<?xml version="1.0" encoding="UTF-8"?>
<protocol name="pointer_gestures_unstable_v1">

  <interface name="zwp_pointer_gestures_v1" version="2">
    <description summary="touchpad gestures">
      A global interface to provide semantic touchpad gestures for a given
      pointer.

      Two gestures are currently supported: swipe and zoom/rotate.
      All gestures follow a three-stage cycle: begin, update, end and
      are identified by a unique id.

      Warning! The protocol described in this file is experimental and
      backward incompatible changes may be made. Backward compatible changes
      may be added together with the corresponding interface version bump.
      Backward incompatible changes are done by bumping the version number in
      the protocol and interface names and resetting the interface version.
      Once the protocol is to be declared stable, the 'z' prefix and the
      version number in the protocol and interface names are removed and the
      interface version number is reset.
    </description>

    <request name="get_swipe_gesture">
      <description summary="get swipe gesture">
	Create a swipe gesture object. See the
	wl_pointer_gesture_swipe interface for details.
      </description>
      <arg name="id" type="new_id" interface="zwp_pointer_gesture_swipe_v1"/>
      <arg name="pointer" type="object" interface="wl_pointer"/>
    </request>

    <request name="get_pinch_gesture">
      <description summary="get pinch gesture">
	Create a pinch gesture object. See the
	wl_pointer_gesture_pinch interface for details.
      </description>
      <arg name="id" type="new_id" interface="zwp_pointer_gesture_pinch_v1"/>
      <arg name="pointer" type="object" interface="wl_pointer"/>
    </request>

    <!-- Version 2 additions -->

    <request name="release" type="destructor" since="2">
      <description summary="destroy the pointer gesture object">
	Destroy the pointer gesture object. Swipe and pinch objects created via this
	gesture object remain valid.
      </description>
    </request>
  </interface>

  <interface name="zwp_pointer_gesture_swipe_v1" version="2">
    <description summary="a swipe gesture object">
      A swipe gesture object notifies a client about a multi-finger swipe
      gesture detected on an indirect input device such as a touchpad.
      The gesture is usually initiated by multiple fingers moving in the
      same direction but once initiated the direction may change.
      The precise conditions of when such a gesture is detected are
      implementation-dependent.

      A gesture consists of three stages: begin, update (optional) and end.
      There cannot be multiple simultaneous pinch or swipe gestures on a
      same pointer/seat, how compositors prevent these situations is
      implementation-dependent.

      A gesture may be cancelled by the compositor or the hardware.
      Clients should not consider performing permanent or irreversible
      actions until the end of a gesture has been received.
    </description>

    <request name="destroy" type="destructor">
      <description summary="destroy the pointer swipe gesture object"/>
    </request>

    <event name="begin">
      <description summary="multi-finger swipe begin">
	This event is sent when a multi-finger swipe gesture is detected
	on the device.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="fingers" type="uint" summary="number of fingers"/>
    </event>

    <event name="update">
      <description summary="multi-finger swipe motion">
	This event is sent when a multi-finger swipe gesture changes the
	position of the logical center.

	The dx and dy coordinates are relative coordinates of the logical
	center of the gesture compared to the previous event.
      </description>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="dx" type="fixed" summary="delta x coordinate in surface coordinate space"/>
      <arg name="dy" type="fixed" summary="delta y coordinate in surface coordinate space"/>
    </event>

    <event name="end">
      <description summary="multi-finger swipe end">
	This event is sent when a multi-finger swipe gesture ceases to
	be valid. This may happen when one or more fingers are lifted or
	the gesture is cancelled.

	When a gesture is cancelled, the client should undo state changes
	caused by this gesture. What causes a gesture to be cancelled is
	implementation-dependent.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="cancelled" type="int" summary="1 if the gesture was cancelled, 0 otherwise"/>
    </event>
  </interface>

  <interface name="zwp_pointer_gesture_pinch_v1" version="2">
    <description summary="a pinch gesture object">
      A pinch gesture object notifies a client about a multi-finger pinch
      gesture detected on an indirect input device such as a touchpad.
      The gesture is usually initiated by multiple fingers moving towards
      each other or away from each other, or by two or more fingers rotating
      around a logical center of gravity. The precise conditions of when
      such a gesture is detected are implementation-dependent.

      A gesture consists of three stages: begin, update (optional) and end.
      There cannot be multiple simultaneous pinch or swipe gestures on a
      same pointer/seat, how compositors prevent these situations is
      implementation-dependent.

      A gesture may be cancelled by the compositor or the hardware.
      Clients should not consider performing permanent or irreversible
      actions until the end of a gesture has been received.
    </description>

    <request name="destroy" type="destructor">
      <description summary="destroy the pinch gesture object"/>
    </request>

    <event name="begin">
      <description summary="multi-finger pinch begin">
	This event is sent when a multi-finger pinch gesture is detected
	on the device.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="fingers" type="uint" summary="number of fingers"/>
    </event>

    <event name="update">
      <description summary="multi-finger pinch motion">
	This event is sent when a multi-finger pinch gesture changes the
	position of the logical center, the rotation or the relative scale.

	The dx and dy coordinates are relative coordinates in the
	surface coordinate space of the logical center of the gesture.

	The scale factor is an absolute scale compared to the
	pointer_gesture_pinch.begin event, e.g. a scale of 2 means the fingers
	are now twice as far apart as on pointer_gesture_pinch.begin.

	The rotation is the relative angle in degrees clockwise compared to the previous
	pointer_gesture_pinch.begin or pointer_gesture_pinch.update event.
      </description>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="dx" type="fixed" summary="delta x coordinate in surface coordinate space"/>
      <arg name="dy" type="fixed" summary="delta y coordinate in surface coordinate space"/>
      <arg name="scale" type="fixed" summary="scale relative to the initial finger position"/>
      <arg name="rotation" type="fixed" summary="angle in degrees cw relative to the previous event"/>
    </event>

    <event name="end">
      <description summary="multi-finger pinch end">
	This event is sent when a multi-finger pinch gesture ceases to
	be valid. This may happen when one or more fingers are lifted or
	the gesture is cancelled.

	When a gesture is cancelled, the client should undo state changes
	caused by this gesture. What causes a gesture to be cancelled is
	implementation-dependent.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="cancelled" type="int" summary="1 if the gesture was cancelled, 0 otherwise"/>
    </event>
  </interface>

</protocol>
