[W/M] gestures in apps near the edges are detected as edge swipe

[Oren Horev]

Reported against #90 on phone and tablet

NOTE this bug is related to https://bugs.launchpad.net/manhattan/+bug/1129857 but adds on it

edge detection is often activated when scroll, flick or tap occur near the edge (2GU on #90). This is clearly due to the hint area being too big but also because we are not making a distinction between swipes / flicks and taps. A tap near the edge should not be detected as an edge swipe.
For swipe / flicks the edge detection region should be small as possible. An acceptable value is an optimum between reliable edge detection and minimal false activations of non shell interactions.

to reproduce:
phone and tablet
start and app
tap near the bottom edge. Toolbar begins to appear.

phone
launch notepad, focus on note
on OSK type and tap backspace - a right edge is detected new app start to slide in

in notepad create new note
tap and hold on the top left corner
launcher slides in and app launched from the launcher

launch browser
double tap ubuntu.com page
tap close button on top right corner - a right edge is detected new app start to slide in

expected behaviour:
tap near the edge
no edge detection take place, app receives the gesture

[Oren Horev (oreneeshy)]

As noted in the top of the bug this is not s duplicate of bug #1129857. It includes the issue reported in that bug but adds all additional edges.

[Michał Sawicz (saviq)]

See https://bugs.launchpad.net/marumbi/+bug/1129857/comments/2 for a list of issues with edge gestures that we may encounter.

[Oren Horev (oreneeshy)]

manta #90
tablet analysis conclusion

In general
my impression is that the edges are not equal in size left seems about 1gu, the right 2gu and the bottom 10gu

browser
- bottom edge is vulnerable for scrolls up - currently I can grab the bottom edge at more than 10GU away from the edge - a natural position to flick a web page
- right edge is also vulnerable to pinch and zoom and dismissal of selection boxes (this might be a non issue as selection seems too general - highlights an entire page very easily)

camera (landscape)
- right edge is conflicting with camera easily. Its is difficult not to hit the edge while using camera especial the shutter
- left edge generally safe

Gallery
- bottom edge is vulnerable for scrolls up (events and photos tabs particularly) - same as browser
- Left edge - not too volatile but can be destructive as when using the HUD sliders and app stack (can be handled with margins on the design side)

[Florian Boucault (fboucault)]

Still valid. Michael has very useful thoughts about how the N9 does it nicely.

[Michał Sawicz (saviq)]

Marking as dupe of #1236290 that has more detail.