Refactored ShelfItemDelegate::ItemSelected(ui::Event) to return the action

performed by the selection.

Previously ShelfItemDelegate::ItemSelected(ui::Event) returned a bool value
which was insufficient for the many different actions that could be taken.
This work is making it possible to add an UMA stat to track when a window
is minimized by the shelf.

BUG=471354

Review URL: https://codereview.chromium.org/1070343002

Cr-Commit-Position: refs/heads/master@{#325928}

11 files changed, 55 insertions, 24 deletions

diff --git a/ash/shelf/app_list_shelf_item_delegate.cc b/ash/shelf/app_list_shelf_item_delegate.cc
index 99c58e1e..a0c1873 100644
--- a/ash/shelf/app_list_shelf_item_delegate.cc
+++ b/ash/shelf/app_list_shelf_item_delegate.cc
@@ -23,10 +23,11 @@ AppListShelfItemDelegate::~AppListShelfItemDelegate() {
   // ShelfItemDelegateManager owns and destroys this class.
 }
 
-bool AppListShelfItemDelegate::ItemSelected(const ui::Event& event) {
+ShelfItemDelegate::PerformedAction AppListShelfItemDelegate::ItemSelected(
+    const ui::Event& event) {
   // Pass NULL here to show the app list in the currently active RootWindow.
   Shell::GetInstance()->ToggleAppList(NULL);
-  return false;
+  return ShelfItemDelegate::kAppListMenuShown;
 }
 
 base::string16 AppListShelfItemDelegate::GetTitle() {
diff --git a/ash/shelf/app_list_shelf_item_delegate.h b/ash/shelf/app_list_shelf_item_delegate.h
index 5d04fac..67b617b 100644
--- a/ash/shelf/app_list_shelf_item_delegate.h
+++ b/ash/shelf/app_list_shelf_item_delegate.h
@@ -19,7 +19,8 @@ class AppListShelfItemDelegate : public ShelfItemDelegate {
   ~AppListShelfItemDelegate() override;
 
   // ShelfItemDelegate:
-  bool ItemSelected(const ui::Event& event) override;
+  ShelfItemDelegate::PerformedAction ItemSelected(
+      const ui::Event& event) override;
   base::string16 GetTitle() override;
   ui::MenuModel* CreateContextMenu(aura::Window* root_window) override;
   ShelfMenuModel* CreateApplicationMenu(int event_flags) override;
diff --git a/ash/shelf/shelf_item_delegate.h b/ash/shelf/shelf_item_delegate.h
index 46f282a..41bc0b6 100644
--- a/ash/shelf/shelf_item_delegate.h
+++ b/ash/shelf/shelf_item_delegate.h
@@ -24,6 +24,20 @@ class ShelfMenuModel;
 // Delegate for the ShelfItem.
 class ASH_EXPORT ShelfItemDelegate {
  public:
+  // The return type for the ShelfItemDelegate::ItemSelected method.
+  enum PerformedAction {
+    // No action was taken.
+    kNoAction,
+    // A new window was created.
+    kNewWindowCreated,
+    // An existing window which was not currently active was activated.
+    kExistingWindowActivated,
+    // The currently active window was minimized.
+    kExistingWindowMinimized,
+    // The app list launcher menu was shown.
+    kAppListMenuShown,
+  };
+
   virtual ~ShelfItemDelegate() {}
 
   // Invoked when the user clicks on a window entry in the launcher.
@@ -32,8 +46,8 @@ class ASH_EXPORT ShelfItemDelegate {
   // but not |aura::Window|. If the |event| is of type KeyEvent, it is assumed
   // that this was triggered by keyboard action (Alt+<number>) and special
   // handling might happen.
-  // Returns true if a new item was created.
-  virtual bool ItemSelected(const ui::Event& event) = 0;
+  // Returns the action performed by selecting the item.
+  virtual PerformedAction ItemSelected(const ui::Event& event) = 0;
 
   // Returns the title to display.
   virtual base::string16 GetTitle() = 0;
diff --git a/ash/shelf/shelf_view.cc b/ash/shelf/shelf_view.cc
index b4a3b72..21651b4 100644
--- a/ash/shelf/shelf_view.cc
+++ b/ash/shelf/shelf_view.cc
@@ -1754,13 +1754,18 @@ void ShelfView::ButtonPressed(views::Button* sender, const ui::Event& event) {
 
     RecordIconActivatedAction(event);
 
-    ShelfItemDelegate* item_delegate =
-        item_manager_->GetShelfItemDelegate(model_->items()[view_index].id);
-    if (!item_delegate->ItemSelected(event)) {
-      ShowListMenuForView(model_->items()[view_index], sender, event);
-    } else {
-      Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-          UMA_LAUNCHER_LAUNCH_TASK);
+    switch (item_manager_->GetShelfItemDelegate(model_->items()[view_index].id)
+                ->ItemSelected(event)) {
+      case ShelfItemDelegate::kNoAction:
+      case ShelfItemDelegate::kExistingWindowActivated:
+      case ShelfItemDelegate::kExistingWindowMinimized:
+      case ShelfItemDelegate::kAppListMenuShown:
+        ShowListMenuForView(model_->items()[view_index], sender, event);
+        break;
+      case ShelfItemDelegate::kNewWindowCreated:
+        Shell::GetInstance()->metrics()->RecordUserMetricsAction(
+            UMA_LAUNCHER_LAUNCH_TASK);
+        break;
     }
   }
 }
diff --git a/ash/shelf/shelf_view_unittest.cc b/ash/shelf/shelf_view_unittest.cc
index 177dc00..39afb9a 100644
--- a/ash/shelf/shelf_view_unittest.cc
+++ b/ash/shelf/shelf_view_unittest.cc
@@ -5,6 +5,7 @@
 #include "ash/shelf/shelf_view.h"
 
 #include <algorithm>
+#include <utility>
 #include <vector>
 
 #include "ash/root_window_controller.h"
@@ -134,9 +135,10 @@ class ShelfItemSelectionTracker : public TestShelfItemDelegate {
   }
 
   // TestShelfItemDelegate:
-  bool ItemSelected(const ui::Event& event) override {
+  ShelfItemDelegate::PerformedAction ItemSelected(
+      const ui::Event& event) override {
     selected_ = true;
-    return false;
+    return kNoAction;
   }
 
  private:
diff --git a/ash/shelf/shelf_window_watcher_item_delegate.cc b/ash/shelf/shelf_window_watcher_item_delegate.cc
index 005d2d4..172b6d1 100644
--- a/ash/shelf/shelf_window_watcher_item_delegate.cc
+++ b/ash/shelf/shelf_window_watcher_item_delegate.cc
@@ -28,19 +28,21 @@ void ShelfWindowWatcherItemDelegate::Close() {
   views::Widget::GetWidgetForNativeWindow(window_)->Close();
 }
 
-bool ShelfWindowWatcherItemDelegate::ItemSelected(const ui::Event& event) {
+ShelfItemDelegate::PerformedAction ShelfWindowWatcherItemDelegate::ItemSelected(
+    const ui::Event& event) {
   wm::WindowState* window_state = wm::GetWindowState(window_);
   if (window_state->IsActive()) {
     if (event.type() & ui::ET_KEY_RELEASED) {
       ::wm::AnimateWindow(window_, ::wm::WINDOW_ANIMATION_TYPE_BOUNCE);
+      return kNoAction;
     } else {
       window_state->Minimize();
+      return kExistingWindowMinimized;
     }
   } else {
     window_state->Activate();
+    return kExistingWindowActivated;
   }
-
-  return false;
 }
 
 base::string16 ShelfWindowWatcherItemDelegate::GetTitle() {
diff --git a/ash/shelf/shelf_window_watcher_item_delegate.h b/ash/shelf/shelf_window_watcher_item_delegate.h
index d2733d3..0cca9da 100644
--- a/ash/shelf/shelf_window_watcher_item_delegate.h
+++ b/ash/shelf/shelf_window_watcher_item_delegate.h
@@ -25,7 +25,8 @@ class ShelfWindowWatcherItemDelegate : public ShelfItemDelegate {
 
  private:
   // ShelfItemDelegate overrides:
-  bool ItemSelected(const ui::Event& event) override;
+  ShelfItemDelegate::PerformedAction ItemSelected(
+      const ui::Event& event) override;
   base::string16 GetTitle() override;
   ui::MenuModel* CreateContextMenu(aura::Window* root_window) override;
   ShelfMenuModel* CreateApplicationMenu(int event_flags) override;
diff --git a/ash/shell/window_watcher_shelf_item_delegate.cc b/ash/shell/window_watcher_shelf_item_delegate.cc
index 4a8f364..6e3f2a1 100644
--- a/ash/shell/window_watcher_shelf_item_delegate.cc
+++ b/ash/shell/window_watcher_shelf_item_delegate.cc
@@ -22,13 +22,14 @@ WindowWatcherShelfItemDelegate::WindowWatcherShelfItemDelegate(
 WindowWatcherShelfItemDelegate::~WindowWatcherShelfItemDelegate() {
 }
 
-bool WindowWatcherShelfItemDelegate::ItemSelected(const ui::Event& event) {
+ShelfItemDelegate::PerformedAction WindowWatcherShelfItemDelegate::ItemSelected(
+    const ui::Event& event) {
   aura::Window* window = watcher_->GetWindowByID(id_);
   if (window->type() == ui::wm::WINDOW_TYPE_PANEL)
     wm::MoveWindowToEventRoot(window, event);
   window->Show();
   wm::ActivateWindow(window);
-  return false;
+  return kExistingWindowActivated;
 }
 
 base::string16 WindowWatcherShelfItemDelegate::GetTitle() {
diff --git a/ash/shell/window_watcher_shelf_item_delegate.h b/ash/shell/window_watcher_shelf_item_delegate.h
index 117156b..e3c493b 100644
--- a/ash/shell/window_watcher_shelf_item_delegate.h
+++ b/ash/shell/window_watcher_shelf_item_delegate.h
@@ -22,7 +22,8 @@ class WindowWatcherShelfItemDelegate : public ShelfItemDelegate {
   ~WindowWatcherShelfItemDelegate() override;
 
   // ShelfItemDelegate:
-  bool ItemSelected(const ui::Event& event) override;
+  ShelfItemDelegate::PerformedAction ItemSelected(
+      const ui::Event& event) override;
   base::string16 GetTitle() override;
   ui::MenuModel* CreateContextMenu(aura::Window* root_window) override;
   ShelfMenuModel* CreateApplicationMenu(int event_flags) override;
diff --git a/ash/test/test_shelf_item_delegate.cc b/ash/test/test_shelf_item_delegate.cc
index e8f4780..a70b451 100644
--- a/ash/test/test_shelf_item_delegate.cc
+++ b/ash/test/test_shelf_item_delegate.cc
@@ -17,14 +17,16 @@ TestShelfItemDelegate::TestShelfItemDelegate(aura::Window* window)
 TestShelfItemDelegate::~TestShelfItemDelegate() {
 }
 
-bool TestShelfItemDelegate::ItemSelected(const ui::Event& event) {
+ShelfItemDelegate::PerformedAction TestShelfItemDelegate::ItemSelected(
+    const ui::Event& event) {
   if (window_) {
     if (window_->type() == ui::wm::WINDOW_TYPE_PANEL)
       wm::MoveWindowToEventRoot(window_, event);
     window_->Show();
     wm::ActivateWindow(window_);
+    return kExistingWindowActivated;
   }
-  return false;
+  return kNoAction;
 }
 
 base::string16 TestShelfItemDelegate::GetTitle() {
diff --git a/ash/test/test_shelf_item_delegate.h b/ash/test/test_shelf_item_delegate.h
index 836f5f1..e69ef69 100644
--- a/ash/test/test_shelf_item_delegate.h
+++ b/ash/test/test_shelf_item_delegate.h
@@ -23,7 +23,8 @@ class TestShelfItemDelegate : public ShelfItemDelegate {
   ~TestShelfItemDelegate() override;
 
   // ShelfItemDelegate:
-  bool ItemSelected(const ui::Event& event) override;
+  ShelfItemDelegate::PerformedAction ItemSelected(
+      const ui::Event& event) override;
   base::string16 GetTitle() override;
   ui::MenuModel* CreateContextMenu(aura::Window* root_window) override;
   ShelfMenuModel* CreateApplicationMenu(int event_flags) override;