Proposed alternative for supporting ChromeVox keyboard commands.

chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc

Index: chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
diff --git a/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc b/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a1c1120ca4ce192df1d007239e58a3ba984be47e
--- /dev/null
+++ b/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
@@ -0,0 +1,72 @@
+// Copyright 2015 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 "chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.h"
+
+#include <string>
+
+#include "base/values.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/common/extensions/api/commands/commands_handler.h"
+#include "chrome/common/extensions/extension_constants.h"
+#include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry.h"
+#include "ui/events/event.h"
+
+SpokenFeedbackEventRewriter::SpokenFeedbackEventRewriter() {
+}
+
+SpokenFeedbackEventRewriter::~SpokenFeedbackEventRewriter() {
+}
+
+ui::EventRewriteStatus SpokenFeedbackEventRewriter::RewriteEvent(
+    const ui::Event& event,
+    scoped_ptr<ui::Event>* new_event) {
+  if (!chromeos::AccessibilityManager::Get()->IsSpokenFeedbackEnabled() ||
+      event.type() != ui::ET_KEY_PRESSED ||
+      !g_browser_process->profile_manager())
+    return ui::EVENT_REWRITE_CONTINUE;
+
+  content::BrowserContext* context =
+      g_browser_process->profile_manager()->GetLastUsedProfile();
+
+  const extensions::Extension* extension =
+      extensions::ExtensionRegistry::Get(context)->enabled_extensions().GetByID(
+          extension_misc::kChromeVoxExtensionId);

[Finnur, 2015/06/16 11:29:49]

if (!extension)
  return ui::EVENT_REWRITE_CONTINUE;

GetNamedCommands does not support nullptr being passed in.

[David Tseng, 2015/06/16 15:31:36]

Done.

+  const extensions::CommandMap* commands =
+      extensions::CommandsInfo::GetNamedCommands(extension);
+  if (!commands)
+    return ui::EVENT_REWRITE_CONTINUE;
+
+  const ui::KeyEvent key_event = static_cast<const ui::KeyEvent&>(event);
+  std::string command_name;
+  for (extensions::CommandMap::const_iterator iter = commands->begin();
+       iter != commands->end(); ++iter) {
+    if (iter->second.accelerator().key_code() == key_event.key_code() &&
+        iter->second.accelerator().modifiers() == key_event.flags())
+      command_name = iter->second.command_name();
+  }
+
+  if (command_name.empty())
+    return ui::EVENT_REWRITE_CONTINUE;
+
+  scoped_ptr<base::ListValue> args(new base::ListValue());
+  args->Append(new base::StringValue(command_name));
+
+  scoped_ptr<extensions::Event> extension_event(
+      new extensions::Event("commands.onCommand", args.Pass()));
+
+  extensions::EventRouter::Get(context)->DispatchEventToExtension(
+      extension_misc::kChromeVoxExtensionId, extension_event.Pass());

[Finnur, 2015/06/16 11:29:48]

The ExtensionKeybindingRegistry uses:

  event->restrict_to_browser_context = browser_context_;
  event->user_gesture = EventRouter::USER_GESTURE_ENABLED;

Wondering if you'd benefit from one or both of those? I know restricting to a
browser context was a problem before (because the context didn't match what you
needed it to). But now it should, right?

I mention the user-gesture one just so you are aware of it -- not as an action
item to add it even if you don't need it. If things work for you as is then you
are probably better off not using it. But if you find things breaking then it is
at least fresh in your head.

[David Tseng, 2015/06/16 15:31:37]

Added. Yes; with the last profile/context logic this is working in all the
places I need.
Great; I'll keep that in mind.

+
+  return ui::EVENT_REWRITE_DISCARD;
+}
+
+ui::EventRewriteStatus SpokenFeedbackEventRewriter::NextDispatchEvent(
+    const ui::Event& last_event,
+    scoped_ptr<ui::Event>* new_event) {
+  return ui::EVENT_REWRITE_CONTINUE;
+}