[PATCH weston] desktop-shell: Don't crash on zoom without a pointer in the seat

[Derek Foreman]

On 06/01/15 04:04 PM, Peter Hutterer wrote:
> On Tue, Jan 06, 2015 at 02:28:13PM -0600, Derek Foreman wrote:
>> The zoom effect zooms at the seat's current pointer location.  When no
>> pointer is present the zoom key bindings cause a crash.
>>
>> Instead, check for the absence of a pointer and log a warning.
>>
>> Signed-off-by: Derek Foreman <derekf at osg.samsung.com>
> 
> it would be a bit more involved but I think it'd be more obvious to a user
> if the zoom just happened around the center of the output. Or if you want to

Which output? :)

> get fancy on the center of the surface with the keyboard focus.

I actually started off with that in mind, and chickened out when things
got sticky.  Wasn't really sure I could come up with sensible semantics
for all the cases.  But I can give it a try.

> that way the user still sees something happening when the key is hit.

If I have multiple outputs, I don't know which to use - though if a
window has keyboard focus I could use the center of that (as you suggest).

If I plug in a mouse, should zoom begin to follow it?  Hooking up the
motion handler on hotplug isn't intractable, but the pointer gets pretty
silly default co-ordinates and this will result in a jump.  no big deal?
 (Maybe the pointer should instantiate at the center of the zoomed area?
 Multiple outputs confuse life yet again?)

If I unplug the mouse the pointer isn't freed, it's just sort of
orphaned.  So if I use the hot key after unplugging the mouse it still
zooms about the old cursor co-ordinates.  I'll send a patch for that
right away - I'm a little worried about any potential side effects it
might have.  I don't know if the current behavior is intentional.

> having said that, this patch looks fine for what it does
> Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
> 
> Cheers,
>    Peter
> 
>> ---
>>  desktop-shell/shell.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
>> index a7514f7..0ec6d33 100644
>> --- a/desktop-shell/shell.c
>> +++ b/desktop-shell/shell.c
>> @@ -4671,6 +4671,11 @@ do_zoom(struct weston_seat *seat, uint32_t time, uint32_t key, uint32_t axis,
>>  	struct weston_output *output;
>>  	float increment;
>>  
>> +	if (!seat->pointer) {
>> +		weston_log("Zoom hotkey pressed but seat '%s' contains no pointer.\n", seat->seat_name);
>> +		return;
>> +	}
>> +
>>  	wl_list_for_each(output, &compositor->output_list, link) {
>>  		if (pixman_region32_contains_point(&output->region,
>>  						   wl_fixed_to_double(seat->pointer->x),
>> -- 
>> 2.1.4
>>
>> _______________________________________________
>> wayland-devel mailing list
>> wayland-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/wayland-devel
>>