…ader (Impeller-only). (#169293)"

This reverts commit 03736a2.

flutter/flutter@f4334d2...52af7a5

2025-08-15 [email protected] Roll Packages from 09533b7 to 5c52c55 (6 revisions) (flutter/flutter#173854)
2025-08-15 [email protected] Roll Skia from 46ec77ae3954 to 5654ac32ede0 (1 revision) (flutter/flutter#173848)
2025-08-15 [email protected] Roll Skia from 162f47d6b6bd to 46ec77ae3954 (2 revisions) (flutter/flutter#173833)
2025-08-15 [email protected] Roll Dart SDK from c7faab270f27 to cc008dc8e7aa (2 revisions) (flutter/flutter#173826)
2025-08-15 [email protected] Roll Skia from ad5d04000101 to 162f47d6b6bd (5 revisions) (flutter/flutter#173822)
2025-08-15 [email protected] Update the RBE configuration for the recent Clang update (flutter/flutter#173803)
2025-08-15 [email protected] Stop writing legacy `FLUTTER_ROOT/version` file (by default?) (flutter/flutter#172793)
2025-08-15 [email protected] Remove `luci_flags.parallel_download_builds` and friends (flutter/flutter#173799)
2025-08-14 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Predictive back route transitions by default (#165832)" (flutter/flutter#173809)
2025-08-14 [email protected] Roll Skia from dca5f05fee87 to ad5d04000101 (8 revisions) (flutter/flutter#173798)
2025-08-14 [email protected] [web] Cleanup usages of deprecated `routeUpdated` message (flutter/flutter#173782)
2025-08-14 [email protected] Make sure that DataTable, DataColumn, DataRow, and DataCell don't crash in 0x0 environment (flutter/flutter#173515)
2025-08-14 [email protected] Make sure that a TableRowInkWell doesn't crash in 0x0 environment (flutter/flutter#173627)
2025-08-14 [email protected] Make sure that a DatePickerDialog doesn't crash in 0x0 environment (flutter/flutter#173677)
2025-08-14 [email protected] Return result of setting OpenGL contexts back to Flutter (flutter/flutter#173757)
2025-08-14 [email protected] Read `bin/cache/flutter.version.json` instead of `version` for `flutter_gallery` (flutter/flutter#173797)
2025-08-14 [email protected] Predictive back route transitions by default (flutter/flutter#165832)
2025-08-14 [email protected] feat: add onLongPressUp callback to InkWell widget (flutter/flutter#173221)
2025-08-14 [email protected] Roll Dart SDK from 214a7f829913 to c7faab270f27 (1 revision) (flutter/flutter#173792)
2025-08-14 [email protected] Add error handling for `Element` lifecycle user callbacks (flutter/flutter#173148)
2025-08-14 [email protected] Roll Fuchsia Linux SDK from I1TfNmsqTp7t3rO8e... to zWRpLglb48zC1vZLv... (flutter/flutter#173784)
2025-08-14 [email protected] [Range slider] Tap on active range,  the thumb closest to the mouse cursor should move to the cursor position. (flutter/flutter#173725)
2025-08-14 [email protected] Roll Packages from 6cb9113 to 09533b7 (4 revisions) (flutter/flutter#173789)
2025-08-14 [email protected] Implements the Android native stretch effect as a fragment shader (Impeller-only). (flutter/flutter#169293)
2025-08-14 [email protected] Sync `CHANGELOG.md` (3.35 -> `master`) (flutter/flutter#173790)
2025-08-14 [email protected] [VPAT][A11y] Announce Autocomplete search results status (flutter/flutter#173480)
2025-08-14 [email protected] Fix InputDecorator label padding (flutter/flutter#173344)
2025-08-14 [email protected] Fix default minimumSize in dropdownMenu when maximumSize is null (flutter/flutter#169438)
2025-08-14 [email protected] Thread sub-builders for every engine-uploading builder (flutter/flutter#173742)

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],[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

…hader (Impeller-only). (#169293)" (#173865)

<!-- start_original_pr_link -->
Reverts: #169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR #169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes #82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…peller-only). (flutter#169293)

> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…hader (Impeller-only). (flutter#169293)" (flutter#173865)

<!-- start_original_pr_link -->
Reverts: flutter#169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…r#9832)

flutter/flutter@f4334d2...52af7a5

2025-08-15 [email protected] Roll Packages from 09533b7 to 5c52c55 (6 revisions) (flutter/flutter#173854)
2025-08-15 [email protected] Roll Skia from 46ec77ae3954 to 5654ac32ede0 (1 revision) (flutter/flutter#173848)
2025-08-15 [email protected] Roll Skia from 162f47d6b6bd to 46ec77ae3954 (2 revisions) (flutter/flutter#173833)
2025-08-15 [email protected] Roll Dart SDK from c7faab270f27 to cc008dc8e7aa (2 revisions) (flutter/flutter#173826)
2025-08-15 [email protected] Roll Skia from ad5d04000101 to 162f47d6b6bd (5 revisions) (flutter/flutter#173822)
2025-08-15 [email protected] Update the RBE configuration for the recent Clang update (flutter/flutter#173803)
2025-08-15 [email protected] Stop writing legacy `FLUTTER_ROOT/version` file (by default?) (flutter/flutter#172793)
2025-08-15 [email protected] Remove `luci_flags.parallel_download_builds` and friends (flutter/flutter#173799)
2025-08-14 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Predictive back route transitions by default (#165832)" (flutter/flutter#173809)
2025-08-14 [email protected] Roll Skia from dca5f05fee87 to ad5d04000101 (8 revisions) (flutter/flutter#173798)
2025-08-14 [email protected] [web] Cleanup usages of deprecated `routeUpdated` message (flutter/flutter#173782)
2025-08-14 [email protected] Make sure that DataTable, DataColumn, DataRow, and DataCell don't crash in 0x0 environment (flutter/flutter#173515)
2025-08-14 [email protected] Make sure that a TableRowInkWell doesn't crash in 0x0 environment (flutter/flutter#173627)
2025-08-14 [email protected] Make sure that a DatePickerDialog doesn't crash in 0x0 environment (flutter/flutter#173677)
2025-08-14 [email protected] Return result of setting OpenGL contexts back to Flutter (flutter/flutter#173757)
2025-08-14 [email protected] Read `bin/cache/flutter.version.json` instead of `version` for `flutter_gallery` (flutter/flutter#173797)
2025-08-14 [email protected] Predictive back route transitions by default (flutter/flutter#165832)
2025-08-14 [email protected] feat: add onLongPressUp callback to InkWell widget (flutter/flutter#173221)
2025-08-14 [email protected] Roll Dart SDK from 214a7f829913 to c7faab270f27 (1 revision) (flutter/flutter#173792)
2025-08-14 [email protected] Add error handling for `Element` lifecycle user callbacks (flutter/flutter#173148)
2025-08-14 [email protected] Roll Fuchsia Linux SDK from I1TfNmsqTp7t3rO8e... to zWRpLglb48zC1vZLv... (flutter/flutter#173784)
2025-08-14 [email protected] [Range slider] Tap on active range,  the thumb closest to the mouse cursor should move to the cursor position. (flutter/flutter#173725)
2025-08-14 [email protected] Roll Packages from 6cb9113 to 09533b7 (4 revisions) (flutter/flutter#173789)
2025-08-14 [email protected] Implements the Android native stretch effect as a fragment shader (Impeller-only). (flutter/flutter#169293)
2025-08-14 [email protected] Sync `CHANGELOG.md` (3.35 -> `master`) (flutter/flutter#173790)
2025-08-14 [email protected] [VPAT][A11y] Announce Autocomplete search results status (flutter/flutter#173480)
2025-08-14 [email protected] Fix InputDecorator label padding (flutter/flutter#173344)
2025-08-14 [email protected] Fix default minimumSize in dropdownMenu when maximumSize is null (flutter/flutter#169438)
2025-08-14 [email protected] Thread sub-builders for every engine-uploading builder (flutter/flutter#173742)

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],[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

…hader (Impeller-only). (flutter#169293)" (flutter#173865)

<!-- start_original_pr_link -->
Reverts: flutter#169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…hader (Impeller-only). (flutter#169293)" (flutter#173865)

<!-- start_original_pr_link -->
Reverts: flutter#169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…der (Impeller-only)." (#173885)

This PR retries the previously reverted PR #169293.

> [!NOTE]
> This feature was originally intended to be Impeller-only, and it was
agreed that no additional engine changes were necessary. However, during
testing on the Metal backend, a shader loading issue occurred. In my
view, this seems to be a simple problem caused by the shader not being
included in the engine’s runtime_stages.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…peller-only). (flutter#169293)

> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…hader (Impeller-only). (flutter#169293)" (flutter#173865)

<!-- start_original_pr_link -->
Reverts: flutter#169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…der (Impeller-only)." (flutter#173885)

This PR retries the previously reverted PR flutter#169293.

> [!NOTE]
> This feature was originally intended to be Impeller-only, and it was
agreed that no additional engine changes were necessary. However, during
testing on the Metal backend, a shader loading issue occurred. In my
view, this seems to be a simple problem caused by the shader not being
included in the engine’s runtime_stages.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…peller-only). (flutter#169293)

> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…hader (Impeller-only). (flutter#169293)" (flutter#173865)

<!-- start_original_pr_link -->
Reverts: flutter#169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…der (Impeller-only)." (flutter#173885)

This PR retries the previously reverted PR flutter#169293.

> [!NOTE]
> This feature was originally intended to be Impeller-only, and it was
agreed that no additional engine changes were necessary. However, during
testing on the Metal backend, a shader loading issue occurred. In my
view, this seems to be a simple problem caused by the shader not being
included in the engine’s runtime_stages.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…der (Impeller-only)." (flutter#173885)

This PR retries the previously reverted PR flutter#169293.

> [!NOTE]
> This feature was originally intended to be Impeller-only, and it was
agreed that no additional engine changes were necessary. However, during
testing on the Metal backend, a shader loading issue occurred. In my
view, this seems to be a simple problem caused by the shader not being
included in the engine’s runtime_stages.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…shader (Impeller-only). (flutter/flutter#169293)

…peller-only). (flutter#169293)

> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>

…hader (Impeller-only). (flutter#169293)" (flutter#173865)

<!-- start_original_pr_link -->
Reverts: flutter#169293
<!-- end_original_pr_link -->
<!-- start_initiating_author -->
Initiated by: matanlurey
<!-- end_initiating_author -->
<!-- start_revert_reason -->
Reason for reverting: Does not work on Metal (iOS/macOS):

```
The following _Exception was thrown running a test:
Exception: Asset 'shaders/stretch_effect.frag' does not contain appropriate runtime stage data for current backend (Metal).
```
<!-- end_revert_reason -->
<!-- start_original_pr_author -->
Original PR Author: MTtankkeo
<!-- end_original_pr_author -->

<!-- start_reviewers -->
Reviewed By: {dkwingsmt, justinmc, chunhtai}
<!-- end_reviewers -->

<!-- start_revert_body -->
This change reverts the following previous change:
> Sorry, Closing PR flutter#169196 and reopening this in a new PR for clarity
and a cleaner commit history.

Fixes flutter#82906

In the existing Flutter implementation, the Android stretch overscroll
effect is achieved using Transform. However, this approach does not
evenly stretch the screen as it does in the native Android environment.
Therefore, in the Impeller environment, add or modify files to implement
the effect using a fragment shader identical to the one used in native
Android.

> [!NOTE]
> - The addition of a separate test file for StretchOverscrollEffect was
not included because it would likely duplicate coverage already provided
by the changes made in overscroll_stretch_indicator_test.dart within
this PR.
>> However, since determining whether stretching occurred by referencing
global coordinates is currently considered impossible with the new
Fragment Shader approach, the code was modified to partially exclude the
relevant test logic in the Impeller.
>>
>> For reference, in the page_view_test.dart test, there was an issue
with referencing the child Transform widget, but because the
StretchOverscrollEffect widget is defined instead of the Transform
widget in the Impeller environment, the code logic was adjusted
accordingly.
> 
> - Golden image tests were updated as the visual effect changes.

## Reference Source
-
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/libs/hwui/effects/StretchEffect.cpp

## `Old` Skia (Using Transform)

https://github.com/user-attachments/assets/22d8ff96-d875-4722-bf6f-f0ad15b9077d

## `New` Impeller (Using fragment shader)

https://github.com/user-attachments/assets/73b6ef18-06b2-42ea-9793-c391ec2ce282

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

<!-- end_revert_body -->

Co-authored-by: auto-submit[bot] <[email protected]>

…der (Impeller-only)." (flutter#173885)

This PR retries the previously reverted PR flutter#169293.

> [!NOTE]
> This feature was originally intended to be Impeller-only, and it was
agreed that no additional engine changes were necessary. However, during
testing on the Metal backend, a shader loading issue occurred. In my
view, this seems to be a simple problem caused by the shader not being
included in the engine’s runtime_stages.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Tong Mu <[email protected]>
Co-authored-by: Kate Lovett <[email protected]>