feat(desktop-widgets): add text opacity slider to label widget

Author: Ly-sec

src/shell/desktop/desktop_widget_factory.cpp

@@ -286,7 +286,7 @@ std::unique_ptr<DesktopWidget> DesktopWidgetFactory::create(
     auto widget = std::make_unique<DesktopLabelWidget>(
         getStringSetting(settings, "title", "Title"), getStringSetting(settings, "description"),
         getColorSpecSetting(settings, "color", colorSpecFromRole(ColorRole::OnSurface)),
-        getBoolSetting(settings, "shadow", true)
+        std::clamp(getFloatSetting(settings, "opacity", 1.0f), 0.0f, 1.0f), getBoolSetting(settings, "shadow", true)
     );
     applyCommonSettings(*widget, settings);
     widget->setContentScale(contentScale);

src/shell/desktop/desktop_widget_settings_registry.cpp

@@ -315,6 +315,7 @@ namespace desktop_settings {
       add(stringSpec("title", "Title"));
       add(stringSpec("description"));
       add(colorSpec("color", "on_surface"));
+      add(doubleSpec("opacity", 1.0, 0.0, 1.0, 0.01));
       add(fontFamilySpec());
       add(boolSpec("shadow", true));
     } else if (type == "button") {

src/shell/desktop/desktop_widgets_controller.cpp

@@ -37,7 +37,7 @@ namespace {
   void normalizeDesktopWidgetSettings(DesktopWidgetState& widget) {
     clampOpacitySetting(widget, "background_opacity", 0.8);
 
-    if (widget.type == "sticker") {
+    if (widget.type == "sticker" || widget.type == "label") {
       const auto opacityIt = widget.settings.find("opacity");
       if (opacityIt == widget.settings.end()) {
         widget.settings.insert_or_assign("opacity", 1.0);

src/shell/desktop/widgets/desktop_label_widget.cpp

@@ -20,8 +20,11 @@ namespace {
 
 } // namespace
 
-DesktopLabelWidget::DesktopLabelWidget(std::string title, std::string description, ColorSpec color, bool shadow)
-    : m_title(std::move(title)), m_description(std::move(description)), m_color(color), m_shadow(shadow) {}
+DesktopLabelWidget::DesktopLabelWidget(
+    std::string title, std::string description, ColorSpec color, float opacity, bool shadow
+)
+    : m_title(std::move(title)), m_description(std::move(description)), m_color(color),
+      m_opacity(std::clamp(opacity, 0.0f, 1.0f)), m_shadow(shadow) {}
 
 void DesktopLabelWidget::create() {
   auto rootNode = std::make_unique<Node>();
@@ -49,6 +52,7 @@ void DesktopLabelWidget::create() {
   rootNode->addChild(std::move(descriptionLabel));
 
   setRoot(std::move(rootNode));
+  applyLabelColors();
   applyShadow();
 }
 
@@ -81,17 +85,27 @@ bool DesktopLabelWidget::applySetting(
   if (key == "color") {
     if (const auto* v = std::get_if<std::string>(&value)) {
       m_color = colorSpecFromConfigString(*v, key);
-      if (m_titleLabel != nullptr) {
-        m_titleLabel->setColor(m_color);
-      }
-      if (m_descriptionLabel != nullptr) {
-        m_descriptionLabel->setColor(m_color);
-      }
+      applyLabelColors();
       requestLayout();
       return true;
     }
     return false;
   }
+  if (key == "opacity") {
+    if (const auto* v = std::get_if<double>(&value)) {
+      m_opacity = std::clamp(static_cast<float>(*v), 0.0f, 1.0f);
+      applyLabelColors();
+      applyShadow();
+      return true;
+    }
+    if (const auto* v = std::get_if<std::int64_t>(&value)) {
+      m_opacity = std::clamp(static_cast<float>(*v), 0.0f, 1.0f);
+      applyLabelColors();
+      applyShadow();
+      return true;
+    }
+    return false;
+  }
   if (key == "shadow") {
     if (const auto* v = std::get_if<bool>(&value)) {
       m_shadow = *v;
@@ -142,12 +156,24 @@ void DesktopLabelWidget::doLayout(Renderer& renderer) {
 
   m_titleLabel->setPosition(0.0f, 0.0f);
   root()->setSize(width, height);
+  applyLabelColors();
   applyShadow();
 }
 
+void DesktopLabelWidget::applyLabelColors() {
+  ColorSpec effective = m_color;
+  effective.alpha *= m_opacity;
+  if (m_titleLabel != nullptr) {
+    m_titleLabel->setColor(effective);
+  }
+  if (m_descriptionLabel != nullptr) {
+    m_descriptionLabel->setColor(effective);
+  }
+}
+
 void DesktopLabelWidget::applyShadow() {
   const float offset = kShadowOffset * contentScale();
-  const Color shadowColor(0.0f, 0.0f, 0.0f, kShadowAlpha);
+  const Color shadowColor(0.0f, 0.0f, 0.0f, kShadowAlpha * m_opacity);
 
   auto applyTo = [this, offset, shadowColor](Label* label) {
     if (label == nullptr) {

src/shell/desktop/widgets/desktop_label_widget.h

@@ -9,7 +9,7 @@ class Label;
 
 class DesktopLabelWidget : public DesktopWidget {
 public:
-  DesktopLabelWidget(std::string title, std::string description, ColorSpec color, bool shadow);
+  DesktopLabelWidget(std::string title, std::string description, ColorSpec color, float opacity, bool shadow);
 
   void create() override;
   bool applySetting(
@@ -20,11 +20,13 @@ class DesktopLabelWidget : public DesktopWidget {
 private:
   void doLayout(Renderer& renderer) override;
   void onFontFamilyChanged(const std::string& family, Renderer& renderer) override;
+  void applyLabelColors();
   void applyShadow();
 
   std::string m_title;
   std::string m_description;
   ColorSpec m_color;
+  float m_opacity = 1.0f;
   bool m_shadow;
   Label* m_titleLabel = nullptr;
   Label* m_descriptionLabel = nullptr;