AnimationSheetBuilder class
Records the frames of an animating widget, and later displays the frames as a grid in an animation sheet.
This class does not support Web, because the animation sheet utilizes taking
screenshots, which is unsupported on the Web. Tests that use this class must
be noted with skip: isBrowser
.
(https://github.com/flutter/flutter/issues/56001)
Using this class includes the following steps:
- Create an instance of this class.
- Register dispose to the test's tear down callbacks.
- Pump frames that render the target widget wrapped in record. Every frame
that has
recording
being true will be recorded. - Acquire the output image with collate and compare against the golden file.
The following example shows how to record an animation sheet of an InkWell
being pressed then released.
link
testWidgets('Inkwell animation sheet', (WidgetTester tester) async {
// Create instance
final AnimationSheetBuilder animationSheet = AnimationSheetBuilder(frameSize: const Size(48, 24));
addTearDown(animationSheet.dispose);
final Widget target = Material(
child: Directionality(
textDirection: TextDirection.ltr,
child: InkWell(
splashColor: Colors.blue,
onTap: () {},
),
),
);
// Optional: setup before recording (`recording` is false)
await tester.pumpWidget(animationSheet.record(
target,
recording: false,
));
final TestGesture gesture = await tester.startGesture(tester.getCenter(find.byType(InkWell)));
// Start recording (`recording` is true)
await tester.pumpFrames(animationSheet.record(
target,
recording: true, // ignore: avoid_redundant_argument_values
), const Duration(seconds: 1));
await gesture.up();
await tester.pumpFrames(animationSheet.record(
target,
recording: true, // ignore: avoid_redundant_argument_values
), const Duration(seconds: 1));
// Compare against golden file
await expectLater(
animationSheet.collate(800),
matchesGoldenFile('inkwell.press.animation.png'),
);
}, skip: isBrowser); // Animation sheet does not support browser https://github.com/flutter/flutter/issues/56001
See also:
- GoldenFileComparator, which introduces Golden File Testing.
Constructors
- AnimationSheetBuilder({required Size frameSize, bool allLayers = false})
- Starts a session of building an animation sheet.
Properties
- allLayers → bool
-
Whether the captured image comes from the entire tree, or only the
subtree of record.
final
- frameSize → Size
-
The size of the child to be recorded.
final
- hashCode → int
-
The hash code for this object.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
collate(
int cellsPerRow) → Future< Image> - Returns an result image by putting all frames together in a table.
-
dispose(
) → Future< void> - Dispose all recorded frames and result images.
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
record(
Widget child, {Key? key, bool recording = true}) → Widget - Returns a widget that renders a widget in a box that can be recorded.
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited