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)
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