LibGUI: Add alpha preview to ColorPicker

lanmonster · Sep 25, 2020 · 5b7decc · 5b7decc
1 parent 59a0e5b
commit 5b7decc
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Showing 2 changed files with 46 additions and 17 deletions.
diff --git a/Libraries/LibGUI/ColorPicker.cpp b/Libraries/LibGUI/ColorPicker.cpp
@@ -118,6 +118,19 @@ class ColorSlider final : public GUI::Frame {
  virtual void resize_event(ResizeEvent&) override;
 };
 
+class ColorPreview final : public GUI::Widget {
+ C_OBJECT(ColorPreview);
+
+public:
+ void set_color(Color);
+
+private:
+ ColorPreview(Color);
+
+ Color m_color;
+ virtual void paint_event(GUI::PaintEvent&) override;
+};
+
 class CustomColorWidget final : public GUI::Widget {
  C_OBJECT(CustomColorWidget);
 
@@ -257,20 +270,10 @@ void ColorPicker::build_ui_custom(Widget& root_container)
  preview_container.set_preferred_size(0, 128);
 
  // Current color
- auto& current_color_widget = preview_container.add<Widget>();
- current_color_widget.set_fill_with_background_color(true);
-
- auto pal1 = current_color_widget.palette();
- pal1.set_color(ColorRole::Background, m_color);
- current_color_widget.set_palette(pal1);
+ preview_container.add<ColorPreview>(m_color);
 
  // Preview selected color
- m_preview_widget = preview_container.add<Widget>();
- m_preview_widget->set_fill_with_background_color(true);
-
- auto pal2 = m_preview_widget->palette();
- pal2.set_color(ColorRole::Background, m_color);
- m_preview_widget->set_palette(pal2);
+ m_preview_widget = preview_container.add<ColorPreview>(m_color);
 
  vertical_container.layout()->add_spacer();
 
@@ -367,10 +370,7 @@ void ColorPicker::build_ui_custom(Widget& root_container)
 
 void ColorPicker::update_color_widgets()
 {
- auto pal = m_preview_widget->palette();
- pal.set_color(ColorRole::Background, m_color);
- m_preview_widget->set_palette(pal);
- m_preview_widget->update();
+ m_preview_widget->set_color(m_color);
 
  m_html_text->set_text(m_color_has_alpha_channel ? m_color.to_string() : m_color.to_string_without_alpha());
 
@@ -702,4 +702,32 @@ void ColorSlider::resize_event(ResizeEvent&)
  recalculate_position();
 }
 
+ColorPreview::ColorPreview(Color color)
+ : m_color(color)
+{
+}
+
+void ColorPreview::set_color(Color color)
+{
+ if (m_color == color)
+ return;
+
+ m_color = color;
+ update();
+}
+
+void ColorPreview::paint_event(PaintEvent& event)
+{
+ Painter painter(*this);
+ painter.add_clip_rect(event.rect());
+
+ if (m_color.alpha() < 255) {
+ Gfx::StylePainter::paint_transparency_grid(painter, rect(), palette());
+ painter.fill_rect(rect(), m_color);
+ painter.fill_rect({ 0, 0, rect().width() / 4, rect().height() }, m_color.with_alpha(255));
+ } else {
+ painter.fill_rect(rect(), m_color);
+ }
+}
+
 }
diff --git a/Libraries/LibGUI/ColorPicker.h b/Libraries/LibGUI/ColorPicker.h
@@ -32,6 +32,7 @@
 namespace GUI {
 
 class ColorButton;
+class ColorPreview;
 class CustomColorWidget;
 
 class ColorPicker final : public Dialog {
@@ -58,7 +59,7 @@ class ColorPicker final : public Dialog {
 
  Vector<ColorButton*> m_color_widgets;
  RefPtr<CustomColorWidget> m_custom_color;
- RefPtr<Widget> m_preview_widget;
+ RefPtr<ColorPreview> m_preview_widget;
  RefPtr<TextBox> m_html_text;
  RefPtr<SpinBox> m_red_spinbox;
  RefPtr<SpinBox> m_green_spinbox;