Adds an extension API of the event on changing volume.

- experimental.accessibility.onVolumeChange

I run chrome/common/extensions/docs/build/build.py, but no documents about a11y was changed. So this CL doesn't include any changes of documents.

BUG=chromium-os:16592
TEST=call the APIs manually on chromium-os

Review URL: http://codereview.chromium.org/7708025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98948 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/accessibility_events.cc

@@ -8,25 +8,34 @@
 
 #include "chrome/browser/extensions/extension_accessibility_api_constants.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/common/chrome_notification_types.h"
 #include "content/common/content_notification_types.h"
 #include "content/common/notification_service.h"
 
 namespace keys = extension_accessibility_api_constants;
 
 void SendAccessibilityNotification(
-    int type, AccessibilityControlInfo* info) {
+    int type, AccessibilityEventInfo* info) {
   Profile *profile = info->profile();
   if (profile->ShouldSendAccessibilityEvents()) {
     NotificationService::current()->Notify(
         type,
         Source<Profile>(profile),
-        Details<AccessibilityControlInfo>(info));
+        Details<AccessibilityEventInfo>(info));
   }
 }
 
+void SendAccessibilityVolumeNotification(double volume, bool is_muted) {
+  Profile* profile = ProfileManager::GetDefaultProfile();
+  AccessibilityVolumeInfo info(profile, volume, is_muted);
+  SendAccessibilityNotification(
+      chrome::NOTIFICATION_ACCESSIBILITY_VOLUME_CHANGED, &info);
+}
+
 AccessibilityControlInfo::AccessibilityControlInfo(
     Profile* profile, const std::string& control_name)
-    : profile_(profile), name_(control_name) {
+    : AccessibilityEventInfo(profile), name_(control_name) {
 }
 
 AccessibilityControlInfo::~AccessibilityControlInfo() {
@@ -188,6 +197,22 @@ void AccessibilityListBoxInfo::SerializeToDict(DictionaryValue *dict) const {
   dict->SetInteger(keys::kItemCountKey, item_count_);
 }
 
+AccessibilityVolumeInfo::AccessibilityVolumeInfo(Profile* profile,
+                                                 double volume,
+                                                 bool is_muted)
+    : AccessibilityEventInfo(profile),
+      volume_(volume),
+      is_muted_(is_muted) {
+  DCHECK(profile);
+  DCHECK_GE(volume, 0.0);
+  DCHECK_LE(volume, 100.0);
+}
+
+void AccessibilityVolumeInfo::SerializeToDict(DictionaryValue *dict) const {
+  dict->SetDouble(keys::kVolumeKey, volume_);
+  dict->SetBoolean(keys::kIsVolumeMutedKey, is_muted_);
+}
+
 AccessibilityMenuInfo::AccessibilityMenuInfo(Profile* profile,
                                              const std::string& menu_name)
     : AccessibilityControlInfo(profile, menu_name) {

chrome/browser/accessibility_events.h

@@ -7,8 +7,9 @@
 #pragma once
 
 #include <string>
+#include "base/compiler_specific.h"
 
-class AccessibilityControlInfo;
+class AccessibilityEventInfo;
 class Profile;
 
 namespace base {
@@ -16,36 +17,51 @@ class DictionaryValue;
 }
 
 // Use the NotificationService to post the given accessibility
-// notification type with AccessibilityControlInfo details to any
+// notification type with AccessibilityEventInfo details to any
 // listeners.  Will not send if the profile's pause level is nonzero
 // (using profile->PauseAccessibilityEvents).
 void SendAccessibilityNotification(
-    int type, AccessibilityControlInfo* info);
+    int type, AccessibilityEventInfo* info);
+void SendAccessibilityVolumeNotification(double volume, bool is_muted);
+
+// Abstract parent class for accessibility event information passed to event
+// listeners.
+class AccessibilityEventInfo {
+ public:
+  virtual ~AccessibilityEventInfo() {}
+
+  // Serialize this class as a DictionaryValue that can be converted to
+  // a JavaScript object.
+  virtual void SerializeToDict(base::DictionaryValue* dict) const = 0;
+
+  Profile* profile() const { return profile_; }
+
+ protected:
+  explicit AccessibilityEventInfo(Profile* profile) : profile_(profile) {}
+
+  // The profile this control belongs to.
+  Profile* profile_;
+};
 
 // Abstract parent class for accessibility information about a control
 // passed to event listeners.
-class AccessibilityControlInfo {
+class AccessibilityControlInfo : public AccessibilityEventInfo {
  public:
   virtual ~AccessibilityControlInfo();
 
   // Serialize this class as a DictionaryValue that can be converted to
   // a JavaScript object.
-  virtual void SerializeToDict(base::DictionaryValue* dict) const;
+  virtual void SerializeToDict(base::DictionaryValue* dict) const OVERRIDE;
 
   // Return the specific type of this control, which will be one of the
   // string constants defined in extension_accessibility_api_constants.h.
   virtual const char* type() const = 0;
 
-  Profile* profile() const { return profile_; }
-
   const std::string& name() const { return name_; }
 
  protected:
   AccessibilityControlInfo(Profile* profile, const std::string& control_name);
 
-  // The profile this control belongs to.
-  Profile* profile_;
-
   // The name of the control, like "OK" or "Password".
   std::string name_;
 };
@@ -255,6 +271,20 @@ class AccessibilityMenuInfo : public AccessibilityControlInfo {
   virtual const char* type() const;
 };
 
+// Accessibility information about a volume; this class is used by
+// onVolumeUp, onVolumeDown, and onVolumeMute event listeners.
+class AccessibilityVolumeInfo : public AccessibilityEventInfo {
+ public:
+  // |volume| must range between 0 to 100.
+  AccessibilityVolumeInfo(Profile* profile, double volume, bool is_muted);
+
+  virtual void SerializeToDict(base::DictionaryValue* dict) const;
+
+ private:
+  double volume_;
+  bool is_muted_;
+};
+
 // Accessibility information about a menu item; this class is used by
 // onControlFocused event listeners.
 class AccessibilityMenuItemInfo : public AccessibilityControlInfo {

chrome/browser/chromeos/system_key_event_listener.cc

@@ -8,6 +8,7 @@
 #include <X11/XF86keysym.h>
 #include <X11/XKBlib.h>
 
+#include "chrome/browser/accessibility_events.h"
 #include "chrome/browser/chromeos/audio_handler.h"
 #include "chrome/browser/chromeos/brightness_bubble.h"
 #include "chrome/browser/chromeos/input_method/xkeyboard.h"
@@ -174,6 +175,11 @@ void SystemKeyEventListener::OnVolumeMute() {
   // Always muting (and not toggling) as per final decision on
   // http://crosbug.com/3751
   audio_handler_->SetMuted(true);
+
+  SendAccessibilityVolumeNotification(
+      audio_handler_->GetVolumePercent(),
+      audio_handler_->IsMuted());
+
   ShowVolumeBubble();
 }
 
@@ -185,6 +191,11 @@ void SystemKeyEventListener::OnVolumeDown() {
     audio_handler_->SetVolumePercent(0.0);
   else
     audio_handler_->AdjustVolumeByPercent(-kStepPercentage);
+
+  SendAccessibilityVolumeNotification(
+      audio_handler_->GetVolumePercent(),
+      audio_handler_->IsMuted());
+
   ShowVolumeBubble();
 }
 
@@ -199,6 +210,11 @@ void SystemKeyEventListener::OnVolumeUp() {
   } else {
     audio_handler_->AdjustVolumeByPercent(kStepPercentage);
   }
+
+  SendAccessibilityVolumeNotification(
+      audio_handler_->GetVolumePercent(),
+      audio_handler_->IsMuted());
+
   ShowVolumeBubble();
 }
 

chrome/browser/extensions/extension_accessibility_api.cc

@@ -25,7 +25,7 @@ namespace keys = extension_accessibility_api_constants;
 // Returns the AccessibilityControlInfo serialized into a JSON string,
 // consisting of an array of a single object of type AccessibilityObject,
 // as defined in the accessibility extension api's json schema.
-std::string ControlInfoToJsonString(const AccessibilityControlInfo* info) {
+std::string ControlInfoToJsonString(const AccessibilityEventInfo* info) {
   ListValue args;
   DictionaryValue* dict = new DictionaryValue();
   info->SerializeToDict(dict);
@@ -73,6 +73,9 @@ void ExtensionAccessibilityEventRouter::ObserveProfile(Profile* profile) {
     registrar_.Add(this,
                    chrome::NOTIFICATION_ACCESSIBILITY_MENU_CLOSED,
                    NotificationService::AllSources());
+    registrar_.Add(this,
+                   chrome::NOTIFICATION_ACCESSIBILITY_VOLUME_CHANGED,
+                   NotificationService::AllSources());
   }
 }
 
@@ -102,6 +105,9 @@ void ExtensionAccessibilityEventRouter::Observe(
     case chrome::NOTIFICATION_ACCESSIBILITY_MENU_CLOSED:
       OnMenuClosed(Details<const AccessibilityMenuInfo>(details).ptr());
       break;
+    case chrome::NOTIFICATION_ACCESSIBILITY_VOLUME_CHANGED:
+      OnVolumeChanged(Details<const AccessibilityVolumeInfo>(details).ptr());
+      break;
     default:
       NOTREACHED();
   }
@@ -180,6 +186,12 @@ void ExtensionAccessibilityEventRouter::OnMenuClosed(
   DispatchEvent(info->profile(), keys::kOnMenuClosed, json_args);
 }
 
+void ExtensionAccessibilityEventRouter::OnVolumeChanged(
+    const AccessibilityVolumeInfo* info) {
+  std::string json_args = ControlInfoToJsonString(info);
+  DispatchEvent(info->profile(), keys::kOnVolumeChanged, json_args);
+}
+
 void ExtensionAccessibilityEventRouter::DispatchEvent(
     Profile* profile,
     const char* event_name,

chrome/browser/extensions/extension_accessibility_api.h

@@ -62,6 +62,7 @@ class ExtensionAccessibilityEventRouter : public NotificationObserver {
   void OnTextChanged(const AccessibilityControlInfo* details);
   void OnMenuOpened(const AccessibilityMenuInfo* details);
   void OnMenuClosed(const AccessibilityMenuInfo* details);
+  void OnVolumeChanged(const AccessibilityVolumeInfo* details);
 
   void DispatchEvent(Profile* profile,
                      const char* event_name,

chrome/browser/extensions/extension_accessibility_api_constants.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -18,6 +18,8 @@ const char kSelectionStartKey[] = "details.selectionStart";
 const char kSelectionEndKey[] = "details.selectionEnd";
 const char kCheckedKey[] = "details.isChecked";
 const char kHasSubmenuKey[] = "details.hasSubmenu";
+const char kVolumeKey[] = "volume";
+const char kIsVolumeMutedKey[] = "isVolumeMuted";
 
 // Events.
 const char kOnWindowOpened[] = "experimental.accessibility.onWindowOpened";
@@ -27,6 +29,7 @@ const char kOnControlAction[] = "experimental.accessibility.onControlAction";
 const char kOnTextChanged[] = "experimental.accessibility.onTextChanged";
 const char kOnMenuOpened[] = "experimental.accessibility.onMenuOpened";
 const char kOnMenuClosed[] = "experimental.accessibility.onMenuClosed";
+const char kOnVolumeChanged[] = "experimental.accessibility.onVolumeChanged";
 
 // Types of controls that can receive accessibility events.
 const char kTypeButton[] = "button";

chrome/browser/extensions/extension_accessibility_api_constants.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -22,6 +22,8 @@ extern const char kSelectionStartKey[];
 extern const char kSelectionEndKey[];
 extern const char kCheckedKey[];
 extern const char kHasSubmenuKey[];
+extern const char kVolumeKey[];
+extern const char kIsVolumeMutedKey[];
 
 // Events.
 extern const char kOnWindowOpened[];
@@ -31,6 +33,7 @@ extern const char kOnControlAction[];
 extern const char kOnTextChanged[];
 extern const char kOnMenuOpened[];
 extern const char kOnMenuClosed[];
+extern const char kOnVolumeChanged[];
 
 // Types of controls that can receive accessibility events
 extern const char kTypeButton[];
@@ -43,6 +46,7 @@ extern const char kTypeMenuItem[];
 extern const char kTypeRadioButton[];
 extern const char kTypeTab[];
 extern const char kTypeTextBox[];
+extern const char kTypeVolume[];
 extern const char kTypeWindow[];
 
 };  // namespace extension_accessibility_api_constants

chrome/common/chrome_notification_types.h

@@ -626,6 +626,11 @@ enum {
   // Details will be an AccessibilityMenuInfo.
   NOTIFICATION_ACCESSIBILITY_MENU_CLOSED,
 
+  // Notification that the volume was changed, for propagating
+  // to an accessibility extension.
+  // Details will be an AccessibilityVolumeInfo.
+  NOTIFICATION_ACCESSIBILITY_VOLUME_CHANGED,
+
   // Content Settings --------------------------------------------------------
 
   // Sent when content settings change. The source is a HostContentSettings

chrome/common/extensions/api/extension_api.json

@@ -382,6 +382,15 @@
           "selectionStart": {"type": "integer", "description": "The index of the character where the selection starts, if this control contains editable text."},
           "selectionEnd": {"type": "integer", "description": "The index of the character where the selection ends, if this control contains editable text."}
         }
+      },
+      {
+        "id": "AccessibilityVolumeInfo",
+        "type": "object",
+        "description": "Information about the volume.",
+        "properties": {
+          "volume": {"type": "double", "description": "The value of the volume percent. This must be between 0.0 and 100.0."},
+          "isVolumeMuted": {"type": "boolean", "description": "True if the volume is muted."}
+        }
       }
     ],
     "functions": [
@@ -503,6 +512,18 @@
             "description": "Information about the menu that was closed."
           }
         ]
+      },
+      {
+        "name": "onVolumeChanged",
+        "type": "function",
+        "description": "Fired when the volume is changed.",
+        "parameters": [
+          {
+            "$ref": "AccessibilityVolumeInfo",
+            "name": "volume",
+            "description": "Information about the current state of the system volume control, including whether it is muted."
+          }
+        ]
       }
     ]
   },