A plugin for svg.js that enables panzoom for viewport elements
npm install svg.panzoom.js
npm install svg.panzoom.js
`
`js
// enables panZoom
var draw = SVG('id').size(1000,1000).panZoom()
// zoom programatically
draw.zoom(lvl, point)
`
You can configure panZoom by passing options to it.
- zoomMin: Minimal zoom level
- zoomMax: Maximal zoom level
- zoomFactor: How much is zoomed by one mouse wheel step
This could look like this:
`js
var draw = SVG('id').size(1000,1000).panZoom({zoomMin: 0.5, zoomMax: 20})
`
Setting the min and max value will automatically restrict the zoom to the provided level.
However you are still able to change the zoom out of that bonds by calling zoom(lvl) programatically.
On touchable devices a pinchZoom gesture is supported. Min and max values also apply here.
Zooming is animatable, too:
`js
draw.zoom(1) // uses center of viewport by default
.animate()
.zoom(2, {x:100, y:100}) // zoom into specified point
`
To disable panZoom or change its options just call it again with false or the new options.
API
svg.panzoom.js adds the .zoom() method to all [viewbox][¹] elements.
- zoom() - returns current zoom level
- zoom(Number) - will zoom in or out depending if the Number is greater or less than the current zoom level
- zoom(Number, {x,y}) - will zoom with the x/y coordinate as center point
- zoom(Number, new SVG.Point(x,y)) - will zoom with the x/y coordinate as center point
| Method | Return Value |
| ---------------------------------- | ------------ |
| zoom() | Number |
| zoom(Number) | element |
| zoom(Number, {x,y}) | element |
| zoom(Number, new SVG.Point(x,y)) | element |
[¹]: #viewbox-elements
$3
- SVG.Doc
- SVG.Nested
Events
Multiple events are fired doing different actions. This allow you to respond
to actions and in some cases stop an action via preventDefault().
zoom is fired when a mouse wheel event or programmable zoom() triggers
a zoom. This usually doesn't happen on mobile devices, in which case
pinchZoomStart is fired when a zoom happens.
Events fired from SVG.js are CustomEvents,
so the arguments passed from svg.panzoom.js are in in the .detail property.
| Event Name | Argument Value | preventDefault support |
| -------------- | ---------------- | ---------------------- |
| zoom | { box, focus } | YES |
| panStart | { event } | NO |
| panEnd | { event } | NO |
| pinchZoomStart | { event } | YES |
| pinchZoomEnd | { event } | NO |
Where box is the new viewport,
focus is point of zoom
and event is the event that triggered the action.
An example of stopping a pan-zoom action:
`js
var draw = SVG('id').size(1000,1000).panZoom()
draw.on('pinchZoomStart', function(ev) {
ev.preventDefault()
...
})
``