[MouseJump] WIP - long-lived executable with hotkey handler (#26073)

[mikeclayton]

Summary of the Pull Request

Changes the way activation works in Mouse Jump to use a long-lived background process that handles its own hotkey activation, rather than having the main runner launch a short-lived instance of MouseJumpUI.exe every time the activation keys are pressed.

This reduces the time to display the preview popup since the Mouse Jump application itself doesn't have to load up from scratch for every activation.

PR Checklist

• Closes:
  • Guidance needed - Mouse Jump long-lived background task for faster activation #26073
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
  • sorta-kinda discussed in Guidance needed - Mouse Jump long-lived background task for faster activation #26073
• Tests: Added/updated and all pass
  • no new features added. existing tests all pass
• Localization: All end user facing strings can be localized
  • no new localisation strings added
• Dev docs: Added/updated
• New binaries: Added on the required places
  • no new binaries added
• Documentation updated: If checked, please file a pull request on [our docs repo]
  • no new features added

Detailed Description of the Pull Request / Additional comments

The main PowerToys runner now simply starts MouseJumpUI.exe when the tool is enabled, and terminates the process when the tool is disabled - this is similar to how FancyZones works, except there's no graceful IPC at present to signal to the MouseJumpUI.exe instance to close itself before it gets terminated.

MouseJumpUI.exe installs its own hotkey monitor (using the shared config file to determine what key sequence to register, and listens for activation. When it receives a Windows message that thee hotkey has been activated it displays the popup form, and hides it again when the user clicks or cancels the popup form.

Validation Steps Performed

• Automated tests passing locally
• Minimal actions workflow (spelling check) passing for PR
• Full actions workflow (msbuild) passing for PR
• Manual regression-testing scenarios
  • Happy path - clicking the thumbnail image works and cursor moves to the correct location
  • Works on multiple monitors with different dpi scaling settings (e.g. 100% vs 150%)
    • [Mouse Jump] - new feature - #23216 #23566 (comment)
    • [Mouse Jump] - new feature - #23216 #23566 (comment)
  • Handling negative coordinates on non-primary monitors if higher or "lefter" than primary monitor
    • [Mouse Jump] - new feature - #23216 #23566 (comment)
  • Mouse crosshair moves when Mouse Jump moves the cursor (mouse clicks and keyboard shortcuts)
    • Mouse pointer Crosshair & Mouse Jump Issue #24523
    • [MouseJump]Also simulate mouse input event #24527
  • Starting PowerToys Runner launches MouseJumpUI.exe when enabled, and not when disabled
  • Enabling / disabling Mouse Jump in settings starts / stops MouseJumpUI.exe
  • Hotkey and size settings are reloaded when config file is modified (from Settings, and manually edited)

[mikeclayton]

There's a lot of files touched in this PR, so here's a summary in case it helps work though it quicker...

MouseJump

• main.cpp - changed the module interface to remove the activation shortcut code and just stop / start a long-lived MouseJumpUI.exe when the module is enabled / disabled

MouseJumpUI

• Helpers\ConfigHelper.cs - loads the config file and starts a FileSystemWatcher to reload it whenever it's changed (including activation shortcut)
• HotKeys\** - implements a background message loop that registers a hotkey and listens for a WM_HOTKEY message on the configured shortcut
• Models\** - added some classes and code to read the settings file
• NativeMethods** - adds a bunch more WIn32 declarations to support Hotkeys and all the associated window / message functions

The remaining handful of changes are really just to integrate the ones above into the application.

[mikeclayton]

Btw, I don't have any hard stats on performance, but it certainly feels a lot more responsive now that it's a long-lived background task rather than having to launch a whole new MouseJump.exe process every time the hotkey is activated.

Have a play with the current PowerToys release first to get a feel for how quickly the popup is displayed before you try the one in this PR, and see if it feels faster...

[jaimecbernardo]

Hi @mikeclayton ,

Thank you for the contribution!
Sorry for the delay in reviewing the PR, since we had entered "wrap up release" mode last week.
Giving the PR a try, there's some shortcuts that are not supported anymore, but they were without the changes. I tested Win+J, for example. This is through the use of shortcuts instead of low level keyboard hooks. LLKH however shouldn't be used in C#.

I think a better approach here would be to let the module interface keep handling activation by using a event instead to signal actiavation to MouseJumpUI. No need to add all that boiler code to the project this way.
This is used, for example, by Peek, ColorPicker, TextExtractor(PowerOCR) and even PowerLauncher when using the centralized key hook.

TextExtractor might be the best one to look at to understand this, since it's pretty similar in what it does (running in the background to then show an overlay). If you look in the solution for the strings SHOW_POWEROCR_SHARED_EVENT and ShowPowerOCRSharedEvent it should give a good idea of the workflow. The modules interface registers the event and then the UI listens for it with NativeEventWaiter.WaitForEventLoop.

What do you think about this?

[jaimecbernardo]

Someone in the core team can help bring this method in if you want :)

[mikeclayton]

@jaimecbernardo - No worries. I'm on leave at the moment, but I'll take a look when I'm back home - I'll give it a go myself and yell if I get stuck :-)..

I'll put this back to WIP in the meantime...

[mikeclayton]

I'm going to close this PR as the proposed fix re Windows Events is probably easiest to just start on again from main...