1 files changed, 30 insertions, 74 deletions

diff --git a/chrome/views/custom_frame_window.cc b/chrome/views/custom_frame_window.cc
index af94798..0febe17 100644
--- a/chrome/views/custom_frame_window.cc
+++ b/chrome/views/custom_frame_window.cc
@@ -25,52 +25,45 @@
 
 namespace views {
 
-// When the user presses the mouse down in the non-client area of the window,
-// Windows sends WM_SYSCOMMAND with one of these notification codes. They
-// represent frame size/move operations initiated by the user's direct mouse
-// gesture-driven manipulation of the frame, as opposed to SC_SIZE/SC_MOVE
-// which are the result of system menu operations.
-static const int SC_FRAMESIZE = 0xF002;
-static const int SC_FRAMEMOVE = 0xF012;
-
-// A scoping class that prevents a window from being able to redraw in response
-// to invalidations that may occur within it for the lifetime of the object.
+// A scoping class that removes the WS_VISIBLE style of a window.
 //
 // Why would we want such a thing? Well, it turns out Windows has some
 // "unorthodox" behavior when it comes to painting its non-client areas.
-// Occasionally, Windows will paint portions of the default non-client area
-// right over the top of the custom frame. This is not simply fixed by handling
-// WM_NCPAINT/WM_PAINT, with some investigation it turns out that this
-// rendering is being done *inside* the default implementation of some message
-// handlers and functions:
-//  . WM_SETTEXT
-//  . WM_SETICON
-//  . WM_NCLBUTTONDOWN
-//  . EnableMenuItem, called from our WM_INITMENU handler
-// The solution is to handle these messages and call DefWindowProc ourselves,
-// but prevent the window from being able to update itself for the duration of
-// the call. We do this with this class, which automatically calls its
-// associated CustomFrameWindow's lock and unlock functions as it is created
-// and destroyed. See documentation in those methods for the technique used.
-//
-// IMPORTANT: Do not use this scoping object for large scopes or periods of
-//            time! IT WILL PREVENT THE WINDOW FROM BEING REDRAWN! (duh).
-//
+// Sadly, the default implementation of some messages, e.g. WM_SETTEXT and
+// WM_SETICON actually paint all or parts of the native title bar of the
+// application. That's right, they just paint it. They don't go through
+// WM_NCPAINT or anything like that that we already override. What this means
+// is that we end up with occasional flicker of bits of the normal Windows
+// title bar whenever we do things like change the title text, or right click
+// on the caption. The solution turns out to be to handle these messages,
+// use this scoped object to remove the WS_VISIBLE style which prevents this
+// rendering from happening, call the default window procedure, then add the
+// WS_VISIBLE style back when this object goes out of scope.
 // I would love to hear Raymond Chen's explanation for all this. And maybe a
 // list of other messages that this applies to ;-)
-class CustomFrameWindow::ScopedRedrawLock {
+//
+// *** Sigh. ***
+class ScopedVisibilityRemover {
  public:
-  explicit ScopedRedrawLock(CustomFrameWindow* window) : window_(window) {
-    window_->LockUpdates();
+  explicit ScopedVisibilityRemover(HWND hwnd)
+      : hwnd_(hwnd),
+        window_style_(0) {
+    window_style_ = GetWindowLong(hwnd_, GWL_STYLE);
+    if (window_style_ & WS_VISIBLE)
+      SetWindowLong(hwnd_, GWL_STYLE, window_style_ & ~WS_VISIBLE);
   }
 
-  ~ScopedRedrawLock() {
-    window_->UnlockUpdates();
+  ~ScopedVisibilityRemover() {
+    if (window_style_ & WS_VISIBLE)
+      SetWindowLong(hwnd_, GWL_STYLE, window_style_);
   }
 
  private:
   // The window having its style changed.
-  CustomFrameWindow* window_;
+  HWND hwnd_;
+
+  // The original style of the window, including WS_VISIBLE if present.
+  DWORD window_style_;
 };
 
 HCURSOR CustomFrameWindow::resize_cursors_[6];
@@ -885,8 +878,7 @@ class NonClientViewLayout : public LayoutManager {
 
 CustomFrameWindow::CustomFrameWindow(WindowDelegate* window_delegate)
     : Window(window_delegate),
-      is_active_(false),
-      lock_updates_(false) {
+      is_active_(false) {
   InitClass();
   non_client_view_ = new DefaultNonClientView(this);
 }
@@ -1024,7 +1016,6 @@ void CustomFrameWindow::OnInitMenu(HMENU menu) {
   bool maximized = IsMaximized();
   bool minimized_or_maximized = minimized || maximized;
 
-  ScopedRedrawLock lock(this);
   EnableMenuItem(menu, SC_RESTORE,
                  window_delegate()->CanMaximize() && minimized_or_maximized);
   EnableMenuItem(menu, SC_MOVE, !minimized_or_maximized);
@@ -1203,17 +1194,6 @@ void CustomFrameWindow::OnNCLButtonDown(UINT ht_component,
     }
     default:
       Window::OnNCLButtonDown(ht_component, point);
-      if (!IsMsgHandled()) {
-        // Window::OnNCLButtonDown set the message as unhandled. This normally
-        // means ContainerWin::ProcessWindowMessage will pass it to
-        // DefWindowProc. Sadly, DefWindowProc for WM_NCLBUTTONDOWN does weird
-        // non-client painting, so we need to call it directly here inside a
-        // scoped update lock.
-        ScopedRedrawLock lock(this);
-        DefWindowProc(GetHWND(), WM_NCLBUTTONDOWN, ht_component,
-                      MAKELPARAM(point.x, point.y));
-        SetMsgHandled(TRUE);
-      }
       break;
   }
 }
@@ -1280,13 +1260,13 @@ LRESULT CustomFrameWindow::OnSetCursor(HWND window, UINT hittest_code,
 }
 
 LRESULT CustomFrameWindow::OnSetIcon(UINT size_type, HICON new_icon) {
-  ScopedRedrawLock lock(this);
+  ScopedVisibilityRemover remover(GetHWND());
   return DefWindowProc(GetHWND(), WM_SETICON, size_type,
                        reinterpret_cast<LPARAM>(new_icon));
 }
 
 LRESULT CustomFrameWindow::OnSetText(const wchar_t* text) {
-  ScopedRedrawLock lock(this);
+  ScopedVisibilityRemover remover(GetHWND());
   return DefWindowProc(GetHWND(), WM_SETTEXT, NULL,
                        reinterpret_cast<LPARAM>(text));
 }
@@ -1299,18 +1279,6 @@ void CustomFrameWindow::OnSize(UINT param, const CSize& size) {
   ResetWindowRegion();
 }
 
-void CustomFrameWindow::OnSysCommand(UINT notification_code, CPoint click) {
-  if (notification_code == SC_FRAMEMOVE || notification_code == SC_FRAMESIZE) {
-    if (lock_updates_) {
-      // We were locked, before entering a resize or move modal loop. Now that
-      // we've begun to move the window, we need to unlock updates so that the
-      // sizing/moving feedback can be continuous.
-      UnlockUpdates();
-    }
-  }
-  Window::OnSysCommand(notification_code, click);
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 // CustomFrameWindow, private:
 
@@ -1327,18 +1295,6 @@ void CustomFrameWindow::InitClass() {
   }
 }
 
-void CustomFrameWindow::LockUpdates() {
-  lock_updates_ = true;
-  // This message causes invalidations to be discarded until it is called again
-  // with WPARAM TRUE (see UnlockUpdates).
-  SendMessage(GetHWND(), WM_SETREDRAW, FALSE, 0);
-}
-
-void CustomFrameWindow::UnlockUpdates() {
-  SendMessage(GetHWND(), WM_SETREDRAW, TRUE, 0);
-  lock_updates_ = false;
-}
-
 void CustomFrameWindow::ResetWindowRegion() {
   // Changing the window region is going to force a paint. Only change the
   // window region if the region really differs.