Defect 248426: Speak rendered text when no selection is made on Mac

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index 34ff9bff0c4c67ba9027a346fffa47bac8f3e303..2ce4f9c2a1d059e9e4865c613aaf7efaf40c39e3 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -151,6 +151,7 @@ static BOOL SupportsBackingPropertiesChangedNotification() {
 - (void)updateScreenProperties;
 - (void)setResponderDelegate:
         (NSObject<RenderWidgetHostViewMacDelegate>*)delegate;
+- (void)speakText:(NSString*)text;
 @end
 
 // A window subclass that allows the fullscreen window to become main and gain
@@ -654,6 +655,8 @@ bool RenderWidgetHostViewMac::OnMessageReceived(const IPC::Message& message) {
   IPC_BEGIN_MESSAGE_MAP(RenderWidgetHostViewMac, message)
     IPC_MESSAGE_HANDLER(ViewHostMsg_PluginFocusChanged, OnPluginFocusChanged)
     IPC_MESSAGE_HANDLER(ViewHostMsg_StartPluginIme, OnStartPluginIme)
+    IPC_MESSAGE_HANDLER(ViewMsg_GetRenderedTextCompleted,
+        OnGetRenderedTextCompleted)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -1080,8 +1083,19 @@ bool RenderWidgetHostViewMac::SupportsSpeech() const {
 }
 
 void RenderWidgetHostViewMac::SpeakSelection() {
-  if ([NSApp respondsToSelector:@selector(speakString:)])
-    [NSApp speakString:base::SysUTF8ToNSString(selected_text_)];
+  if (![NSApp respondsToSelector:@selector(speakString:)])
+    return;
+
+  if (selected_text_.empty() && render_widget_host_) {
+    // If there's no selection, speak all text. Send an asynchronous IPC
+    // request for all the text in the webcontents.
+    // ViewMsg_GetRenderedTextCompleted is sent back to IPC Message receiver.
+    render_widget_host_->Send(new ViewMsg_GetRenderedText(
+        render_widget_host_->GetRoutingID()));
+    return;
+  }
+
+  [cocoa_view_ speakText:base::SysUTF8ToNSString(selected_text_)];
 }
 
 bool RenderWidgetHostViewMac::IsSpeaking() const {
@@ -2101,6 +2115,15 @@ void RenderWidgetHostViewMac::OnStartPluginIme() {
   [cocoa_view_ setPluginImeActive:YES];
 }
 
+void RenderWidgetHostViewMac::OnGetRenderedTextCompleted(
+    const std::string& text) {
+  // Let TTS speak the text returned from call back
+  if (text.empty())

[dcheng, 2014/08/06 02:09:28]

Why does the empty case need special handling?

+    return;
+
+  [cocoa_view_ speakText:base::SysUTF8ToNSString(text)];
+}
+
 gfx::Rect RenderWidgetHostViewMac::GetScaledOpenGLPixelRect(
     const gfx::Rect& rect) {
   gfx::Rect src_gl_subrect = rect;
@@ -2942,6 +2965,10 @@ void RenderWidgetHostViewMac::AcceleratedLayerDidDrawFrame(bool succeeded) {
   }
 }
 
+- (void)speakText:(NSString *) text {

[dcheng, 2014/08/06 02:09:28]

NSString*

+  [NSApp speakString:text];
+}
+
 - (void)viewWillMoveToWindow:(NSWindow*)newWindow {
   NSWindow* oldWindow = [self window];