dix: Implement internal gesture state handling

Xi/exevents.c

@@ -691,6 +691,25 @@ DeepCopyPointerClasses(DeviceIntPtr from, DeviceIntPtr to)
     /* Don't remove touch class if from->touch is non-existent. The to device
      * may have an active touch grab, so we need to keep the touch class record
      * around. */
+
+    if (from->gesture) {
+        if (!to->gesture) {
+            classes = to->unused_classes;
+            to->gesture = classes->gesture;
+            if (!to->gesture) {
+                if (!InitGestureClassDeviceStruct(to, from->gesture->max_touches))
+                    FatalError("[Xi] no memory for class shift.\n");
+            }
+            else
+                classes->gesture = NULL;
+        }
+
+        to->gesture->sourceid = from->gesture->sourceid;
+        /* to->gesture->gesture is separate on the master,  don't copy */
+    }
+    /* Don't remove gesture class if from->gesture is non-existent. The to device
+     * may have an active gesture grab, so we need to keep the gesture class record
+     * around. */
 }
 
 /**

dix/Makefile.am

@@ -23,6 +23,7 @@ libdix_la_SOURCES = 	\
 	extension.c	\
 	gc.c		\
 	getevents.c	\
+	gestures.c	\
 	globals.c	\
 	glyphcurs.c	\
 	grabs.c		\

dix/devices.c

@@ -1670,6 +1670,32 @@ InitTouchClassDeviceStruct(DeviceIntPtr device, unsigned int max_touches,
     return FALSE;
 }
 
+/**
+ * Sets up gesture capabilities on @device.
+ *
+ * @max_touches The maximum number of simultaneous touches, or 0 for unlimited.
+ */
+Bool
+InitGestureClassDeviceStruct(DeviceIntPtr device, unsigned int max_touches)
+{
+    GestureClassPtr g;
+
+    BUG_RETURN_VAL(device == NULL, FALSE);
+    BUG_RETURN_VAL(device->gesture != NULL, FALSE);
+
+    g = calloc(1, sizeof(*g));
+    if (!g)
+        return FALSE;
+
+    g->sourceid = device->id;
+    g->max_touches = max_touches;
+    GestureInitGestureInfo(&g->gesture);
+
+    device->gesture = g;
+
+    return TRUE;
+}
+
 /*
  * Check if the given buffer contains elements between low (inclusive) and
  * high (inclusive) only.

dix/gestures.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright © 2011 Collabra Ltd.
+ * Copyright © 2011 Red Hat, Inc.
+ * Copyright © 2020 Povilas Kanapickas  <povilas@radix.lt>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include "inputstr.h"
+#include "scrnintstr.h"
+#include "dixgrabs.h"
+
+#include "eventstr.h"
+#include "exevents.h"
+#include "exglobals.h"
+#include "inpututils.h"
+#include "eventconvert.h"
+#include "windowstr.h"
+#include "mi.h"
+
+Bool
+GestureInitGestureInfo(GestureInfoPtr gi)
+{
+    memset(gi, 0, sizeof(*gi));
+
+    gi->sprite.spriteTrace = calloc(32, sizeof(*gi->sprite.spriteTrace));
+    if (!gi->sprite.spriteTrace) {
+        return FALSE;
+    }
+    gi->sprite.spriteTraceSize = 32;
+    gi->sprite.spriteTrace[0] = screenInfo.screens[0]->root;
+    gi->sprite.hot.pScreen = screenInfo.screens[0];
+    gi->sprite.hotPhys.pScreen = screenInfo.screens[0];
+
+    return TRUE;
+}

dix/meson.build

@@ -12,6 +12,7 @@ srcs_dix = [
     'eventconvert.c',
     'extension.c',
     'gc.c',
+    'gestures.c',
     'getevents.c',
     'globals.c',
     'glyphcurs.c',

include/input.h

@@ -153,7 +153,9 @@ typedef struct _ValuatorClassRec *ValuatorClassPtr;
 typedef struct _ClassesRec *ClassesPtr;
 typedef struct _SpriteRec *SpritePtr;
 typedef struct _TouchClassRec *TouchClassPtr;
+typedef struct _GestureClassRec *GestureClassPtr;
 typedef struct _TouchPointInfo *TouchPointInfoPtr;
+typedef struct _GestureInfo *GestureInfoPtr;
 typedef struct _DDXTouchPointInfo *DDXTouchPointInfoPtr;
 typedef union _GrabMask GrabMask;
 
@@ -340,6 +342,9 @@ extern _X_EXPORT Bool InitTouchClassDeviceStruct(DeviceIntPtr /*device */ ,
                                                  unsigned int /*mode */ ,
                                                  unsigned int /*numAxes */ );
 
+extern _X_EXPORT Bool InitGestureClassDeviceStruct(DeviceIntPtr device,
+                                                   unsigned int max_touches);
+
 typedef void (*BellProcPtr) (int percent,
                              DeviceIntPtr device,
                              void *ctrl,
@@ -576,6 +581,12 @@ enum TouchListenerType {
     TOUCH_LISTENER_POINTER_REGULAR,
 };
 
+enum GestureListenerType {
+    GESTURE_LISTENER_GRAB,
+    GESTURE_LISTENER_NONGESTURE_GRAB,
+    GESTURE_LISTENER_REGULAR
+};
+
 extern void TouchInitDDXTouchPoint(DeviceIntPtr dev,
                                    DDXTouchPointInfoPtr ddxtouch);
 extern DDXTouchPointInfoPtr TouchBeginDDXTouch(DeviceIntPtr dev,
@@ -621,6 +632,7 @@ extern void TouchEndPhysicallyActiveTouches(DeviceIntPtr dev);
 extern void TouchEmitTouchEnd(DeviceIntPtr dev, TouchPointInfoPtr ti, int flags, XID resource);
 extern void TouchAcceptAndEnd(DeviceIntPtr dev, int touchid);
 
+extern Bool GestureInitGestureInfo(GestureInfoPtr gesture);
 /* misc event helpers */
 extern Mask GetEventMask(DeviceIntPtr dev, xEvent *ev, InputClientsPtr clients);
 extern Mask GetEventFilter(DeviceIntPtr dev, xEvent *event);

include/inputstr.h

@@ -352,6 +352,32 @@ typedef struct _TouchClassRec {
     Mask motionMask;
 } TouchClassRec;
 
+typedef struct _GestureListener {
+    XID listener;           /* grabs/event selection IDs receiving
+                             * events for this gesture */
+    int resource_type;      /* listener's resource type */
+    enum GestureListenerType type;
+    WindowPtr window;
+    GrabPtr grab;
+} GestureListener;
+
+typedef struct _GestureInfo {
+    int sourceid;               /* Source device's ID for this gesture */
+    Bool active;                /* whether or not the gesture is active */
+    uint8_t type;               /* Gesture type: either ET_GesturePinchBegin or
+                                   ET_GestureSwipeBegin. Valid if active == TRUE */
+    int num_touches;            /* The number of touches in the gesture */
+    SpriteRec sprite;           /* window trace for delivery */
+    GestureListener listener;   /* the listener that will receive events */
+    Bool has_listener;          /* true if listener has been setup already */
+} GestureInfoRec;
+
+typedef struct _GestureClassRec {
+    int sourceid;
+    GestureInfoRec gesture;
+    unsigned short max_touches; /* maximum number of touches, may be 0 */
+} GestureClassRec;
+
 typedef struct _ButtonClassRec {
     int sourceid;
     CARD8 numButtons;
@@ -435,6 +461,7 @@ typedef struct _ClassesRec {
     KeyClassPtr key;
     ValuatorClassPtr valuator;
     TouchClassPtr touch;
+    GestureClassPtr gesture;
     ButtonClassPtr button;
     FocusClassPtr focus;
     ProximityClassPtr proximity;
@@ -550,6 +577,7 @@ typedef struct _DeviceIntRec {
     KeyClassPtr key;
     ValuatorClassPtr valuator;
     TouchClassPtr touch;
+    GestureClassPtr gesture;
     ButtonClassPtr button;
     FocusClassPtr focus;
     ProximityClassPtr proximity;