input: add a TouchClassRec to the devices

These structs will be used to store touch-related data, events and
information.

Drivers must call InitTouchClassDeviceStruct to set up a multi-touch capable
device.

Touchpoints for the DDX and the DIX are handled separately - touchpoints
submitted by the driver/DDX will be stored in the DDXTouchPointInfoRec. Once
the touchpoints are processed by the DIX, new TouchPointInfoRecs are created
and stored. This process is already used for pointer events with the
last.valuators field.

Note that this patch does not actually add the generation of touch events,
only the required structs.

TouchListeners are (future) recipients of touch or emulated pointer events.
Each listener is in a state, depending which event they have already
received. The type of listener defines how the listener got to be one.

Co-authored-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Chase Douglas <chase.douglas@canonical.com>

1 files changed, 86 insertions, 1 deletions

diff --git a/dix/devices.c b/dix/devices.c
index 9ca8fe055..7478ad67a 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -263,6 +263,7 @@ AddInputDevice(ClientPtr client, DeviceProc deviceProc, Bool autoStart)
 	return (DeviceIntPtr)NULL;
 
     dev->last.scroll = NULL;
+    dev->last.touches = NULL;
     dev->id = devid;
     dev->public.processInputProc = ProcessOtherEvent;
     dev->public.realInputProc = ProcessOtherEvent;
@@ -761,6 +762,21 @@ FreeDeviceClass(int type, pointer *class)
                 free((*v));
                 break;
             }
+        case XITouchClass:
+            {
+                TouchClassPtr *t = (TouchClassPtr*)class;
+                int i;
+
+                for (i = 0; i < (*t)->num_touches; i++)
+                {
+                    free((*t)->touches[i].sprite.spriteTrace);
+                    free((*t)->touches[i].listeners);
+                    free((*t)->touches[i].valuators);
+                }
+
+                free((*t));
+                break;
+            }
         case FocusClass:
             {
                 FocusClassPtr *f = (FocusClassPtr*)class;
@@ -869,6 +885,7 @@ FreeAllDeviceClasses(ClassesPtr classes)
 
     FreeDeviceClass(KeyClass, (pointer)&classes->key);
     FreeDeviceClass(ValuatorClass, (pointer)&classes->valuator);
+    FreeDeviceClass(XITouchClass, (pointer)&classes->touch);
     FreeDeviceClass(ButtonClass, (pointer)&classes->button);
     FreeDeviceClass(FocusClass, (pointer)&classes->focus);
     FreeDeviceClass(ProximityClass, (pointer)&classes->proximity);
@@ -948,6 +965,9 @@ CloseDevice(DeviceIntPtr dev)
     free(dev->deviceGrab.sync.event);
     free(dev->config_info);     /* Allocated in xf86ActivateDevice. */
     free(dev->last.scroll);
+    for (j = 0; j < dev->last.num_touches; j++)
+        free(dev->last.touches[j].valuators);
+    free(dev->last.touches);
     dev->config_info = NULL;
     dixFreeObjectWithPrivates(dev, PRIVATE_DEVICE);
 }
@@ -1419,7 +1439,6 @@ InitPtrFeedbackClassDeviceStruct(DeviceIntPtr dev, PtrCtrlProcPtr controlProc)
     return TRUE;
 }
 
-
 static LedCtrl defaultLedControl = {
 	DEFAULT_LEDS, DEFAULT_LEDS_MASK, 0};
 
@@ -1542,6 +1561,72 @@ InitPointerDeviceStruct(DevicePtr device, CARD8 *map, int numButtons, Atom* btn_
 	   InitPtrFeedbackClassDeviceStruct(dev, controlProc));
 }
 
+/**
+ * Sets up multitouch capabilities on @device.
+ *
+ * @max_touches The maximum number of simultaneous touches, or 0 for unlimited.
+ * @mode The mode of the touch device (XIDirectTouch or XIDependentTouch).
+ * @num_axes The number of touch valuator axes.
+ */
+Bool
+InitTouchClassDeviceStruct(DeviceIntPtr device, unsigned int max_touches,
+                           unsigned int mode, unsigned int num_axes)
+{
+    TouchClassPtr touch;
+    int i;
+
+    if (device->touch || !device->valuator)
+        return FALSE;
+
+    /* Check the mode is valid, and at least X and Y axes. */
+    if (mode != XIDirectTouch && mode != XIDependentTouch)
+        return FALSE;
+    if (num_axes < 2)
+        return FALSE;
+
+    if (num_axes > MAX_VALUATORS)
+    {
+        LogMessage(X_WARNING,
+                   "Device '%s' has %d touch axes, only using first %d.\n",
+                   device->name, num_axes, MAX_VALUATORS);
+        num_axes = MAX_VALUATORS;
+    }
+
+    touch = calloc(1, sizeof(*touch));
+    if (!touch)
+        return FALSE;
+
+    touch->max_touches = max_touches;
+    if (max_touches == 0)
+        max_touches = 5; /* arbitrary number plucked out of the air */
+    touch->touches = calloc(max_touches, sizeof(*touch->touches));
+    if (!touch->touches)
+        goto err;
+    touch->num_touches = max_touches;
+    for (i = 0; i < max_touches; i++)
+        TouchInitTouchPoint(touch, device->valuator, i);
+
+    touch->mode = mode;
+    touch->sourceid = device->id;
+
+    device->touch = touch;
+    device->last.touches = calloc(max_touches, sizeof(*device->last.touches));
+    device->last.num_touches = touch->num_touches;
+    for (i = 0; i < touch->num_touches; i++)
+        TouchInitDDXTouchPoint(device, &device->last.touches[i]);
+
+    return TRUE;
+
+err:
+    for (i = 0; i < touch->num_touches; i++)
+        TouchFreeTouchPoint(device, i);
+
+    free(touch->touches);
+    free(touch);
+
+    return FALSE;
+}
+
 /*
  * Check if the given buffer contains elements between low (inclusive) and
  * high (inclusive) only.