This adds two new builders to the `Image` class:
* `frameBuilder`, which allows callers to control the widget
created by an [Image].
* `loadingBuilder`, which allows callers fine-grained control
over how to display loading progress of an image to the user.
`FadeInImage` can be simplified by migrating to the new API.
This is done in a follow-on commit.
https://github.com/flutter/flutter/issues/32374
This re-lands the Focus changes in #30040. Correctness changes in routes.dart, and removes the automatic requesting of focus on reparent when there is no current focus, which caused undesirable selections.
Addresses #11344, #1608, #13264, and #1678Fixes#30084Fixes#26704
Implements focus traversal for desktop platforms, including re-implementing the existing focus manager and focus tree.
This implements a Focus widget that can be put into a widget tree to allow input focus to be given to a particular part of a widget tree.
It incorporates with the existing FocusScope and FocusNode infrastructure, and has minimal breakage to the API, although FocusScope.reparentIfNeeded is removed, replaced by a call to FocusAttachment.reparent(), so this is a breaking change:
FocusScopeNodes must now be attached to the focus tree using FocusScopeNode.attach, which takes a context and an optional onKey callback, and returns a FocusAttachment that should be kept by the widget that hosts the FocusScopeNode. This is necessary because of the need to make sure that the focus tree reflects the widget hierarchy.
Callers that used to call FocusScope(context).reparentIfNeeded in their build method will call reparent on a FocusAttachment instead, which they will obtain by calling FocusScopeNode.attach in their initState method. Widgets that own FocusNodes will need to call dispose on the focus node in their dispose method.
Addresses #11344, #1608, #13264, and #1678Fixes#30084Fixes#26704
This converts all remaining "## Sample code" segments into snippets, and fixes
the snippet generator to handle multiple snippets in the same dartdoc block
properly.
I also generated, compiled, and ran each of the existing application samples,
and fixed them up to be more useful and/or just run without errors.
This PR fixes these problems with examples:
1. Switching tabs in a snippet now works if there is more than one snippet in
a single dartdoc block.
2. Generation of snippet code now works if there is more than one snippet.
3. Contrast of text and links in the code sample block has been improved to
recommended levels.
4. Added five new snippet templates, including a "freeform" template to make
it possible to show examples that need to change the app instantiation.
5. Fixed several examples to run properly, a couple by adding the "Scaffold"
widget to the template, a couple by just fixing their code.
6. Fixed visual look of some of the samples when they run by placing many
samples inside of a Scaffold.
7. In order to make it easier to run locally, changed the sample analyzer to
remove the contents of the supplied temp directory before running, since
having files that hang around is problematic (only a problem when running
locally with the `--temp` argument).
8. Added a `SampleCheckerException` class, and handle sample checking
exceptions more gracefully.
9. Deprecated the old "## Sample code" designation, and added enforcement for
the deprecation.
10. Removed unnecessary `new` from templates (although they never appeared in
the samples thanks to dartfmt, but still).
Fixes#26398Fixes#27411
This converts existing ## Sample code samples to {@tool sample}...{@end-tool} form.
Also:
1. Fixed a minor bug in analyze-sample-code.dart
2. Made the snippet tool only insert descriptions if the description is non-empty.
3. Moved the Card diagram to before the code sample.
This rewrites the sample code analysis script to be a little less of a hack (but still not pretty), and to handle snippets as well.
It also changes the semantics of how sample code is handled: the namespace for the sample code is now limited to the file that it appears in, so some additional "Examples can assume:" blocks were added. The upside of this is that there will be far fewer name collisions.
I fixed the output too: no longer will you get 4000 lines of numbered output with the error at the top and have to grep for the actual problem. It gives the filename and line number of the original location of the code (in the comment in the tree), and prints out the source code on the line that caused the problem along with the error.
For snippets, it prints out the location of the start of the snippet and the source code line that causes the problem. It can't print out the original line, because snippets get formatted when they are written, so the line might not be in the same place.
This creates a custom dartdoc tool that will generate snippet blocks in our API docs that allow the user to copy easily to the clipboard, and will also embed the snippet code into a template to show it in a larger context with an app.
This PR adds the snippet tool, a template, and a couple of HTML skeleton files, one for snippets that are designed to be in an application setting, and one where it simply puts a nice container around existing snippets, making them easier to copy to the clipboard.
