Simplify accelerated paint and remove windows CanvasSkiaPaint

ui/views/win/hwnd_message_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/trace_event/trace_event.h"
 #include "base/tracked_objects.h"
 #include "base/win/scoped_gdi_object.h"
 #include "base/win/win_util.h"
 #include "base/win/windows_version.h"
 #include "ui/base/touch/touch_enabled.h"
 #include "ui/base/view_prop.h"
 #include "ui/base/win/internal_constants.h"
 #include "ui/base/win/lock_state.h"
 #include "ui/base/win/mouse_wheel_util.h"
 #include "ui/base/win/shell.h"
 #include "ui/base/win/touch_input.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/keycodes/keyboard_code_conversion_win.h"
 #include "ui/gfx/canvas.h"
-#include "ui/gfx/canvas_skia_paint.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/icon_util.h"
 #include "ui/gfx/path.h"
 #include "ui/gfx/path_win.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/win/dpi.h"
 #include "ui/gfx/win/hwnd_util.h"
 #include "ui/native_theme/native_theme_win.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/monitor_win.h"
@@ skipping 159 matching lines @@
   EnableMenuItem(menu, command, flags);
 }
 
 // Callback used to notify child windows that the top level window received a
 // DWMCompositionChanged message.
 BOOL CALLBACK SendDwmCompositionChanged(HWND window, LPARAM param) {
   SendMessage(window, WM_DWMCOMPOSITIONCHANGED, 0, 0);
   return TRUE;
 }
 
-// See comments in OnNCPaint() for details of this struct.
-struct ClipState {
-  // The window being painted.
-  HWND parent;
-
-  // DC painting to.
-  HDC dc;
-
-  // Origin of the window in terms of the screen.
-  int x;
-  int y;
-};
-
-// See comments in OnNCPaint() for details of this function.
-static BOOL CALLBACK ClipDCToChild(HWND window, LPARAM param) {
-  ClipState* clip_state = reinterpret_cast<ClipState*>(param);
-  if (GetParent(window) == clip_state->parent && IsWindowVisible(window)) {
-    RECT bounds;
-    GetWindowRect(window, &bounds);
-    ExcludeClipRect(clip_state->dc,
-      bounds.left - clip_state->x,
-      bounds.top - clip_state->y,
-      bounds.right - clip_state->x,
-      bounds.bottom - clip_state->y);
-  }
-  return TRUE;
-}
-
 // The thickness of an auto-hide taskbar in pixels.
 const int kAutoHideTaskbarThicknessPx = 2;
 
 bool IsTopLevelWindow(HWND window) {
   long style = ::GetWindowLong(window, GWL_STYLE);
   if (!(style & WS_CHILD))
     return true;
   HWND parent = ::GetParent(window);
   return !parent || (parent == ::GetDesktopWindow());
 }
@@ skipping 1828 matching lines @@
   } else {
     RECT rgn_bounding_box;
     GetRgnBox(rgn, &rgn_bounding_box);
     if (!IntersectRect(&dirty_region, &rgn_bounding_box, &window_rect))
       return;  // Dirty region doesn't intersect window bounds, bale.
 
     // rgn_bounding_box is in screen coordinates. Map it to window coordinates.
     OffsetRect(&dirty_region, -window_rect.left, -window_rect.top);
   }
 
-  // In theory GetDCEx should do what we want, but I couldn't get it to work.
-  // In particular the docs mentiond DCX_CLIPCHILDREN, but as far as I can tell
-  // it doesn't work at all. So, instead we get the DC for the window then
-  // manually clip out the children.
-  HDC dc = GetWindowDC(hwnd());
-  ClipState clip_state;
-  clip_state.x = window_rect.left;
-  clip_state.y = window_rect.top;
-  clip_state.parent = hwnd();
-  clip_state.dc = dc;
-  EnumChildWindows(hwnd(), &ClipDCToChild,
-                   reinterpret_cast<LPARAM>(&clip_state));
-
   gfx::Rect old_paint_region = invalid_rect_;
   if (!old_paint_region.IsEmpty()) {
     // The root view has a region that needs to be painted. Include it in the
     // region we're going to paint.
 
     RECT old_paint_region_crect = old_paint_region.ToRECT();
     RECT tmp = dirty_region;
     UnionRect(&dirty_region, &tmp, &old_paint_region_crect);
   }
 
   SchedulePaintInRect(gfx::Rect(dirty_region));
+  delegate_->HandlePaintAccelerated(gfx::Rect(dirty_region));
 
-  // gfx::CanvasSkiaPaint's destructor does the actual painting. As such, wrap
-  // the following in a block to force paint to occur so that we can release
-  // the dc.
-  if (!delegate_->HandlePaintAccelerated(gfx::Rect(dirty_region))) {
-    gfx::CanvasSkiaPaint canvas(dc,
-                                true,
-                                dirty_region.left,
-                                dirty_region.top,
-                                dirty_region.right - dirty_region.left,
-                                dirty_region.bottom - dirty_region.top);
-    delegate_->HandlePaint(&canvas);
-  }
-
-  ReleaseDC(hwnd(), dc);
   // When using a custom frame, we want to avoid calling DefWindowProc() since
   // that may render artifacts.
   SetMsgHandled(delegate_->IsUsingCustomFrame());
 }
 
 LRESULT HWNDMessageHandler::OnNCUAHDrawCaption(UINT message,
                                                WPARAM w_param,
                                                LPARAM l_param) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
@@ skipping 36 matching lines @@
       FROM_HERE_WITH_EXPLICIT_FUNCTION("440919 HWNDMessageHandler::OnPaint"));
 
   // Call BeginPaint()/EndPaint() around the paint handling, as that seems
   // to do more to actually validate the window's drawing region. This only
   // appears to matter for Windows that have the WS_EX_COMPOSITED style set
   // but will be valid in general too.
   PAINTSTRUCT ps;
   HDC display_dc = BeginPaint(hwnd(), &ps);
   CHECK(display_dc);
 
-  // Try to paint accelerated first.
-  if (!IsRectEmpty(&ps.rcPaint) &&
-      !delegate_->HandlePaintAccelerated(gfx::Rect(ps.rcPaint))) {
-    delegate_->HandlePaint(NULL);
-  }
+  if (!IsRectEmpty(&ps.rcPaint))
+    delegate_->HandlePaintAccelerated(gfx::Rect(ps.rcPaint));
 
   EndPaint(hwnd(), &ps);
 }
 
 LRESULT HWNDMessageHandler::OnReflectedMessage(UINT message,
                                                WPARAM w_param,
                                                LPARAM l_param) {
   SetMsgHandled(FALSE);
   return 0;
 }
@@ skipping 670 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views