Limit display of the virtual keyboard to state changes triggered from a user gesture.

ui/keyboard/keyboard_controller.cc

 // Copyright (c) 2013 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 "ui/keyboard/keyboard_controller.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window.h"
@@ skipping 202 matching lines @@
 
 void KeyboardController::SetOverrideContentUrl(const GURL& url) {
   proxy_->SetOverrideContentUrl(url);
 }
 
 void KeyboardController::OnTextInputStateChanged(
     const ui::TextInputClient* client) {
   if (!container_.get())
     return;
 
-  bool was_showing = keyboard_visible_;
-  bool should_show = was_showing;
+  if (IsKeyboardUsabilityExperimentEnabled()) {
+    OnShowImeIfNeeded();
+    return;
+  }
+
   ui::TextInputType type =
       client ? client->GetTextInputType() : ui::TEXT_INPUT_TYPE_NONE;
-  if (type == ui::TEXT_INPUT_TYPE_NONE &&
-      !IsKeyboardUsabilityExperimentEnabled() &&
-      !lock_keyboard_) {
-    should_show = false;
-  } else {
-    if (container_->children().empty()) {
-      keyboard::MarkKeyboardLoadStarted();
-      aura::Window* keyboard = proxy_->GetKeyboardWindow();
-      keyboard->Show();
-      container_->AddChild(keyboard);
-    }
-    if (type != ui::TEXT_INPUT_TYPE_NONE)
-      proxy_->SetUpdateInputType(type);
-    container_->parent()->StackChildAtTop(container_.get());
-    should_show = true;
-  }
-
-  if (was_showing != should_show) {
-    if (should_show) {
-      keyboard_visible_ = true;
-
-      // If the controller is in the process of hiding the keyboard, do not log
-      // the stat here since the keyboard will not actually be shown.
-      if (!WillHideKeyboard())
-        keyboard::LogKeyboardControlEvent(keyboard::KEYBOARD_CONTROL_SHOW);
-
-      weak_factory_.InvalidateWeakPtrs();
-      if (container_->IsVisible())
-        return;
-
-      NotifyKeyboardBoundsChanging(container_->children()[0]->bounds());
-
-      proxy_->ShowKeyboardContainer(container_.get());
-    } else {
+  if (type == ui::TEXT_INPUT_TYPE_NONE && !lock_keyboard_) {
+    if (keyboard_visible_ /* &&  !IsKeyboardUsabilityExperimentEnabled() */) {
       // Set the visibility state here so that any queries for visibility
       // before the timer fires returns the correct future value.
       keyboard_visible_ = false;
       base::MessageLoop::current()->PostDelayedTask(
           FROM_HERE,
           base::Bind(&KeyboardController::HideKeyboard,
                      weak_factory_.GetWeakPtr(), HIDE_REASON_AUTOMATIC),
           base::TimeDelta::FromMilliseconds(kHideKeyboardDelayMs));
     }
+  } else {
+    // Abort a pending keyboard hide.
+    if (WillHideKeyboard()) {
+      weak_factory_.InvalidateWeakPtrs();
+      keyboard_visible_ = true;
+    }
+    proxy_->SetUpdateInputType(type);
   }
   // TODO(bryeung): whenever the TextInputClient changes we need to notify the
   // keyboard (with the TextInputType) so that it can reset it's state (e.g.
   // abandon compositions in progress)
 }
 
 void KeyboardController::OnInputMethodDestroyed(
     const ui::InputMethod* input_method) {
   DCHECK_EQ(input_method_, input_method);
   input_method_ = NULL;
 }
 
+void KeyboardController::OnShowImeIfNeeded() {
+  if (!container_.get())
+    return;
+
+  if (container_->children().empty()) {
+    aura::Window* keyboard = proxy_->GetKeyboardWindow();
+    keyboard->Show();
+    container_->AddChild(keyboard);
+    container_->layout_manager()->OnWindowResized();

[Shu Chen, 2014/01/09 04:21:17]

unnecessary call to OnWindowResized(), because now its OnWindowAddedToLayout()
will call ResizeKeyboardToDefault().

[kevers, 2014/01/09 15:29:09]

Done.

+  }
+  if (keyboard_visible_)
+    return;
+
+  keyboard_visible_ = true;
+
+  // If the controller is in the process of hiding the keyboard, do not log
+  // the stat here since the keyboard will not actually be shown.
+  if (!WillHideKeyboard())
+    keyboard::LogKeyboardControlEvent(keyboard::KEYBOARD_CONTROL_SHOW);
+
+  weak_factory_.InvalidateWeakPtrs();
+  if (container_->IsVisible())
+    return;
+
+  FOR_EACH_OBSERVER(
+      KeyboardControllerObserver,
+      observer_list_,
+      OnKeyboardBoundsChanging(container_->children()[0]->bounds()));

[Shu Chen, 2014/01/09 04:21:17]

Why not use this?
NotifyKeyboardBoundsChanging(container_->children()[0]->bounds());

[kevers, 2014/01/09 15:29:09]

Done.

+  proxy_->ShowKeyboardContainer(container_.get());
+}
+
 bool KeyboardController::WillHideKeyboard() const {
   return weak_factory_.HasWeakPtrs();
 }
 
 }  // namespace keyboard