669501 - unable to pan diagonally if initial movement direction is 90 degrees

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: Panning/Zooming, defect)

Description

[:Atoll]

Problem: If I start panning around a web page with a vertical drag, and then try to pan diagonally, Fennec ignores the non-vertical component of the pan.  The same problem occurs with a horizontal drag.

Workaround: Starting every drag with a diagonal drag permits panning in any direction.

Parity: Stock browser initially locks to vertical pan only in the same way as Fennec, but then realizes that I'm trying to pan sideways and unlocks the panning.

Comment 1

[Wesley Johnston (:wesj)]

Attachment: Patch

We currently refuse to release the lock if you've moved more than a little bit away from the start point. This removes that check.

We then also base deciding whether to lock based on how far you have moved in the x-direction vs. the y-direction. This changes that. Still building to test on device. Will ask for review after.

Comment 2

[Wesley Johnston (:wesj)]

Attachment: Patch

Note we we will only revert this if you move 0.8 inches in the new direction. On my phone, for verticals pans starting in the middle of the screen, moving that far in the horizontal direction is barely possible.

Stock seems to allow this, but it seemed kinda sporadic to me too. Sometimes it would allow changing the lock. Sometimes not. So... not entirely sure if we want this or not.

Comment 3

[Benjamin Stover (:stechz)]

Comment on attachment 547232 [details] [diff] [review]
Patch

The problem with this patch is that I can't put my finger down and move around in a small circle because it's locked. I can go out of my way to unlock it, but it feels more restrictive to me than before.

Perhaps reduce the lock revert threshold?

Comment 4

[Benjamin Stover (:stechz)]

I do think this is worth investigating, as we were in a totally different world when this was written. Sidebars came out all the time and they were very slow too.

We could do much more free locking as long as quick swipes never start bringing out the sidebars. Perhaps the locking behavior should depend on the size of the pan for the past, say, 400msecs. If it was a violent stroke, keep it in line. If there is more finesse, allow leeway.