Bind Skottie's Animation Builder

[mattleibow]

Description of Change

This PR adds a few of the essential APIs to enable loading embedded files in the Lottie animation. Currently, there is just the support for file-based and data URI-based assets.

Bugs Fixed

• Fixes Skottie cannot draw animations that have embedded images #2173

API Changes

class Animation {
  public static AnimationBuilder CreateBuilder (AnimationBuilderFlags flags = AnimationBuilderFlags.None);
}

public sealed unsafe class AnimationBuilder : SKObject, ISKSkipObjectRegistration {
  public AnimationBuilder SetFontManager (SKFontManager fontManager);
  public AnimationBuilder SetResourceProvider (ResourceProvider resourceProvider);
  public AnimationBuilderStats Stats { get; }
  public Animation? Build (Stream stream);
  public Animation? Build (SKStream stream);
  public Animation? Build (SKData data);
  public Animation? Build (string path);
}

public struct AnimationBuilderStats {
  public readonly TimeSpan TotalLoadTime { get; }
  public readonly TimeSpan JsonParseTime { get; }
  public readonly TimeSpan SceneParseTime { get; }
  public readonly int JsonSize  { get; }
  public readonly int AnimatorCount  { get; }
}

public abstract unsafe class ResourceProvider : SKObject, ISKReferenceCounted, ISKSkipObjectRegistration {
  public SKData? Load (string resourceName);
  public SKData? Load (string resourcePath, string resourceName);
}

public class CachingResourceProvider : ResourceProvider {
  public CachingResourceProvider (ResourceProvider resourceProvider);
}

public class DataUriResourceProvider : ResourceProvider {
  public DataUriResourceProvider (bool preDecode = false);
  public DataUriResourceProvider (ResourceProvider? fallbackProvider, bool preDecode = false);
}

public class FileResourceProvider : ResourceProvider {
  public FileResourceProvider (string baseDirectory, bool preDecode = false);
}

Behavioral Changes

None.

Required skia PR

mono/skia#114

PR Checklist

• Has tests (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Merged related skia PRs
• Changes adhere to coding standard
• Updated documentation

[thisisthekap]

@mattleibow When is this going to released?

[imms20]

Hi @mattleibow any idea when will it be released? i have done migration of an app and i am only blocked by lottie animations which uses files. if there is not plan for release, then will it be fine if i just checkout this branch and create build and use the dlls? i only need it for ios and android

[mattleibow]

I notice that the fact I override the

sk_sp<SkPicture> SkDrawable::onMakePictureSnapshot()

function in C++ for the managed drawable is causing a crash. If i change it to

SkPicture* SkDrawable::onMakePictureSnapshot()

stops the crash. I noticed this locally on macOS. Not sure why it passes on CI.

Issue: #2760

[mattleibow]

Note to future self. Don't forget to correctly apply the ISKReferenceCounted interface and NOT explicitly delete the reference counted types. This causes a hard-to-debug crash because the type is deleted while in use. Ot sometimes crashes in a debug build with a better log message, but not often.

[github-actions]

The backport to release/2.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release/2.x release/2.x
# Navigate to the new working tree
cd .worktrees/backport-release/2.x
# Create a new branch
git switch --create backport/pr-2630-to-release/2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 42fc0181e0f9d2cda2d7f4f9359de2dd5252fcc1
# Push it to GitHub
git push --set-upstream origin backport/pr-2630-to-release/2.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release/2.x

Then, create a pull request where the base branch is release/2.x and the compare/head branch is backport/pr-2630-to-release/2.x.