Xephyr: option to disable grabbing the host

This patch makes it possible to use C-S key combinations
within Xephyr without losing access to the host window manager's
commands.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

3 files changed, 18 insertions, 3 deletions

diff --git a/hw/kdrive/ephyr/ephyr.c b/hw/kdrive/ephyr/ephyr.c
index 8b88f3e6d..57617107d 100644
--- a/hw/kdrive/ephyr/ephyr.c
+++ b/hw/kdrive/ephyr/ephyr.c
@@ -68,6 +68,7 @@ typedef struct _EphyrInputPrivate {
 
 Bool EphyrWantGrayScale = 0;
 Bool EphyrWantResize = 0;
+Bool EphyrWantNoHostGrab = 0;
 
 Bool
 host_has_extension(xcb_extension_t *extension)
@@ -649,7 +650,11 @@ ephyrInitScreen(ScreenPtr pScreen)
 
     EPHYR_LOG("pScreen->myNum:%d\n", pScreen->myNum);
     hostx_set_screen_number(screen, pScreen->myNum);
-    hostx_set_win_title(screen, "(ctrl+shift grabs mouse and keyboard)");
+    if (EphyrWantNoHostGrab) {
+        hostx_set_win_title(screen, "xephyr");
+    } else {
+        hostx_set_win_title(screen, "(ctrl+shift grabs mouse and keyboard)");
+    }
     pScreen->CreateColormap = ephyrCreateColormap;
 
 #ifdef XV
@@ -1092,12 +1097,13 @@ ephyrProcessKeyRelease(xcb_generic_event_t *xev)
     if (!keysyms)
         keysyms = xcb_key_symbols_alloc(conn);
 
-    if (((xcb_key_symbols_get_keysym(keysyms, key->detail, 0) == XK_Shift_L
+    if (!EphyrWantNoHostGrab &&
+        (((xcb_key_symbols_get_keysym(keysyms, key->detail, 0) == XK_Shift_L
           || xcb_key_symbols_get_keysym(keysyms, key->detail, 0) == XK_Shift_R)
          && (key->state & XCB_MOD_MASK_CONTROL)) ||
         ((xcb_key_symbols_get_keysym(keysyms, key->detail, 0) == XK_Control_L
           || xcb_key_symbols_get_keysym(keysyms, key->detail, 0) == XK_Control_R)
-         && (key->state & XCB_MOD_MASK_SHIFT))) {
+         && (key->state & XCB_MOD_MASK_SHIFT)))) {
         KdScreenInfo *screen = screen_from_window(key->event);
         EphyrScrPriv *scrpriv = screen->driver;
 
diff --git a/hw/kdrive/ephyr/ephyrinit.c b/hw/kdrive/ephyr/ephyrinit.c
index 36935318a..bcfb7506d 100644
--- a/hw/kdrive/ephyr/ephyrinit.c
+++ b/hw/kdrive/ephyr/ephyrinit.c
@@ -33,6 +33,7 @@
 extern Window EphyrPreExistingHostWin;
 extern Bool EphyrWantGrayScale;
 extern Bool EphyrWantResize;
+extern Bool EphyrWantNoHostGrab;
 extern Bool kdHasPointer;
 extern Bool kdHasKbd;
 extern Bool ephyr_glamor, ephyr_glamor_gles2;
@@ -153,6 +154,7 @@ ddxUseMsg(void)
     ErrorF("-name [name]         define the name in the WM_CLASS property\n");
     ErrorF
         ("-title [title]       set the window title in the WM_NAME property\n");
+    ErrorF("-no-host-grab        Disable grabbing the keyboard and mouse.\n");
     ErrorF("\n");
 }
 
@@ -360,6 +362,10 @@ ddxProcessArgument(int argc, char **argv, int i)
         return 2;
     }
     /* end Xnest compat */
+    else if (!strcmp(argv[i], "-no-host-grab")) {
+        EphyrWantNoHostGrab = 1;
+        return 2;
+    }
 
     return KdProcessArgument(argc, argv, i);
 }
diff --git a/hw/kdrive/ephyr/man/Xephyr.man b/hw/kdrive/ephyr/man/Xephyr.man
index f14f6c864..c04379035 100644
--- a/hw/kdrive/ephyr/man/Xephyr.man
+++ b/hw/kdrive/ephyr/man/Xephyr.man
@@ -63,6 +63,9 @@ improvement is negligible.
 .B -resizeable
 Allow the Xephyr window to be resized, even if not embedded into a parent
 window. By default, the Xephyr window has a fixed size.
+.TP 8
+.B -no-host-grab
+Disable grabbing the keyboard and mouse.
 .SH "SIGNALS"
 Send a SIGUSR1 to the server (e.g. pkill -USR1 Xephyr) to
 toggle the debugging mode.