Input: Add initial multitouch support from Xi 2.1

Xi 2.1 adds TouchClasses to devices, as well as TouchBegin, TouchMotion
and TouchEnd events, to allow support for multiple touchpoints on a
single device.

Signed-off-by: Daniel Stone <daniel@fooishbar.org>
Co-authored-by: Chase Douglas <chase.douglas@canonical.com>

6 files changed, 125 insertions, 2 deletions

diff --git a/include/events.h b/include/events.h
index 375173adc..222cc3d19 100644
--- a/include/events.h
+++ b/include/events.h
@@ -26,6 +26,7 @@
 #define EVENTS_H
 typedef struct _DeviceEvent DeviceEvent;
 typedef struct _DeviceChangedEvent DeviceChangedEvent;
+typedef struct _TouchOwnershipEvent TouchOwnershipEvent;
 #if XFreeXDGA
 typedef struct _DGAEvent DGAEvent;
 #endif
diff --git a/include/eventstr.h b/include/eventstr.h
index e1f5003f9..cf02efe80 100644
--- a/include/eventstr.h
+++ b/include/eventstr.h
@@ -65,6 +65,11 @@ enum EventType {
     ET_RawButtonRelease,
     ET_RawMotion,
     ET_XQuartz,
+    ET_TouchBegin,
+    ET_TouchEnd,
+    ET_TouchMotion,
+    ET_TouchMotionUnowned,
+    ET_TouchOwnership,
     ET_Internal = 0xFF /* First byte */
 };
 
@@ -90,6 +95,7 @@ struct _DeviceEvent
     union {
         uint32_t button;  /**< Button number */
         uint32_t key;     /**< Key code */
+        uint32_t touch;   /**< Touch ID (client_id) */
     } detail;
     int16_t root_x;       /**< Pos relative to root window in integral data */
     float root_x_frac;    /**< Pos relative to root window in frac part */
@@ -120,6 +126,24 @@ struct _DeviceEvent
     uint32_t flags;   /**< Flags to be copied into the generated event */
 };
 
+/**
+ * Generated internally whenever a touch ownership chain changes - an owner
+ * has accepted or rejected a touch, or a grab/event selection in the delivery
+ * chain has been removed.
+ */
+struct _TouchOwnershipEvent
+{
+    unsigned char header; /**< Always ET_Internal */
+    enum EventType type;  /**< One of EventType */
+    int length;           /**< Length in bytes */
+    Time time;            /**< Time in ms */
+    int deviceid;         /**< Device to post this event for */
+    int sourceid;         /**< The physical source device */
+    uint32_t touchid;     /**< Touch ID (client_id) */
+    uint8_t reason;       /**< ::XITouchOwnerAccepted, ::XITouchOwnerRejected */
+    uint32_t resource;    /**< Provoking grab or event selection */
+    uint32_t flags;       /**< Flags to be copied into the generated event */
+};
 
 /* Flags used in DeviceChangedEvent to signal if the slave has changed */
 #define DEVCHANGE_SLAVE_SWITCH 0x2
@@ -235,6 +259,7 @@ union _InternalEvent {
         } any;
         DeviceEvent device_event;
         DeviceChangedEvent changed_event;
+        TouchOwnershipEvent touch_ownership_event;
 #if XFreeXDGA
         DGAEvent dga_event;
 #endif
diff --git a/include/exevents.h b/include/exevents.h
index dc594304f..32a3962a7 100644
--- a/include/exevents.h
+++ b/include/exevents.h
@@ -51,6 +51,14 @@ extern _X_EXPORT void InitValuatorAxisStruct(
 	int                    /* max_res */,
 	int                    /* mode */);
 
+extern _X_EXPORT void InitTouchValuatorAxisStruct(
+	DeviceIntPtr           /* dev */,
+	int                    /* axnum */,
+	Atom                   /* label */,
+	int                    /* minval */,
+	int                    /* maxval */,
+	int                    /* resolution */);
+
 /* Input device properties */
 extern _X_EXPORT void XIDeleteAllDeviceProperties(
         DeviceIntPtr            /* device */
@@ -199,6 +207,14 @@ GrabWindow(
 	GrabMask*              /* eventMask */);
 
 extern int
+GrabTouch(
+	ClientPtr              /* client */,
+	DeviceIntPtr           /* dev */,
+	DeviceIntPtr           /* mod_dev */,
+	GrabParameters*        /* param */,
+	GrabMask*              /* eventMask */);
+
+extern int
 SelectForWindow(
 	DeviceIntPtr           /* dev */,
 	WindowPtr              /* pWin */,
@@ -222,6 +238,10 @@ InputClientGone(
 	WindowPtr              /* pWin */,
 	XID                    /* id */);
 
+extern void
+WindowGone(
+	WindowPtr              /* win */);
+
 extern int
 SendEvent (
 	ClientPtr              /* client */,
diff --git a/include/input.h b/include/input.h
index f96a0a988..60cf714fd 100644
--- a/include/input.h
+++ b/include/input.h
@@ -104,6 +104,8 @@ typedef struct _InputClients *InputClientsPtr;
 typedef struct _DeviceIntRec *DeviceIntPtr;
 typedef struct _ClassesRec *ClassesPtr;
 typedef struct _SpriteRec *SpritePtr;
+typedef struct _TouchClassRec *TouchClassPtr;
+typedef struct _TouchPointInfo *TouchPointInfoPtr;
 typedef union _GrabMask GrabMask;
 
 typedef struct _EventList {
@@ -314,6 +316,12 @@ extern _X_EXPORT Bool InitAbsoluteClassDeviceStruct(
 extern _X_EXPORT Bool InitFocusClassDeviceStruct(
     DeviceIntPtr /*device*/);
 
+extern _X_EXPORT Bool InitTouchClassDeviceStruct(
+    DeviceIntPtr /*device*/,
+    unsigned int /*max_touches*/,
+    unsigned int /*mode*/,
+    unsigned int /*numAxes*/);
+
 typedef void (*BellProcPtr)(
     int /*percent*/,
     DeviceIntPtr /*device*/,
@@ -463,6 +471,22 @@ extern int GetKeyboardValuatorEvents(
     int key_code,
     const ValuatorMask *mask);
 
+extern int GetTouchEvents(
+    EventListPtr events,
+    DeviceIntPtr pDev,
+    TouchPointInfoPtr ti,
+    uint16_t type,
+    uint32_t flags,
+    const ValuatorMask *mask);
+
+extern int GetTouchOwnershipEvents(
+    EventListPtr events,
+    DeviceIntPtr pDev,
+    TouchPointInfoPtr ti,
+    uint8_t mode,
+    XID resource,
+    uint32_t flags);
+
 extern int GetProximityEvents(
     EventListPtr events,
     DeviceIntPtr pDev,
@@ -525,6 +549,19 @@ extern void SendDevicePresenceEvent(int deviceid, int type);
 extern _X_EXPORT InputAttributes *DuplicateInputAttributes(InputAttributes *attrs);
 extern _X_EXPORT void FreeInputAttributes(InputAttributes *attrs);
 
+/* DDX touch API: create with CreateTouchPoint, use its returned ID to lookup
+ * with FindTouchPoint, and eventually end with FinishTouchPoint. */
+extern TouchPointInfoPtr BeginTouchPoint(DeviceIntPtr dev, uint32_t ddx_id);
+extern TouchPointInfoPtr FindTouchPointByDDXID(DeviceIntPtr dev,
+                                               uint32_t ddx_id);
+extern TouchPointInfoPtr FindTouchPointByClientID(DeviceIntPtr dev,
+                                                  uint32_t client_id);
+extern void EndTouchPoint(DeviceIntPtr dev, TouchPointInfoPtr ti);
+/* Internal use only, DDX this is not for you */
+extern Bool InitTouchPoint(TouchClassPtr touch, int index);
+extern void FreeTouchPoint(DeviceIntPtr dev, int index);
+extern void TouchListenerGone(XID resource);
+
 /* misc event helpers */
 extern Mask GetEventMask(DeviceIntPtr dev, xEvent* ev, InputClientsPtr clients);
 extern Mask GetEventFilter(DeviceIntPtr dev, xEvent *event);
diff --git a/include/inputstr.h b/include/inputstr.h
index a19b9a9d8..3d86b34e0 100644
--- a/include/inputstr.h
+++ b/include/inputstr.h
@@ -49,6 +49,8 @@ SOFTWARE.
 #ifndef INPUTSTRUCT_H
 #define INPUTSTRUCT_H
 
+#include <X11/extensions/XI2proto.h>
+
 #include <pixman.h>
 #include "input.h"
 #include "window.h"
@@ -71,7 +73,7 @@ extern _X_EXPORT int CountBits(const uint8_t *mask, int len);
  * events to the protocol, the server will not support these events until
  * this number here is bumped.
  */
-#define XI2LASTEVENT    17 /* XI_RawMotion */
+#define XI2LASTEVENT    XI_TouchMotionUnowned
 #define XI2MASKSIZE     ((XI2LASTEVENT + 7)/8) /* no of bits for masks */
 
 /**
@@ -287,6 +289,42 @@ typedef struct _ValuatorClassRec {
     ValuatorAccelerationRec	accelScheme;
 } ValuatorClassRec, *ValuatorClassPtr;
 
+typedef struct _TouchPointInfo {
+    Bool        active;             /* whether or not the touch is active */
+    Bool        pending_finish;     /* true if the touch is physically inactive
+                                     * but still owned by a grab */
+    uint32_t    client_id;          /* touch ID as seen in client events */
+    uint32_t    ddx_id;             /* touch ID given by the DDX */
+    SpriteRec   sprite;             /* window trace for delivery */
+    int         *valuators;         /* last recorded axis values */
+    int         num_valuators;      /* == TouchClassInfo::num_axes */
+    XID         *listeners;         /* grabs/event selection IDs receiving
+                                     * events for this touch */
+    int         num_listeners;
+    int         num_grabs;          /* number of open grabs on this touch
+                                     * which have not accepted or rejected */
+    Bool        emulate_pointer;
+} TouchPointInfoRec;
+
+typedef struct _TouchAxisInfo {
+    int		resolution;
+    int		min_value;
+    int		max_value;
+    Atom	label;
+} TouchAxisInfoRec, *TouchAxisInfoPtr;
+
+typedef struct _TouchClassRec {
+    TouchAxisInfoPtr   axes;
+    unsigned short     num_axes;
+    TouchPointInfoPtr  touches;
+    unsigned short     num_touches;    /* number of allocated touches */
+    unsigned short     max_touches;    /* maximum number of touches, may be 0 */
+    CARD8              mode;           /* ::XIDirectTouch, XIDependentTouch */
+    uint32_t           next_client_id; /* next client_id to give out */
+    int                x_axis;         /* axis number of x axis */
+    int                y_axis;         /* axis number of y axis */
+} TouchClassRec;
+
 typedef struct _ButtonClassRec {
     int			sourceid;
     CARD8		numButtons;
@@ -391,6 +429,7 @@ typedef struct _LedFeedbackClassRec {
 typedef struct _ClassesRec {
     KeyClassPtr		key;
     ValuatorClassPtr	valuator;
+    TouchClassPtr	touch;
     ButtonClassPtr	button;
     FocusClassPtr	focus;
     ProximityClassPtr	proximity;
@@ -515,6 +554,7 @@ typedef struct _DeviceIntRec {
     int			id;
     KeyClassPtr		key;
     ValuatorClassPtr	valuator;
+    TouchClassPtr	touch;
     ButtonClassPtr	button;
     FocusClassPtr	focus;
     ProximityClassPtr	proximity;
diff --git a/include/protocol-versions.h b/include/protocol-versions.h
index c8c7f5fc0..42b7d0eb7 100644
--- a/include/protocol-versions.h
+++ b/include/protocol-versions.h
@@ -131,7 +131,7 @@
 
 /* X Input */
 #define SERVER_XI_MAJOR_VERSION			2
-#define SERVER_XI_MINOR_VERSION			0
+#define SERVER_XI_MINOR_VERSION			1
 
 /* XKB */
 #define SERVER_XKB_MAJOR_VERSION		1