Enable middle-mouse button emulation.

Ported from xf86-input-mouse, with a few cleanups.

1 files changed, 308 insertions, 0 deletions

diff --git a/src/emuMB.c b/src/emuMB.c
new file mode 100644
index 0000000..2855632
--- /dev/null
+++ b/src/emuMB.c
@@ -0,0 +1,308 @@
+/*
+ * 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
+ *
+ * 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 Red Hat
+ * not be used in advertising or publicity pertaining to distribution
+ * of the software without specific, written prior permission.  Red
+ * Hat makes 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.
+ *
+ */
+
+/* Middle mouse button emulation code. */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "evdev.h"
+
+/*
+ * Lets create a simple finite-state machine for 3 button emulation:
+ *
+ * We track buttons 1 and 3 (left and right).  There are 11 states:
+ *   0 ground           - initial state
+ *   1 delayed left     - left pressed, waiting for right
+ *   2 delayed right    - right pressed, waiting for left
+ *   3 pressed middle   - right and left pressed, emulated middle sent
+ *   4 pressed left     - left pressed and sent
+ *   5 pressed right    - right pressed and sent
+ *   6 released left    - left released after emulated middle
+ *   7 released right   - right released after emulated middle
+ *   8 repressed left   - left pressed after released left
+ *   9 repressed right  - right pressed after released right
+ *  10 pressed both     - both pressed, not emulating middle
+ *
+ * At each state, we need handlers for the following events
+ *   0: no buttons down
+ *   1: left button down
+ *   2: right button down
+ *   3: both buttons down
+ *   4: emulate3Timeout passed without a button change
+ * Note that button events are not deltas, they are the set of buttons being
+ * pressed now.  It's possible (ie, mouse hardware does it) to go from (eg)
+ * left down to right down without anything in between, so all cases must be
+ * handled.
+ *
+ * a handler consists of three values:
+ *   0: action1
+ *   1: action2
+ *   2: new emulation state
+ *
+ * action > 0: ButtonPress
+ * action = 0: nothing
+ * action < 0: ButtonRelease
+ *
+ * The comment preceeding each section is the current emulation state.
+ * The comments to the right are of the form
+ *      <button state> (<events>) -> <new emulation state>
+ * which should be read as
+ *      If the buttons are in <button state>, generate <events> then go to
+ *      <new emulation state>.
+ */
+static signed char stateTab[11][5][3] = {
+/* 0 ground */
+  {
+    {  0,  0,  0 },   /* nothing -> ground (no change) */
+    {  0,  0,  1 },   /* left -> delayed left */
+    {  0,  0,  2 },   /* right -> delayed right */
+    {  2,  0,  3 },   /* left & right (middle press) -> pressed middle */
+    {  0,  0, -1 }    /* timeout N/A */
+  },
+/* 1 delayed left */
+  {
+    {  1, -1,  0 },   /* nothing (left event) -> ground */
+    {  0,  0,  1 },   /* left -> delayed left (no change) */
+    {  1, -1,  2 },   /* right (left event) -> delayed right */
+    {  2,  0,  3 },   /* left & right (middle press) -> pressed middle */
+    {  1,  0,  4 },   /* timeout (left press) -> pressed left */
+  },
+/* 2 delayed right */
+  {
+    {  3, -3,  0 },   /* nothing (right event) -> ground */
+    {  3, -3,  1 },   /* left (right event) -> delayed left (no change) */
+    {  0,  0,  2 },   /* right -> delayed right (no change) */
+    {  2,  0,  3 },   /* left & right (middle press) -> pressed middle */
+    {  3,  0,  5 },   /* timeout (right press) -> pressed right */
+  },
+/* 3 pressed middle */
+  {
+    { -2,  0,  0 },   /* nothing (middle release) -> ground */
+    {  0,  0,  7 },   /* left -> released right */
+    {  0,  0,  6 },   /* right -> released left */
+    {  0,  0,  3 },   /* left & right -> pressed middle (no change) */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 4 pressed left */
+  {
+    { -1,  0,  0 },   /* nothing (left release) -> ground */
+    {  0,  0,  4 },   /* left -> pressed left (no change) */
+    { -1,  0,  2 },   /* right (left release) -> delayed right */
+    {  3,  0, 10 },   /* left & right (right press) -> pressed both */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 5 pressed right */
+  {
+    { -3,  0,  0 },   /* nothing (right release) -> ground */
+    { -3,  0,  1 },   /* left (right release) -> delayed left */
+    {  0,  0,  5 },   /* right -> pressed right (no change) */
+    {  1,  0, 10 },   /* left & right (left press) -> pressed both */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 6 released left */
+  {
+    { -2,  0,  0 },   /* nothing (middle release) -> ground */
+    { -2,  0,  1 },   /* left (middle release) -> delayed left */
+    {  0,  0,  6 },   /* right -> released left (no change) */
+    {  1,  0,  8 },   /* left & right (left press) -> repressed left */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 7 released right */
+  {
+    { -2,  0,  0 },   /* nothing (middle release) -> ground */
+    {  0,  0,  7 },   /* left -> released right (no change) */
+    { -2,  0,  2 },   /* right (middle release) -> delayed right */
+    {  3,  0,  9 },   /* left & right (right press) -> repressed right */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 8 repressed left */
+  {
+    { -2, -1,  0 },   /* nothing (middle release, left release) -> ground */
+    { -2,  0,  4 },   /* left (middle release) -> pressed left */
+    { -1,  0,  6 },   /* right (left release) -> released left */
+    {  0,  0,  8 },   /* left & right -> repressed left (no change) */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 9 repressed right */
+  {
+    { -2, -3,  0 },   /* nothing (middle release, right release) -> ground */
+    { -3,  0,  7 },   /* left (right release) -> released right */
+    { -2,  0,  5 },   /* right (middle release) -> pressed right */
+    {  0,  0,  9 },   /* left & right -> repressed right (no change) */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+/* 10 pressed both */
+  {
+    { -1, -3,  0 },   /* nothing (left release, right release) -> ground */
+    { -3,  0,  4 },   /* left (right release) -> pressed left */
+    { -1,  0,  5 },   /* right (left release) -> pressed right */
+    {  0,  0, 10 },   /* left & right -> pressed both (no change) */
+    {  0,  0, -1 },   /* timeout N/A */
+  },
+};
+
+
+int
+EvdevMBEmuTimer(InputInfoPtr pInfo)
+{
+    EvdevPtr pEvdev = pInfo->private;
+    int	sigstate;
+    int id;
+
+    sigstate = xf86BlockSIGIO ();
+
+    pEvdev->emulateMB.pending = FALSE;
+    if ((id = stateTab[pEvdev->emulateMB.state][4][0]) != 0) {
+        xf86PostButtonEvent(pInfo->dev, 0, abs(id), (id >= 0), 0, 0);
+        pEvdev->emulateMB.state =
+            stateTab[pEvdev->emulateMB.state][4][2];
+    } else {
+        ErrorF("Got unexpected buttonTimer in state %d\n",
+                pEvdev->emulateMB.state);
+    }
+
+    xf86UnblockSIGIO (sigstate);
+    return 0;
+}
+
+
+/**
+ * Emulate a middle button on button press.
+ *
+ * @param code Evdev event code (BTN_LEFT or BTN_RIGHT)
+ * @param press TRUE if press, FALSE if release.
+ *
+ * @return TRUE if event was swallowed by middle mouse button emulation, FALSE
+ * otherwise.
+ */
+BOOL
+EvdevMBEmuFilterEvent(InputInfoPtr pInfo, int code, BOOL press)
+{
+    EvdevPtr pEvdev = pInfo->private;
+    int id;
+    int *btstate;
+    int ret = FALSE;
+
+    if (!pEvdev->emulateMB.enabled)
+        return ret;
+
+    /* don't care about other buttons */
+    if (code != BTN_LEFT && code != BTN_RIGHT)
+        return ret;
+
+    btstate = &pEvdev->emulateMB.buttonstate;
+    if (press)
+        *btstate |= (code == BTN_LEFT) ? 0x1 : 0x2;
+    else
+        *btstate &= (code == BTN_LEFT) ? ~0x1 : ~0x2;
+
+    if ((id = stateTab[pEvdev->emulateMB.state][*btstate][0]) != 0)
+    {
+        xf86PostButtonEvent(pInfo->dev, 0, abs(id), (id >= 0), 0, 0);
+        ret = TRUE;
+    }
+    if ((id = stateTab[pEvdev->emulateMB.state][*btstate][1]) != 0)
+    {
+        xf86PostButtonEvent(pInfo->dev, 0, abs(id), (id >= 0), 0, 0);
+        ret = TRUE;
+    }
+
+    pEvdev->emulateMB.state =
+        stateTab[pEvdev->emulateMB.state][*btstate][2];
+
+    if (stateTab[pEvdev->emulateMB.state][4][0] != 0) {
+        pEvdev->emulateMB.expires = GetTimeInMillis () + pEvdev->emulateMB.timeout;
+        pEvdev->emulateMB.pending = TRUE;
+        ret = TRUE;
+    } else {
+        pEvdev->emulateMB.pending = FALSE;
+    }
+
+    return ret;
+}
+
+
+void EvdevMBEmuWakeupHandler(pointer data,
+                             int i,
+                             pointer LastSelectMask)
+{
+    InputInfoPtr pInfo = (InputInfoPtr)data;
+    EvdevPtr     pEvdev = (EvdevPtr)pInfo->private;
+    int ms;
+
+    if (pEvdev->emulateMB.pending)
+    {
+        ms = pEvdev->emulateMB.expires - GetTimeInMillis();
+        if (ms <= 0)
+            EvdevMBEmuTimer(pInfo);
+    }
+}
+
+void EvdevMBEmuBlockHandler(pointer data,
+                            struct timeval **waitTime,
+                            pointer LastSelectMask)
+{
+    InputInfoPtr    pInfo = (InputInfoPtr) data;
+    EvdevPtr        pEvdev= (EvdevPtr) pInfo->private;
+    int             ms;
+
+    if (pEvdev->emulateMB.pending)
+    {
+        ms = pEvdev->emulateMB.expires - GetTimeInMillis ();
+        if (ms <= 0)
+            ms = 0;
+        AdjustWaitForDelay (waitTime, ms);
+    }
+}
+
+void
+EvdevMBEmuPreInit(InputInfoPtr pInfo)
+{
+    EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
+
+    pEvdev->emulateMB.enabled = xf86SetBoolOption(pInfo->options,
+                                                  "Emulate3Buttons", TRUE);
+    pEvdev->emulateMB.timeout = xf86SetIntOption(pInfo->options,
+                                                 "Emulate3Timeout", 50);
+    RegisterBlockAndWakeupHandlers (EvdevMBEmuBlockHandler,
+                                    EvdevMBEmuWakeupHandler,
+                                    (pointer)pInfo);
+
+}
+
+/* Enable/disable middle mouse button emulation. */
+void
+EvdevMBEmuEnable(InputInfoPtr pInfo, BOOL enable)
+{
+    EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
+    pEvdev->emulateMB.enabled = enable;
+}