vue-croppa

vue-croppa

A simple straightforward customizable lightweight mobile-friendly image cropper for Vue 2.0.

Features

• Straightforward: What you see is what you get
• Highly customizable: You can almost customize anything except the core functionalities
• Lightweight: 24kb in total (33kb since v0.3.0)
• Mobile-friendly: Supports drag to move and pinch with two fingers to zoom on mobile devices
• EXIF orientation: v0.2.0+ Support correctly show image with EXIF orientation

Browser Support

• IE 10+
• Firefox 3.6+
• Chrome 6+
• Safari 6+
• Opera 11.5+
• iOS Safari 6.1+
• Android Browser 3+

Template Example

<croppa v-model="myCroppa"
        :width="400"
        :height="400"
        :canvas-color="'default'"
        :placeholder="'Choose an image'"
        :placeholder-font-size="0"
        :placeholder-color="'default'"
        :input-accept="'image/*'"
        :file-size-limit="0"
        :quality="2"
        :zoom-speed="3"
        :disabled="false"
        :disable-drag-and-drop="false"
        :disable-click-to-choose="false"
        :disable-drag-to-move="false"
        :disable-scroll-to-zoom="false"
        :disable-rotation="false"
        :prevent-white-space="false"
        :reverse-scroll-to-zoom="false"
        :show-remove-button="true"
        :remove-button-color="'red'"
        :remove-button-size="0"
        :initial-image="'path/to/initial-image.png'"
        @init="handleCroppaInit"
        @file-choose="handleCroppaFileChoose"
        @file-size-exceed="handleCroppaFileSizeExceed"
        @file-type-mismatch="handleCroppaFileTypeMismatch"
        @image-remove="handleImageRemove"
        @move="handleCroppaMove"
        @zoom="handleCroppaZoom"></croppa>

NOTE: This is an almost-full-use example. Usually you don't need to specify so many props, because they all have default values. Most simply, you can even do:

<croppa v-model="myCroppa"></croppa>

Method Examples

this.myCroppa.remove()

this.myCroppa.zoomIn()

alert(this.myCroppa.generateDataUrl())

Quick Start

1. Import vue-croppa into your vue.js project.

Using build tools:

npm install --save vue-croppa

import Vue from 'vue'
import Croppa from 'vue-croppa'

Vue.use(Croppa) 

// If your build tool supports css module
import 'vue-croppa/dist/vue-croppa.css'

Not using build tools:

<link href="https://unpkg.com/vue-croppa/dist/vue-croppa.min.css" rel="stylesheet" type="text/css">
<script src="https://unpkg.com/vue-croppa/dist/vue-croppa.min.js"></script>

Vue.use(Croppa)

2. Now you have it. The simplest usage:

<croppa v-model="myCroppa"></croppa>

new Vue({
  // ... other vm options omitted
  data: {
    myCroppa: {}
  },

  methods: {
    uploadCroppedImage() {
      this.myCroppa.generateBlob((blob) => {
        // write code to upload the cropped image file (a file is a blob)
      }, 'image/jpeg', 0.8) // 80% compressed jpeg file
    }
  }
})

Live example: https://jsfiddle.net/jdcvpvty/2/

NOTE:

• Since v0.1.0, you can change the default component name to anything you want.

import Vue from 'vue'
import Croppa from 'vue-croppa'

Vue.use(Croppa, { componentName: 'my-image-cropper' })

<my-image-cropper v-model="myCroppa"></my-image-cropper>

• Since v0.1.1, you can get the component object with Croppa.component. This is useful when you want to register the component by yourself manually.

Vue.component('croppa', Croppa.component)

// Register async component (Webpack 2 + ES2015 Example). More about async component: https://vuejs.org/v2/guide/components.html#Async-Components
Vue.component('croppa', () => import(Croppa.component))

Documentation

🌱 Props

v-model

A two-way binding prop. It syncs an object from within the croppa component with a data in parent. We can use this object to invoke useful methods (Check out "Methods" section).

• type: object
• live example: https://jsfiddle.net/jdcvpvty/2/

width

Display width of the preview container.

• type: number
• default: 200
• valid: val > 0

height

Display height of the preview container.

• type: number
• default: 200
• valid: val > 0

placeholder

Placeholder text of the preview container. It shows up when there is no image.

• type: string
• default: 'Choose an image'

placeholder-color

Placeholder text color.

• type: same as what CanvasRenderingContext2D.fillStyle accepts.
• default: '#606060'

placeholder-font-size

Placeholder text font size in pixel. When set to 0, the font size will be ajust automatically so that the whole placehoder only takes up 2/3 of the container's width.

• type: number
• default: 0

canvas-color

Initial background color and white space color if there is an image.

• type: same as what CanvasRenderingContext2D.fillStyle accepts.
• default: before v0.2.0 - '#e6e6e6'; after v0.2.0 - 'transparent'

quality

Specifies how many times larger the actual image is than the container's display size.

• type: number
• default: 2
• valid: `isInteger(val) && val > 0

zoom-speed

Specifies how fast the zoom is reacting to scroll gestures. Default to level 3.

• type: number
• default: 3
• valid: val > 0

accept

Limits the types of files that users can choose.

• type: same as what accept attribute of HTML input element takes.
• default: '.jpg,.jpeg,.png,.gif,.bmp,.webp,.svg,.tiff'

file-size-limit

Limits the byte size of file that users can choose. If set to 0, then no limit.

• type: number
• default: 0

disabled

Disables user interaction.

• type: boolean
• default: false

disable-drag-and-drop

Disables the default "drag and drop a file" user interaction. You can instead trigger the file chooser window programmatically by "click to choose" functionality or invoking chooseFile() method.

• type: boolean
• default: false

disable-click-to-choose

Disables the default "click to choose a file" ("tab" on mobile) user interaction. You can instead trigger the file chooser window programmatically by "drag and drop" functionality or invoking chooseFile() method.

• type: boolean
• default: false

disable-drag-to-move

Disables the default "drag to move" user interaction. You can instead move the image programmatically by invoking moveUpwards() / moveDownwards() / moveLeftwards() / moveRightwards() methods.

• type: boolean
• default: false

disable-scroll-to-zoom

Disables the default "scroll to zoom" user interaction. You can instead zoom the image programmatically by invoking zoomIn() / zoomOut() methods.

• type: boolean
• default: false

disable-pinch-to-zoom

Disables the default "pinch with two fingers to zoom" user interaction on mobile. You can instead zoom the image programmatically by invoking zoomIn() / zoomOut() methods.

• type: boolean
• default: false

disable-rotation

(v0.2.0+) Rotation methods won't work if this is set to true

• type: boolean
• default: false

reverse-zooming-gesture

Deprecated @v0.0.20+ Please use reverse-scroll-to-zoom instead. The name isn't proper because you can not reverse pinch to zoom.

Reverses the zoom-in/zoom-out direction when scrolling.

• type: boolean
• default: false

reverse-scroll-to-zoom

Reverses the zoom-in/zoom-out direction when scrolling.

• type: boolean
• default: false

prevent-white-space

Prevents revealing background white space when moving or zooming the image.

• type: boolean
• default: false

show-remove-button

Specifies whether to show the built-in remove-button. You can change the button's color and size using the following two props. If you still find it ugly, hide it and use the remove() method to implement your own trigger.

• type: boolean
• default: false

remove-button-color

Changes the default color of the remove-button. Accepts any css color format.

• type: string
• default: 'red'

remove-button-size

Specifies the remove-button's width and height (they are equal). If set to 0, then it use the default size.

• type: number
• default: default size is ajust accordingly to container's size

initial-image

(v0.1.0+) Set initial image. You can pass a string as the url or an Image object (HTMLImageElement instance). This is an alternative way to set initial image besides using slot. Useful when you want to set cross origin image as initial image.

• type: string or object (HTMLImageElement instance)
• default: undefined

initial-size

(v0.2.0+) works similar to css's background-size. It specifies the image's size when it is first loaded on croppa.

• type: string
• default: 'cover'
• valid: one of 'cover', 'contain', 'natural'

initial-position

(v0.2.0+) works similar to css's background-position. It specifies the image's position relative to croppa container when it is first loaded.

• type: string
• default: 'center'
• valid:
  • 'center' (default value)
  • '30% 40%' (similar to background-position in css)
  • 'top'
  • 'bottom'
  • 'left'
  • 'right'
  • 'top left' or 'left top'
  • 'top right' or 'right top'
  • 'bottom left' or 'left bottom'
  • 'bottom right' or 'right bottom'

---

🌱 Slots

initial

• You can provide an initial image by putting an <img> node as a named slot initial. For example:

<croppa v-model="myCroppa">
  <img slot="initial" :src="initialImageUrl" />
</croppa>

NOTE:

• You need to explicitly call .refresh() method after changing inital image.
• If you provide both the slot and initial-image prop, the slot will be the one that is used.

---

placeholder

• If you are not satified with the simple text placeholder. Since v0.3.0, you can apply an <img> slot named placeholder to get an image placeholder! The image will be draw on croppa under the placeholder text when it is empty.

<croppa v-model="myCroppa">
  <img slot="placeholder" src="static/placeholder-image.png" />
</croppa>

NOTE:

• It is recommended to use a small-sized image as the placeholder image.
• The image will be drawn with 100% width and height of croppa container, i.e. it will cover the container. So it is recommended to use a images with the same aspect ratio as the container.
• Find demo "Image Placeholder" in the demo page

🌱 Methods

getCanvas()

• returns the canvas object

getContext()

• returns the canvas context object

getChosenFile()

getActualImageSize()

• Return an object { width, height } describing the real image size (preview size * quality)

moveUpwards( amountInPx: number )

moveDownwards( amountInPx: number )

moveLeftwards( amountInPx: number )

moveRightwards( amountInPx: number )

zoomIn()

zoomOut()

rotate(step: number)

• 1 step = 90 deg
• positive number: rotates clockwise
• negative number: rotates counterclockwise.

flipX()

• Horizontally flip image.

flipY()

• Vertically flip image.

chooseFile()

• Opens the file chooser window to Choose an image. Useful when default click-to-choose interaction is disabled.

myCroppa.reset()

• To Be Deprecated This will be deprecated in the future due to misnaming 😅 . Please use remove() instead.
• Removes the current image, can be used to implement your own remove-button.

remove()

• Removes the current image, can be used to implement your own remove-button.

refresh()

• Reinitialize the component. Useful when you want to change initial image.

hasImage()

• Return boolean value indicating whether currently there is a image.

generateDataUrl( type: string, compressionRate: number )

• Returns a data-URL containing a representation of the image in the format specified by the type parameter (defaults to png).
• compressionRate (v0.2.0+) defaults to 1, you can pass a number between 0 and 1 to get a compressed output image.

generateBlob( callback: function, mimeType: string, compressionRate: number )

• Creates a Blob object representing the image contained in the canvas. Look up argument definition here.

promisedBlob( mimeType: string, compressionRate: number )

• This method returns a Promise wrapping around generateBlob(), so that you can use async/await syntax instead of a callback to get blob data, it's simpler.

const blob = await this.myCroppa.promisedBlob()

getMetadata()

• Require v0.3.0+
• Get metadata that describes current user manipulations (moving, zooming, rotating).

var metadata = this.myCroppa.getMetadata()
console.log(metadata)

/* in console
{
  startX:-535.5180530546083,
  startY:-358.0699623303261,
  scale:2.2502626424905396,
  orientation:6
} 
*/

• Find demo "Use Metadata" in the demo page.

applyMetadata(metadata)

• Require v0.3.0+
• Apply metadata to get to a certain manipulation state (moving, zooming, rotating).
• metadata can have one or more of these 4 properties: startX, startY, scale, orientation. Usually you will use the object returned by getMetadata().

var metadata = {
  startX:-535.5180530546083,
  startY:-358.0699623303261,
  scale:2.2502626424905396,
  orientation:6
}

this.myCroppa.applyMetadata(metadata)

• Find demo "Use Metadata" in the demo page.

supportDetection()

• Return an object indicating browser supports. Like this:

{
  basic: true, // supports basic functionality
  dnd: false // does not support drag and drop
}

---

🌱 Events

init

• handler(croppa)
  • croppa is a croppa object to invoke methods - same as what v-model binds.

file-choose

• emitted when user choose an image from the poppup window or "drag and drop" a file into the container.
• handler(file)
  • file is a file object - same as what getChosenFile() returns.

file-size-exceed:

• emitted when the chosen file's size exceeds the limit specified by prop fileSizeLimit.
• handler(file)
  • file is a file object - same as what getChosenFile() returns.

file-type-mismatch:

• emitted when the chosen file does not match the specified type, which btw is specified using prop accept.
• handler(file)
  • file is a file object - same as what getChosenFile() returns.

new-image

• emitted when new valid image is set onto croppa (v0.2.0).

image-remove

• emitted when image remove from croppa.

move

zoom

draw

• emitted on every view update (including init, move, zoom, rotate) when it is not empty. It is useful when you want to add attachment on image.
• handler(ctx)
  • ctx is the CanvasRenderingContext2D object for you to draw anything you want on the current image. You can also get it with the method getContext().
• Find demo "Attachments" in the demo page.

initial-image-loaded

• emitted when initial image loaded. It can be useful when you provide initial image with the initial-image prop.

---

🌱 Customize styles

• Check out default css styles. You can add more css styles to those selectors to get a different look. Be careful if you try to overwrite existing styles.
• Note that CSS styles will not have any effect on the output image.

Development

1. Fork and clone the repo.

2. Install dependencies.

$ cd vue-croppa
$ npm install

$ cd docs
$ npm install

3. Start developing.

# under vue-croppa/
$ npm run dev

# under vue-croppa/docs/
$ npm run dev

Edit file ./docs/simple-test.html and open http://localhost:3000/simple-test.html to test while developing.

4. Build

# under vue-croppa/
$ npm run build

To Do

• Keep image scale state after rotation (when prevent-white-space is false)