1ebbef3ed1
Render the WebView2 preview on a transparent background and keep the alpha channel when resizing, so SVGs with transparency no longer render as black thumbnails. This also ensures we return an ARGB bitmap that matches what is the expected in SvgThumbnailProvider.cpp with `WTS_ALPHATYPE::WTSAT_ARGB`. <!-- Enter a brief description/summary of your PR here. What does it fix/what does it change/how was it tested (even manually, if necessary)? --> ## Summary of the Pull Request <!-- Please review the items on the PR checklist before submitting--> ## PR Checklist - [X] Closes: #36234 <!-- - [ ] Closes: #yyy (add separate lines for additional resolved issues) --> - [ ] **Communication:** I've discussed this with core contributors already. If the work hasn't been agreed, this work might be rejected - [X] **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 <!-- Provide a more detailed description of the PR, other things fixed, or any additional comments/features here --> ## Detailed Description of the Pull Request / Additional comments **The fix** is a single line — `_browser.DefaultBackgroundColor = Color.Transparent` in `SvgThumbnailProvider.GetThumbnailImpl`. Without it WebView2 composites onto an opaque background, so `CapturePreviewAsync` returns a PNG with no usable alpha. The native side already advertised `WTS_ALPHATYPE::WTSAT_ARGB` (`SvgThumbnailProviderCpp/SvgThumbnailProvider.cpp:168`), so it was promising Explorer an ARGB bitmap that the managed side never actually produced. **On the `ResizeImage` changes** (`Format32bppArgb` + dropping `graphics.Clear(Color.White)`): I measured these and they are strictly defensive — neither alters output. `new Bitmap(w, h)` already defaults to `Format32bppArgb`, and the `Clear` was entirely overwritten by the full-coverage `DrawImage` under `CompositingMode.SourceCopy`. I've kept them because they make the intent explicit and match the Gcode/Qoi/Bgcode providers, but they are not what fixes the bug. **Also fixed:** `ResizeImage` never disposed its source image, leaking a GDI bitmap per resize. The three sibling providers all dispose it; SVG was the only one that didn't. **Why the BMP round-trip doesn't lose the alpha:** the managed process saves to a `.bmp` (`Program.cs:35`) which the native handler reloads via `LoadImage` (`SvgThumbnailProvider.cpp:167`). The GDI+ BMP encoder writes 32bpp with the alpha bytes intact, and `LoadImage` preserves them, so transparency survives end to end — as the screenshots below show. ## Screenshots ### Before <img width="2289" height="1301" alt="image" src="https://github.com/user-attachments/assets/b08c468a-fa74-4bf6-a007-f45212357503" /> ### After <img width="2279" height="1296" alt="image" src="https://github.com/user-attachments/assets/df586ddc-70d3-4a5f-8939-5a1e3976e465" /> (FWIW, the blank icons are expected as those icons where incorrectly exported) <!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well --> ## Validation Steps Performed - Viewed a folder of SVGs with transparent backgrounds in File Explorer at various thumbnail sizes — see before/after above. - Two tests added to `Preview.SvgThumbnailProvider.UnitTests`: - `GetThumbnailShouldPreserveTransparentBackground` — renders an SVG covering only part of the viewBox, asserts the corner pixel stays at `A=0`. Fails without this fix. - `ResizeImageShouldPreserveAlphaChannel` — asserts `ResizeImage` returns `Format32bppArgb` and does not force opacity. - Full suite green locally: 15/15. --------- Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 7b3fb20d-6e9d-4fef-a5cd-f8921d28c220
Microsoft PowerToys
Microsoft PowerToys is a collection of utilities that help you customize Windows and streamline everyday tasks.
Installation · Documentation · Blog · Release notes
🔨 Utilities
PowerToys includes over 30 utilities to help you customize and optimize your Windows experience:
Advanced Paste
Always on Top
Awake
Color Picker
Command Not Found
Command Palette
Crop And Lock
Environment Variables
FancyZones
File Explorer Add-ons
File Locksmith
Grab And Move
Hosts File Editor
Image Resizer
Keyboard Manager
Light Switch
Mouse Utilities
Mouse Without Borders
New+
Peek
PowerDisplay
PowerRename
PowerToys Run
Quick Accent
Registry Preview
Screen Ruler
Shortcut Guide
Text Extractor
Workspaces
ZoomIt📦 Installation
For detailed installation instructions and system requirements, visit the installation docs.
But to get started quickly, choose one of the installation methods below:
Download the .exe file from GitHub
Go to the PowerToys GitHub releases, scroll down and select Assets to reveal the installation files, and choose the one that matches your architecture and install scope. For most devices, that would be x64 per-user.
Microsoft Store
You can easily install PowerToys from the Microsoft Store:
WinGet
Download PowerToys from [WinGet](https://github.com/microsoft/winget-cli#installing-the-client). Updating PowerToys via winget will respect the current PowerToys installation scope. To install PowerToys, run the following command from the command line / PowerShell:
- User scope installer (default)
winget install Microsoft.PowerToys -s winget
- Machine-wide scope installer
winget install --scope machine Microsoft.PowerToys -s winget
Other methods
There are [community driven install methods](https://learn.microsoft.com/windows/powertoys/install#community-driven-install-tools) such as Chocolatey and Scoop. If these are your preferred install solutions, you can find the install instructions there.
✨ What's new?
To see what's new, check out the release notes.
🛣️ Roadmap
We are planning some nice new features and improvements for the next releases – a brand-new Shortcut Guide experience, ensuring it's easier to find and install Command Palette extensions and so much more! Stay tuned for v0.100!
❤️ PowerToys Community
The PowerToys team is extremely grateful to have the support of an amazing active community. The work you do is incredibly important. PowerToys wouldn't be nearly what it is today without your help filing bugs, updating documentation, guiding the design, or writing features. We want to say thank you and take time to recognize your work. Your contributions and feedback improve PowerToys month after month!
Contributing
This project welcomes contributions of all types. Besides coding features / bug fixes, other ways to assist include spec writing, design, documentation, and finding bugs. We are excited to work with the power user community to build a set of tools for helping you get the most out of Windows. We ask that before you start work on a feature that you would like to contribute, please read our Contributor's Guide. We would be happy to work with you to figure out the best approach, provide guidance and mentorship throughout feature development, and help avoid any wasted or duplicate effort. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you grant us the rights to use your contribution and that you have permission to do so. For guidance on developing for PowerToys, please read the developer docs for a detailed breakdown. This includes how to setup your computer to compile.
Code of conduct
This project has adopted the Microsoft Open Source Code of Conduct.
Privacy statement
The application logs basic diagnostic data (telemetry). For more privacy information and what we collect, see our PowerToys Data and Privacy documentation.