[Android] Select text when stylus first button is pressed.

content/browser/renderer_host/input/gesture_text_selector.h

+// Copyright 2014 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.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_GESTURE_TEXT_SELECTOR_H_
+#define CONTENT_BROWSER_RENDERER_HOST_INPUT_GESTURE_TEXT_SELECTOR_H_
+
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "content/common/content_export.h"
+
+namespace ui {
+struct GestureEventData;
+class MotionEvent;
+}
+
+namespace content {
+class GestureTextSelectorTest;
+
+// Interface with which GestureTextSelector can select, unselect, or show
+// selection handles.
+class CONTENT_EXPORT GestureTextSelectorClient {
+ public:
+  virtual ~GestureTextSelectorClient() {}
+
+  virtual void ShowSelectionHandlesAutomatically() = 0;
+  virtual void SelectRange(float x1, float y1, float x2, float y2) = 0;
+  virtual void Unselect() = 0;
+};
+
+// A class to handle gesture-based text selection, such as when clicking first
+// button on stylus input.
+class CONTENT_EXPORT GestureTextSelector {
+ public:
+  explicit GestureTextSelector(GestureTextSelectorClient* client);
+  virtual ~GestureTextSelector();
+
+  // This should be called after gesture detection but before associated
+  // gestures are dispatched. Returns whether it will consume |event|.
+  bool OnTouchEvent(const ui::MotionEvent& event);
+
+  // Returns whether it will consume the event.
+  bool OnGestureEvent(const ui::GestureEventData& gesture);
+
+ private:
+  friend class GestureTextSelectorTest;
+  FRIEND_TEST_ALL_PREFIXES(GestureTextSelectorTest,
+                           ShouldStartTextSelection);
+
+  static bool ShouldStartTextSelection(const ui::MotionEvent& event);
+
+  GestureTextSelectorClient* client_;
+  bool text_selection_triggered_;
+  float anchor_x_;
+  float anchor_y_;
+
+  DISALLOW_COPY_AND_ASSIGN(GestureTextSelector);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_GESTURE_TEXT_SELECTOR_H_