WindowServer: Factor out some parts of compose().

The main compositing loop was getting pretty unwieldy. Break out some parts
into functions so it's more understandable.

Servers/WindowServer/WSWindowManager.cpp

@@ -719,6 +719,58 @@ void WSWindowManager::clear_resize_candidate()
  m_resize_candidate = nullptr;
 }
 
+bool WSWindowManager::any_opaque_window_contains_rect(const Rect& rect)
+{
+ bool found_containing_window = false;
+ for_each_window([&] (WSWindow& window) {
+ if (!window.is_visible())
+ return IterationDecision::Continue;
+ if (window.is_minimized())
+ return IterationDecision::Continue;
+ if (window.opacity() < 1.0f)
+ return IterationDecision::Continue;
+ if (window.has_alpha_channel()) {
+ // FIXME: Just because the window has an alpha channel doesn't mean it's not opaque.
+ // Maybe there's some way we could know this?
+ return IterationDecision::Continue;
+ }
+ if (window.frame().rect().contains(rect)) {
+ found_containing_window = true;
+ return IterationDecision::Abort;
+ }
+ return IterationDecision::Continue;
+ });
+ return found_containing_window;
+};
+
+bool WSWindowManager::any_opaque_window_above_this_one_contains_rect(const WSWindow& a_window, const Rect& rect)
+{
+ bool found_containing_window = false;
+ bool checking = false;
+ for_each_visible_window_from_back_to_front([&] (WSWindow& window) {
+ if (&window == &a_window) {
+ checking = true;
+ return IterationDecision::Continue;
+ }
+ if (!checking)
+ return IterationDecision::Continue;
+ if (!window.is_visible())
+ return IterationDecision::Continue;
+ if (window.is_minimized())
+ return IterationDecision::Continue;
+ if (window.opacity() < 1.0f)
+ return IterationDecision::Continue;
+ if (window.has_alpha_channel())
+ return IterationDecision::Continue;
+ if (window.frame().rect().contains(rect)) {
+ found_containing_window = true;
+ return IterationDecision::Abort;
+ }
+ return IterationDecision::Continue;
+ });
+ return found_containing_window;
+};
+
 void WSWindowManager::compose()
 {
  auto dirty_rects = move(m_dirty_rects);
@@ -729,52 +781,6 @@ void WSWindowManager::compose()
  dbgprintf("[WM] compose #%u (%u rects)\n", ++m_compose_count, dirty_rects.rects().size());
 #endif
 
- auto any_opaque_window_contains_rect = [this] (const Rect& r) {
- for (auto* window = m_windows_in_order.head(); window; window = window->next()) {
- if (!window->is_visible())
- continue;
- if (window->is_minimized())
- continue;
- if (window->opacity() < 1.0f)
- continue;
- if (window->has_alpha_channel()) {
- // FIXME: Just because the window has an alpha channel doesn't mean it's not opaque.
- // Maybe there's some way we could know this?
- continue;
- }
- if (window->frame().rect().contains(r))
- return true;
- }
- return false;
- };
-
- auto any_opaque_window_above_this_one_contains_rect = [this] (const WSWindow& a_window, const Rect& rect) -> bool {
- bool found = false;
- bool checking = false;
- for_each_visible_window_from_back_to_front([&] (WSWindow& window) {
- if (&window == &a_window) {
- checking = true;
- return IterationDecision::Continue;
- }
- if (!checking)
- return IterationDecision::Continue;
- if (!window.is_visible())
- return IterationDecision::Continue;
- if (window.is_minimized())
- return IterationDecision::Continue;
- if (window.opacity() < 1.0f)
- return IterationDecision::Continue;
- if (window.has_alpha_channel())
- return IterationDecision::Continue;
- if (window.frame().rect().contains(rect)) {
- found = true;
- return IterationDecision::Abort;
- }
- return IterationDecision::Continue;
- });
- return found;
- };
-
  auto any_dirty_rect_intersects_window = [&dirty_rects] (const WSWindow& window) {
  auto window_frame_rect = window.frame().rect();
  for (auto& dirty_rect : dirty_rects.rects()) {
@@ -794,11 +800,11 @@ void WSWindowManager::compose()
  }
 
  for_each_visible_window_from_back_to_front([&] (WSWindow& window) {
- RetainPtr<GraphicsBitmap> backing_store = window.backing_store();
  if (!any_dirty_rect_intersects_window(window))
  return IterationDecision::Continue;
  PainterStateSaver saver(*m_back_painter);
  m_back_painter->add_clip_rect(window.frame().rect());
+ RetainPtr<GraphicsBitmap> backing_store = window.backing_store();
  for (auto& dirty_rect : dirty_rects.rects()) {
  if (any_opaque_window_above_this_one_contains_rect(window, dirty_rect))
  continue;
@@ -813,31 +819,12 @@ void WSWindowManager::compose()
  dirty_rect_in_window_coordinates.move_by(-window.position());
  auto dst = window.position();
  dst.move_by(dirty_rect_in_window_coordinates.location());
- if (window.opacity() == 1.0f)
- m_back_painter->blit(dst, *backing_store, dirty_rect_in_window_coordinates);
- else
- m_back_painter->blit_with_opacity(dst, *backing_store, dirty_rect_in_window_coordinates, window.opacity());
+ m_back_painter->blit(dst, *backing_store, dirty_rect_in_window_coordinates, window.opacity());
  }
  return IterationDecision::Continue;
  });
 
- if (auto* window_being_moved_or_resized = m_drag_window ? m_drag_window.ptr() : (m_resize_window ? m_resize_window.ptr() : nullptr)) {
- auto geometry_string = window_being_moved_or_resized->rect().to_string();
- if (!window_being_moved_or_resized->size_increment().is_null()) {
- int width_steps = (window_being_moved_or_resized->width() - window_being_moved_or_resized->base_size().width()) / window_being_moved_or_resized->size_increment().width();
- int height_steps = (window_being_moved_or_resized->height() - window_being_moved_or_resized->base_size().height()) / window_being_moved_or_resized->size_increment().height();
- geometry_string = String::format("%s (%dx%d)", geometry_string.characters(), width_steps, height_steps);
- }
- auto geometry_label_rect = Rect { 0, 0, font().width(geometry_string) + 16, font().glyph_height() + 10 };
- geometry_label_rect.center_within(window_being_moved_or_resized->rect());
- m_back_painter->fill_rect(geometry_label_rect, Color::LightGray);
- m_back_painter->draw_rect(geometry_label_rect, Color::DarkGray);
- m_back_painter->draw_text(geometry_label_rect, geometry_string, TextAlignment::Center);
- m_last_geometry_label_rect = geometry_label_rect;
- } else {
- m_last_geometry_label_rect = { };
- }
-
+ draw_geometry_label();
  draw_menubar();
  draw_cursor();
 
@@ -937,6 +924,27 @@ void WSWindowManager::draw_window_switcher()
  m_switcher.draw();
 }
 
+void WSWindowManager::draw_geometry_label()
+{
+ auto* window_being_moved_or_resized = m_drag_window ? m_drag_window.ptr() : (m_resize_window ? m_resize_window.ptr() : nullptr);
+ if (!window_being_moved_or_resized) {
+ m_last_geometry_label_rect = { };
+ return;
+ }
+ auto geometry_string = window_being_moved_or_resized->rect().to_string();
+ if (!window_being_moved_or_resized->size_increment().is_null()) {
+ int width_steps = (window_being_moved_or_resized->width() - window_being_moved_or_resized->base_size().width()) / window_being_moved_or_resized->size_increment().width();
+ int height_steps = (window_being_moved_or_resized->height() - window_being_moved_or_resized->base_size().height()) / window_being_moved_or_resized->size_increment().height();
+ geometry_string = String::format("%s (%dx%d)", geometry_string.characters(), width_steps, height_steps);
+ }
+ auto geometry_label_rect = Rect { 0, 0, font().width(geometry_string) + 16, font().glyph_height() + 10 };
+ geometry_label_rect.center_within(window_being_moved_or_resized->rect());
+ m_back_painter->fill_rect(geometry_label_rect, Color::LightGray);
+ m_back_painter->draw_rect(geometry_label_rect, Color::DarkGray);
+ m_back_painter->draw_text(geometry_label_rect, geometry_string, TextAlignment::Center);
+ m_last_geometry_label_rect = geometry_label_rect;
+}
+
 void WSWindowManager::draw_cursor()
 {
  Rect cursor_rect = current_cursor_rect();

Servers/WindowServer/WSWindowManager.h

@@ -59,6 +59,7 @@ class WSWindowManager : public WSMessageReceiver {
  void draw_cursor();
  void draw_menubar();
  void draw_window_switcher();
+ void draw_geometry_label();
 
  Rect menubar_rect() const;
  WSMenuBar* current_menubar() { return m_current_menubar.ptr(); }
@@ -107,6 +108,9 @@ class WSWindowManager : public WSMessageReceiver {
  void set_resize_candidate(WSWindow&, ResizeDirection);
  void clear_resize_candidate();
 
+ bool any_opaque_window_contains_rect(const Rect&);
+ bool any_opaque_window_above_this_one_contains_rect(const WSWindow&, const Rect&);
+
 private:
  void process_mouse_event(const WSMouseEvent&, WSWindow*& event_window);
  bool process_ongoing_window_resize(const WSMouseEvent&, WSWindow*& event_window);

SharedGraphics/Painter.cpp

@@ -271,8 +271,10 @@ void Painter::blit_with_alpha(const Point& position, const GraphicsBitmap& sourc
  }
 }
 
-void Painter::blit(const Point& position, const GraphicsBitmap& source, const Rect& src_rect)
+void Painter::blit(const Point& position, const GraphicsBitmap& source, const Rect& src_rect, float opacity)
 {
+ if (opacity < 1.0f)
+ return blit_with_opacity(position, source, src_rect, opacity);
  if (source.has_alpha_channel())
  return blit_with_alpha(position, source, src_rect);
  auto safe_src_rect = Rect::intersection(src_rect, source.rect());

SharedGraphics/Painter.h

@@ -26,8 +26,7 @@ class Painter {
  void draw_line(const Point&, const Point&, Color);
  void draw_focus_rect(const Rect&);
  void draw_scaled_bitmap(const Rect& dst_rect, const GraphicsBitmap&, const Rect& src_rect);
- void blit(const Point&, const GraphicsBitmap&, const Rect& src_rect);
- void blit_with_opacity(const Point&, const GraphicsBitmap&, const Rect& src_rect, float opacity);
+ void blit(const Point&, const GraphicsBitmap&, const Rect& src_rect, float opacity = 1.0f);
 
  void draw_text(const Rect&, const char* text, int length, const Font&, TextAlignment = TextAlignment::TopLeft, Color = Color::Black, TextElision = TextElision::None);
  void draw_text(const Rect&, const char* text, int length, TextAlignment = TextAlignment::TopLeft, Color = Color::Black, TextElision = TextElision::None);
@@ -61,6 +60,7 @@ class Painter {
  void set_pixel_with_draw_op(dword& pixel, const Color&);
  void fill_rect_with_draw_op(const Rect&, Color);
  void blit_with_alpha(const Point&, const GraphicsBitmap&, const Rect& src_rect);
+ void blit_with_opacity(const Point&, const GraphicsBitmap&, const Rect& src_rect, float opacity);
 
  struct State {
  const Font* font;