Listen for tab close notifications and cancel active speech sessions.

chrome/browser/speech/speech_input_bubble_controller.cc

Index: chrome/browser/speech/speech_input_bubble_controller.cc
diff --git a/chrome/browser/speech/speech_input_bubble_controller.cc b/chrome/browser/speech/speech_input_bubble_controller.cc
index 682d0283d27bc4ebbea220175f1e754ccecbb4c0..f17342c5813648a8daf19315c80d6e203a767561 100644
--- a/chrome/browser/speech/speech_input_bubble_controller.cc
+++ b/chrome/browser/speech/speech_input_bubble_controller.cc
@@ -7,13 +7,17 @@
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/tab_contents/tab_util.h"
+#include "chrome/common/notification_registrar.h"
+#include "chrome/common/notification_source.h"
+#include "chrome/common/notification_type.h"
 #include "gfx/rect.h"
 
 namespace speech_input {
 
 SpeechInputBubbleController::SpeechInputBubbleController(Delegate* delegate)
     : delegate_(delegate),
-      current_bubble_caller_id_(0) {
+      current_bubble_caller_id_(0),
+      registrar_(new NotificationRegistrar) {
 }
 
 SpeechInputBubbleController::~SpeechInputBubbleController() {
@@ -43,6 +47,16 @@ void SpeechInputBubbleController::CreateBubble(int caller_id,
     return;
 
   bubbles_[caller_id] = bubble;
+
+  // If this is the first bubble in our list for this TabContents, register

[hans, 2011/01/06 12:30:54]

"First in our list", but the call is to IsOnlyBubbleForTab, and the comment for
that says "only bubble in list"..

+  // for notifications when the tab closes. This ensures that we can safely
+  // kill the bubble and recording session even if the user clicked on the
+  // speech button and immediately closes the tab, or if the tab crashes in

[bulach, 2011/01/06 12:32:39]

s/in the somewhere/

+  // the somewhere while the bubble & recording are active.

[hans, 2011/01/06 12:30:54]

nit: "crashes in the somewhere" sounds weird

+  if (IsOnlyBubbleForTab(caller_id)) {

[bulach, 2011/01/06 12:32:39]

as we chatted, the "IsOnlyBubbleForTab" is the best name, but it's the comments
are split in two places and it makes it slightly less clear to understand..
suggest using something like "ManageNotificationRegistration" on both places
with an enum, and then the comments would be in one single place..

+    registrar_->Add(this, NotificationType::TAB_CONTENTS_DESTROYED,
+                    Source<TabContents>(tab_contents));
+  }
 }
 
 void SpeechInputBubbleController::CloseBubble(int caller_id) {
@@ -70,6 +84,47 @@ void SpeechInputBubbleController::SetBubbleMessage(int caller_id,
   ProcessRequestInUiThread(caller_id, REQUEST_SET_MESSAGE, text, 0);
 }
 
+bool SpeechInputBubbleController::IsOnlyBubbleForTab(int caller_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  TabContents* tab_contents = bubbles_[caller_id]->tab_contents();
+  for (BubbleCallerIdMap::iterator iter = bubbles_.begin();
+       iter != bubbles_.end(); ++iter) {
+    if (iter->second->tab_contents() == tab_contents &&
+        iter->first != caller_id) {
+      // At least one other bubble exists for the same TabContents.

[bulach, 2011/01/06 12:32:39]

yeah, as above, this would be the best place to say something like:
// At least one other bubble exists for the same TabContents,
// no need to register / unregister for the notifications.

+      return false;
+    }
+  }
+  return true;
+}
+
+void SpeechInputBubbleController::Observe(NotificationType type,
+                                          const NotificationSource& source,
+                                          const NotificationDetails& details) {
+  if (type == NotificationType::TAB_CONTENTS_DESTROYED) {
+    // Cancel all bubbles and active recognition sessions for this tab.
+    TabContents* tab_contents = Source<TabContents>(source).ptr();
+    BubbleCallerIdMap::iterator iter = bubbles_.begin();
+    while (iter != bubbles_.end()) {
+      if (iter->second->tab_contents() == tab_contents) {
+        BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+            NewRunnableMethod(
+                this,
+                &SpeechInputBubbleController::InvokeDelegateButtonClicked,
+                iter->first, SpeechInputBubble::BUTTON_CANCEL));
+        CloseBubble(iter->first);
+        // We expect to have a very small number of items in this map so
+        // redo-ing from start is ok.
+        iter = bubbles_.begin();
+      } else {
+        ++iter;
+      }
+    }
+  } else {
+    NOTREACHED() << "Unknown notification";
+  }
+}
+
 void SpeechInputBubbleController::ProcessRequestInUiThread(
     int caller_id, RequestType type, const string16& text, float volume) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
@@ -109,6 +164,12 @@ void SpeechInputBubbleController::ProcessRequestInUiThread(
     case REQUEST_CLOSE:
       if (current_bubble_caller_id_ == caller_id)
         current_bubble_caller_id_ = 0;
+      // If this is the last bubble for this TabContents, unregister from
+      // close notifications.
+      if (IsOnlyBubbleForTab(caller_id)) {
+        registrar_->Remove(this, NotificationType::TAB_CONTENTS_DESTROYED,
+                           Source<TabContents>(bubble->tab_contents()));
+      }
       delete bubble;
       bubbles_.erase(caller_id);
       break;