Wire up the system text scaler from `PlatformDispatcher` #159999

LongCatIsLooong · 2024-12-09T22:24:55Z

The equality of 2 SystemTextScaler is determined by the platform's textScaleFactor scalar, because the scale method is always monotonically increasing wrt textScaleFactor.
On Android the scalar reflects the user configuration in system preference it seems: https://developer.android.com/reference/android/content/res/Configuration#fontScale

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Piinks · 2025-02-26T00:45:43Z

(Triage) Confirmed with @LongCatIsLooong this is still on their radar

Flutter PR flutter/flutter#159999 (fixing a bug where MediaQuery provides an incorrect TextScaler) breaks this test; fix it with isSystemTextScaler. [chris: rewrote commit message; used package:legacy_checks]

Flutter PR flutter/flutter#159999 (fixing a bug where MediaQuery provides an incorrect TextScaler) breaks this test; fix it with isSystemTextScaler. Co-authored-by: Chris Bobbe <[email protected]>

chunhtai · 2025-03-20T19:04:19Z

packages/flutter/lib/src/painting/text_scaler.dart

    if (identical(this, other)) {
      return true;
    }
+    assert(minScale < maxScale);


If this is the only place to enforce this constraint, we should do it where these two values are set instead. a crash here won't help us much in tracing down the bug

This is enforced in the (private) constructor (if minScale == maxScale the public API will return a different type of TextScaler). The assert is to indicate this is a valid assumption one can make for readers. Does it make more sense to make this a code comment then?

as long as there is not the first fail safe point, I am fine either way.

I'm also fine either way, but maybe a comment is better to avoid the confusion that started this thread.

removed the assert.

chunhtai · 2025-03-20T19:05:51Z

packages/flutter/lib/src/painting/text_scaler.dart

      minScale == maxScale ? minScale.hashCode : Object.hash(scaler, minScale, maxScale);
+
+  @override
+  String toString() => '$scaler clamped [$minScale, $maxScale]';


consider use Diagnosticable

That doesn't seem to reduce the amount of code I have to write, are there other benefits of using Diagnosticable?

it provide a better api to fill in properties for printing the string representation. Besides that, I think devtools uses that api to get details about an object, but i am not too familiar with that part of the code.

This is what it looks like now:

'│└RichText(softWrap: wrapping at box width, textScaler: SystemTextScaler (no scaling), maxLines: unlimited, text: "A", dependencies: [Directionality], renderObject: RenderParagraph#00000 relayoutBoundary=up1)\n'

So that still works. I'd keep the class hierarchy simple for now in case someone wants to implement the class instead of extending.

yeah makes sense

For my own understanding I wonder if @kenzieschmoll has any thoughts on when to use Diagnosticable in cases like this? I've wondered about this before.

flutter/flutter#159999

LongCatIsLooong · 2025-03-24T20:16:07Z

@chunhtai @justinmc made a few changes after your last LGTM (diff). Does this still LGTY?

justinmc

Renewing my LGTM 👍

justinmc · 2025-03-29T00:01:28Z

packages/flutter/lib/src/painting/text_painter.dart

    )
    double textScaleFactor = 1.0,
-    TextScaler textScaler = TextScaler.noScaling,
+    TextScaler textScaler = const _UnspecifiedTextScaler(),


Excellent use of the sentinel pattern 💂

justinmc · 2025-03-29T00:10:40Z

packages/flutter/lib/src/widgets/media_query.dart

+      SystemTextScaler(:final double textScaleFactor) => this.textScaleFactor == textScaleFactor,
+      // When textScaleFactor is 1.0, the two TextScalers are extensionally
+      // equivalent.
+      TextScaler.noScaling => textScaleFactor == 1.0,


Good catch.

dkwingsmt · 2025-04-23T18:03:28Z

There are two Google test failures and are flakes. There are also a conflict.

LongCatIsLooong · 2025-05-12T19:51:23Z

Waiting for my CL to land before merging this.

auto-submit · 2025-05-13T08:20:31Z

autosubmit label was removed for flutter/flutter/159999, because - The status or check suite Google testing has failed. Please fix the issues identified (or deflake) before re-applying this label.

…lutter/flutter#159999)

flutter/flutter@336a7ec...0b9f928 2025-05-14 [email protected] Fix Linux Impeller support broken by incorrect deletion of stencil buffer. (flutter/flutter#168668) 2025-05-14 [email protected] Roll Fuchsia Linux SDK from 6J81agNhuK4q255Jj... to fSvuEJgRmHxnewRJr... (flutter/flutter#168794) 2025-05-14 [email protected] Run `{Platform} flutter_packaging` builders on release candidates. (flutter/flutter#168762) 2025-05-14 [email protected] Remove `docs_deploy_beta`, fix `docs_publish`, add comments. (flutter/flutter#168754) 2025-05-14 [email protected] Add `titleAlignment` to `CheckboxListTile` and `RadioListTile` (flutter/flutter#168666) 2025-05-14 [email protected] Remove deprecated todo about caching (flutter/flutter#168534) 2025-05-13 [email protected] Replace hardcoded host and app level build.gradle paths with `AndroidProject`-level getters in `gradle_errors.dart` (flutter/flutter#167949) 2025-05-13 [email protected] Improve documentation for KeyedSubtree constructor (flutter/flutter#167198) 2025-05-13 [email protected] Wire up the system text scaler from `PlatformDispatcher` (flutter/flutter#159999) 2025-05-13 [email protected] Roll Dart SDK from 645d04a7a964 to b3520981e0f0 (3 revisions) (flutter/flutter#168721) 2025-05-13 [email protected] [a11y] Semanctis flag refactor step 3: framework part (flutter/flutter#167771) 2025-05-13 [email protected] Remove/replace the `team` label with `c: contributor-productivity`. (flutter/flutter#168702) 2025-05-13 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Clip search artifacts in CupertinoSliverNavigationBar searchable-to-searchable transitions (#168510)" (flutter/flutter#168775) 2025-05-13 [email protected] Use live region in error text input decorator for Android (flutter/flutter#165531) 2025-05-13 [email protected] [tool] Fix deprecated API calls within tool (flutter/flutter#168200) 2025-05-13 [email protected] Clip search artifacts in CupertinoSliverNavigationBar searchable-to-searchable transitions (flutter/flutter#168510) 2025-05-13 [email protected] Fixes hero not shown when remove pages without animation (flutter/flutter#168617) 2025-05-13 [email protected] [iOS] Do not hide selection handles when platform hides system context menu (flutter/flutter#168678) 2025-05-13 [email protected] Updated execution path to silently include --start-paused and updated tests (flutter/flutter#168400) 2025-05-13 [email protected] Roll Packages from 6a28ad9 to 2e166de (2 revisions) (flutter/flutter#168736) 2025-05-13 [email protected] [web] Fix multiline input selection in Chrome. (flutter/flutter#168217) 2025-05-13 [email protected] Call xcode_backend.dart from macos_assemble.sh (flutter/flutter#168108) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

…r#9251) flutter/flutter@336a7ec...0b9f928 2025-05-14 [email protected] Fix Linux Impeller support broken by incorrect deletion of stencil buffer. (flutter/flutter#168668) 2025-05-14 [email protected] Roll Fuchsia Linux SDK from 6J81agNhuK4q255Jj... to fSvuEJgRmHxnewRJr... (flutter/flutter#168794) 2025-05-14 [email protected] Run `{Platform} flutter_packaging` builders on release candidates. (flutter/flutter#168762) 2025-05-14 [email protected] Remove `docs_deploy_beta`, fix `docs_publish`, add comments. (flutter/flutter#168754) 2025-05-14 [email protected] Add `titleAlignment` to `CheckboxListTile` and `RadioListTile` (flutter/flutter#168666) 2025-05-14 [email protected] Remove deprecated todo about caching (flutter/flutter#168534) 2025-05-13 [email protected] Replace hardcoded host and app level build.gradle paths with `AndroidProject`-level getters in `gradle_errors.dart` (flutter/flutter#167949) 2025-05-13 [email protected] Improve documentation for KeyedSubtree constructor (flutter/flutter#167198) 2025-05-13 [email protected] Wire up the system text scaler from `PlatformDispatcher` (flutter/flutter#159999) 2025-05-13 [email protected] Roll Dart SDK from 645d04a7a964 to b3520981e0f0 (3 revisions) (flutter/flutter#168721) 2025-05-13 [email protected] [a11y] Semanctis flag refactor step 3: framework part (flutter/flutter#167771) 2025-05-13 [email protected] Remove/replace the `team` label with `c: contributor-productivity`. (flutter/flutter#168702) 2025-05-13 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Clip search artifacts in CupertinoSliverNavigationBar searchable-to-searchable transitions (#168510)" (flutter/flutter#168775) 2025-05-13 [email protected] Use live region in error text input decorator for Android (flutter/flutter#165531) 2025-05-13 [email protected] [tool] Fix deprecated API calls within tool (flutter/flutter#168200) 2025-05-13 [email protected] Clip search artifacts in CupertinoSliverNavigationBar searchable-to-searchable transitions (flutter/flutter#168510) 2025-05-13 [email protected] Fixes hero not shown when remove pages without animation (flutter/flutter#168617) 2025-05-13 [email protected] [iOS] Do not hide selection handles when platform hides system context menu (flutter/flutter#168678) 2025-05-13 [email protected] Updated execution path to silently include --start-paused and updated tests (flutter/flutter#168400) 2025-05-13 [email protected] Roll Packages from 6a28ad9 to 2e166de (2 revisions) (flutter/flutter#168736) 2025-05-13 [email protected] [web] Fix multiline input selection in Chrome. (flutter/flutter#168217) 2025-05-13 [email protected] Call xcode_backend.dart from macos_assemble.sh (flutter/flutter#168108) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

…lutter/flutter#159999)

github-actions bot added a: tests "flutter test", flutter_test, or one of our tests a: text input Entering text in a text field or keyboard related problems framework flutter/packages/flutter repository. See also f: labels. labels Dec 9, 2024

wire up PlatformDispatcher text scaler

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LongCatIsLooong force-pushed the text-scaler branch from 862c54c to 6f263bb Compare December 9, 2024 22:38

LongCatIsLooong mentioned this pull request Dec 11, 2024

Add a isSystemTextScaler matcher #160120

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Merge remote-tracking branch 'upstream/master' into text-scaler

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_ClampedTextScaler.toString

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fix tests

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LongCatIsLooong marked this pull request as ready for review March 19, 2025 23:12

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[Flutter Migration] migrate emoji_reaction_test.dart zulip/zulip-flutter#1424

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flutter/flutter#159999

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Bump zulip.test to2117fe176aa740d00ff4e6be5ac38bd98eab8a3d flutter/tests#449

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textScalar.clamp throws Failed assertion: line 118 pos 80: 'maxScale > minScale': is not true. #174828

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Wire up the system text scaler from PlatformDispatcher #159999

Wire up the system text scaler from PlatformDispatcher #159999

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LongCatIsLooong commented Dec 9, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Wire up the system text scaler from `PlatformDispatcher` #159999

Wire up the system text scaler from `PlatformDispatcher` #159999

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