ChromeOS: The centered app list's top is now forced to be >= 10.

ash/wm/app_list_controller.cc

Index: ash/wm/app_list_controller.cc
diff --git a/ash/wm/app_list_controller.cc b/ash/wm/app_list_controller.cc
index 45915c49ae1a7a95b52cf913843f787d38097a0e..6acf1aef33e2e868892ad2757babfeb9d190a142 100644
--- a/ash/wm/app_list_controller.cc
+++ b/ash/wm/app_list_controller.cc
@@ -44,6 +44,9 @@ const int kMaxOverScrollShift = 48;
 // result of minimal bubble arrow sizes and offsets.
 const int kMinimalAnchorPositionOffset = 57;
 
+// The minimal margin (in pixels) around the app list when in centered mode.
+const int kMinimalCenteredAppListMargin = 10;
+
 ui::Layer* GetLayer(views::Widget* widget) {
   return widget->GetNativeView()->layer();
 }
@@ -115,8 +118,11 @@ gfx::Vector2d GetAnchorPositionOffsetToShelf(
 }
 
 // Gets the point at the center of the display that a particular view is on.
-// This calculation excludes the virtual keyboard area.
-gfx::Point GetCenterOfDisplayForView(const views::View* view) {
+// This calculation excludes the virtual keyboard area. If the height of the
+// display area is less than |minimum_height|, its bottom will be extended to
+// that height (so that the app list never starts above the top of the screen).
+gfx::Point GetCenterOfDisplayForView(const views::View* view,
+                                     int minimum_height) {
   gfx::Rect bounds = Shell::GetScreen()->GetDisplayNearestWindow(
       view->GetWidget()->GetNativeView()).bounds();
 
@@ -129,9 +135,18 @@ gfx::Point GetCenterOfDisplayForView(const views::View* view) {
   if (keyboard_controller && keyboard_controller->keyboard_visible())
     bounds.Subtract(keyboard_controller->current_keyboard_bounds());
 
+  // Apply the |minimum_height|.
+  if (bounds.height() < minimum_height)
+    bounds.set_height(minimum_height);
+
   return bounds.CenterPoint();
 }
 
+// Gets the minimum height of the rectangle to center the app list in.
+int GetMinimumBoundsHeightForAppList(const app_list::AppListView* app_list) {
+  return app_list->bounds().height() + 2 * kMinimalCenteredAppListMargin;
+}
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -189,15 +204,19 @@ void AppListController::SetVisible(bool visible, aura::Window* window) {
         Shelf::ForWindow(container)->GetAppListButtonView();
     is_centered_ = view->ShouldCenterWindow();
     if (is_centered_) {
-      // The experimental app list is centered over the display of the app list
-      // button that was pressed (if triggered via keyboard, this is the display
-      // with the currently focused window).
+      // Note: We can't center the app list until we have its dimensions, so we
+      // init at (0, 0) and then reset its anchor point.
       view->InitAsBubbleAtFixedLocation(
           container,
           pagination_model_.get(),
-          GetCenterOfDisplayForView(applist_button),
+          gfx::Point(),
           views::BubbleBorder::FLOAT,
           true /* border_accepts_events */);
+      // The experimental app list is centered over the display of the app list
+      // button that was pressed (if triggered via keyboard, this is the display
+      // with the currently focused window).
+      view->SetAnchorPoint(GetCenterOfDisplayForView(
+          applist_button, GetMinimumBoundsHeightForAppList(view)));

[varkha, 2014/05/13 03:25:31]

Would it be clearer if s/applist_button/view?

[Matt Giuca, 2014/05/13 04:02:12]

Yes, but it *has* to be the button, or we regress http://crbug.com/368974. The
reason we use the button is because we want the app launcher to open on the same
display that the button that the user clicked is on.

If we use view here (which would nicely simplify the code), we would create the
view at (0, 0) and then move it to the center of the display with (0, 0) on it.

[varkha, 2014/05/13 04:40:11]

I see. I guess UpdateBounds never moves to another display so that's OK.

     } else {
       gfx::Rect applist_button_bounds = applist_button->GetBoundsInScreen();
       // We need the location of the button within the local screen.
@@ -340,7 +359,8 @@ void AppListController::UpdateBounds() {
   view_->UpdateBounds();
 
   if (is_centered_)
-    view_->SetAnchorPoint(GetCenterOfDisplayForView(view_));
+    view_->SetAnchorPoint(GetCenterOfDisplayForView(
+        view_, GetMinimumBoundsHeightForAppList(view_)));
 }
 
 ////////////////////////////////////////////////////////////////////////////////