Move _activeCardDragEndPoint near build() so it's more obvious that it
is part of the build state.
Make a couple of functions use setState() since they modify variables
that are used by build().
Add a more detailed comment to the empty setState() call, since those
are dubious in general and need explaining when they occur, lest people
start using them as magic incantations to Make Things Work.
If a StatefulComponent marks itself dirty, gets rebuilt, then its parent
gets rebuilt, its parent will find that its child is from a newer
generation and hasn't changed. Previously, we considered two stateful
nodes to not be syncable even if they were the same; combined with the
way the "old" node looks like it's been put elsewhere (since it's
already been synced), we end up confused as to why the new node is
already mounted.
This fixes the problem by making the canSync logic consider two
identical nodes as syncable (since they are; syncChild() short-circuits
that case), and by changing syncChildren to consider identical nodes as
matches even if they are already synced.
This specifically improves the reporting of exceptions in syncChild(),
and makes the way we've been adding information to toStringName() less
ad-hoc and easier to extend.
Also:
- don't mark a node as from the new generation if it is dirty, since we
know it still has to be built.
- establish the rule that you can't call setState() during initState()
or build().
- make syncChild() return early for unchanged children.
- update the tests, including adding a new one.
Surface all the constructor arguments of AnimationTiming in all its subclasses.
Remove some pointless casts.
Fix some typos.
Put constructors first in class declarations.
Remove some blank lines where they just confused the structure of the code.
- Add documentation for AnimationTiming.
- typo: defaules -> defaults.
- added type information to isWatching() signature.
- made Widget.toStringName() include more useful information.
- cleaned up StatefulComponent._sync(): more specific signature, change
redundant if to else, remove redundant cast.
- change order of TransitionBase arguments for consistency.
- prevent TransitionBase from affecting the performance in its
constructor when it didn't create it (but see #1103).
- remove TODO() from @mpcomplete... no, there is not currently a better
way to inherit a constructor, unfortunately.
If it's a StatefulComponent, then it's ok to reuse it so long as it
hasn't been initialised.
If it's a regular Component or a TagNode, then it's always ok to reuse.
If it's a RenderObjectWrapper, then it's ok to reuse so long as it
doesn't have a renderObject.
To put it another way, this changes how we prevent the following
nonsensical situations from arising:
- Sync two stateful StatefulComponents together
- Sync two RenderObjectWrappers with RenderObjects together
When either of those cases happen, we just drop the old one on the
ground and use the new one unchanged.
Dismissable now only depends on GestureDetector.
Added a unit test that verifies that issue #1068 has been fixed. It's commented out for now.
Cleaned up VelocityTracker.cc et al a little.
That way the fling engages in the same direction as the scroll. For example, if
you have a horizontal scroll nested inside a vertical scroll, the fling will
take place in the same direction as the scroll.
Previously, if you used a number of nested Blocks, they'd each try to register
drag gesture detectors even though they can't actually scroll. This CL teaches
Scrollable to watch for drag gestures only when it can actually scroll.
Allows a non-initialised stateful component to be used as a source of
settings more than once. Instead of asserting that it was only being
used once, we assert that once you are stateful you don't get used as a
bag of settings, which is the real thing we were trying to avoid.
A lot of code ends up using StatefulComponents as a source multiple
times in a row, and before this would fail.
Patch by Ian Hickson
Added FlingGestureRecognizer and exposed it in the GestureDetector class. FlingGestureRecognizer is based on the Android/Chromium VelocityTracker class which computes a velocity vector for for a list of X,Y,Time tuples.
The Scrollable classes now use the FlingGestureRecognizer. Dismissable and Drawer still need to be updated
