Re: [Qemu-devel] [PATCH] ui/cocoa.m: fix sending mouse event to guest

[Programmingkid]

On Apr 2, 2016, at 1:35 PM, Peter Maydell wrote:

> On 2 April 2016 at 18:25, Programmingkid <address@hidden> wrote:
>> 
>> On Apr 2, 2016, at 1:07 PM, Peter Maydell wrote:
>> 
>>> On 2 April 2016 at 17:56, Programmingkid <address@hidden> wrote:
>>>> The mouse down event should not be sent to the guest if the mouse down 
>>>> event
>>>> causes an activation of QEMU. This patch prevents activation clicks from 
>>>> going
>>>> to the guest.
>>>> 
>>>> Signed-off-by: John Arbuckle <address@hidden>
>>>> ---
>>>> ui/cocoa.m | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>> 
>>>> diff --git a/ui/cocoa.m b/ui/cocoa.m
>>>> index 60a7c07..07d9c86 100644
>>>> --- a/ui/cocoa.m
>>>> +++ b/ui/cocoa.m
>>>> @@ -698,7 +698,7 @@ QemuCocoaView *cocoaView;
>>>>         * call below. We definitely don't want to pass that click through
>>>>         * to the guest.
>>>>         */
>>>> -        if ((isMouseGrabbed || [[self window] isKeyWindow]) &&
>>>> +        if ((isMouseGrabbed && [[self window] isKeyWindow]) &&
>>>>            (last_buttons != buttons)) {
>>>>            static uint32_t bmap[INPUT_BUTTON__MAX] = {
>>>>                [INPUT_BUTTON_LEFT]       = MOUSE_EVENT_LBUTTON,
>>>> --
>>>> 2.7.2
>>> 
>>> I'm afraid I don't really understand why you think this
>>> should change. On the face of it the current code looks right:
>>> we pass through the mouse button if:
>>>  (1) we've got the mouse grab
>>> or (2) our window has the focus, even if it's not grabbed
>>> 
>>> I would expect the "activation click" to be "we don't have
>>> the mouse grab, and we don't have focus either (some other
>>> app is foreground)".
>> 
>> When QEMU's main window is in the background and the user clicks on it,
>> the NSLeftMouseUp case in the handleEvent: method will set the
>> isMouseGrabbed variable to true. This means the
>> "if ((isMouseGrabbed || [[self window] isKeyWindow]) &&
>> (last_buttons != buttons))" code will always be true for a left
>> mouse button click. The mouse event will be sent to the guest
>> when it shouldn't be.
> 
> OK, that sounds like a bug, but this doesn't look like the
> right way to fix it, because with your change we won't
> pass through the click if this is a click on the window
> when it's not in the background.

I think logically this is the best solution. If the window is in the foreground 
and doesn't have the mouse grabbed, the user can't move the mouse pointer in 
the guest. This could cause stuff to be clicked that might cause undesirable 
effects.