[PATCH 2/2] clients: Maximize window when double touch on title bar

[Pekka Paalanen]

On Tue, 9 Sep 2014 10:11:51 +0000
"Zhang, Xiong Y" <xiong.y.zhang at intel.com> wrote:

> > > > Signed-off-by: Xiong Zhang <xiong.y.zhang at intel.com>
> > > ---
> > >  clients/window.c    | 26 ++++++++++++++++++++++++--
> > >  shared/cairo-util.h |  7 +++++++
> > >  shared/frame.c      | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 80 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/clients/window.c b/clients/window.c index 
> > > 7c9c518..a608a84 100644
> > > --- a/clients/window.c
> > > +++ b/clients/window.c
> > > @@ -363,6 +363,7 @@ struct window_frame {
> > >
> > >       uint32_t last_time;
> > >       uint32_t did_double, double_click;
> > > +     int32_t last_id, double_id;
> > >  };
> > >
> > >  struct menu {
> > > @@ -2380,7 +2381,23 @@ frame_touch_down_handler(struct widget 
> > > *widget, struct input *input,  {
> > >       struct window_frame *frame = data;
> > >
> > > -     frame_touch_down(frame->frame, input, id, x, y);
> > > +     frame->double_click = 0;
> > > +     if (time - frame->last_time <= DOUBLE_CLICK_PERIOD &&
> > > +         frame->last_id == id) {
> > > +             frame->double_click = 1;
> > > +             frame->did_double = 1;
> > > +             frame->double_id = id;
> > > +     } else
> > > +             frame->did_double = 0;
> > > +
> > > +     frame->last_time = time;
> > > +     frame->last_id = id;
> > > +
> > > +     if (frame->double_click)
> > > +             frame_double_touch_down(frame->frame, input, id, x, y);
> > > +     else
> > > +             frame_touch_down(frame->frame, input, id, x, y);
> > > +
> > >       frame_handle_status(frame, input, time, 
> > > THEME_LOCATION_CLIENT_AREA);
> > 
> > >Hi,
> > 
> > >hmm, should this perhaps be restricted to the case, where you start 
> > >with no touches down, then one touch id does down-up, then again 
> > >down-up, and only interpret that as a double-touch?
> > 
> > In order to support multi touch, I didn't do this restriction.
> > 
> > >With your current code, isn't is possible to keep, say, one finger 
> > >down while double-touching with another finger? Is that intended?
> > >Thanks,
> > >pq
> > 
> > It is my intend to keep one finger down while double-touching with another finger.
> > So that we can operate with both hands and support multi touch.
> 
> >But touch points are never independent, are they?
> >Doesn't putting one finger down take an implicit grab, which causes all additional fingers to be restricted to the 
> >surface with the grab?
> Yes, I agree with you.
> 
> >You cannot distinguish left hand from right, fingers all create just arbitrary touch points.
> 
> >In src/input.c it is written around line 1523:
> >		/* the first finger down picks the view, and all further go
> >		 * to that view for the remainder of the touch session i.e.
> >		 * until all touch points are up again. */
> 
> >So that means that you cannot hold a finger down on one window, and then double-tap another window.
> So this means that all touch points must be in one window in order to support multi touch. Weston have given us such limitation.
> 
> >Does it really make sense to be able to hold one finger down on the same window, and double-tap with another?
> 
> >If I hold a finger down on the window, can I usually use another finger to push button widgets on the same
> >window? By "usually" I mean in whatever touch interfaces there are on the market / in the wild.
> In a virtual key board, one finger could hold Shift key and another finger could single or double touch other key to enter capital like physical key board.
> 

I guess it might make sense in that case. However, here we are talking
about maximizing a window. When you maximize a window, everything tends
to move, which means that the things that were under the existing touch
points are no longer there.

> >How would you distinguish a "left thumb down on something, drag & drop something else with right index 
> >finger" from the "zoom pinch gesture"?
> 
> If all touch points are in one window at the same time, each touch point has a unique touch ID. Using this ID, APP could identify them. Left thumb's drog & dorp and Right index finger 's zoom gesture are independent.
> 

The ID does not identify the finger or hand. On touch-down, an
arbitrary ID is allocated regardless of what is touching the screen,
and on touch-up the ID is released for re-use. Therefore the pinch
gesture is indistinguishable from two simultaneous unrelated touches
without some additional context information.

> My current code is compatible with your proposal restriction, and it could also add multi touch support in one window.

Okay, judging from comments here and elsewhere, it seems everything
goes with touch user interfaces.

So if no-one objects, this one is queued for 1.7.


Thanks,
pq