| // Copyright 2018 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_TOUCHPAD_PINCH_EVENT_QUEUE_H_ |
| #define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCHPAD_PINCH_EVENT_QUEUE_H_ |
| |
| #include <memory> |
| |
| #include "base/containers/circular_deque.h" |
| #include "base/optional.h" |
| #include "content/common/content_export.h" |
| #include "content/common/input/event_with_latency_info.h" |
| #include "content/public/common/input_event_ack_source.h" |
| #include "content/public/common/input_event_ack_state.h" |
| #include "third_party/blink/public/platform/web_input_event.h" |
| |
| namespace ui { |
| class LatencyInfo; |
| } // namespace ui |
| |
| namespace content { |
| |
| class QueuedTouchpadPinchEvent; |
| |
| // Interface with which TouchpadPinchEventQueue can forward synthetic mouse |
| // wheel events and notify of pinch events. |
| class CONTENT_EXPORT TouchpadPinchEventQueueClient { |
| public: |
| virtual ~TouchpadPinchEventQueueClient() = default; |
| |
| virtual void SendMouseWheelEventForPinchImmediately( |
| const MouseWheelEventWithLatencyInfo& event) = 0; |
| virtual void OnGestureEventForPinchAck( |
| const GestureEventWithLatencyInfo& event, |
| InputEventAckSource ack_source, |
| InputEventAckState ack_result) = 0; |
| }; |
| |
| // A queue for sending synthetic mouse wheel events for touchpad pinches. |
| // In order for a page to prevent touchpad pinch zooming, we send synthetic |
| // wheel events which may be cancelled. Once we've determined whether a page |
| // has prevented the pinch, the TouchpadPinchEventQueueClient may proceed with |
| // handling the pinch. |
| // See README.md for further details. |
| class CONTENT_EXPORT TouchpadPinchEventQueue { |
| public: |
| // The |client| must outlive the TouchpadPinchEventQueue. |
| TouchpadPinchEventQueue(TouchpadPinchEventQueueClient* client); |
| ~TouchpadPinchEventQueue(); |
| |
| // Adds the given touchpad pinch |event| to the queue. The event may be |
| // coalesced with previously queued events. |
| void QueueEvent(const GestureEventWithLatencyInfo& event); |
| |
| // Notifies the queue that a synthetic mouse wheel event has been processed |
| // by the renderer. |
| void ProcessMouseWheelAck(InputEventAckSource ack_source, |
| InputEventAckState ack_result, |
| const ui::LatencyInfo& latency_info); |
| |
| bool has_pending() const WARN_UNUSED_RESULT; |
| |
| private: |
| void TryForwardNextEventToRenderer(); |
| |
| const bool touchpad_async_pinch_events_; |
| TouchpadPinchEventQueueClient* client_; |
| |
| base::circular_deque<std::unique_ptr<QueuedTouchpadPinchEvent>> pinch_queue_; |
| std::unique_ptr<QueuedTouchpadPinchEvent> pinch_event_awaiting_ack_; |
| base::Optional<bool> first_event_prevented_; |
| |
| DISALLOW_COPY_AND_ASSIGN(TouchpadPinchEventQueue); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCHPAD_PINCH_EVENT_QUEUE_H_ |