Adding in DragLockButtons functionality.

Signed-off-by: Peter Hutterer <peter.hutterer@redhat.com>

man/evdev.man

@@ -78,6 +78,18 @@ For example, a left-handed mouse with deactivated scroll-wheel would use a
 mapping of "3 2 1 0 0". Invalid mappings are ignored and the default mapping
 is used. Buttons not specified in the user's mapping use the default mapping.
 .TP 7
+.BI "Option \*qDragLockButtons\*q \*q" "L1 B2 L3 B4" \*q
+Sets \*qdrag lock buttons\*q that simulate holding a button down, so
+that low dexterity people do not have to hold a button down at the
+same time they move a mouse cursor. Button numbers occur in pairs,
+with the lock button number occurring first, followed by the button
+number that is the target of the lock button.
+.TP 7
+.BI "Option \*qDragLockButtons\*q \*q" "M1" \*q
+Sets a \*qmaster drag lock button\*q that acts as a \*qMeta Key\*q
+indicating that the next button pressed is to be
+\*qdrag locked\*q.
+.TP 7
 .BI "Option \*qEmulateWheel\*q \*q" boolean \*q
 Enable/disable "wheel" emulation.  Wheel emulation means emulating button
 press/release events when the mouse is moved while a specific real button

src/Makefile.am

@@ -31,5 +31,6 @@
 @DRIVER_NAME@_drv_la_SOURCES = @DRIVER_NAME@.c \
                                @DRIVER_NAME@.h \
                                emuMB.c \
-                               emuWheel.c
+                               emuWheel.c \
+                               draglock.c
 

src/draglock.c

@@ -0,0 +1,203 @@
+/*
+ * Copyright 1990,91 by Thomas Roell, Dinkelscherben, Germany.
+ * Copyright 1993 by David Dawes <dawes@xfree86.org>
+ * Copyright 2002 by SuSE Linux AG, Author: Egbert Eich
+ * Copyright 1994-2002 by The XFree86 Project, Inc.
+ * Copyright 2002 by Paul Elliott
+ * (Ported from xf86-input-mouse, above copyrights taken from there)
+ * Copyright © 2008 University of South Australia
+ * Copyright 2008 by Chris Salch
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of the authors
+ * not be used in advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.  The authors make no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
+ * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+/* Draglock code */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <xf86.h>
+#include <xf86Xinput.h>
+
+#include "evdev.h"
+
+void EvdevDragLockLockButton(InputInfoPtr pInfo, unsigned int button);
+
+
+/* Setup and configuration code */
+void
+EvdevDragLockInit(InputInfoPtr pInfo)
+{
+    EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
+    char *option_string = NULL;
+    int meta_button = 0;
+    int lock_button = 0;
+    char *next_num = NULL;
+    char *end_str = NULL;
+    BOOL pairs = FALSE;
+
+    option_string = xf86CheckStrOption(pInfo->options, "DragLockButtons",NULL);
+
+    if (!option_string)
+        return;
+
+    next_num = option_string;
+
+    /* Loop until we hit the end of our option string */
+    while (next_num != NULL) {
+        lock_button = 0;
+        meta_button = strtol(next_num, &end_str, 10);
+
+        /* check to see if we found anything */
+        if (next_num != end_str) {
+            /* setup for the next number */
+            next_num = end_str;
+        } else {
+            /* we have nothing more to parse, drop out of the loop */
+            next_num = NULL;
+        }
+
+        /* Check for a button to lock if we have a meta button */
+        if (meta_button != 0 && next_num != NULL ) {
+            lock_button = strtol(next_num, &end_str, 10);
+
+            /* check to see if we found anything */
+            if (next_num != end_str) {
+                /* setup for the next number */
+                next_num = end_str;
+            } else {
+                /* we have nothing more to parse, drop out of the loop */
+                next_num = NULL;
+            }
+        }
+
+        /* Ok, let the user know what we found on this look */
+        if (meta_button != 0) {
+            if (lock_button == 0) {
+                if (!pairs) {
+                    /* We only have a meta button */
+                    pEvdev->dragLock.meta = meta_button;
+
+                    xf86Msg(X_CONFIG, "%s: DragLockButtons : "
+                            "%i as meta\n",
+                            pInfo->name, meta_button);
+                } else {
+                    xf86Msg(X_ERROR, "%s: DragLockButtons : "
+                            "Incomplete pair specifying button pairs %s\n",
+                            pInfo->name, option_string);
+                }
+            } else {
+
+                /* Do bounds checking to make sure we don't crash */
+                if ((meta_button <= EVDEV_MAXBUTTONS) && (meta_button >= 0 ) &&
+                    (lock_button <= EVDEV_MAXBUTTONS) && (lock_button >= 0)) {
+
+                    xf86Msg(X_CONFIG, "%s: DragLockButtons : %i -> %i\n",
+                            pInfo->name, meta_button, lock_button);
+
+                    pEvdev->dragLock.lock_pair[meta_button - 1] = lock_button;
+                    pairs=TRUE;
+                } else {
+                    /* Let the user know something was wrong
+                       with this pair of buttons */
+                    xf86Msg(X_CONFIG, "%s: DragLockButtons : "
+                            "Invalid button pair %i -> %i\n",
+                            pInfo->name, meta_button, lock_button);
+                }
+            }
+        } else {
+            xf86Msg(X_ERROR, "%s: Found DragLockButtons "
+                    "with  invalid lock button string : '%s'\n",
+                    pInfo->name, option_string);
+
+            /* This should be the case anyhow, just make sure */
+            next_num = NULL;
+        }
+
+        /* Check for end of string, to avoid annoying error */
+        if (next_num != NULL && *next_num == '\0')
+            next_num = NULL;
+    }
+}
+
+/* Updates DragLock button state and firest button event messges */
+void
+EvdevDragLockLockButton(InputInfoPtr pInfo, unsigned int button)
+{
+    EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
+    BOOL state=0;
+
+    /* update button state */
+    state = pEvdev->dragLock.lock_state[button - 1] ? FALSE : TRUE;
+    pEvdev->dragLock.lock_state[button - 1] = state;
+
+    xf86PostButtonEvent(pInfo->dev, 0, button, state, 0, 0);
+}
+
+/* Filter button presses looking for either a meta button or the
+ * control of a button pair.
+ *
+ * @param button button number (1 for left, 3 for right)
+ * @param value TRUE if button press, FALSE if release
+ *
+ * @return TRUE if the event was swallowed here, FALSE otherwise.
+ */
+BOOL
+EvdevDragLockFilterEvent(InputInfoPtr pInfo, unsigned int button, int value)
+{
+    EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
+
+    if (button == 0)
+        return FALSE;
+
+    /* Do we have a single meta key or
+       several button pairings? */
+    if (pEvdev->dragLock.meta != 0) {
+
+        if (pEvdev->dragLock.meta == button) {
+
+            /* setup up for button lock */
+            if (value)
+                pEvdev->dragLock.meta_state = TRUE;
+
+            return TRUE;
+        } else if (pEvdev->dragLock.meta_state) { /* waiting to lock */
+
+            pEvdev->dragLock.meta_state = FALSE;
+
+            EvdevDragLockLockButton(pInfo, button);
+
+            return TRUE;
+        }
+    } else if (pEvdev->dragLock.lock_pair[button - 1] && value) {
+        /* A meta button in a meta/lock pair was pressed */
+        EvdevDragLockLockButton(pInfo, pEvdev->dragLock.lock_pair[button - 1]);
+        return TRUE;
+    }
+
+    /* Eat events for buttons that are locked */
+    if (pEvdev->dragLock.lock_state[button - 1])
+        return TRUE;
+
+    return FALSE;
+}
+

src/evdev.c

@@ -287,6 +287,10 @@ EvdevReadInput(InputInfoPtr pInfo)
             default:
 		button = EvdevUtilButtonEventToButtonNumber(ev.code);
 
+		/* Handle drag lock */
+		if (EvdevDragLockFilterEvent(pInfo, button, value))
+		    break;
+
 		if (EvdevWheelEmuFilterButton(pInfo, button, value))
 		   break;
 
@@ -952,6 +956,7 @@ EvdevProc(DeviceIntPtr device, int what)
             {
                 EvdevMBEmuPreInit(pInfo);
                 EvdevWheelEmuPreInit(pInfo);
+                EvdevDragLockInit(pInfo);
             }
             device->public.on = TRUE;
         }

src/evdev.h

@@ -77,6 +77,12 @@ typedef struct {
         Time                expires;     /* time of expiry */
         Time                timeout;
     } emulateMB;
+    struct {
+	int                 meta;           /* meta key to lock any button */
+	BOOL                meta_state;     /* meta_button state */
+	unsigned int        lock_pair[EVDEV_MAXBUTTONS];  /* specify a meta/lock pair */
+	BOOL                lock_state[EVDEV_MAXBUTTONS]; /* state of any locked buttons */
+    } dragLock;
     struct {
         BOOL                enabled;
         int                 button;
@@ -113,5 +119,7 @@ void EvdevWheelEmuPreInit(InputInfoPtr pInfo);
 BOOL EvdevWheelEmuFilterButton(InputInfoPtr pInfo, unsigned int button, int value);
 BOOL EvdevWheelEmuFilterMotion(InputInfoPtr pInfo, struct input_event *pEv);
 
-
+/* Draglock code */
+void EvdevDragLockInit(InputInfoPtr pInfo);
+BOOL EvdevDragLockFilterEvent(InputInfoPtr pInfo, unsigned int button, int value);
 #endif