Add a new image provider for `MarkdownTextBlock` that allows loading
images from additional sources:
- **file scheme**
- Enables loading images using the `file:` scheme.
- Intentionally restricts file URIs to absolute paths to ensure correct
resolution when passed through the CmdPal extension/host boundary. (In
most cases, 3rd-party extensions will provide the paths, but the CmdPal
host performs the actual loading and would otherwise resolve paths
relative to itself.)
- **data scheme**
- Enables loading images from URIs with the `data:` scheme (both Base64
and URL-encoded forms).
- Note: the Markdown control itself cannot handle large input and may
hang before the code introduced in this PR is invoked.
- **ms-appx scheme**
- This scheme is now supported for loading images.
- However, since the Command Palette host performs the loading,
`ms-appx:` resolution applies to the host and not the extensions, which
limits its usefulness.
- **ms-appdata scheme**
- This scheme is now supported for loading images.
- Similar to `ms-appx:`, resolution applies to the host, not the
extensions, limiting its usefulness.
---
Additionally, this PR introduces the concept of **_image source
hints_**, implemented as query string parameters piggy-backed on the
original URI.
These hints allow users to influence the behavior of images within
Markdown content.
- `--x-cmdpal-fit`
- `none`: no automatic scaling, provides image as is (default)
- `fit`: scale to fit the available space
- `--x-cmdpal-upscale`
- `true`: allow upscaling
- `false`: downscale only (default)
- `--x-cmdpal-width`: desired width in pixels
- `--x-cmdpal-height`: desired height in pixels
- `--x-cmdpal-maxwidth`: max width in pixels
- `--x-cmdpal-maxheight`: max height in pixels
---
Since `MarkdownTextBlock` requires conforming to the `IImageProvider`
interface—which accepts only a raw URI and must return an `Image`
control—this PR also introduces a new class `RtbInlineImageFactory`.
The factory hooks into the root text block upon loading and listens for
events related to **layout** and **DPI changes**, ensuring that images
adapt correctly to the control’s environment.
```csharp
public interface IImageProvider
{
Task<Image> GetImage(string url);
bool ShouldUseThisProvider(string url);
}
```
---
Pictures? Videos!
Loading images from new schemes:
https://github.com/user-attachments/assets/e0f4308d-30b2-4c81-86db-353048c708c1
New image source scaling options:
https://github.com/user-attachments/assets/ec5b007d-3140-4f0a-b163-7b278233ad40
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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
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## PR Checklist
- [x] Closes: #41752
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx
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## Detailed Description of the Pull Request / Additional comments
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## Validation Steps Performed
---------
Co-authored-by: Michael Jolley <mike@baldbeardedbuilder.com>
**WARNING:** This PR will probably blow up all in-flight PRs
at some point in the early days of CmdPal, two of us created seperate
`Exts` and `exts` dirs. Depending on what the casing was on the branch
that you checked one of those out from, it'd get stuck like that on your
PC forever.
Windows didn't care, so we never noticed.
But GitHub does care, and now browsing the source on GitHub is basically
impossible.
Closes#38081
