The problematic scenario is when the page is exactly the height of the screen
(with dynamic toolbar not visible). In this case, the scrollable() function in
Axis.java returns false on the vertical axis, and so the JavaPanZoomController
never does any scrolling. This in turns means that the scrollBy code in
LayerMarginsAnimator never gets to run, so you can never drag the toolbar back
into being visible. The patch ensures that scrollable() returns true when some
or all of the margins are not visible, ensuring that in these scenarios the
user can still scroll the toolbar back onto the screen. This patch also adds
some comments/asserts to verify the new code is threadsafe.
Move the margin animation-cancelling call into the margins-pinned check block
in LayerMarginsAnimator to make sure margin animations aren't cancelled by
scrolling when margins are locked.
This stops margins from being exposed unless the drag was started in an area
of the viewport that's near said margin. The margins will always be exposed
when reaching the edge of the page.
Refactor the dynamic toolbar code so that the ownership of various properties
is clearer, and the page is offset by the toolbar instead of being overlapped.
This fixes problems with the scroll origin of the page not corresponding to
the visible origin on the screen.
Refactor the dynamic toolbar code so that the ownership of various properties
is clearer, and the page is offset by the toolbar instead of being overlapped.
This fixes problems with the scroll origin of the page not corresponding to
the visible origin on the screen.
