emuMB: default to disabled mouse button emulation for touchscreens.

Because touchscreens only use one button (see EvdevProcessKeyEvent())
EvdevMBEmuFilterEvent() never calls EvdevMBEmuEnable(..., FALSE) to
disable emulation. This results in touchscreen devices incurring a delay
of Emulate3Timeout (typically 50 ms.)

Default to MBEMU_DISABLED for touchscreen devices (unless overwritten by
Xorg.conf.)

Signed-off-by: Oliver McFadden <oliver.mcfadden@nokia.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

man/evdev.man

@@ -76,8 +76,9 @@ indicating that the next button pressed is to be
 .BI "Option \*qEmulate3Buttons\*q \*q" boolean \*q
 Enable/disable the emulation of the third (middle) mouse button for mice
 which only have two physical buttons.  The third button is emulated by
-pressing both buttons simultaneously.  Default: on, until a middle mouse
+pressing both buttons simultaneously.  Default: off for touchscreens, otherwise
-button event is registered. Property: "Evdev Middle Button Emulation".
+on until a middle mouse button event is registered. Property: "Evdev Middle
+Button Emulation".
 .TP 7
 .BI "Option \*qEmulate3Timeout\*q \*q" integer \*q
 Sets the timeout (in milliseconds) that the driver waits before deciding

src/emuMB.c

@@ -309,7 +309,11 @@ void
 EvdevMBEmuPreInit(InputInfoPtr pInfo)
 {
     EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
-    pEvdev->emulateMB.enabled = MBEMU_AUTO;
+
+    if (pEvdev->flags & EVDEV_TOUCHSCREEN)
+        pEvdev->emulateMB.enabled = MBEMU_DISABLED;
+    else
+        pEvdev->emulateMB.enabled = MBEMU_AUTO;
 
     if (xf86FindOption(pInfo->options, "Emulate3Buttons"))
     {

src/evdev.c

@@ -81,20 +81,6 @@
 
 #define ArrayLength(a) (sizeof(a) / (sizeof((a)[0])))
 
-/* evdev flags */
-#define EVDEV_KEYBOARD_EVENTS	(1 << 0)
-#define EVDEV_BUTTON_EVENTS	(1 << 1)
-#define EVDEV_RELATIVE_EVENTS	(1 << 2)
-#define EVDEV_ABSOLUTE_EVENTS	(1 << 3)
-#define EVDEV_TOUCHPAD		(1 << 4)
-#define EVDEV_INITIALIZED	(1 << 5) /* WheelInit etc. called already? */
-#define EVDEV_TOUCHSCREEN	(1 << 6)
-#define EVDEV_CALIBRATED	(1 << 7) /* run-time calibrated? */
-#define EVDEV_TABLET		(1 << 8) /* device looks like a tablet? */
-#define EVDEV_UNIGNORE_ABSOLUTE (1 << 9) /* explicitly unignore abs axes */
-#define EVDEV_UNIGNORE_RELATIVE (1 << 10) /* explicitly unignore rel axes */
-#define EVDEV_RELATIVE_MODE	(1 << 11) /* Force relative events for devices with absolute axes */
-
 #define MIN_KEYCODE 8
 #define GLYPHS_PER_KEY 2
 #define AltMask		Mod1Mask

src/evdev.h

@@ -57,6 +57,20 @@
 #define EVDEV_MAXBUTTONS 32
 #define EVDEV_MAXQUEUE 32
 
+/* evdev flags */
+#define EVDEV_KEYBOARD_EVENTS	(1 << 0)
+#define EVDEV_BUTTON_EVENTS	(1 << 1)
+#define EVDEV_RELATIVE_EVENTS	(1 << 2)
+#define EVDEV_ABSOLUTE_EVENTS	(1 << 3)
+#define EVDEV_TOUCHPAD		(1 << 4)
+#define EVDEV_INITIALIZED	(1 << 5) /* WheelInit etc. called already? */
+#define EVDEV_TOUCHSCREEN	(1 << 6)
+#define EVDEV_CALIBRATED	(1 << 7) /* run-time calibrated? */
+#define EVDEV_TABLET		(1 << 8) /* device looks like a tablet? */
+#define EVDEV_UNIGNORE_ABSOLUTE (1 << 9) /* explicitly unignore abs axes */
+#define EVDEV_UNIGNORE_RELATIVE (1 << 10) /* explicitly unignore rel axes */
+#define EVDEV_RELATIVE_MODE	(1 << 11) /* Force relative events for devices with absolute axes */
+
 #if GET_ABI_MAJOR(ABI_XINPUT_VERSION) >= 3
 #define HAVE_PROPERTIES 1
 #endif