[Qemu-devel] [PATCH] ui/cocoa: Pass command key through to guest when VM has mousegrab

[Peter Maydell <peter.maydell@linaro.org>]

The guest might want to be able to use the command key for its won
purposes (as command if it is MacOS X, or for the Windows key if
it is a PC guest, for instance). In line with other UI frontends,
pass it through if the guest has mousegrab, and only use it for
host UI menu accelerators if not grabbed.

Thanks to John Arbuckle for reporting this problem, helping
us work through what the best solution would be and providing
a patch which was the initial inspiration for this one.

Reported-by: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
John -- my apologies for having let this issue (and your patch
http://patchwork.ozlabs.org/patch/267627/ ) lie around
unaddressed/unreviewed for such a long time. I finally got
some time to look at the problem, and I think this patch should
fix the problem of Mac guests not getting the command key
(and also of Windows guests not getting Windows keys, since
they're the same scancode).

Tested with an x86/Linux guest and "showkeys" to confirm that
when mousegrab is enabled the command keys are passed through.

 ui/cocoa.m | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/ui/cocoa.m b/ui/cocoa.m
index be49179..d38cf22 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -129,8 +129,8 @@ int keymap[] =
     14, //  51      0x33    0x0e            BKSP    QZ_BACKSPACE
     0,  //  52      0x34    Undefined
     1,  //  53      0x35    0x01            ESC     QZ_ESCAPE
-    0,  //  54      0x36                            QZ_RMETA
-    0,  //  55      0x37                            QZ_LMETA
+    220, // 54      0x36    0xdc    E0,5C   R GUI   QZ_RMETA
+    219, // 55      0x37    0xdb    E0,5B   L GUI   QZ_LMETA
     42, //  56      0x38    0x2a            L SHFT  QZ_LSHIFT
     58, //  57      0x39    0x3a            CAPS    QZ_CAPSLOCK
     56, //  58      0x3A    0x38            L ALT   QZ_LALT
@@ -206,8 +206,6 @@ int keymap[] =
 
 /* Aditional 104 Key XP-Keyboard Scancodes from http://www.computer-engineering.org/ps2keyboard/scancodes1.html */
 /*
-    219 //          0xdb            e0,5b   L GUI
-    220 //          0xdc            e0,5c   R GUI
     221 //          0xdd            e0,5d   APPS
         //              E0,2A,E0,37         PRNT SCRN
         //              E1,1D,45,E1,9D,C5   PAUSE
@@ -494,6 +492,12 @@ QemuCocoaView *cocoaView;
     switch ([event type]) {
         case NSFlagsChanged:
             keycode = cocoa_keycode_to_qemu([event keyCode]);
+
+            if ((keycode == 219 || keycode == 220) && !isMouseGrabed) {
+              /* Don't pass command key changes to guest unless mouse is grabbed */
+              keycode = 0;
+            }
+
             if (keycode) {
                 if (keycode == 58 || keycode == 69) { // emulate caps lock and num lock keydown and keyup
                     kbd_put_keycode(keycode);
@@ -517,15 +521,15 @@ QemuCocoaView *cocoaView;
             }
             break;
         case NSKeyDown:
+            keycode = cocoa_keycode_to_qemu([event keyCode]);
 
-            // forward command Key Combos
-            if ([event modifierFlags] & NSCommandKeyMask) {
+            // forward command key combos to the host UI unless the mouse is grabbed
+            if (!isMouseGrabed && ([event modifierFlags] & NSCommandKeyMask)) {
                 [NSApp sendEvent:event];
                 return;
             }
 
             // default
-            keycode = cocoa_keycode_to_qemu([event keyCode]);
 
             // handle control + alt Key Combos (ctrl+alt is reserved for QEMU)
             if (([event modifierFlags] & NSControlKeyMask) && ([event modifierFlags] & NSAlternateKeyMask)) {
@@ -581,6 +585,13 @@ QemuCocoaView *cocoaView;
             break;
         case NSKeyUp:
             keycode = cocoa_keycode_to_qemu([event keyCode]);
+
+            // don't pass the guest a spurious key-up if we treated this
+            // command-key combo as a host UI action
+            if (!isMouseGrabed && ([event modifierFlags] & NSCommandKeyMask)) {
+                return;
+            }
+
             if (qemu_console_is_graphic(NULL)) {
                 if (keycode & 0x80)
                     kbd_put_keycode(0xe0);
-- 
1.7.11.4