DragScroll

This small utility provides a drag-to-scroll mechanism for macOS. It runs in the background and does not interfere until either a mouse button is pressed (button 5 by default) or some modifier keys are held down (the Shift key by default), both of which activate drag scrolling mode. In this mode, the mouse cursor is locked in place and mouse movement is interpreted as scrolling. Pressing the mouse button again or releasing the modifier keys deactivates drag scrolling mode.

This application is especially useful with a trackball: you can activate drag scrolling and roll the ball to quickly scroll through a large website or a document. It also works with the trackpad, for instance allowing you to drag scroll with a single finger while holding down the modifier keys.

Note

The two means of activation operate independently of each other: if you first press the mouse button to activate and then press and release the modifier keys, drag scrolling mode stays active until you press the mouse button again.

Supported versions

As of May 2024, this application works on macOS versions 10.9–14.0.

Installation

You may download the binary here. DragScroll requires access to accessibility features. Upon startup, if it does not have access, it will prompt you and wait. You do not need to restart the application after you grant it access to accessibility features.

Caution

You should not revoke accessibility access for DragScroll while it is running. Otherwise, your mouse might become unresponsive, requiring a reboot to fix.

If you want the application to run automatically when you log in, do the following:

1. On macOS 13.0 and later, go to System Settings > General > Login Items; otherwise, go to System Preferences > Users & Groups > Login Items.
2. Add DragScroll to the list.

If you want to quit the application, either run killall DragScroll or do the following:

1. Launch Activity Monitor.
2. Search for DragScroll and select it.
3. Click the stop button in the upper-left corner and choose Quit.

Configuration

• Mouse button: The default mouse button for toggling drag scrolling is button 5. If you want to use a different mouse button, run the following command, replacing BUTTON with a button number between 3 and 32. (Button numbers are one-based, so 1 and 2 represent left and right mouse buttons. You cannot use those in DragScroll.)

  defaults write com.emreyolcu.DragScroll button -int BUTTON
  

  If you do not want to use mouse buttons with DragScroll, set button to 0.

• Modifier keys: The default modifier key for activating drag scrolling is the Shift key. If you want to use a different set of modifiers, run the following command, replacing [KEYS...] by a space-separated set of modifier keys chosen from among capslock, shift, control, option, command. (Unlike the other modifiers, Caps Lock works as a toggle.)

  defaults write com.emreyolcu.DragScroll keys -array [KEYS...]
  

  For instance, if you want to activate drag scrolling by holding down Control and Command together, run:

  defaults write com.emreyolcu.DragScroll keys -array control command
  

  If you do not want to use modifier keys with DragScroll, set keys to an empty array:

  defaults write com.emreyolcu.DragScroll keys -array
  

• Scrolling speed: If you want to change scrolling speed, run the following command, replacing SPEED with a small number (default is 3). This number may even be negative, which inverts scrolling direction.

  defaults write com.emreyolcu.DragScroll speed -int SPEED
  

Warning

If you set a preference to an unexpected value (e.g., of the wrong type), then its default value is used as a fallback.

You should restart the application for these settings to take effect.

Uninstallation

To uninstall DragScroll, quit the application, move it to trash, and remove it from the lists for accessibility access and login items. You can remove any stored preferences by running the following:

defaults delete com.emreyolcu.DragScroll

Potential problems

Recent versions of macOS have made it difficult to run unsigned binaries.

If you experience issues launching the application, try the following:

• Remove the quarantine attribute by running the command xattr -dr com.apple.quarantine /path/to/DragScroll.app, where the path points to the application bundle.
• Disable Gatekeeper by running the command spctl --add /path/to/DragScroll.app, where the path points to the application bundle.

If on startup the application asks for accessibility permissions even though you have previously granted it access, try the following:

1. On macOS 13.0 and later, go to System Settings > Privacy & Security > Accessibility; otherwise, go to System Preferences > Security & Privacy > Privacy > Accessibility.
2. Remove DragScroll from the list and add it again.

History

v1.3.1 (2024-06-05)

• Fix: Release event tap and run loop source after adding source.

v1.3.0 (2024-06-02)

• Change "scale" to "speed".
• Remove accessibility observer once granted access.

v1.2.0 (2024-05-31)

• Observe changes in accessibility access continuously.

v1.1.0 (2024-05-29)

• Allow using modifier keys in addition to mouse buttons.

v1.0.0 (2024-05-27)

• Handle errors and check for accessibility access.
• Allow configuring the toggle button and scrolling speed.
• Rename project from "PixelScroll" to "DragScroll".

v0.1.0 (2018-05-26)

• Initial release.