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      1 // Copyright 2014 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "ui/events/gestures/gesture_provider_aura.h"
      6 
      7 #include "base/auto_reset.h"
      8 #include "base/logging.h"
      9 #include "ui/events/event.h"
     10 #include "ui/events/gesture_detection/gesture_config_helper.h"
     11 #include "ui/events/gesture_detection/gesture_event_data.h"
     12 #include "ui/events/gestures/gesture_configuration.h"
     13 
     14 namespace ui {
     15 
     16 GestureProviderAura::GestureProviderAura(GestureProviderAuraClient* client)
     17     : client_(client),
     18       filtered_gesture_provider_(ui::DefaultGestureProviderConfig(), this),
     19       handling_event_(false) {
     20   filtered_gesture_provider_.SetDoubleTapSupportForPlatformEnabled(false);
     21 }
     22 
     23 GestureProviderAura::~GestureProviderAura() {}
     24 
     25 bool GestureProviderAura::OnTouchEvent(const TouchEvent& event) {
     26   int index = pointer_state_.FindPointerIndexOfId(event.touch_id());
     27   bool pointer_id_is_active = index != -1;
     28 
     29   if (event.type() == ET_TOUCH_PRESSED && pointer_id_is_active) {
     30     // Ignore touch press events if we already believe the pointer is down.
     31     return false;
     32   } else if (event.type() != ET_TOUCH_PRESSED && !pointer_id_is_active) {
     33     // We could have an active touch stream transfered to us, resulting in touch
     34     // move or touch up events without associated touch down events. Ignore
     35     // them.
     36     return false;
     37   }
     38 
     39   // If this is a touchmove event, and it isn't different from the last
     40   // event, ignore it.
     41   if (event.type() == ET_TOUCH_MOVED &&
     42       event.x() == pointer_state_.GetX(index) &&
     43       event.y() == pointer_state_.GetY(index)) {
     44     return false;
     45   }
     46 
     47   last_touch_event_latency_info_ = *event.latency();
     48   pointer_state_.OnTouch(event);
     49 
     50   bool result = filtered_gesture_provider_.OnTouchEvent(pointer_state_);
     51   pointer_state_.CleanupRemovedTouchPoints(event);
     52   return result;
     53 }
     54 
     55 void GestureProviderAura::OnTouchEventAck(bool event_consumed) {
     56   DCHECK(pending_gestures_.empty());
     57   DCHECK(!handling_event_);
     58   base::AutoReset<bool> handling_event(&handling_event_, true);
     59   filtered_gesture_provider_.OnTouchEventAck(event_consumed);
     60   last_touch_event_latency_info_.Clear();
     61 }
     62 
     63 void GestureProviderAura::OnGestureEvent(
     64     const GestureEventData& gesture) {
     65   GestureEventDetails details = gesture.details;
     66   details.set_oldest_touch_id(gesture.motion_event_id);
     67 
     68   if (gesture.type() == ET_GESTURE_TAP) {
     69     int tap_count = 1;
     70     if (previous_tap_ && IsConsideredDoubleTap(*previous_tap_, gesture))
     71       tap_count = 1 + (previous_tap_->details.tap_count() % 3);
     72     details.set_tap_count(tap_count);
     73     if (!previous_tap_)
     74       previous_tap_.reset(new GestureEventData(gesture));
     75     else
     76       *previous_tap_ = gesture;
     77     previous_tap_->details = details;
     78   } else if (gesture.type() == ET_GESTURE_TAP_CANCEL) {
     79     previous_tap_.reset();
     80   }
     81 
     82   scoped_ptr<ui::GestureEvent> event(
     83       new ui::GestureEvent(gesture.x,
     84                            gesture.y,
     85                            gesture.flags,
     86                            gesture.time - base::TimeTicks(),
     87                            details));
     88 
     89   ui::LatencyInfo* gesture_latency = event->latency();
     90 
     91   gesture_latency->CopyLatencyFrom(
     92       last_touch_event_latency_info_,
     93       ui::INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT);
     94   gesture_latency->CopyLatencyFrom(
     95       last_touch_event_latency_info_,
     96       ui::INPUT_EVENT_LATENCY_UI_COMPONENT);
     97   gesture_latency->CopyLatencyFrom(
     98       last_touch_event_latency_info_,
     99       ui::INPUT_EVENT_LATENCY_ACKED_TOUCH_COMPONENT);
    100 
    101   if (!handling_event_) {
    102     // Dispatching event caused by timer.
    103     client_->OnGestureEvent(event.get());
    104   } else {
    105     // Memory managed by ScopedVector pending_gestures_.
    106     pending_gestures_.push_back(event.release());
    107   }
    108 }
    109 
    110 ScopedVector<GestureEvent>* GestureProviderAura::GetAndResetPendingGestures() {
    111   if (pending_gestures_.empty())
    112     return NULL;
    113   // Caller is responsible for deleting old_pending_gestures.
    114   ScopedVector<GestureEvent>* old_pending_gestures =
    115       new ScopedVector<GestureEvent>();
    116   old_pending_gestures->swap(pending_gestures_);
    117   return old_pending_gestures;
    118 }
    119 
    120 bool GestureProviderAura::IsConsideredDoubleTap(
    121     const GestureEventData& previous_tap,
    122     const GestureEventData& current_tap) const {
    123   if (current_tap.time - previous_tap.time >
    124       base::TimeDelta::FromMilliseconds(
    125           ui::GestureConfiguration::max_seconds_between_double_click() *
    126           1000)) {
    127     return false;
    128   }
    129 
    130   double double_tap_slop_square =
    131       GestureConfiguration::max_distance_between_taps_for_double_tap();
    132   double_tap_slop_square *= double_tap_slop_square;
    133   const float delta_x = previous_tap.x - current_tap.x;
    134   const float delta_y = previous_tap.y - current_tap.y;
    135   return (delta_x * delta_x + delta_y * delta_y < double_tap_slop_square);
    136 }
    137 
    138 }  // namespace content
    139