Layout panels on top of their launcher icons

ash/launcher/launcher_view.cc

Index: ash/launcher/launcher_view.cc
diff --git a/ash/launcher/launcher_view.cc b/ash/launcher/launcher_view.cc
index f844b7ed87658bc4dd270de6ec7ca4b4de6bfad5..0d373d5404f6e1e13a3809a23d70049cd07ce34e 100644
--- a/ash/launcher/launcher_view.cc
+++ b/ash/launcher/launcher_view.cc
@@ -6,6 +6,7 @@
 
 #include "ash/launcher/launcher_button.h"
 #include "ash/launcher/launcher_delegate.h"
+#include "ash/launcher/launcher_icon_observer.h"
 #include "ash/launcher/launcher_model.h"
 #include "ash/launcher/tabbed_launcher_button.h"
 #include "ash/shell.h"
@@ -255,6 +256,7 @@ LauncherView::LauncherView(LauncherModel* model, LauncherDelegate* delegate)
     : model_(model),
       delegate_(delegate),
       view_model_(new views::ViewModel),
+      last_visible_index_(-1),
       overflow_button_(NULL),
       dragging_(NULL),
       drag_view_(NULL),
@@ -305,7 +307,7 @@ void LauncherView::Init() {
 
 gfx::Rect LauncherView::GetIdealBoundsOfItemIcon(LauncherID id) {
   int index = model_->ItemIndexByID(id);
-  if (index == -1 || !view_model_->view_at(index)->visible())
+  if (index == -1 || index > last_visible_index_)
     return gfx::Rect();
   const gfx::Rect& ideal_bounds(view_model_->ideal_bounds(index));
   DCHECK_NE(TYPE_APP_LIST, model_->items()[index].type);
@@ -347,6 +349,8 @@ void LauncherView::LayoutToIdealBounds() {
   CalculateIdealBounds(&ideal_bounds);
   views::ViewModelUtils::SetViewBoundsToIdealBounds(*view_model_);
   overflow_button_->SetBoundsRect(ideal_bounds.overflow_bounds);
+  FOR_EACH_OBSERVER(LauncherIconObserver, observers_,
+                    OnLauncherIconPositionsChanged());
 }
 
 void LauncherView::CalculateIdealBounds(IdealBounds* bounds) {
@@ -364,19 +368,19 @@ void LauncherView::CalculateIdealBounds(IdealBounds* bounds) {
   }
 
   bounds->overflow_bounds.set_size(gfx::Size(kButtonWidth, kButtonHeight));
-  int last_visible_index = DetermineLastVisibleIndex(
+  last_visible_index_ = DetermineLastVisibleIndex(
       available_width - kLeadingInset - bounds->overflow_bounds.width() -
       kButtonSpacing - kButtonWidth);
   bool show_overflow =
-      (last_visible_index + 1 != view_model_->view_size());
+      (last_visible_index_ + 1 != view_model_->view_size());
   int app_list_index = view_model_->view_size() - 1;
   if (overflow_button_->visible() != show_overflow) {
     // Only change visibility of the views if the visibility of the overflow
     // button changes. Otherwise we'll effect the insertion animation, which
     // changes the visibility.
-    for (int i = 0; i <= last_visible_index; ++i)
+    for (int i = 0; i <= last_visible_index_; ++i)
       view_model_->view_at(i)->SetVisible(true);
-    for (int i = last_visible_index + 1; i < view_model_->view_size(); ++i) {
+    for (int i = last_visible_index_ + 1; i < view_model_->view_size(); ++i) {
       if (i != app_list_index)
         view_model_->view_at(i)->SetVisible(false);
     }
@@ -386,8 +390,8 @@ void LauncherView::CalculateIdealBounds(IdealBounds* bounds) {
     DCHECK_NE(0, view_model_->view_size());
     // We always want the app list visible.
     gfx::Rect app_list_bounds = view_model_->ideal_bounds(app_list_index);
-    x = last_visible_index == -1 ?
-        kLeadingInset : view_model_->ideal_bounds(last_visible_index).right();
+    x = last_visible_index_ == -1 ?
+        kLeadingInset : view_model_->ideal_bounds(last_visible_index_).right();
     app_list_bounds.set_x(x);
     view_model_->set_ideal_bounds(app_list_index, app_list_bounds);
     x = app_list_bounds.right() + kButtonSpacing;
@@ -404,6 +408,14 @@ int LauncherView::DetermineLastVisibleIndex(int max_x) {
   return index;
 }
 
+void LauncherView::AddIconObserver(LauncherIconObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void LauncherView::RemoveIconObserver(LauncherIconObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 void LauncherView::AnimateToIdealBounds() {
   IdealBounds ideal_bounds;
   CalculateIdealBounds(&ideal_bounds);
@@ -412,6 +424,8 @@ void LauncherView::AnimateToIdealBounds() {
                                     view_model_->ideal_bounds(i));
   }
   overflow_button_->SetBoundsRect(ideal_bounds.overflow_bounds);
+  FOR_EACH_OBSERVER(LauncherIconObserver, observers_,
+                    OnLauncherIconPositionsChanged());
 }
 
 views::View* LauncherView::CreateViewForItem(const LauncherItem& item) {