PowerToys/doc/devdocs/modules/mouseutils

Mouse Utilities

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Mouse Utilities is a collection of tools designed to enhance mouse and cursor functionality on Windows. The module contains several sub-utilities that provide different mouse-related features.

Overview

Mouse Utilities includes the following sub-modules:

• Find My Mouse: Helps locate the mouse pointer by creating a visual spotlight effect when activated
• Mouse Highlighter: Visualizes mouse clicks with customizable highlights
• Mouse Jump: Allows quick cursor movement to specific screen locations
• Mouse Pointer Crosshairs: Displays crosshair lines that follow the mouse cursor
• Mouse Button Lock: A ClickLock equivalent for the left, right, and middle mouse buttons - hold a button to lock it down for hands-free dragging, then click any button to release (left is optional and off by default)

Architecture

Most of the sub-modules (Find My Mouse, Mouse Highlighter, Mouse Pointer Crosshairs, and Mouse Button Lock) run within the PowerToys Runner process as separate threads. Mouse Jump is more complex and runs as a separate process that communicates with the Runner via events.

Code Structure

Settings UI

• MouseUtilsPage.xaml
• MouseJumpPanel.xaml
• MouseJumpPanel.xaml.cs
• MouseUtilsViewModel.cs
• MouseUtilsViewModel_MouseJump.cs

Runner and Module Implementation

• FindMyMouse
• MouseHighlighter
• MousePointerCrosshairs
• MouseJump
• MouseJumpUI
• MouseJump.Common
• MouseButtonLock

Community Contributors

• Michael Clayton (@mikeclayton): Contributed the initial version of the Mouse Jump tool and several updates based on his FancyMouse utility
• Raymond Chen (@oldnewthing): Find My Mouse is based on Raymond Chen's SuperSonar

Known Issues

• Mouse Highlighter has a reported bug where the highlight color stays on after toggling opacity to 0

UI Test Automation

Mouse Utilities is currently undergoing a UI Test migration process to improve automated testing coverage. You can track the progress of this migration at:

Mouse Utils UI Test Migration Progress

See Also

For more detailed implementation information, please refer to the individual utility documentation pages linked above.

Activation Process

1. A keyboard hook detects the activation shortcut (typically double-press of Ctrl)
2. A WM_PRIV_SHORTCUT message is sent to the sonar window
3. StartSonar() is called to display a spotlight animation centered on the mouse pointer
4. The animation automatically fades or can be cancelled by user input

Mouse Highlighter

Mouse Highlighter visualizes mouse clicks by displaying a highlight effect around the cursor when clicked.

Key Components

• Uses Windows Composition API for rendering
• Main implementation in MouseHighlighter.cpp
• Core logic handled by the WndProc function

Activation Process

1. When activated, it creates a transparent overlay window
2. A mouse hook monitors for click events
3. On click detection, the highlighter draws a circle or other visual indicator
4. The highlight effect fades over time based on user settings

Mouse Pointer Crosshairs

Displays horizontal and vertical lines that intersect at the mouse cursor position.

Key Components

• Uses Windows Composition API for rendering
• Core implementation in InclusiveCrosshairs.cpp
• Main logic handled by the WndProc function

Activation Process

1. Creates a transparent, layered window for drawing crosshairs
2. When activated via shortcut, calls StartDrawing()
3. Sets a low-level mouse hook to track cursor movement
4. Updates crosshairs position on every mouse movement
5. Includes auto-hide functionality for cursor inactivity

Mouse Jump

Allows quick mouse cursor repositioning to any screen location through a grid-based UI.

Key Components

• Runs as a separate process (PowerToys.MouseJumpUI.exe)
• Communicates with Runner process via events
• UI implemented in MainForm.cs

Activation Process

1. When shortcut is pressed, Runner triggers the shared event MOUSE_JUMP_SHOW_PREVIEW_EVENT
2. The MouseJumpUI process displays a screen overlay
3. User selects a destination point on the overlay
4. Mouse cursor is moved to the selected position
5. The UI process can be terminated via the TERMINATE_MOUSE_JUMP_SHARED_EVENT

Debugging

Find My Mouse, Mouse Highlighter, and Mouse Pointer Crosshairs

• Debug by attaching to the Runner process directly
• Set breakpoints in the respective utility code files (e.g., FindMyMouse.cpp, MouseHighlighter.cpp, InclusiveCrosshairs.cpp)
• Call the respective utility by using the activation shortcut (e.g., double Ctrl press for Find My Mouse)
• During debugging, visual effects may appear glitchy due to the debugger's overhead

Mouse Jump

• Start by debugging the Runner process
• Then attach the debugger to the MouseJumpUI process
• Note: Debugging MouseJumpUI directly is challenging as it requires the Runner's process ID as a parameter

Known Issues

• Mouse Highlighter has a reported bug where the highlight color stays on after toggling opacity to 0