	set_toggle_mode(true);
 	set_process_shortcut_input(true);
 	set_text_alignment(HORIZONTAL_ALIGNMENT_LEFT);

scene/theme/default_theme.cpp

@@ -225,20 +225,20 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	// OptionButton
 	theme->set_stylebox("focus", "OptionButton", focus);
 
-	Ref<StyleBox> sb_optbutton_normal = make_flat_stylebox(style_normal_color, 2 * default_margin, default_margin, 21, default_margin);
-	Ref<StyleBox> sb_optbutton_hover = make_flat_stylebox(style_hover_color, 2 * default_margin, default_margin, 21, default_margin);
-	Ref<StyleBox> sb_optbutton_pressed = make_flat_stylebox(style_pressed_color, 2 * default_margin, default_margin, 21, default_margin);
-	Ref<StyleBox> sb_optbutton_disabled = make_flat_stylebox(style_disabled_color, 2 * default_margin, default_margin, 21, default_margin);
+	Ref<StyleBox> sb_optbutton_normal = make_flat_stylebox(style_normal_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_hover = make_flat_stylebox(style_hover_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_pressed = make_flat_stylebox(style_pressed_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_disabled = make_flat_stylebox(style_disabled_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
 
 	theme->set_stylebox("normal", "OptionButton", sb_optbutton_normal);
 	theme->set_stylebox("hover", "OptionButton", sb_optbutton_hover);
 	theme->set_stylebox("pressed", "OptionButton", sb_optbutton_pressed);
 	theme->set_stylebox("disabled", "OptionButton", sb_optbutton_disabled);
 
-	Ref<StyleBox> sb_optbutton_normal_mirrored = make_flat_stylebox(style_normal_color, 21, default_margin, 2 * default_margin, default_margin);
-	Ref<StyleBox> sb_optbutton_hover_mirrored = make_flat_stylebox(style_hover_color, 21, default_margin, 2 * default_margin, default_margin);
-	Ref<StyleBox> sb_optbutton_pressed_mirrored = make_flat_stylebox(style_pressed_color, 21, default_margin, 2 * default_margin, default_margin);
-	Ref<StyleBox> sb_optbutton_disabled_mirrored = make_flat_stylebox(style_disabled_color, 21, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_normal_mirrored = make_flat_stylebox(style_normal_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_hover_mirrored = make_flat_stylebox(style_hover_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_pressed_mirrored = make_flat_stylebox(style_pressed_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
+	Ref<StyleBox> sb_optbutton_disabled_mirrored = make_flat_stylebox(style_disabled_color, 2 * default_margin, default_margin, 2 * default_margin, default_margin);
 
 	theme->set_stylebox("normal_mirrored", "OptionButton", sb_optbutton_normal_mirrored);
 	theme->set_stylebox("hover_mirrored", "OptionButton", sb_optbutton_hover_mirrored);