Fix black titlebar rendering when toggling DWM when the window is maximized:

- restore window after hiding it, since our hide hack only works for non-maximized windows
- handle WM_WINDOWPOSCHANGING in this case to make sure the window isn't made visible by the restore action

http://crbug.com/8526

Review URL: http://codereview.chromium.org/43052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@11401 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 34 insertions, 3 deletions

diff --git a/chrome/views/non_client_view.cc b/chrome/views/non_client_view.cc
index 8568969..79448af 100644
--- a/chrome/views/non_client_view.cc
+++ b/chrome/views/non_client_view.cc
@@ -66,6 +66,13 @@ void NonClientView::SystemThemeChanged() {
   GetWindowPlacement(frame_->GetHWND(), &saved_window_placement);
   frame_->Hide();
 
+  // Important step: restore the window first, since our hiding hack doesn't
+  // work for maximized windows! We tell the frame not to allow itself to be
+  // made visible though, which removes the brief flicker.
+  frame_->set_force_hidden(true);
+  ShowWindow(frame_->GetHWND(), SW_RESTORE);
+  frame_->set_force_hidden(false);
+  
   SetUseNativeFrame(win_util::ShouldUseVistaFrame());
 
   // Now that we've updated the frame, we'll want to restore our saved placement
diff --git a/chrome/views/widget_win.h b/chrome/views/widget_win.h
index 4ec5acb..cf2274e 100644
--- a/chrome/views/widget_win.h
+++ b/chrome/views/widget_win.h
@@ -244,6 +244,7 @@ class WidgetWin : public Widget,
     MSG_WM_SYSCOMMAND(OnSysCommand)
     MSG_WM_THEMECHANGED(OnThemeChanged)
     MSG_WM_VSCROLL(OnVScroll)
+    MSG_WM_WINDOWPOSCHANGING(OnWindowPosChanging)
     MSG_WM_WINDOWPOSCHANGED(OnWindowPosChanged)
   END_MSG_MAP()
 
@@ -476,6 +477,9 @@ class WidgetWin : public Widget,
   virtual void OnVScroll(int scroll_type, short position, HWND scrollbar) {
     SetMsgHandled(FALSE);
   }
+  virtual void OnWindowPosChanging(WINDOWPOS* window_pos) {
+    SetMsgHandled(FALSE);
+  }
   virtual void OnWindowPosChanged(WINDOWPOS* window_pos) {
     SetMsgHandled(FALSE);
   }
diff --git a/chrome/views/window.cc b/chrome/views/window.cc
index d8ea0e9..0548fa4 100644
--- a/chrome/views/window.cc
+++ b/chrome/views/window.cc
@@ -325,7 +325,8 @@ Window::Window(WindowDelegate* window_delegate)
       is_active_(false),
       lock_updates_(false),
       saved_window_style_(0),
-      saved_maximized_state_(0) {
+      saved_maximized_state_(0),
+      force_hidden_(false) {
   InitClass();
   DCHECK(window_delegate_);
   window_delegate_->window_.reset(this);
@@ -650,8 +651,10 @@ static BOOL CALLBACK ClipDCToChild(HWND window, LPARAM param) {
 
 void Window::OnNCPaint(HRGN rgn) {
   // We only do non-client painting if we're not using the native frame.
-  if (non_client_view_->UseNativeFrame())
-    return WidgetWin::OnNCPaint(rgn);
+  if (non_client_view_->UseNativeFrame()) {
+    WidgetWin::OnNCPaint(rgn);
+    return;
+  }
 
   // We have an NC region and need to paint it. We expand the NC region to
   // include the dirty region of the root view. This is done to minimize
@@ -917,6 +920,15 @@ void Window::OnSysCommand(UINT notification_code, CPoint click) {
   }
 }
 
+void Window::OnWindowPosChanging(WINDOWPOS* window_pos) {
+  if (force_hidden_) {
+    // Prevent the window from being made visible if we've been asked to do so.
+    // See comment in header as to why we might want this.
+    window_pos->flags &= ~SWP_SHOWWINDOW;
+  }
+  WidgetWin::OnWindowPosChanging(window_pos);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Window, private:
 
diff --git a/chrome/views/window.h b/chrome/views/window.h
index c6c3d37..9fe85dd 100644
--- a/chrome/views/window.h
+++ b/chrome/views/window.h
@@ -116,6 +116,7 @@ class Window : public WidgetWin,
   void set_focus_on_creation(bool focus_on_creation) {
     focus_on_creation_ = focus_on_creation;
   }
+  void set_force_hidden(bool force_hidden) { force_hidden_ = force_hidden; }
 
   // Returns the preferred size of the contents view of this window based on
   // its localized size data. The width in cols is held in a localized string
@@ -178,6 +179,7 @@ class Window : public WidgetWin,
   virtual LRESULT OnSetText(const wchar_t* text);
   virtual void OnSize(UINT size_param, const CSize& new_size);
   virtual void OnSysCommand(UINT notification_code, CPoint click);
+  virtual void OnWindowPosChanging(WINDOWPOS* window_pos);
   virtual Window* AsWindow() { return this; }
   virtual const Window* AsWindow() const { return this; }
 
@@ -304,6 +306,12 @@ class Window : public WidgetWin,
   // that explains why we save this.
   bool saved_maximized_state_;
 
+  // True if we should prevent attempts to make the window visible when we
+  // handle WM_WINDOWPOSCHANGING. Some calls like ShowWindow(SW_RESTORE) make
+  // the window visible in addition to restoring it, when all we want to do is
+  // restore it.
+  bool force_hidden_;
+
   // Hold onto notifications.
   NotificationRegistrar notification_registrar_;