Fixing the dynamic positioning (move with anchor) for the app launcher

ash/wm/app_list_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/app_list_controller.h"
 
 #include "ash/ash_switches.h"
 #include "ash/launcher/launcher.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
@@ skipping 21 matching lines @@
 
 // Duration for show/hide animation in milliseconds.
 const int kAnimationDurationMs = 200;
 
 // Offset in pixels to animation away/towards the launcher.
 const int kAnimationOffset = 8;
 
 // The maximum shift in pixels when over-scroll happens.
 const int kMaxOverScrollShift = 48;
 
-// The alternate shelf style adjusts the bubble to be flush with the shelf
-// when there is no bubble-tip. This is the tip height which needs to be
-// offsetted.
-const int kArrowTipHeight = 10;

[James Cook, 2013/09/05 20:05:17]

Nice that you found this thing to clean up.

[Mr4D (OOO till 08-26), 2013/09/05 20:52:00]

Sure thing!

-
 // The minimal anchor position offset to make sure that the bubble is still on
 // the screen with 8 pixels spacing on the left / right. This constant is a
 // result of minimal bubble arrow sizes and offsets.
 const int kMinimalAnchorPositionOffset = 57;
 
 ui::Layer* GetLayer(views::Widget* widget) {
   return widget->GetNativeView()->layer();
 }
 
 // Gets arrow location based on shelf alignment.
@@ skipping 24 matching lines @@
       offseted.Offset(kAnimationOffset, 0);
       break;
     case SHELF_ALIGNMENT_TOP:
       offseted.Offset(0, -kAnimationOffset);
       break;
   }
 
   return offseted;
 }
 
-// Using |button_bounds|, determine the anchor so that the bubble gets shown
-// above the shelf (used for the alternate shelf theme).
-gfx::Point GetAdjustAnchorPositionToShelf(
+// Using |button_bounds|, determine the anchor offset so that the bubble gets
+// shown above the shelf (used for the alternate shelf theme).
+gfx::Point GetAnchorPositionOffsetToShelf(
     const gfx::Rect& button_bounds, views::Widget* widget) {
   DCHECK(Shell::HasInstance());
   ShelfAlignment shelf_alignment = Shell::GetInstance()->GetShelfAlignment(
       widget->GetNativeView()->GetRootWindow());
   gfx::Point anchor(button_bounds.CenterPoint());
   switch (shelf_alignment) {
     case SHELF_ALIGNMENT_TOP:
     case SHELF_ALIGNMENT_BOTTOM:
       {
         if (base::i18n::IsRTL()) {
           int screen_width = widget->GetWorkAreaBoundsInScreen().width();
-          anchor.set_x(std::min(screen_width - kMinimalAnchorPositionOffset,
-                                anchor.x()));
+          anchor.set_x(
+              std::min(screen_width - kMinimalAnchorPositionOffset - anchor.x(),
+                       0));
         } else {
-          anchor.set_x(std::max(kMinimalAnchorPositionOffset, anchor.x()));
+          anchor.set_x(std::max(kMinimalAnchorPositionOffset - anchor.x(), 0));
         }
-        int offset = button_bounds.height() / 2 - kArrowTipHeight;
-        if (shelf_alignment == SHELF_ALIGNMENT_TOP)
-          offset = -offset;
-        anchor.set_y(anchor.y() - offset);
+        anchor.set_y(0);
       }
       break;
     case SHELF_ALIGNMENT_LEFT:
-      anchor.set_x(button_bounds.right() - kArrowTipHeight);
-      anchor.set_y(std::max(kMinimalAnchorPositionOffset, anchor.y()));
+      anchor.set_x(0);
+      anchor.set_y(std::max(kMinimalAnchorPositionOffset - anchor.y(), 0));
       break;
     case SHELF_ALIGNMENT_RIGHT:
-      anchor.set_x(button_bounds.x() + kArrowTipHeight);
-      anchor.set_y(std::max(kMinimalAnchorPositionOffset, anchor.y()));
+      anchor.set_x(0);
+      anchor.set_y(std::max(kMinimalAnchorPositionOffset - anchor.y(), 0));
       break;
   }
 
   return anchor;
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListController, public:
@@ skipping 36 matching lines @@
     app_list::AppListView* view = new app_list::AppListView(
         Shell::GetInstance()->delegate()->CreateAppListViewDelegate());
     aura::Window* container = GetRootWindowController(window->GetRootWindow())->
         GetContainer(kShellWindowId_AppListContainer);
     if (ash::switches::UseAlternateShelfLayout()) {
       gfx::Rect applist_button_bounds = Launcher::ForWindow(container)->
           GetAppListButtonView()->GetBoundsInScreen();
       view->InitAsBubble(
           container,
           pagination_model_.get(),
-          NULL,
-          GetAdjustAnchorPositionToShelf(applist_button_bounds,
+          Launcher::ForWindow(container)->GetAppListButtonView(),
+          GetAnchorPositionOffsetToShelf(applist_button_bounds,
               Launcher::ForWindow(container)->GetAppListButtonView()->
                   GetWidget()),
           GetBubbleArrow(container),
           true /* border_accepts_events */);
       view->SetArrowPaintType(views::BubbleBorder::PAINT_NONE);
     } else {
       view->InitAsBubble(
           container,
           pagination_model_.get(),
           Launcher::ForWindow(container)->GetAppListButtonView(),
@@ skipping 231 matching lines @@
     should_snap_back_ = false;
     ui::ScopedLayerAnimationSettings animation(widget_animator);
     animation.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
         app_list::kOverscrollPageTransitionDurationMs));
     widget->SetBounds(view_bounds_);
   }
 }
 
 }  // namespace internal
 }  // namespace ash