Support InputMethodManager#updateCursorAnchorInfo for Android 5.0

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 71bde17b44c3d978dee81d1b5c9e99ab48666b4f..62cff944a74e6b2eda1cfe0c4a2b77017b312004 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -19,6 +19,7 @@
 #include "cc/layers/layer.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/output/begin_frame_args.h"
+#include "cc/output/viewport_selection_bound.h"
 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
 #include "content/browser/android/gesture_event_type.h"
 #include "content/browser/android/interstitial_page_delegate_android.h"
@@ -419,7 +420,8 @@ void ContentViewCoreImpl::UpdateFrameInfo(
     const gfx::SizeF& viewport_size,
     const gfx::Vector2dF& controls_offset,
     const gfx::Vector2dF& content_offset,
-    bool is_mobile_optimized_hint) {
+    bool is_mobile_optimized_hint,
+    const cc::ViewportSelectionBound& selection_start) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
   if (obj.is_null() || !window_android_)
@@ -430,6 +432,25 @@ void ContentViewCoreImpl::UpdateFrameInfo(
 
   page_scale_ = page_scale_factor;
 
+  // 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

[Ted C, 2016/03/07 21:31:45]

While I think this comment is informative, it seems a bit too details for the
code.

I think this is sufficient:
"The CursorAnchorInfo API in Android only support zero width selection bounds"

The other things can live in the crbug, but here it's not very actionable.

[kinaba, 2016/03/10 06:24:12]

Done.

+  // 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 jboolean has_insertion_marker =
+      selection_start.type == cc::SELECTION_BOUND_CENTER;

[Ted C, 2016/03/07 21:31:45]

I assume SELECTION_BOUND_CENTER is the only bit that is needed to determine a
zero width selection bounds?

[kinaba, 2016/03/10 06:24:12]

Yes.
To be precice it's an enum with 4 possible values
{LEFT=0,RIGHT=1,CENTER=2,EMPTY=3} not a bitmasks.
LEFT/RIGHT means ranged selection and EMPTY for no selection; CENTER is the one
corresponding to zero-width.

+  const jboolean is_insertion_marker_visible = selection_start.visible;
+  const jfloat insertion_marker_horizontal =
+      has_insertion_marker ? selection_start.edge_top.x() : 0.0f;
+  const jfloat insertion_marker_top =
+      has_insertion_marker ? selection_start.edge_top.y() : 0.0f;
+  const jfloat insertion_marker_bottom =
+      has_insertion_marker ? selection_start.edge_bottom.y() : 0.0f;
+
   Java_ContentViewCore_updateFrameInfo(
       env, obj.obj(),
       scroll_offset.x(),
@@ -443,7 +464,12 @@ void ContentViewCoreImpl::UpdateFrameInfo(
       viewport_size.height(),
       controls_offset.y(),
       content_offset.y(),
-      is_mobile_optimized_hint);
+      is_mobile_optimized_hint,
+      has_insertion_marker,
+      is_insertion_marker_visible,
+      insertion_marker_horizontal,
+      insertion_marker_top,
+      insertion_marker_bottom);
 }
 
 void ContentViewCoreImpl::SetTitle(const base::string16& title) {