components/input/touch_action_filter.h - chromium/src - Git at Google

 // Copyright 2013 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #ifndef COMPONENTS_INPUT_TOUCH_ACTION_FILTER_H_
 #define COMPONENTS_INPUT_TOUCH_ACTION_FILTER_H_

 #include <optional>

 #include "cc/input/touch_action.h"
 #include "base/component_export.h"

 namespace blink {
 class WebGestureEvent;
 }

 namespace content {
 class InputRouterImplTest;
 class InputRouterImplTestBase;
 class MockRenderWidgetHost;
 class SitePerProcessBrowserTouchActionTest;
 } // namespace content

 namespace input {

 enum class FilterGestureEventResult { kAllowed, kFiltered, kDelayed };

 // The TouchActionFilter is responsible for filtering scroll and pinch gesture
 // events according to the CSS touch-action values the renderer has sent for
 // each touch point.
 // For details see the touch-action design doc at http://goo.gl/KcKbxQ.
 class COMPONENT_EXPORT(INPUT) TouchActionFilter {
  public:
   TouchActionFilter();

   TouchActionFilter(const TouchActionFilter&) = delete;
   TouchActionFilter& operator=(const TouchActionFilter&) = delete;

   ~TouchActionFilter();

   // Returns kFiltered if the supplied gesture event should be dropped based on
   // current touch-action state. kDelayed if the |scrolling_touch_action_| has
   // no value. Returns kAllowed, and possibly modifies the event's directional
   // parameters to make the event compatible with the effective touch-action.
   FilterGestureEventResult FilterGestureEvent(
       blink::WebGestureEvent* gesture_event);

   // Called when a set-touch-action message is received from the renderer
   // for a touch start event that is currently in flight.
   void OnSetTouchAction(cc::TouchAction touch_action);

   // Called at the end of a touch action sequence in order to log when a
   // compositor allowed touch action is or is not equivalent to the allowed
   // touch action.
   void ReportAndResetTouchAction();

   // Called when a set-compositor-allowed-touch-action message is received from
   // the renderer for a touch start event that is currently in flight.
   void OnSetCompositorAllowedTouchAction(cc::TouchAction);

   std::optional<cc::TouchAction> allowed_touch_action() const {
     return allowed_touch_action_;
   }

   std::optional<cc::TouchAction> active_touch_action() const {
     return active_touch_action_;
   }

   cc::TouchAction compositor_allowed_touch_action() const {
     return compositor_allowed_touch_action_;
   }

   bool has_touch_event_handler_for_testing() const {
     return has_touch_event_handler_;
   }

   void SetForceEnableZoom(bool enabled) { force_enable_zoom_ = enabled; }

   void OnHasTouchEventHandlers(bool has_handlers);

   void IncreaseActiveTouches();
   void DecreaseActiveTouches();

   void ForceResetTouchActionForTest();

  private:
   friend class content::InputRouterImplTest;
   friend class content::InputRouterImplTestBase;
   friend class content::MockRenderWidgetHost;
   friend class TouchActionFilterTest;
   friend class TouchActionFilterPinchTest;
   friend class content::SitePerProcessBrowserTouchActionTest;

   bool ShouldSuppressScrolling(const blink::WebGestureEvent&,
                                cc::TouchAction touch_action,
                                bool is_active_touch_action);
   FilterGestureEventResult FilterScrollEventAndResetState();
   FilterGestureEventResult FilterPinchEventAndResetState();
   void ResetTouchAction();
   void SetTouchAction(cc::TouchAction touch_action);

   // Whether scroll gestures should be discarded due to touch-action.
   bool drop_scroll_events_ = false;

   // Whether pinch gestures should be discarded due to touch-action.
   bool drop_pinch_events_ = false;

   // Whether a tap ending event in this sequence should be discarded because a
   // previous GestureTapUnconfirmed event was turned into a GestureTap.
   bool drop_current_tap_ending_event_ = false;

   // True iff the touch action of the last TapUnconfirmed or Tap event was
   // TOUCH_ACTION_AUTO. The double tap event depends on the touch action of the
   // previous tap or tap unconfirmed. Only valid between a TapUnconfirmed or Tap
   // and the next DoubleTap.
   bool allow_current_double_tap_event_ = true;

   // Force enable zoom for Accessibility.
   bool force_enable_zoom_ = false;

   // Indicates whether this page has touch event handler or not. Set by
   // InputRouterImpl::OnHasTouchEventHandlers. Default to false because one
   // could not scroll anyways when there is no content, and this is consistent
   // with the default state committed after DocumentLoader::DidCommitNavigation.
   // TODO(savella): Split touch_event_handler into touch_event_handler and
   // non_auto_touch_action.
   bool has_touch_event_handler_ = false;

   // True if an active gesture sequence is in progress. i.e. after GTD and
   // before GSE.
   bool gesture_sequence_in_progress_ = false;

   bool has_deferred_events_ = false;

   // True if scroll gestures are allowed to be used for cursor control. We set
   // this to false if a long press or double press has occurred in the current
   // gesture sequence, to prevent the cursor control feature from interfering
   // with long press drag selection and double press drag selection.
   bool allow_cursor_control_ = true;

   // Increment at receiving ACK for touch start and decrement at touch end.
   int num_of_active_touches_ = 0;

   // What touch actions are currently permitted.
   std::optional<cc::TouchAction> allowed_touch_action_;

   // The touch action that is used for the current gesture sequence. At the
   // touch sequence end, the |allowed_touch_action_| is reset while this remains
   // set as the effective touch action, for the still in progress gesture
   // sequence due to fling.
   std::optional<cc::TouchAction> active_touch_action_;

   // Allowed touch action received from the compositor.
   cc::TouchAction compositor_allowed_touch_action_;
 };

 }  // namespace input

 #endif  // COMPONENTS_INPUT_TOUCH_ACTION_FILTER_H_
	// Copyright 2013 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#ifndef COMPONENTS_INPUT_TOUCH_ACTION_FILTER_H_
	#define COMPONENTS_INPUT_TOUCH_ACTION_FILTER_H_

	#include <optional>

	#include "cc/input/touch_action.h"
	#include "base/component_export.h"

	namespace blink {
	class WebGestureEvent;
	}

	namespace content {
	class InputRouterImplTest;
	class InputRouterImplTestBase;
	class MockRenderWidgetHost;
	class SitePerProcessBrowserTouchActionTest;
	} // namespace content

	namespace input {

	enum class FilterGestureEventResult { kAllowed, kFiltered, kDelayed };

	// The TouchActionFilter is responsible for filtering scroll and pinch gesture
	// events according to the CSS touch-action values the renderer has sent for
	// each touch point.
	// For details see the touch-action design doc at http://goo.gl/KcKbxQ.
	class COMPONENT_EXPORT(INPUT) TouchActionFilter {
	public:
	TouchActionFilter();

	TouchActionFilter(const TouchActionFilter&) = delete;
	TouchActionFilter& operator=(const TouchActionFilter&) = delete;

	~TouchActionFilter();

	// Returns kFiltered if the supplied gesture event should be dropped based on
	// current touch-action state. kDelayed if the \|scrolling_touch_action_\| has
	// no value. Returns kAllowed, and possibly modifies the event's directional
	// parameters to make the event compatible with the effective touch-action.
	FilterGestureEventResult FilterGestureEvent(
	blink::WebGestureEvent* gesture_event);

	// Called when a set-touch-action message is received from the renderer
	// for a touch start event that is currently in flight.
	void OnSetTouchAction(cc::TouchAction touch_action);

	// Called at the end of a touch action sequence in order to log when a
	// compositor allowed touch action is or is not equivalent to the allowed
	// touch action.
	void ReportAndResetTouchAction();

	// Called when a set-compositor-allowed-touch-action message is received from
	// the renderer for a touch start event that is currently in flight.
	void OnSetCompositorAllowedTouchAction(cc::TouchAction);

	std::optional<cc::TouchAction> allowed_touch_action() const {
	return allowed_touch_action_;
	}

	std::optional<cc::TouchAction> active_touch_action() const {
	return active_touch_action_;
	}

	cc::TouchAction compositor_allowed_touch_action() const {
	return compositor_allowed_touch_action_;
	}

	bool has_touch_event_handler_for_testing() const {
	return has_touch_event_handler_;
	}

	void SetForceEnableZoom(bool enabled) { force_enable_zoom_ = enabled; }

	void OnHasTouchEventHandlers(bool has_handlers);

	void IncreaseActiveTouches();
	void DecreaseActiveTouches();

	void ForceResetTouchActionForTest();

	private:
	friend class content::InputRouterImplTest;
	friend class content::InputRouterImplTestBase;
	friend class content::MockRenderWidgetHost;
	friend class TouchActionFilterTest;
	friend class TouchActionFilterPinchTest;
	friend class content::SitePerProcessBrowserTouchActionTest;

	bool ShouldSuppressScrolling(const blink::WebGestureEvent&,
	cc::TouchAction touch_action,
	bool is_active_touch_action);
	FilterGestureEventResult FilterScrollEventAndResetState();
	FilterGestureEventResult FilterPinchEventAndResetState();
	void ResetTouchAction();
	void SetTouchAction(cc::TouchAction touch_action);

	// Whether scroll gestures should be discarded due to touch-action.
	bool drop_scroll_events_ = false;

	// Whether pinch gestures should be discarded due to touch-action.
	bool drop_pinch_events_ = false;

	// Whether a tap ending event in this sequence should be discarded because a
	// previous GestureTapUnconfirmed event was turned into a GestureTap.
	bool drop_current_tap_ending_event_ = false;

	// True iff the touch action of the last TapUnconfirmed or Tap event was
	// TOUCH_ACTION_AUTO. The double tap event depends on the touch action of the
	// previous tap or tap unconfirmed. Only valid between a TapUnconfirmed or Tap
	// and the next DoubleTap.
	bool allow_current_double_tap_event_ = true;

	// Force enable zoom for Accessibility.
	bool force_enable_zoom_ = false;

	// Indicates whether this page has touch event handler or not. Set by
	// InputRouterImpl::OnHasTouchEventHandlers. Default to false because one
	// could not scroll anyways when there is no content, and this is consistent
	// with the default state committed after DocumentLoader::DidCommitNavigation.
	// TODO(savella): Split touch_event_handler into touch_event_handler and
	// non_auto_touch_action.
	bool has_touch_event_handler_ = false;

	// True if an active gesture sequence is in progress. i.e. after GTD and
	// before GSE.
	bool gesture_sequence_in_progress_ = false;

	bool has_deferred_events_ = false;

	// True if scroll gestures are allowed to be used for cursor control. We set
	// this to false if a long press or double press has occurred in the current
	// gesture sequence, to prevent the cursor control feature from interfering
	// with long press drag selection and double press drag selection.
	bool allow_cursor_control_ = true;

	// Increment at receiving ACK for touch start and decrement at touch end.
	int num_of_active_touches_ = 0;

	// What touch actions are currently permitted.
	std::optional<cc::TouchAction> allowed_touch_action_;

	// The touch action that is used for the current gesture sequence. At the
	// touch sequence end, the \|allowed_touch_action_\| is reset while this remains
	// set as the effective touch action, for the still in progress gesture
	// sequence due to fling.
	std::optional<cc::TouchAction> active_touch_action_;

	// Allowed touch action received from the compositor.
	cc::TouchAction compositor_allowed_touch_action_;
	};

	} // namespace input

	#endif // COMPONENTS_INPUT_TOUCH_ACTION_FILTER_H_