Dragscroll-zoom NPM

dragscroll-zoom

Dragscroll-Zoom is a micro JavaScript library (910 bytes minified) which enables scrolling via holding the mouse button ("drag and drop" or "click and hold" style, online demo). It has no dependencies and is written in vanilla JavaScript (which means it works anywhere).

And I added a zoom function. (It is getting better)

Usage

Install it using npm:

$ npm install dragscroll-zoom

Load the dragscroll.js in a preferable way (that is an UMD module):

<script src="path/to/dragscroll.js"></script>

Add the dragscroll class to a scrollable element:

<button id="zoom-in" onclick="zoomIn(20);">+</button>
<button id="zoom-out" onclick="zoomOut(20);">-</button>
<div class="dragscroll">
  <!-- dragsimg's style(width) specify arbitrary values. DON'T USE CSS -->
  <img id="dragsimg" src="./test.png" style="width:100%"/>
</div>

That's it! Now you can scroll it by dragging. You can also add the dragscroll class to the <body> element and drag the whole page.

Keep in mind that now it is not possible to select the content with mouse, so apply the cursor: default; CSS style to prevent confusing the users (or even cursor: grab; in case the content is not a text).

You can use zoom-in(number),zoom-out(number) to zoom in and zoom out a dragsimg.
You have to put a number in zoom-in(number),zoom-out(number).
The image's size changes by a number.

If you add or remove the dragscroll class dynamically, invoke dragscroll.reset() to update the listeners.

You can also add the nochilddrag attribute to a scrollable element, which will only enable drag-scrolling for an element itself, but not for its subchildren. This can be usefull, if you want to enable the scrolling the area by dragging its empty space, but keep the opportunity to select the text (see example).

Thank you for use this lib.

This project began as a fork of dragscroll