Refactor and send voice interaction structure

components/arc/common/voice_interaction_arc_home.mojom

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Next MinVersion: 1
+
+module arc.mojom;
+
+import "mojo/common/string16.mojom";
+import "screen_rect.mojom";
+
+// Represents the start and end unicode char indices of the selected
+// portion of the text [start, end).
+struct TextSelection {
+  int32 start_selection;
+  int32 end_selection;
+};
+
+// Represents view structure to be passed to ARC. The view
+// structure is synthesized from the AXStructure, which
+// is a simplified representation of the DOM tree. We
+// map each node of the AXStructure into a view element.
+// The naming convention of the fields kept consistent with
+// AccessibilitySnapshotNode.java used in Android Chromium.
+struct VoiceInteractionStructure {
+  // Geometry of the view in pixels
+  ScreenRect rect;
+
+  // Text of the view.
+  mojo.common.mojom.String16 text;
+
+  // Text properties
+  float text_size;
+  int32 color;
+  int32 bgcolor;
+  bool bold;
+  bool italic;
+  bool underline;
+  bool line_through;
+
+  // Selected portion of the text.
+  TextSelection? selection;
+
+  // Fake Android view class name of the element.  Each node is assigned
+  // a closest approximation of Android's views.
+  string class_name;
+
+  // Children of current node
+  array<VoiceInteractionStructure> children;
+};
+
+// Handles voice interaction queries from Android.
+// Next method ID: 1
+interface VoiceInteractionArcHomeHost {
+  // Returns view hierarchy of current window represented as
+  // VoiceInteractionStructure. Returns empty if the request
+  // fails.
+  GetVoiceInteractionStructure@1() => (VoiceInteractionStructure? structure);
+};
+
+// Connects with ArcHome.
+// Next method ID: 1
+interface VoiceInteractionArcHomeInstance {
+  Init@0(VoiceInteractionArcHomeHost host_ptr);
+};