This allows the scheduler library to depend on the services library
and the painting library to depend on the scheduler library without
the services library having to depend on the scheduler library.
While I was at it I also cleaned up some of the binding logic: the
licenses logic can now be overridden (and the test library does so),
and the image cache can now be overridden as well.
This is a bug in my previous CL: instead of cancelling the timer if
there are no more listeners, I canceled it if there were listeners (I
can claim I just missed a not :) ).
Not cancelling the timer when removing the last listener was not that bad, as
the timer callback is guarded by a check to see if there are listeners.
So the animation will not continue.
But in the case there were multiple listeners on the same stream, and
one of them is removed, this bug will stop the animation for all other
listeners.
I added a test case for this scenario.
This makes sure that we don't decode frames when we don't need to run
the animation.
For example, prior to this CL: an animated image in a page that is not
currently at the top of the page stack (it is covered by another page),
will keep the the image stream listener, and thus frames will still be
decoded.
* Implement MultiFrameImageStreamCompleter
* only decode frames while there are active listeners
* review comments followup
* multiply animation frame timer duration by time dilation
* lint
Since MethodCall equality checks are limited to test scenarios, this
patch replaces them with an equivalent test matcher. At present
MethodCalls are always used in scenarios where indentity-based
equality/hashing is appropriate.
This change avoids an assertion failure when MethodCall args are
Iterable (possible since args are of type dyanmic), and hashValue() from
dart:ui asserts that its input is not an Iterable.
The alternative of implementing support for deep equality in dart:ui was
rejected on the basis that if we're to encourage performant code,
expensive checks should be obviously-expensive to the author.
* FadeInImage: shows a placeholder while loading then fades in
* fix dartdoc quotes
* license headers; imports
* use ImageProvider; docs; constructors
* _resolveImage when placeholder changes
* address comments
* docs re ImageProvider changes; unsubscribe from placeholder
* rebase
* address comments
Breaking change: removed deprecated methods of PlatformMessages, leaving only binary messaging there. All other use of platform communication now goes through PlatformMessageChannel and PlatformMethodChannels. Retained use of String and JSON codecs for now.
Companion engine PR: flutter/engine#3482
Now IconThemeData.fallback is a factory constructor and IconThemeData.of() does
the work of computing the fallback for its clients.
Also, add tests for ImageIcon and ListItems.
This rewrites imports of various mojom.dart files from the Flutter
engine repo to instead import normal-looking dart files from the
(new) flutter_services package. This package handles exporting the
correct symbols from generated code wherever that may live.
Includes an engine roll to 3551e7a48e2e336777b15c7637af92fd7605b6c5
which contains the new flutter_services package.
Overview
========
This patch refactors images to achieve the following goals:
* it allows references to unresolved assets to be passed
around (previously, almost every layer of the system had to know about
whether an image came from an asset bundle or the network or
elsewhere, and had to manually interact with the image cache).
* it allows decorations to use the same API for declaring images as the
widget tree.
It requires some minor changes to call sites that use images, as
discussed below.
Widgets
-------
Change this:
```dart
child: new AssetImage(
name: 'my_asset.png',
...
)
```
...to this:
```dart
child: new Image(
image: new AssetImage('my_asset.png'),
...
)
```
Decorations
-----------
Change this:
```dart
child: new DecoratedBox(
decoration: new BoxDecoration(
backgroundImage: new BackgroundImage(
image: DefaultAssetBundle.of(context).loadImage('my_asset.png'),
...
),
...
),
child: ...
)
```
...to this:
```dart
child: new DecoratedBox(
decoration: new BoxDecoration(
backgroundImage: new BackgroundImage(
image: new AssetImage('my_asset.png'),
...
),
...
),
child: ...
)
```
DETAILED CHANGE LOG
===================
The following APIs have been replaced in this patch:
* The `AssetImage` and `NetworkImage` widgets have been split in two,
with identically-named `ImageProvider` subclasses providing the
image-loading logic, and a single `Image` widget providing all the
widget tree logic.
* `ImageResource` is now `ImageStream`. Rather than configuring it with
a `Future<ImageInfo>`, you complete it with an `ImageStreamCompleter`.
* `ImageCache.load` and `ImageCache.loadProvider` are replaced by
`ImageCache.putIfAbsent`.
The following APIs have changed in this patch:
* `ImageCache` works in terms of arbitrary keys and caches
`ImageStreamCompleter` objects using those keys. With the new model,
you should never need to interact with the cache directly.
* `Decoration` can now be `const`. The state has moved to the
`BoxPainter` class. Instead of a list of listeners, there's now just a
single callback and a `dispose()` method on the painter. The callback
is passed in to the `createBoxPainter()` method. When invoked, you
should repaint the painter.
The following new APIs are introduced:
* `AssetBundle.loadStructuredData`.
* `SynchronousFuture`, a variant of `Future` that calls the `then`
callback synchronously. This enables the asynchronous and
synchronous (in-the-cache) code paths to look identical yet for the
latter to avoid returning to the event loop mid-paint.
* `ExactAssetImage`, a variant of `AssetImage` that doesn't do anything clever.
* `ImageConfiguration`, a class that describes parameters that configure
the `AssetImage` resolver.
The following APIs are entirely removed by this patch:
* `AssetBundle.loadImage` is gone. Use an `AssetImage` instead.
* `AssetVendor` is gone. `AssetImage` handles everything `AssetVendor`
used to handle.
* `RawImageResource` and `AsyncImage` are gone.
The following code-level changes are performed:
* `Image`, which replaces `AsyncImage`, `NetworkImage`, `AssetImage`,
and `RawResourceImage`, lives in `image.dart`.
* `DecoratedBox` and `Container` live in their own file now,
`container.dart` (they reference `image.dart`).
DIRECTIONS FOR FUTURE RESEARCH
==============================
* The `ImageConfiguration` fields are mostly aspirational. Right now
only `devicePixelRatio` and `bundle` are implemented. `locale` isn't
even plumbed through, it will require work on the localisation logic.
* We should go through and make `BoxDecoration`, `AssetImage`, and
`NetworkImage` objects `const` where possible.
* This patch makes supporting animated GIFs much easier.
* This patch makes it possible to create an abstract concept of an
"Icon" that could be either an image or a font-based glyph (using
`IconData` or similar). (see
https://github.com/flutter/flutter/issues/4494)
RELATED ISSUES
==============
Fixes https://github.com/flutter/flutter/issues/4500
Fixes https://github.com/flutter/flutter/issues/4495
Obsoletes https://github.com/flutter/flutter/issues/4496
