Bugzilla

(In reply to Botond Ballo [:botond] from comment #5)
> by writing a gtest to exercise the scenario (something we should do anyways)

Here's a description of the scenario at issue:

 * Suppose the touch-start tolerance is 10 pixels.
 * Page receives a touch-start event at some point, say (0, 50).
 * Page receives a touch-move event, say at (0, 70), where the distance from the previous point (here, 20 pixels) is larger than the tolerance.
    * Currently, this event successfully overcomes the touch-start tolerance, but doesn't actually cause scrolling.
 * Page receives another touch-move event, say at (0, 90), and now scrolls by 20 pixels.

We would like the total distance scrolled to be 30 pixels (the distance the finger moved from (0,50) to (0,90) minus the 10-pixel tolerance), but currently it's only 20 pixels (because the first touch-move event gets discarded completely).

(In reply to Botond Ballo [:botond] from comment #5)
> by writing a gtest to exercise the scenario (something we should do anyways)

Here's a description of the scenario at issue:

 * Suppose the touch-start tolerance is 10 pixels.
 * Page receives a touch-start event at some point, say (50, 50).
 * Page receives a touch-move event, say at (50, 70), where the distance from the previous point (here, 20 pixels) is larger than the tolerance.
    * Currently, this event successfully overcomes the touch-start tolerance, but doesn't actually cause scrolling.
 * Page receives another touch-move event, say at (50, 90), and now scrolls by 20 pixels.

We would like the total distance scrolled to be 30 pixels (the distance the finger moved from (50,50) to (50,90) minus the 10-pixel tolerance), but currently it's only 20 pixels (because the first touch-move event gets discarded completely).

(In reply to Botond Ballo [:botond] from comment #5)
> by writing a gtest to exercise the scenario (something we should do anyways)

Here's a description of the scenario at issue:

 * Suppose the touch-start tolerance is 10 pixels.
 * Page receives a touch-start event at some point, say (50, 50).
 * Page receives a touch-move event, say at (50, 70), where the distance from the previous point (here, 20 pixels) is larger than the tolerance.
    * Currently, this event successfully overcomes the touch-start tolerance, but doesn't itself cause scrolling.
 * Page receives another touch-move event, say at (50, 90), and now scrolls by 20 pixels.

We would like the total distance scrolled to be 30 pixels (the distance the finger moved from (50,50) to (50,90) minus the 10-pixel tolerance), but currently it's only 20 pixels (because the first touch-move event gets discarded completely).