Rather than using a microtask to schedule component build functions, instead
use the scheduler. We now tread building just like layout and painting as a
visual update.
Added an optional duration: to Scrollable.scrollTo(newOffset, duration: d) which animates the scroll to newOffset.
Refactored the Scrollable implementation a little to make the roles of the "toEnd" and "toOffset" animations clearer.
_handlePointerDown() now stops both animations.
Similarly, we only call settleScrollOffset() from the cancel gesture handlers if the animations aren't already running.
This patch contains some minor improvements to the network service:
- We now cache the connection to the network service so we don't need to spin
it up for each request.
- We now manage the lifetime of NetworkServiceImpl in the same way as other
services.
Also, update the workbench sky_tools dependency to the latest version.
This introduces a GlobalKey registry so that you can tell when a key
has gone away (so you can unfocus dead dialogs).
Also I added an assert that you're not calling setState() during a
build. It turns out that doing so means you have a bug, because since
you're dirty already (you're building), you won't get rebuilt.
The focus code itself is gnarly. It uses a Component and an internal
Inherited TagNode to manage the focus state, and does crazy things
like updating its state during build to pretend retroactively that it
was built with some other state, once someone asks for focus the first
time (i.e. the first time it's examined, so you can't tell that it was
in a different state before). It does this so that it can autofocus
controls which otherwise wouldn't be focused.
This moves all the focus management into Navigator and showDialog(),
so the complexity is all buried deep and not visible to apps,
hopefully.
To do something like two tabs that each have an Input widget that
needs to be focused when you switch panes, you'd need to have two
Focus objects, one in each tab, and you need to set their autofocus to
true (maybe that should be the default?).
This removes the need to manually include the dialog builder in the main window's build() function.
It also removes the need to track if a dialog is visible.
Other changes:
- I made dialog.dart a bit more readable.
- I renamed transitionFinished to fullyOpaque since that's what actually matters.
- I made Routes track if they're opaque. Eventually this should probably be more configurable when creating the route.
Directions for Future Research:
- Use this for focus management somehow.
- The popup menu should use something like this.
- We should factor the following out into a showDialog() function that returns a future for the dialog's exit result:
navigator.push(new DialogRoute(builder: (navigator, route) { ... }));
- Maybe navigator.pop() should take a value to return to that Future.
This CL introduces a SkyShell.apk that is separate from the SkyDemo.apk that we
upload to the store to show our demos. The SkyShell.apk is just an empty shell
that can run Sky applications on Android.
I've noticed an anti-pattern emerge where people call scheduleBuild()
when they think they've changed enough state that they should rebuild,
instead of just wrapping their changes in setState(). This leads to
them missing state changes, having extraneous scheduleBuild() calls,
and other similar bugs.
By removing scheduleBuild(), the only way to actually schedule a build
now is to call setState(), and hopefully that'll make it much clearer
that you're only supposed to do this when you change state.
Assert that there are no duplicates.
Export GlobalKey from basic.dart, so that people don't have to import widgets.dart just for that.
Fix the "initialFocus" feature which actually didn't work.
This patch provides a class to manage focus, Focus, and a class to
manage ownership of the keyboard, KeyboardHandle.
Inherited (in widgets.dart) is adjusted to support subclasses that
need to copy state from instance to instance.
A GlobalKey key type is introduced that is basically the same as
UniqueKey. Component classes that need a globally-unique key can
specify that their 'key' constructor argument is a GlobalKey.
Focus
-----
You can use `Focus.at(this)` to determine if you, a Component, are
currently focused.
You can use `Focus.moveTo(this)` to take the focus or give it to a
particular component.
For this to work, there has to be a Focus class in the widget
hierarchy.
Currently, there can only be one Focus class, because nested scopes
aren't supported. We should add support for that in a future patch.
See issue #229.
KeyboardHandle
--------------
Instead of directly interacting with the keyboard service, you now ask
for a KeyboardHandle using `_keyboard.show(client)`. This returns a
KeyboardHandle class. On that class, you can call `handle.release()`
when you want to hide the keyboard. If `handle.attached` is still
true, and you need to reshow the keyboard after the user hid it, then
you can can `handle.showByRequest()`.
The point of this is that the `keyboard.show()` method maintains the
invariant that only one KeyboardHandle is live at a time.
There are some issues with the keyboard service that I filed as a
result of doing this patch: #226#227
If your constraints are tight when you get laid out, you don't get a
relayout subtree root.
If you don't have a relayout subtree root, and you get marked dirty,
you go through layoutWithoutResize() rather than layout(), so we don't
get a parentUsesSize.
If you're not dirty and your constraints didn't change, layout() skips
your layout.
So then if your initial layout had parentUsesSize:true, and then you
got marked dirty directly, you would set your size with
parentCanUseSize=false, and then later if your parent tried to lay you
out then read your size, it would crash because your size wasn't set
up to allow you to get your size.
The fix is to actually remember the last setting of parentUsesSize,
even in the case of the constraints being tight and you later being
marked as needing layout directly.
In theory, before, if you had the same image twice in a scrolling container, you'd get an assertion with no way around it.
This makes those nodes not bother making keys by default, which is cheaper and more correct.
Make SnackBar animate itself.
This introduces a bit of a regression - the FloatingActionButton no longer animates. I'm not sure yet how to animated the FAB along with the SnackBar. Maybe some notion of anchoring a node to another.
Also remove last use of AnimationBuilder.
This fixes some theoretical bugs whereby we were using hashCode to try
to get unique keys for objects, but really we wanted object identity.
It also lays the groundwork for a new GlobalKey concept.
I tried to keep the impact on the code minimal, which is why the "Key"
constructor is actually a factory that returns a StringKey. The code
has this class hierarchy:
```
KeyBase
|
Key--------------+---------------+
| | |
StringKey ObjectKey UniqueKey
```
...where the constructors are Key and Key.stringify (StringKey),
Key.fromObjectIdentity (ObjectKey), and Key.unique (UniqueKey).
We could instead of factory methods use regular constructors with the
following hierarchy:
```
KeyBase
|
LocalKey---------+---------------+
| | |
Key ObjectIdentityKey UniqueKey
```
...with constructors Key, Key.stringify, ObjectIdentityKey, and
UniqueKey, but I felt that that was maybe a more confusing hierarchy.
I don't have a strong opinion on this.
We were declaring that the function passed to setState should return a
Function. In reality, we want the function to return void (and everyone calls
it with a function that returns void).
It turns out that we aren't really using these. The identity logic is sufficient.
Also, add some asserts for a crash I had once but couldn't reproduce, in case that helps catch it next time.
Route (named routes) no longer have a key, and have their own storage for their names.
RouseState no longer has a key, and uses an owner field pointing to a StatefulComponent instead.
As such, RouteBase no longer has a key.
HistoryEntry no longer uses a global int to ensure uniqueness.
Propagated this to stocks app.
When we build widgets during layout we weren't notifying those widgets that
they were mounted. Now we notify mount status changes when exiting build phases
inside layout.
Fixes#176
