Add XIGetSelectedEvents.

4 files changed, 114 insertions, 2 deletions

diff --git a/include/X11/extensions/XInput2.h b/include/X11/extensions/XInput2.h
index 5ef0892..8b3741a 100644
--- a/include/X11/extensions/XInput2.h
+++ b/include/X11/extensions/XInput2.h
@@ -351,6 +351,12 @@ extern int      XISelectEvents(
      int                 num_masks
 );
 
+extern XIEventMask *XIGetSelectedEvents(
+     Display*            dpy,
+     Window              win,
+     int                 *num_masks_return
+);
+
 extern Status XIQueryVersion(
      Display*           dpy,
      int*               major_version_inout,
diff --git a/man/Makefile.am b/man/Makefile.am
index 383c30f..304f993 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -78,7 +78,8 @@ XI2_refpages = \
 	XIUngrabKeysym.man \
 	XIUngrabDevice.man  \
 	XIGetClientPointer.man \
-	XIGetFocus.man
+	XIGetFocus.man \
+	XIGetSelectedEvents.man
 
 libman_ref = \
 	XGetDeviceDontPropagateList.man \
diff --git a/man/XISelectEvents.txt b/man/XISelectEvents.txt
index a822fb3..07b3c8e 100644
--- a/man/XISelectEvents.txt
+++ b/man/XISelectEvents.txt
@@ -4,7 +4,7 @@ XISELECTEVENTS(libmansuffix)
 NAME
 ----
 
-   XISelectEvents - select for XI2 events on the window.
+   XISelectEvents, XIGetSelectedEvents - select for or get selected XI2 events on the window.
 
 SYNOPSIS
 --------
@@ -28,6 +28,19 @@ SYNOPSIS
    win
           Specifies the window.
 
+   XIEventMask *XIGetSelectedEvents( Display *display,
+                                     Window win,
+                                     int *num_masks_return);
+ 
+   display
+          Specifies the connection to the X server.
+
+   num_masks_return
+          Number of masks in the return value.
+
+   win
+          Specifies the window.
+
 DESCRIPTION
 -----------
 
@@ -60,6 +73,16 @@ DESCRIPTION
    XISelectEvents can generate a BadValue, a BadDevice, and a
    BadWindow error.
 
+   XIGetSelectedEvents returns the events selected by this client on the given
+   window. If no events were selected on this window, XIGetSelectedEvents
+   returns NULL and num_masks_return is set to 0. If an internal error occurs,
+   XIGetSelectedEvents returns NULL and num_masks_return is set to -1.
+   Otherwise, XIGetSelectedEvent returns the selected event masks for all
+   devices including the masks for XIAllDevices and XIAllMasterDevices
+
+   The caller must free the returned data using XFree().
+
+
 DIAGNOSTICS
 -----------
 
diff --git a/src/XISelEv.c b/src/XISelEv.c
index fc9f2a2..d76861f 100644
--- a/src/XISelEv.c
+++ b/src/XISelEv.c
@@ -91,3 +91,85 @@ XISelectEvents(Display* dpy, Window win, XIEventMask* masks, int num_masks)
     return Success;
 
 }
+
+XIEventMask*
+XIGetSelectedEvents(Display* dpy, Window win, int *num_masks_return)
+{
+    int i, len = 0;
+    unsigned char *mask;
+    XIEventMask *mask_out = NULL;
+    xXIEventMask *mask_in = NULL, *mi;
+    xXIGetSelectedEventsReq *req;
+    xXIGetSelectedEventsReply reply;
+
+    XExtDisplayInfo *info = XInput_find_display(dpy);
+    LockDisplay(dpy);
+    if (_XiCheckExtInit(dpy, XI_2_Major, info) == -1)
+    {
+        *num_masks_return = -1;
+	return NULL;
+    }
+
+    GetReq(XIGetSelectedEvents, req);
+
+    req->reqType = info->codes->major_opcode;
+    req->ReqType = X_XIGetSelectedEvents;
+    req->window = win;
+
+    if (!_XReply(dpy, (xReply *) &reply, 0, xFalse))
+        goto error;
+
+    if (reply.num_masks == 0)
+    {
+        *num_masks_return = 0;
+        return NULL;
+    }
+
+    mask_in = Xmalloc(reply.length * 4);
+    if (!mask_in)
+        goto error;
+
+    _XRead(dpy, (char*)mask_in, reply.length * 4);
+
+    /* Memory layout of the XIEventMask for a 3 mask reply:
+     * [struct a][struct b][struct c][masks a][masks b][masks c]
+     */
+    len = reply.num_masks * sizeof(XIEventMask);
+
+    for (i = 0, mi = mask_in; i < reply.num_masks; i++)
+    {
+        len += mi->mask_len * 4;
+        mi = (xXIEventMask*)((char*)mi + mi->mask_len * 4);
+        mi++;
+    }
+
+    mask_out = Xmalloc(len);
+    if (!mask_out)
+        goto error;
+
+    mi = mask_in;
+    mask = (unsigned char*)&mask_out[reply.num_masks];
+    for (i = 0; i < reply.num_masks; i++)
+    {
+        mask_out[i].deviceid = mi->deviceid;
+        mask_out[i].mask_len = mi->mask_len * 4;
+        mask_out[i].mask = mask;
+        memcpy(mask_out[i].mask, &mi[1], mask_out[i].mask_len);
+        mask += mask_out[i].mask_len;
+        mi = (xXIEventMask*)((char*)mi + mi->mask_len * 4);
+        mi++;
+    }
+
+    *num_masks_return = reply.num_masks;
+
+    return mask_out;
+
+error:
+    if (mask_in)
+        Xfree(mask_in);
+    *num_masks_return = -1;
+    UnlockDisplay(dpy);
+    SyncHandle();
+    return NULL;
+
+}