More speedup of scrolling when many windowed plugins in a page. Scrolling is...

chrome/browser/render_widget_host_view_win.cc

 // Copyright (c) 2006-2008 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 "chrome/browser/render_widget_host_view_win.h"
 
 #include "base/command_line.h"
 #include "base/gfx/gdi_util.h"
 #include "base/gfx/rect.h"
 #include "base/histogram.h"
 #include "base/win_util.h"
 #include "chrome/browser/browser_accessibility.h"
 #include "chrome/browser/browser_accessibility_manager.h"
 #include "chrome/browser/browser_trial.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 // TODO(beng): (Cleanup) we should not need to include this file... see comment
 //             in |DidBecomeSelected|.
 #include "chrome/browser/render_view_host.h"
 #include "chrome/browser/render_widget_host.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/l10n_util.h"
 #include "chrome/common/plugin_messages.h"
 #include "chrome/common/win_util.h"
 // Included for views::kReflectedMessage - TODO(beng): move this to win_util.h!
 #include "chrome/views/widget_win.h"
+#include "webkit/glue/plugins/plugin_constants_win.h"
+#include "webkit/glue/plugins/webplugin_delegate_impl.h"
 #include "webkit/glue/webcursor.h"
 
 using base::TimeDelta;
 using base::TimeTicks;
 
 namespace {
 
 // Tooltips will wrap after this width. Yes, wrap. Imagine that!
 const int kTooltipMaxWidthPixels = 300;
 
@@ skipping 214 matching lines @@
 void RenderWidgetHostViewWin::IMEUpdateStatus(ViewHostMsg_ImeControl control,
                                               const gfx::Rect& caret_rect) {
   if (control == IME_DISABLE) {
     ime_input_.DisableIME(m_hWnd);
   } else {
     ime_input_.EnableIME(m_hWnd, caret_rect,
                          control == IME_COMPLETE_COMPOSITION);
   }
 }
 
+BOOL CALLBACK EnumChildProc(HWND hwnd, LPARAM lparam) {
+  if (!WebPluginDelegateImpl::IsPluginDelegateWindow(hwnd))
+    return TRUE;
+
+  gfx::Rect* rect = reinterpret_cast<gfx::Rect*>(lparam);
+  static UINT msg = RegisterWindowMessage(kPaintMessageName);
+  WPARAM wparam = rect->x() << 16 | rect->y();
+  lparam = rect->width() << 16 | rect->height();
+
+  // SendMessage gets the message across much quicker than PostMessage, since it
+  // doesn't get queued.  When the plugin thread calls PeakMessage or other

[darin (slow to review), 2009/01/22 00:40:03]

s/PeakMessage/PeekMessage/

[jam, 2009/01/22 01:03:10]

Done.

+  // Win32 APIs, sent messages are dispatched automatically.
+  SendNotifyMessage(hwnd, msg, wparam, lparam);
+
+  return TRUE;
+}
+
+void RenderWidgetHostViewWin::Redraw(const gfx::Rect& rect) {
+  // Paint the invalid region synchronously.  Our caller will not paint again
+  // until we return, so by painting to the screen here, we ensure effective
+  // rate-limiting of backing store updates.  This helps a lot on pages that
+  // have animations or fairly expensive layout (e.g., google maps).
+  //
+  // We paint this window synchronously, however child windows (i.e. plugins)
+  // are painted asynchronously.  By avoiding synchronous cross-process window
+  // message dispatching we allow scrolling to be smooth, and also avoid the
+  // browser process locking up if the plugin process is hung.
+  //
+  RedrawWindow(
+      &rect.ToRECT(), NULL, RDW_INVALIDATE | RDW_UPDATENOW | RDW_NOCHILDREN);
+
+  // Send the invalid rect in screen coordinates.
+  gfx::Rect screen_rect = GetViewBounds();
+  gfx::Rect invalid_screen_rect = rect;
+  invalid_screen_rect.Offset(screen_rect.x(), screen_rect.y());
+
+  LPARAM lparam = reinterpret_cast<LPARAM>(&invalid_screen_rect);
+  EnumChildWindows(m_hWnd, EnumChildProc, lparam);
+}
+
 void RenderWidgetHostViewWin::DidPaintRect(const gfx::Rect& rect) {
   if (is_hidden_)
     return;
 
-  RECT invalid_rect = rect.ToRECT();
-
-  // Paint the invalid region synchronously.  Our caller will not paint again
-  // until we return, so by painting to the screen here, we ensure effective
-  // rate-limiting of backing store updates.  This helps a lot on pages that
-  // have animations or fairly expensive layout (e.g., google maps).
-  //
-  // Please refer to the RenderWidgetHostViewWin::DidScrollRect function for the
-  // reasoning behind the combination of flags passed to RedrawWindow.
-  //
-  RedrawWindow(&invalid_rect, NULL,
-      RDW_INVALIDATE | RDW_UPDATENOW | RDW_ALLCHILDREN | RDW_FRAME);
+  Redraw(rect);
 }
 
 void RenderWidgetHostViewWin::DidScrollRect(
     const gfx::Rect& rect, int dx, int dy) {
   if (is_hidden_)
     return;
 
   // We need to pass in SW_INVALIDATE to ScrollWindowEx.  The MSDN
   // documentation states that it only applies to the HRGN argument, which is
   // wrong.  Not passing in this flag does not invalidate the region which was
   // scrolled from, thus causing painting issues.
   RECT clip_rect = rect.ToRECT();
   ScrollWindowEx(dx, dy, NULL, &clip_rect, NULL, NULL, SW_INVALIDATE);
 
   RECT invalid_rect = {0};
   GetUpdateRect(&invalid_rect);
-
-  // Paint the invalid region synchronously.  Our caller will not paint again
-  // until we return, so by painting to the screen here, we ensure effective
-  // rate-limiting of backing store updates.  This helps a lot on pages that
-  // have animations or fairly expensive layout (e.g., google maps).
-  //
-  // Our RenderWidgetHostViewWin does not have a non-client area, whereas the
-  // children (plugin windows) may.  If we don't pass in RDW_FRAME then the
-  // children don't receive WM_NCPAINT messages while scrolling, which causes
-  // painting problems (http://b/issue?id=923945).  We need to pass
-  // RDW_INVALIDATE as it is required for RDW_FRAME to work.
-  //
-  RedrawWindow(&invalid_rect, NULL,
-      RDW_INVALIDATE | RDW_UPDATENOW | RDW_ALLCHILDREN | RDW_FRAME);
+  Redraw(gfx::Rect(invalid_rect));
 }
 
 void RenderWidgetHostViewWin::RendererGone() {
   // TODO(darin): keep this around, and draw sad-tab into it.
   UpdateCursorIfOverSelf();
   DestroyWindow();
 }
 
 void RenderWidgetHostViewWin::Destroy() {
   // We've been told to destroy.
@@ skipping 580 matching lines @@
   if (::IsWindow(tooltip_hwnd_))
     ::DestroyWindow(tooltip_hwnd_);
   tooltip_hwnd_ = NULL;
 }
 
 void RenderWidgetHostViewWin::ShutdownHost() {
   shutdown_factory_.RevokeAll();
   render_widget_host_->Shutdown();
   // Do not touch any members at this point, |this| has been deleted.
 }