Re: XInput 2 support (again)

[Po Lu]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> @@ -3074,6 +3078,35 @@ x_window (struct frame *f, long window_prompting)
>>    class_hints.res_class = SSDATA (Vx_resource_class);
>>    XSetClassHint (FRAME_X_DISPLAY (f), XtWindow (shell_widget), 
>> &class_hints);
>>  
>> +#ifdef HAVE_XINPUT2
>> +  if (FRAME_DISPLAY_INFO (f)->supports_xi2)
>> +    {
>> +      XIEventMask mask;
>> +      ptrdiff_t l = XIMaskLen (XI_LASTEVENT);
>> +      unsigned char *m;
>> +      mask.mask = m = alloca (l);
>> +      memset (m, 0, l);
>> +      mask.mask_len = l;
>> +      mask.deviceid = XIAllMasterDevices;
>> +
>> +      XISetMask (m, XI_ButtonPress);
>> +      XISetMask (m, XI_ButtonRelease);
>> +      XISetMask (m, XI_KeyPress);
>> +      XISetMask (m, XI_KeyRelease);
>> +      XISetMask (m, XI_Motion);
>> +      XISetMask (m, XI_Enter);
>> +      XISetMask (m, XI_Leave);
>> +      XISetMask (m, XI_FocusIn);
>> +      XISetMask (m, XI_FocusOut);
>> +      XISetMask (m, XI_PropertyEvent);
>> +      XISetMask (m, XI_HierarchyChanged);
>> +      XISetMask (m, XI_DeviceChanged);
>> +      XISelectEvents (FRAME_X_DISPLAY (f),
>> +                  FRAME_X_WINDOW (f),
>> +                  &mask, 1);
>> +    }
>> +#endif
>> +
>>  #ifdef HAVE_X_I18N
>>    FRAME_XIC (f) = NULL;
>>    if (use_xim)
>> @@ -3254,6 +3287,35 @@ x_window (struct frame *f)
>>      }
>>  #endif /* HAVE_X_I18N */
>>  
>> +#ifdef HAVE_XINPUT2
>> +  if (FRAME_DISPLAY_INFO (f)->supports_xi2)
>> +    {
>> +      XIEventMask mask;
>> +      ptrdiff_t l = XIMaskLen (XI_LASTEVENT);
>> +      unsigned char *m;
>> +      mask.mask = m = alloca (l);
>> +      memset (m, 0, l);
>> +      mask.mask_len = l;
>> +      mask.deviceid = XIAllMasterDevices;
>> +
>> +      XISetMask (m, XI_ButtonPress);
>> +      XISetMask (m, XI_ButtonRelease);
>> +      XISetMask (m, XI_KeyPress);
>> +      XISetMask (m, XI_KeyRelease);
>> +      XISetMask (m, XI_Motion);
>> +      XISetMask (m, XI_Enter);
>> +      XISetMask (m, XI_Leave);
>> +      XISetMask (m, XI_FocusIn);
>> +      XISetMask (m, XI_FocusOut);
>> +      XISetMask (m, XI_PropertyEvent);
>> +      XISetMask (m, XI_HierarchyChanged);
>> +      XISetMask (m, XI_DeviceChanged);
>> +      XISelectEvents (FRAME_X_DISPLAY (f),
>> +                  FRAME_X_WINDOW (f),
>> +                  &mask, 1);
>> +    }
>> +#endif
>> +

> Any reason this isn't consolidated into a separate function to avoid the
> code duplication?

Thanks, done.  During development there were a few different masks that
needed to be added to the no-toolkit build.

>> +      struct xi_device_t *xi_device =
>> +        &dpyinfo->devices[actual_devices++];

> The GNU coding standard encourages to cut lines just *before* infix
> operators rather after.  E.g.:
>
>         struct xi_device_t *xi_device
>           = &dpyinfo->devices[actual_devices++];

Also fixed, see attached patch.

> That's a damn large chunk of code to add into a function.

It's `handle_one_xevent' after all.

> A lot of it is copy&pasted from other parts of `handle_one_xevent`.
> Please avoid such code duplication (`handle_one_xevent` is already bad
> enough from this point of view).

I don't know enough about most of the Core Input code to dare change it.
It does mysterious things that I can not understand.

Also, most of the XInput 2 event code differs in subtle ways from the
Core Input code (see for example how the button grab is handled there).

It would make even more of a mess to try to reuse the Core Input 

> Also the code uses more than 80 columns at various places for no good
> reason; that needs to be fixed.

I tried to fix that as well.  Thanks for the comments.

0001-Add-support-for-event-processing-via-XInput-2.patch
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