Replaces textScaleFactor with TextScaler (#128522)

Deprecate `textScaleFactor` in favor of `textScaler`, in preparation for Android 14 [Non-linear font scaling to 200%](https://developer.android.com/about/versions/14/features#non-linear-font-scaling). The `TextScaler` class can be moved to `dart:ui` in the future, if we decide to use the Android platform API or AndroidX to get the scaling curve instead of hard coding the curve in the framework.

I haven't put the Flutter version in the deprecation message so the analyzer checks are failing. Will do so after I finish the migration guide.

**Why `TextScaler.textScaleFactor`**
The author of a `TextScaler` subclass should provide a fallback `textScaleFactor`. By making `TextScaler` also contain the `textScaleFactor` information it also makes it easier to migrate: if a widget overrides `MediaQueryData.textScaler` in the tree, for unmigrated widgets in the subtree it would also have to override `MediaQueryData.textScaleFactor`, and that makes it difficult to remove `MediaQueryData.textScaleFactor` in the future.

## A full list of affected APIs in this PR

Deprecated: The method/getter/setter/argument is annotated with a `@Deprecated()` annotation in this PR, and the caller should replace it with `textScaler` instead. Unless otherwise specified there will be a Flutter fix available to help with migration but it's still recommended to migrate case-by-case.
**Replaced**:  The method this `textScaleFactor` argument belongs to is rarely called directly by user code and is not overridden by any of the registered custom tests, so the argument is directly replaced by `TextScaler`.
**To Be Deprecated**:  The method/getter/setter/argument can't be deprecated in this PR because a registered customer test depends on it and a Flutter fix isn't available (or the test was run without applying flutter fixes first). This method/getter/setter/argument will be deprecated in a followup PR once the registered test is migrated.

### `Painting` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `InlineSpan.build({ double textScaleFactor = 1.0 })` argument | **Replaced** | | 
| `TextStyle.getParagraphStyle({ double TextScaleFactor = 1.0 })` argument | **Replaced** | |
| `TextStyle.getTextStyle({ double TextScaleFactor = 1.0 })`  argument| Deprecated | Can't replace: https://github.com/superlistapp/super_editor/blob/c47fd38dca4b7f43611690913b551a1773c563d7/super_editor/lib/src/infrastructure/super_textfield/desktop/desktop_textfield.dart#L1903-L1905|
| `TextPainter({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `TextPainter.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
| `TextPainter.computeWidth({ double TextScaleFactor = 1.0 })` argument | Deprecated | |
| `TextPainter.computeMaxIntrinsicWidth({ double TextScaleFactor = 1.0 })` argument | Deprecated | |

### `Rendering` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `RenderEditable({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `RenderEditable.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
| `RenderParagraph({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `RenderParagraph.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |

### `Widgets` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `MediaQueryData({ double TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/test/text_scale_factor_test.dart#LL39C21-L39C35 |
| `MediaQueryData.textScaleFactor` getter | Deprecated | |
| `MediaQueryData.copyWith({ double? TextScaleFactor })` argument | Deprecated | |
| `MediaQuery.maybeTextScaleFactorOf(BuildContext context)` static method | Deprecated | No Flutter Fix, not expressible yet  |
| `MediaQuery.textScaleFactorOf(BuildContext context)` static method | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/lib/src/_functions_io.dart#L68-L70, No Flutter Fix, not expressible yet |
| `RichText({ double TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/lib/src/builder.dart#L829-L843 |
| `RichText.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away|
| `Text({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/914d120da12fba458c020210727831c31bd71041/packages/rfw/lib/src/flutter/core_widgets.dart#L647 , No Flutter Fix because of dart-lang/sdk#52664 |
| `Text.rich({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | The default constructor has an argument that can't be deprecated right away. No Flutter Fix because of dart-lang/sdk#52664 |
| `Text.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away |
| `EditableText({ double? TextScaleFactor = 1.0 })` constructor argument | Deprecated | No Flutter Fix because of dart-lang/sdk#52664 |
| `EditableText.textScaleFactor` getter | Deprecated | |

### `Material` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `SelectableText({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/lib/src/builder.dart#L829-L843, No Flutter Fix because of dart-lang/sdk#52664 |
| `SelectableText.rich({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | The default constructor has an argument that can't be deprecated right away. No Flutter Fix because of dart-lang/sdk#52664 |
| `SelectableText.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away |

A lot of material widgets (`Slider`, `RangeSlider`, `TimePicker`, and different types of buttons) also change their layout based on `textScaleFactor`. These need to be handled in a case-by-case fashion and will be migrated in follow-up PRs.

Author: LongCatIsLooong

dev/benchmarks/macrobenchmarks/lib/src/web/bench_pageview_scroll_linethrough.dart

@@ -95,7 +95,7 @@ class _CustomPainter extends CustomPainter {
     yPosition = viewPadding;
     _textPainter.textDirection = TextDirection.ltr;
     _textPainter.textWidthBasis = TextWidthBasis.longestLine;
-    _textPainter.textScaleFactor = 1;
+    _textPainter.textScaler = TextScaler.noScaling;
     const TextStyle textStyle =
         TextStyle(color: Colors.black87, fontSize: 13, fontFamily: 'Roboto');
 

dev/integration_tests/flutter_gallery/lib/demo/shrine/supplemental/product_card.dart

@@ -52,7 +52,8 @@ class ProductCard extends StatelessWidget {
                 child: imageWidget,
               ),
               SizedBox(
-                height: kTextBoxHeight * MediaQuery.of(context).textScaleFactor,
+                // ignore: deprecated_member_use, https://github.com/flutter/flutter/issues/128825
+                height: kTextBoxHeight * MediaQuery.textScalerOf(context).textScaleFactor,
                 width: 121.0,
                 child: Column(
                   mainAxisAlignment: MainAxisAlignment.end,

dev/integration_tests/flutter_gallery/lib/gallery/app.dart

@@ -104,10 +104,10 @@ class _GalleryAppState extends State<GalleryApp> {
   Widget _applyTextScaleFactor(Widget child) {
     return Builder(
       builder: (BuildContext context) {
-        return MediaQuery(
-          data: MediaQuery.of(context).copyWith(
-            textScaleFactor: _options!.textScaleFactor!.scale,
-          ),
+        final double? textScaleFactor = _options!.textScaleFactor!.scale;
+        return MediaQuery.withClampedTextScaling(
+          minScaleFactor: textScaleFactor ?? 0.0,
+          maxScaleFactor: textScaleFactor ?? double.infinity,
           child: child,
         );
       },

dev/integration_tests/flutter_gallery/lib/gallery/home.dart

@@ -178,7 +178,8 @@ class _DemoItem extends StatelessWidget {
   Widget build(BuildContext context) {
     final ThemeData theme = Theme.of(context);
     final bool isDark = theme.brightness == Brightness.dark;
-    final double textScaleFactor = MediaQuery.textScaleFactorOf(context);
+    // ignore: deprecated_member_use, https://github.com/flutter/flutter/issues/128825
+    final double textScaleFactor = MediaQuery.textScalerOf(context).textScaleFactor;
     return RawMaterialButton(
       splashColor: theme.primaryColor.withOpacity(0.12),
       highlightColor: Colors.transparent,

dev/integration_tests/flutter_gallery/lib/gallery/options.dart

@@ -100,7 +100,8 @@ class _OptionsItem extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final double textScaleFactor = MediaQuery.textScaleFactorOf(context);
+    // ignore: deprecated_member_use, https://github.com/flutter/flutter/issues/128825
+    final double textScaleFactor = MediaQuery.textScalerOf(context).textScaleFactor;
 
     return MergeSemantics(
       child: Container(

dev/manual_tests/lib/density.dart

@@ -621,14 +621,17 @@ class _MyHomePageState extends State<MyHomePage> {
               data: Theme.of(context).copyWith(visualDensity: _model.density),
               child: Directionality(
                 textDirection: _model.rtl ? TextDirection.rtl : TextDirection.ltr,
-                child: MediaQuery(
-                  data: MediaQuery.of(context).copyWith(textScaleFactor: _model.size),
-                  child: SizedBox.expand(
-                    child: ListView(
-                      children: tiles,
+                child: Builder(builder: (BuildContext context) {
+                  final MediaQueryData mediaQueryData = MediaQuery.of(context);
+                  return MediaQuery(
+                    data: mediaQueryData.copyWith(textScaler: TextScaler.linear(_model.size)),
+                    child: SizedBox.expand(
+                      child: ListView(
+                        children: tiles,
+                      ),
                     ),
-                  ),
-                ),
+                  );
+                }),
               ),
             ),
           ),

dev/tools/gen_defaults/lib/action_chip_template.dart

@@ -91,7 +91,7 @@ class _${blockName}DefaultsM3 extends ChipThemeData {
   EdgeInsetsGeometry? get labelPadding => EdgeInsets.lerp(
     const EdgeInsets.symmetric(horizontal: 8.0),
     const EdgeInsets.symmetric(horizontal: 4.0),
-    clampDouble(MediaQuery.textScaleFactorOf(context) - 1.0, 0.0, 1.0),
+    clampDouble(MediaQuery.textScalerOf(context).textScaleFactor - 1.0, 0.0, 1.0),
   )!;
 }
 ''';

dev/tools/gen_defaults/lib/chip_template.dart

@@ -70,7 +70,7 @@ class _${blockName}DefaultsM3 extends ChipThemeData {
   EdgeInsetsGeometry? get labelPadding => EdgeInsets.lerp(
     const EdgeInsets.symmetric(horizontal: 8.0),
     const EdgeInsets.symmetric(horizontal: 4.0),
-    clampDouble(MediaQuery.textScaleFactorOf(context) - 1.0, 0.0, 1.0),
+    clampDouble(MediaQuery.textScalerOf(context).textScaleFactor - 1.0, 0.0, 1.0),
   )!;
 }
 ''';

dev/tools/gen_defaults/lib/filter_chip_template.dart

@@ -108,7 +108,7 @@ class _${blockName}DefaultsM3 extends ChipThemeData {
   EdgeInsetsGeometry? get labelPadding => EdgeInsets.lerp(
     const EdgeInsets.symmetric(horizontal: 8.0),
     const EdgeInsets.symmetric(horizontal: 4.0),
-    clampDouble(MediaQuery.textScaleFactorOf(context) - 1.0, 0.0, 1.0),
+    clampDouble(MediaQuery.textScalerOf(context).textScaleFactor - 1.0, 0.0, 1.0),
   )!;
 }
 ''';

dev/tools/gen_defaults/lib/input_chip_template.dart

@@ -85,7 +85,7 @@ class _${blockName}DefaultsM3 extends ChipThemeData {
   EdgeInsetsGeometry? get labelPadding => EdgeInsets.lerp(
     const EdgeInsets.symmetric(horizontal: 8.0),
     const EdgeInsets.symmetric(horizontal: 4.0),
-    clampDouble(MediaQuery.textScaleFactorOf(context) - 1.0, 0.0, 1.0),
+    clampDouble(MediaQuery.textScalerOf(context).textScaleFactor - 1.0, 0.0, 1.0),
   )!;
 }
 ''';