Check if Button is pressed for changing selection

content/browser/renderer_host/input/gesture_text_selector.cc

 // 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.
 
 #include "content/browser/renderer_host/input/gesture_text_selector.h"
 
 #include "ui/events/event_constants.h"
 #include "ui/events/gesture_detection/gesture_config_helper.h"
 #include "ui/events/gesture_detection/gesture_detector.h"
 #include "ui/events/gesture_detection/motion_event.h"
@@ skipping 16 matching lines @@
       new ui::GestureDetector(config, listener, null_double_tap_listener));
   detector->set_longpress_enabled(false);
   detector->set_showpress_enabled(false);
 
   return detector.Pass();
 }
 
 }  // namespace
 
 GestureTextSelector::GestureTextSelector(GestureTextSelectorClient* client)
-    : client_(client), text_selection_triggered_(false) {
+    : client_(client),
+      text_selection_triggered_(false),
+      secondary_button_pressed_(false),
+      anchor_x_(0.0f),
+      anchor_y_(0.0f) {
   DCHECK(client);
 }
 
 GestureTextSelector::~GestureTextSelector() {
 }
 
 bool GestureTextSelector::OnTouchEvent(const MotionEvent& event) {
   if (event.GetAction() == MotionEvent::ACTION_DOWN) {
     // Only trigger selection on ACTION_DOWN to prevent partial touch or gesture
     // sequences from being forwarded.
     text_selection_triggered_ = ShouldStartTextSelection(event);
+    secondary_button_pressed_ =
+        event.GetButtonState() == MotionEvent::BUTTON_SECONDARY;
+    anchor_x_ = event.GetX();
+    anchor_y_ = event.GetY();
   }
 
   if (!text_selection_triggered_)
     return false;
 
+  if (event.GetAction() == MotionEvent::ACTION_MOVE) {
+    secondary_button_pressed_ =
+        event.GetButtonState() == MotionEvent::BUTTON_SECONDARY;
+    if (!secondary_button_pressed_) {
+      anchor_x_ = event.GetX();
+      anchor_y_ = event.GetY();
+    }
+  }
+
   if (!gesture_detector_)
     gesture_detector_ = CreateGestureDetector(this);
 
   gesture_detector_->OnTouchEvent(event);
 
   // Always return true, even if |gesture_detector_| technically doesn't
   // consume the event, to prevent a partial touch stream from being forwarded.
   return true;
 }
 
 bool GestureTextSelector::OnSingleTapUp(const MotionEvent& e) {
   DCHECK(text_selection_triggered_);
   client_->LongPress(e.GetEventTime(), e.GetX(), e.GetY());
   return true;
 }
 
 bool GestureTextSelector::OnScroll(const MotionEvent& e1,
                                    const MotionEvent& e2,
                                    float distance_x,
                                    float distance_y) {
   DCHECK(text_selection_triggered_);
+
+  // Return if Stylus button is not pressed.
+  if (!secondary_button_pressed_)
+    return true;
+
   // TODO(changwan): check if we can show handles after the scroll finishes
   // instead. Currently it is not possible as ShowSelectionHandles should
   // be called before we change the selection.
   client_->ShowSelectionHandlesAutomatically();
-  client_->SelectRange(e1.GetX(), e1.GetY(), e2.GetX(), e2.GetY());
+  client_->SelectRange(anchor_x_, anchor_y_, e2.GetX(), e2.GetY());
   return true;
 }
 
 // static
 bool GestureTextSelector::ShouldStartTextSelection(const MotionEvent& event) {
   DCHECK_GT(event.GetPointerCount(), 0u);
   // Currently we are supporting stylus-only cases.
   const bool is_stylus = event.GetToolType(0) == MotionEvent::TOOL_TYPE_STYLUS;
   const bool is_only_secondary_button_pressed =
       event.GetButtonState() == MotionEvent::BUTTON_SECONDARY;
   return is_stylus && is_only_secondary_button_pressed;
 }
 
 }  // namespace content