WindowServer: Improvements to support alpha channel in window frames

This fixes some issues handling the alpha channel that may be present
in rendered window frames.

Fixes #5303

2 files changed, 19 insertions, 10 deletions

diff --git a/Userland/Services/WindowServer/WindowFrame.cpp b/Userland/Services/WindowServer/WindowFrame.cpp
index 9c17e967d9..349ab999a3 100644
--- a/Userland/Services/WindowServer/WindowFrame.cpp
+++ b/Userland/Services/WindowServer/WindowFrame.cpp
@@ -221,6 +221,8 @@ Gfx::Bitmap* WindowFrame::window_shadow() const
 
 bool WindowFrame::frame_has_alpha() const
 {
+    if (m_has_alpha_channel)
+        return true;
     if (auto* shadow_bitmap = window_shadow(); shadow_bitmap && shadow_bitmap->format() == Gfx::BitmapFormat::RGBA32)
         return true;
     return false;
@@ -347,12 +349,27 @@ void WindowFrame::render(Gfx::Painter& painter)
     }
 }
 
+void WindowFrame::theme_changed()
+{
+    m_dirty = m_shadow_dirty = true;
+    m_top_bottom = nullptr;
+    m_left_right = nullptr;
+    m_bottom_y = m_right_x = 0;
+
+    layout_buttons();
+    set_button_icons();
+
+    m_has_alpha_channel = Gfx::WindowTheme::current().frame_uses_alpha(window_state_for_theme(), WindowManager::the().palette());
+}
+
 void WindowFrame::render_to_cache()
 {
     if (!m_dirty)
         return;
     m_dirty = false;
 
+    m_has_alpha_channel = Gfx::WindowTheme::current().frame_uses_alpha(window_state_for_theme(), WindowManager::the().palette());
+
     static Gfx::Bitmap* s_tmp_bitmap;
     auto frame_rect = rect();
     auto total_frame_rect = frame_rect;
@@ -387,6 +404,7 @@ void WindowFrame::render_to_cache()
     Gfx::IntPoint update_location(m_shadow_dirty ? Gfx::IntPoint { 0, 0 } : m_shadow_offset);
 
     Gfx::Painter painter(*s_tmp_bitmap);
+
     // Clear the frame area, not including the window content area, which we don't care about
     for (auto& rect : frame_rect_to_update.shatter(window_rect))
         painter.clear_rect({ rect.location() - frame_rect_to_update.location(), rect.size() }, { 255, 255, 255, 0 });
diff --git a/Userland/Services/WindowServer/WindowFrame.h b/Userland/Services/WindowServer/WindowFrame.h
index 992ce11921..872597f29a 100644
--- a/Userland/Services/WindowServer/WindowFrame.h
+++ b/Userland/Services/WindowServer/WindowFrame.h
@@ -88,16 +88,7 @@ public:
         m_shadow_dirty |= re_render_shadow;
     }
 
-    void theme_changed()
-    {
-        m_dirty = m_shadow_dirty = true;
-        m_top_bottom = nullptr;
-        m_left_right = nullptr;
-        m_bottom_y = m_right_x = 0;
-
-        layout_buttons();
-        set_button_icons();
-    }
+    void theme_changed();
 
 private:
     void paint_simple_rect_shadow(Gfx::Painter&, const Gfx::IntRect&, const Gfx::Bitmap&) const;