[ash-md] Fades overview header in and out

ash/common/wm/overview/window_grid.cc

Index: ash/common/wm/overview/window_grid.cc
diff --git a/ash/common/wm/overview/window_grid.cc b/ash/common/wm/overview/window_grid.cc
index bd4de0549b2f49611f0962d555f405457ac8f170..3a60eb1225cd174049bc3b8a867729447936acc9 100644
--- a/ash/common/wm/overview/window_grid.cc
+++ b/ash/common/wm/overview/window_grid.cc
@@ -408,6 +408,7 @@ WindowGrid::WindowGrid(WmWindow* root_window,
     ReorderItemsGreedyLeastMovement(&windows_in_root, root_window_,
                                     window_selector_->text_filter_bottom());
   }
+  PrepareForUsingMasksOrShapes(windows_in_root.size());

[bruthig, 2016/08/30 17:57:33]

Correct me if I'm wrong but there is no need for this to be set for each
WindowGrid.  IMO the WindowSelector should be defining whether to use masks or
shapes and the WindowSelectorItem can ask the WindowSelector for this
configuration instead of using statics.

Furthermore, I think we will actually run into an inconsistent state because the
WindowSelectorItem::use_mask_ and use_shape_ are defined as statics.  Consider
multiple WindowGrid instances of which the last one to be constructed only has 1
window.

[varkha, 2016/09/02 11:22:51]

There is since this is dependent on number of windows in each grid (to have the
corner radius correct). I will remove the masks and rounded corners at the
bottom of the window in the next CL however so this will be simplified.

   for (auto* window : windows_in_root) {
     window->AddObserver(this);
     observed_windows_.insert(window);
@@ -430,7 +431,7 @@ void WindowGrid::Shutdown() {
         widget_window->GetLayer()->GetAnimator());
     animation_settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
         kOverviewSelectorTransitionMilliseconds));
-    animation_settings.SetTweenType(gfx::Tween::EASE_IN);
+    animation_settings.SetTweenType(gfx::Tween::EASE_IN_2);
     animation_settings.SetPreemptionStrategy(
         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
     // CleanupAnimationObserver will delete itself (and the shield widget) when
@@ -458,34 +459,7 @@ void WindowGrid::PrepareForOverview() {
 void WindowGrid::PositionWindowsMD(bool animate) {
   if (window_list_.empty())
     return;
-
-  const int kUnlimited = -1;
-  const size_t windows_count = window_list_.size();
-  const base::CommandLine* command_line =
-      base::CommandLine::ForCurrentProcess();
-  int windows_to_use_masks = kMaxWindowsCountToHideHeaderWithMasks;
-  if (command_line->HasSwitch(switches::kAshMaxWindowsToUseMaskInOverview) &&
-      (!base::StringToInt(command_line->GetSwitchValueASCII(
-                              switches::kAshMaxWindowsToUseMaskInOverview),
-                          &windows_to_use_masks) ||
-       windows_to_use_masks <= kUnlimited)) {
-    windows_to_use_masks = kMaxWindowsCountToHideHeaderWithMasks;
-  }
-  int windows_to_use_shapes = kUnlimited;
-  if (command_line->HasSwitch(switches::kAshMaxWindowsToUseShapeInOverview) &&
-      (!base::StringToInt(command_line->GetSwitchValueASCII(
-                              switches::kAshMaxWindowsToUseShapeInOverview),
-                          &windows_to_use_shapes) ||
-       windows_to_use_shapes <= kUnlimited)) {
-    windows_to_use_shapes = kUnlimited;
-  }
-  WindowSelectorItem::set_use_mask(windows_to_use_masks <= kUnlimited ||
-                                   static_cast<int>(windows_count) <=
-                                       windows_to_use_masks);
-  WindowSelectorItem::set_use_shape(windows_to_use_shapes <= kUnlimited ||
-                                    static_cast<int>(windows_count) <=
-                                        windows_to_use_shapes);
-
+  PrepareForUsingMasksOrShapes(window_list_.size());
   gfx::Rect total_bounds =
       root_window_->ConvertRectToScreen(wm::GetDisplayWorkAreaBoundsInParent(
           root_window_->GetChildByShellWindowId(
@@ -594,7 +568,7 @@ void WindowGrid::PositionWindowsMD(bool animate) {
   }
   // Position the windows centering the left-aligned rows vertically.
   gfx::Vector2d offset(0, (total_bounds.bottom() - max_bottom) / 2);
-  for (size_t i = 0; i < windows_count; ++i) {
+  for (size_t i = 0; i < window_list_.size(); ++i) {
     window_list_[i]->SetBounds(
         rects[i] + offset,
         animate
@@ -859,7 +833,7 @@ void WindowGrid::InitShieldWidget() {
       widget_window->GetLayer()->GetAnimator());
   animation_settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
       kOverviewSelectorTransitionMilliseconds));
-  animation_settings.SetTweenType(gfx::Tween::LINEAR_OUT_SLOW_IN);
+  animation_settings.SetTweenType(gfx::Tween::EASE_IN);
   animation_settings.SetPreemptionStrategy(
       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
   shield_widget_->SetOpacity(kShieldOpacity);
@@ -1059,4 +1033,32 @@ bool WindowGrid::FitWindowRectsInBounds(const gfx::Rect& bounds,
   return windows_fit;
 }
 
+void WindowGrid::PrepareForUsingMasksOrShapes(size_t windows_count) const {
+  const int kUnlimited = -1;
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  int windows_to_use_masks = kMaxWindowsCountToHideHeaderWithMasks;
+  if (command_line->HasSwitch(switches::kAshMaxWindowsToUseMaskInOverview) &&
+      (!base::StringToInt(command_line->GetSwitchValueASCII(
+                              switches::kAshMaxWindowsToUseMaskInOverview),
+                          &windows_to_use_masks) ||
+       windows_to_use_masks <= kUnlimited)) {
+    windows_to_use_masks = kMaxWindowsCountToHideHeaderWithMasks;

[bruthig, 2016/08/30 17:57:33]

You could consider adding a warning when the commend line specifies a value but
you don't actually use it.  Same applies below.

[varkha, 2016/09/02 11:22:51]

This flag was temporary scaffolding and Will be removed.

+  }
+  int windows_to_use_shapes = kUnlimited;
+  if (command_line->HasSwitch(switches::kAshMaxWindowsToUseShapeInOverview) &&

[bruthig, 2016/08/30 17:57:33]

Consider wrapping this duplicate logic in a helper function. e.g.

int ReadCmdLineInt(int default, char[] switch);

Invoked like so:

int windows_to_use_masks = ReadCmdLineInt(kMaxWindowsCountToHideHeaderWithMasks,
switches::kAshMaxWindowsToUseMaskInOverview);

[varkha, 2016/09/02 11:22:51]

Ditto, will keep this in mind.

+      (!base::StringToInt(command_line->GetSwitchValueASCII(
+                              switches::kAshMaxWindowsToUseShapeInOverview),
+                          &windows_to_use_shapes) ||
+       windows_to_use_shapes <= kUnlimited)) {
+    windows_to_use_shapes = kUnlimited;
+  }
+  WindowSelectorItem::set_use_mask(windows_to_use_masks <= kUnlimited ||
+                                   static_cast<int>(windows_count) <=
+                                       windows_to_use_masks);
+  WindowSelectorItem::set_use_shape(windows_to_use_shapes <= kUnlimited ||
+                                    static_cast<int>(windows_count) <=
+                                        windows_to_use_shapes);
+}
+
 }  // namespace ash