Support InputMethodManager#updateCursorAnchorInfo for Android 5.0

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 3a2dc883f4031ea824c2b2088f2d1ecfceae9ecb..6f7724801d39df4365a8d3fa665f54bd3a4d8021 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1234,11 +1234,34 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
   if (!content_view_core_)
     return;
 
+  const cc::ViewportSelectionBound& selection_start =
+      frame_metadata.selection_start;
+  const cc::ViewportSelectionBound& selection_end =
+      frame_metadata.selection_start;
   if (selection_controller_) {
-    selection_controller_->OnSelectionBoundsChanged(
-        frame_metadata.selection_start, frame_metadata.selection_end);
+    selection_controller_->OnSelectionBoundsChanged(selection_start,
+                                                    selection_end);
   }
 
+  // We are interested only in zero width selection bounds here because non-zero
+  // width selection bounds cannot be represented in CursorAnchorInfo API in
+  // Android Framework as of API Level 21. Actually supporting non-zero width
+  // selection bounds in CursorAnchorInfo API was once considered in the design
+  // phase of that API, but the idea was abandoned because the IME is still able
+  // to retrieve the same information from the following parameters in
+  // CursorAnchorInfo:
+  // - CursorAnchorInfo#getCharacterBounds and
+  // - CursorAnchorInfo#getSelection{Start, End}.
+  const bool has_insertion_marker =
+      selection_start.type == cc::SELECTION_BOUND_CENTER &&
+      selection_end.type == cc::SELECTION_BOUND_CENTER;
+  const float insertion_marker_x =
+      has_insertion_marker ? selection_start.edge_top.x() : 0.0f;
+  const float insertion_marker_top =
+      has_insertion_marker ? selection_start.edge_top.y() : 0.0f;
+  const float insertion_marker_bottom =
+      has_insertion_marker ? selection_start.edge_bottom.y() : 0.0f;
+
   // All offsets and sizes are in CSS pixels.
   content_view_core_->UpdateFrameInfo(
       frame_metadata.root_scroll_offset,
@@ -1248,7 +1271,11 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
       frame_metadata.root_layer_size,
       frame_metadata.scrollable_viewport_size,
       frame_metadata.location_bar_offset,
-      frame_metadata.location_bar_content_translation);
+      frame_metadata.location_bar_content_translation,
+      has_insertion_marker,

[jdduke (slow), 2014/11/07 01:47:00]

Do we have to go through ContentViewCore? Can we not feed this directly through
to  ime_adapter_android_?

[aelias_OOO_until_Jul13, 2014/11/07 02:04:29]

I would like to keep this method as more of a dumb passthrough.  Can you plumb
through the entire state of the selection start ViewportSelectionBound and then
do this postprocessing in ContentViewCore.java?  Use this mechanism to use the
enum:
https://groups.google.com/a/chromium.org/forum/#!search/Accessing$20C$2B$2B$2...

[yukawa, 2014/11/12 10:21:50]

Technically we could plumb insertion markers directly to ime_adapter_android,
but we can save one JNI call in the current design.  Basically I'm fine with
either way so let me know if you think we should separate them.

[yukawa, 2014/11/12 10:21:50]

Thank you for the pointer. Done in patch set #4.

+      insertion_marker_x,
+      insertion_marker_top,
+      insertion_marker_bottom);
 #if defined(VIDEO_HOLE)
   if (host_ && host_->IsRenderView()) {
     RenderViewHostImpl* rvhi = static_cast<RenderViewHostImpl*>(