image zoom 0.1.2

Basic image zoom functionality as a user-script for your web browser.

This is a user-script for your web browser, you need either Greasemonkey, Violentmonkey or Tampermonkey to install and use it, the later two might be preferred since Greasemonkey v4+ does not support frames yet.

This script allows you to easily zoom an image in a web page with your mouse buttons and wheel.

Installation

Once you have installed either Greasemonkey, Violentmonkey or Tampermonkey for your web browser, you just click on the link to the raw version of this script to install it and your user-script manager extension will ask you to confirm the installation.

Important note for Linux users

On Linux, the context menu is triggered on mousedown (instead of mouseup on Windows), this makes the script to not work properly. With Firefox you can change it to mouseup by setting the about:config option ui.context_menus.after_mouseup to true (see bug 1360278). With Chomium it dosen't seem to be feasable.

Tested platforms

So far the script has been tested successfully on:

• Firefox / Windows
• Chromium / Windows
• Firefox / Linux with the option ui.context_menus.after_mouseup set to true

Features

This script currently has two zoom features:

• Max the image size to the size of the web page window by pressing and holding the right mouse button on an image and then clicking the left mouse button, pressing and holding the right mouse button and then clicking the left mouse button again restores the original size of the image in the web page.
• Incrementally zoom or unzoom an image by pressing and holding the right mouse button on an image and then moving the mouse wheel up or down to unzoom or zoom the image, pressing and holding the right mouse button and then clicking the left mouse button after an incremental zoom restores the original size of the image in the web page.

The following image is there so you can test the script on it:

Tweaking the script

Four settings might be tweaked in the script (you may edit the script from your user-script manager extension):

• The zoom_factor, a double that must be more than 1 and that specifies the amount of zoom or unzoom at each wheel input for the incremental zoom feature (default to 1.25 a.k.a 125%).
• The zoom_direction, the wheel direction to zoom (as opposed to unzoom) for the incremental zoom feature, change to whatever you want to reverse (default to "down").
• zoom_follows_cursor_x and zoom_follows_cursor_y, booleans that make the incremental zoom feature follows the mouse cursor (default both to true).