ash: Start/stop observing KeyboardController via ShellObserver

ash/common/wm/workspace/workspace_layout_manager.cc

Index: ash/common/wm/workspace/workspace_layout_manager.cc
diff --git a/ash/common/wm/workspace/workspace_layout_manager.cc b/ash/common/wm/workspace/workspace_layout_manager.cc
index f33abb0f1ca76828028cc2da1ba117d79d7d0189..c79beb4fecd71922dc350bca2e0c79a9b2d40bef 100644
--- a/ash/common/wm/workspace/workspace_layout_manager.cc
+++ b/ash/common/wm/workspace/workspace_layout_manager.cc
@@ -40,7 +40,8 @@ WorkspaceLayoutManager::WorkspaceLayoutManager(WmWindow* window)
       root_window_controller_(root_window_->GetRootWindowController()),
       shell_(window_->GetShell()),
       work_area_in_parent_(wm::GetDisplayWorkAreaBoundsInParent(window_)),
-      is_fullscreen_(wm::GetWindowForFullscreenMode(window) != nullptr) {
+      is_fullscreen_(wm::GetWindowForFullscreenMode(window) != nullptr),
+      keyboard_observer_(this) {
   Shell::GetInstance()->AddShellObserver(this);
   Shell::GetInstance()->activation_client()->AddObserver(this);
   root_window_->aura_window()->AddObserver(this);
@@ -178,7 +179,9 @@ void WorkspaceLayoutManager::OnKeyboardBoundsChanging(
   }
 }
 
-void WorkspaceLayoutManager::OnKeyboardClosed() {}
+void WorkspaceLayoutManager::OnKeyboardClosed() {
+  keyboard_observer_.RemoveAll();
+}
 
 //////////////////////////////////////////////////////////////////////////////
 // WorkspaceLayoutManager, aura::WindowObserver implementation:
@@ -327,6 +330,22 @@ void WorkspaceLayoutManager::OnPinnedStateChanged(WmWindow* pinned_window) {
   UpdateAlwaysOnTop(WmShell::Get()->IsPinned() ? pinned_window : nullptr);
 }
 
+void WorkspaceLayoutManager::OnVirtualKeyboardStateChanged(
+    bool activated,
+    WmWindow* root_window) {
+  if (root_window != root_window_)

[sky, 2017/03/14 03:23:50]

As this code exists in a handful of places, WDYT of a function like:

UpdateKeyboardObserverFromStateChanged(bool activated,
WmWindow* keyboard_root_window,
WmWindow* root_window,
keyboard_observer).

All the overrides would have the single call to
UpdateKeyboardObserverFromStateChanged, eg:
UpdateKeyboardObserverFromStated(activated, root_window, root_window_,
&keyboard_observer);

And UpdateKeyboardObserverFromStateChanged would go in the file
keyboard_observer_register?

[xiyuan, 2017/03/14 21:25:55]

Good idea. Done.

+    return;
+
+  keyboard::KeyboardController* const keyboard_controller =
+      keyboard::KeyboardController::GetInstance();
+  if (activated && !keyboard_observer_.IsObserving(keyboard_controller)) {
+    keyboard_observer_.Add(keyboard_controller);
+  } else if (!activated &&
+             keyboard_observer_.IsObserving(keyboard_controller)) {
+    keyboard_observer_.Remove(keyboard_controller);
+  }
+}
+
 //////////////////////////////////////////////////////////////////////////////
 // WorkspaceLayoutManager, private: