input: Restrict synthetic touch gesture to view bounds.

content/browser/renderer_host/input/synthetic_touchscreen_pinch_gesture.cc

 // Copyright 2013 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/synthetic_touchscreen_pinch_gesture.h"
 
 #include <stdint.h>
 
+#include <algorithm>
 #include <cmath>
 
 #include "base/logging.h"
 #include "ui/events/latency_info.h"
 
 namespace content {
 
 SyntheticTouchscreenPinchGesture::SyntheticTouchscreenPinchGesture(
     const SyntheticPinchGestureParams& params)
     : params_(params),
@@ skipping 70 matching lines @@
     const base::TimeTicks& timestamp) {
   synthetic_pointer_driver_->Press(params_.anchor.x(), start_y_0_, 0);
   synthetic_pointer_driver_->Press(params_.anchor.x(), start_y_1_, 1);
   synthetic_pointer_driver_->DispatchEvent(target, timestamp);
 }
 
 void SyntheticTouchscreenPinchGesture::MoveTouchPoints(
     SyntheticGestureTarget* target,
     float delta,
     const base::TimeTicks& timestamp) {
+  gfx::Size view_size = target->GetViewSize();
   // The two pointers move in opposite directions.
-  float current_y_0 = start_y_0_ + delta;
-  float current_y_1 = start_y_1_ - delta;
+  float current_y_0 = std::max(start_y_0_ + delta, 0.f);
+  float current_y_1 =
+      std::min(start_y_1_ - delta, static_cast<float>(view_size.height() - 1));
 
   synthetic_pointer_driver_->Move(params_.anchor.x(), current_y_0, 0);
   synthetic_pointer_driver_->Move(params_.anchor.x(), current_y_1, 1);
   synthetic_pointer_driver_->DispatchEvent(target, timestamp);
 }
 
 void SyntheticTouchscreenPinchGesture::ReleaseTouchPoints(
     SyntheticGestureTarget* target,
     const base::TimeTicks& timestamp) {
   synthetic_pointer_driver_->Release(0);
@@ skipping 13 matching lines @@
     final_distance_to_anchor =
         (initial_distance_to_anchor + target->GetTouchSlopInDips()) *
         params_.scale_factor;
   } else {  // zooming out
     final_distance_to_anchor = target->GetMinScalingSpanInDips() / 2.0f;
     initial_distance_to_anchor =
         (final_distance_to_anchor / params_.scale_factor) +
         target->GetTouchSlopInDips();
   }
 
-  start_y_0_ = params_.anchor.y() - initial_distance_to_anchor;
-  start_y_1_ = params_.anchor.y() + initial_distance_to_anchor;
+  gfx::Size view_size = target->GetViewSize();
+  start_y_0_ = std::max(params_.anchor.y() - initial_distance_to_anchor, 0.f);
+  start_y_1_ = std::min(params_.anchor.y() + initial_distance_to_anchor,
+                        static_cast<float>(view_size.height() - 1));
 
   max_pointer_delta_0_ = initial_distance_to_anchor - final_distance_to_anchor;
 
   int64_t total_duration_in_us = static_cast<int64_t>(
       1e6 * (static_cast<double>(std::abs(2 * max_pointer_delta_0_)) /
              params_.relative_pointer_speed_in_pixels_s));
   DCHECK_GT(total_duration_in_us, 0);
   stop_time_ =
       start_time_ + base::TimeDelta::FromMicroseconds(total_duration_in_us);
 }
@@ skipping 16 matching lines @@
     const base::TimeTicks& timestamp) const {
   return std::min(timestamp, stop_time_);
 }
 
 bool SyntheticTouchscreenPinchGesture::HasReachedTarget(
     const base::TimeTicks& timestamp) const {
   return timestamp >= stop_time_;
 }
 
 }  // namespace content