The first step for enabling off-the-spot IME on Pepper on ChromeOS/Linux.

chrome/browser/renderer_host/gtk_im_context_wrapper.cc

Index: chrome/browser/renderer_host/gtk_im_context_wrapper.cc
diff --git a/chrome/browser/renderer_host/gtk_im_context_wrapper.cc b/chrome/browser/renderer_host/gtk_im_context_wrapper.cc
index fc46a9861fb2dac3feec2e416bb67b7ace7bee9f..f6741bce8c41b5c107ab5093d0ba22677df64549 100644
--- a/chrome/browser/renderer_host/gtk_im_context_wrapper.cc
+++ b/chrome/browser/renderer_host/gtk_im_context_wrapper.cc
@@ -61,6 +61,7 @@ GtkIMContextWrapper::GtkIMContextWrapper(RenderWidgetHostViewGtk* host_view)
       context_(gtk_im_multicontext_new()),
       context_simple_(gtk_im_context_simple_new()),
       is_focused_(false),
+      is_ppapi_plugin_focused_(false),
       is_composing_text_(false),
       is_enabled_(false),
       is_in_key_event_handler_(false),
@@ -227,6 +228,9 @@ void GtkIMContextWrapper::ProcessKeyEvent(GdkEventKey* event) {
 
 void GtkIMContextWrapper::UpdateInputMethodState(WebKit::WebTextInputType type,
                                                  const gfx::Rect& caret_rect) {
+  text_input_type_ =  type;
+  caret_rect_ = caret_rect;
+
   suppress_next_commit_ = false;
 
   // The renderer has updated its IME status.
@@ -236,7 +240,9 @@ void GtkIMContextWrapper::UpdateInputMethodState(WebKit::WebTextInputType type,
 
   DCHECK(!is_in_key_event_handler_);
 
-  bool is_enabled = (type == WebKit::WebTextInputTypeText);
+  // If the focus is on a editable text, or on a PPAPI plugin, turn IME on.
+  bool is_enabled = (type == WebKit::WebTextInputTypeText)
+                    || is_ppapi_plugin_focused_;

[kochi, 2011/05/25 06:19:44]

Put || in the end of the previous line, rather than this line.

See
http://dev.chromium.org/developers/coding-style
"Code formatting"

[kinaba, 2011/05/25 22:23:53]

The whole change here is removed from the patch set 2.
Thank you for the pointer. I'll read it carefully.

   if (is_enabled_ != is_enabled) {
     is_enabled_ = is_enabled;
     if (is_enabled)
@@ -309,6 +315,14 @@ void GtkIMContextWrapper::OnFocusOut() {
     host_view_->GetRenderWidgetHost()->SetInputMethodActive(false);
 }
 
+void GtkIMContextWrapper::OnPpapiPluginFocusChanged(bool focused) {
+  if (focused != is_ppapi_plugin_focused_) {
+    is_ppapi_plugin_focused_ = focused;
+    UpdateInputMethodState(text_input_type_, caret_rect_);
+  }
+}
+
+
 #if !defined(TOOLKIT_VIEWS)
 // Not defined for views because the views context menu doesn't
 // implement input methods yet.
@@ -457,12 +471,17 @@ void GtkIMContextWrapper::ProcessInputMethodResult(const GdkEventKey* event,
       is_composing_text_ = true;
       // TODO(suzhe): convert both renderer_host and renderer to use
       // ui::CompositionText.
-      const std::vector<WebKit::WebCompositionUnderline>& underlines =
-          reinterpret_cast<const std::vector<WebKit::WebCompositionUnderline>&>(
-              composition_.underlines);
-      host->ImeSetComposition(composition_.text, underlines,
-                              composition_.selection.start(),
-                              composition_.selection.end());
+
+      // For now, if a PPAPI plugin is focused, we don't send ImeSetCompostion.

[kochi, 2011/05/25 06:19:44]

"For now" sounds ambiguous for any future reference on this
comment.

TODO(kinaba): (what you want to do in the future)

is preferred.

That said, as the similar comments appear in the following lines, how about one
TODO() comment on line 243 to cover why we want to special case PPAPI only?

For this instance, "if a PPAPI plugin is focused, we don't send
ImeSetComposition" says exactly what code does and adds not much information
than the code itself.  Please describe why we have to exclude PPAPI here.

[kinaba, 2011/05/25 22:23:53]

Done (the code is moved to content/renderer/render_view.cc:3951).

+      if (!is_ppapi_plugin_focused_) {
+        const std::vector<WebKit::WebCompositionUnderline>& underlines =
+            reinterpret_cast<
+                const std::vector<WebKit::WebCompositionUnderline>&>(
+                    composition_.underlines);
+        host->ImeSetComposition(composition_.text, underlines,
+                                composition_.selection.start(),
+                                composition_.selection.end());
+      }
     } else if (!committed) {
       host->ImeCancelComposition();
     }
@@ -502,7 +521,19 @@ void GtkIMContextWrapper::HandleCommit(const string16& text) {
   if (!is_in_key_event_handler_ && host_view_->GetRenderWidgetHost()) {
     // Workaround http://crbug.com/45478 by sending fake key down/up events.
     SendFakeCompositionKeyEvent(WebKit::WebInputEvent::RawKeyDown);
-    host_view_->GetRenderWidgetHost()->ImeConfirmComposition(text);
+    if (is_ppapi_plugin_focused_) {
+      // For now, if a PPAPI plugin is focused, we directly emit character
+      // events, instead of sending renderer an IME event.

[kochi, 2011/05/25 06:19:44]

For now -> TODO().

E.g. TODO(kinaba): Until PPAPI has an interface for sending an IME event, we
send character events.

[kinaba, 2011/05/25 22:23:53]

Done (the code is moved to content/renderer/render_view.cc:3967).

+      for (size_t i = 0; i<commit_text_.size(); ++i) {

[kochi, 2011/05/25 06:19:44]

Style nit: spaces around "<".

[kinaba, 2011/05/25 22:23:53]

Done (the code is moved to content/renderer/render_view.cc:3969).

+        NativeWebKeyboardEvent char_event(commit_text_[i],
+                                          0,
+                                          base::Time::Now().ToDoubleT());
+        char_event.skip_in_browser = true;
+        host_view_->ForwardKeyboardEvent(char_event);
+      }
+    } else {
+      host_view_->GetRenderWidgetHost()->ImeConfirmComposition(text);
+    }
     SendFakeCompositionKeyEvent(WebKit::WebInputEvent::KeyUp);
   }
 }
@@ -545,14 +576,17 @@ void GtkIMContextWrapper::HandlePreeditChanged(const gchar* text,
       host_view_->GetRenderWidgetHost()) {
     // Workaround http://crbug.com/45478 by sending fake key down/up events.
     SendFakeCompositionKeyEvent(WebKit::WebInputEvent::RawKeyDown);
-    // TODO(suzhe): convert both renderer_host and renderer to use
-    // ui::CompositionText.
-    const std::vector<WebKit::WebCompositionUnderline>& underlines =
-        reinterpret_cast<const std::vector<WebKit::WebCompositionUnderline>&>(
-            composition_.underlines);
-    host_view_->GetRenderWidgetHost()->ImeSetComposition(
-        composition_.text, underlines, composition_.selection.start(),
-        composition_.selection.end());
+    // For now, if a PPAPI plugin is focused, we don't send ImeSetComposition.

[kochi, 2011/05/25 06:19:44]

Ditto.

[kinaba, 2011/05/25 22:23:53]

Done (content/renderer/render_view.cc:3951).

+    if (!is_ppapi_plugin_focused_) {
+      // TODO(suzhe): convert both renderer_host and renderer to use
+      // ui::CompositionText.
+      const std::vector<WebKit::WebCompositionUnderline>& underlines =
+          reinterpret_cast<const std::vector<WebKit::WebCompositionUnderline>&>(
+              composition_.underlines);
+      host_view_->GetRenderWidgetHost()->ImeSetComposition(
+          composition_.text, underlines, composition_.selection.start(),
+          composition_.selection.end());
+    }
     SendFakeCompositionKeyEvent(WebKit::WebInputEvent::KeyUp);
   }
 }