A pan and zoom component for React, using CSS transformations.
Depends only upon prop-types, react and react-dom modules.
Works on both desktop and mobile.
Online demo here!
- Zoom with the mouse-wheel or a two-finger pinch
- Zoom using double-click or double-tap
- Zoom on selected area and center
- Pan with the mouse pointer or with one finger when zoomed-in
- Intuitive panning depending on available space when zoomed-in
- Adjusts cursor style to indicate in which direction the element can be moved
If you want to contribute, feel free to send a merge request or open a discussion. Currently, I just have time to maintain the package, but not enough to make big changes or add important features.
All contribution would be quite appreciated! 😉
Among changes I would like to apply:
- Migrate to TypeScript
- Transform to a functional component (that could help splitting the code)
- Make motion logic less dependant to React
- Replace Enzyme with another testing library
- The
lockedprop has been replaced byallowZoomandallowPanto handle zooming and panning events separately
- The package now requires React v16.3 or higher (in order to use react references)
- The zoom feature through gestures or mousewheel got some improvements to react better with all devices. You may need to adjust the
scrollVelocityproperty passed to the component in order to keep the same effect.
$ npm i -D react-prismazoomThis project includes a full-featured application demo.
First clone the project.
Go to the subfolder:
$ cd demoThen, install it:
$ npm ciRun the Webpack Dev Server:
$ npm startimport PrismaZoom from 'react-prismazoom'
<PrismaZoom>
<img src="my-image.png" />
<p>A text that can be zoomed and dragged</p>
</PrismaZoom>| Name | Type | Default | Description |
|---|---|---|---|
| className | string | None | Class name to apply on the zoom wrapper. |
| style | object | None | Style to apply on the zoom wrapper. Note that transform, transition, cursor, touch-action and will-change cannot be overridden. Example: style={{backgroundColor: 'red'}}. |
| minZoom | number | 1 | Minimum zoom ratio. |
| maxZoom | number | 5 | Maximum zoom ratio. |
| scrollVelocity | number | 0.1 | Zoom increment or decrement on each scroll wheel detection. |
| onZoomChange | function | null | Function called each time the zoom value changes. |
| onPanChange | function | null | Function called each time the posX or posY value changes (aka images was panned). |
| animDuration | number | 0.25 | Animation duration (in seconds). |
| doubleTouchMaxDelay | number | 300 | Max delay between two taps to consider a double tap (in milliseconds). |
| decelerationDuration | number | 750 | Decelerating movement duration after a mouse up or a touch end event (in milliseconds). |
| allowZoom | boolean | true | Enable or disable zooming in place. |
| allowPan | boolean | true | Enable or disable panning in place. |
| allowTouchEvents | boolean | false | Enables touch event propagation. |
Note: all props are optional.
These functions can be called from parent components.
zoomIn (value)
Increments the zoom with the given value.
Param {value: Number} : Zoom value
zoomOut (value)
Decrements the zoom with the given value.
Param {value: Number} : Zoom value
zoomToZone (relX, relY, relWidth, relHeight)
Zoom-in on the specified zone with the given relative coordinates and dimensions.
Param {relX: Number} : Relative X position of the zone left-top corner in pixels
Param {relY: Number} : Relative Y position of the zone left-top corner in pixels
Param {relWidth: Number} : Zone width in pixels
Param {relHeight: Number} : Zone height in pixels
reset ()
Resets the component to its initial state.
getZoom ()
Returns the current zoom value.
Return {Number} : Zone value
React PrismaZoom is licensed under the ISC license. See the LICENSE.md file for more details.