Makes resize of custom frame window a bit smoother. I tried a whole

slew of variations, and this is the best I could get. From nc calc
size we now return WVR_REDRAW, which indicates we need to redraw the
frame. Without this I believe windows was copying some bits around for
us resulting in the jitter. Additionally in OnNCPaint we do nothing if
the root view's size isn't the same as the window's size. This is done
as during resizes we get a WM_NCPAINT *before* a WM_SIZE. We also get
a WM_NCPAINT after the WM_SIZE, so that it's ok to ignore the first
one.

BUG=1293978
TEST=make sure sizing of task manager/keyword editor doesn't break.


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@1157 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 14 insertions, 1 deletions

diff --git a/chrome/views/custom_frame_window.cc b/chrome/views/custom_frame_window.cc
index 7679e3f..e045e8b 100644
--- a/chrome/views/custom_frame_window.cc
+++ b/chrome/views/custom_frame_window.cc
@@ -986,8 +986,10 @@ LRESULT CustomFrameWindow::OnNCCalcSize(BOOL mode, LPARAM l_param) {
     RECT* rect = reinterpret_cast<RECT*>(l_param);
     *rect = non_client_view_->CalculateClientAreaBounds(
         rect->right - rect->left, rect->bottom - rect->top).ToRECT();
+    return 0;
   }
-  return 0;
+  // We need to repaint all when the window bounds change.
+  return WVR_REDRAW;
 }
 
 LRESULT CustomFrameWindow::OnNCHitTest(const CPoint& point) {
@@ -1043,6 +1045,17 @@ void CustomFrameWindow::OnNCPaint(HRGN rgn) {
   CRect window_rect;
   GetWindowRect(&window_rect);
 
+  if (window_rect.Width() != root_view_->GetWidth() ||
+      window_rect.Height() != root_view_->GetHeight()) {
+    // If the size of the window differs from the size of the root view it
+    // means we're being asked to paint before we've gotten a WM_SIZE. This can
+    // happen when the user is interactively resizing the window. To avoid
+    // mass flickering we don't do anything here. Once we get the WM_SIZE we'll
+    // reset the region of the window which triggers another WM_NCPAINT and
+    // all is well.
+    return;
+  }
+
   CRect dirty_region;
   // A value of 1 indicates paint all.
   if (!rgn || rgn == reinterpret_cast<HRGN>(1)) {