Image Cropper

A Flutter plugin for Android, iOS and Web supports cropping images. This plugin is based on three different native libraries so it comes with different UI between these platforms.

Introduction

Image Cropper doesn't manipulate images in Dart codes directly, instead, the plugin uses Platform Channel to expose Dart APIs that Flutter application can use to communicate with three very powerful native libraries (uCrop, TOCropViewController and Cropper.js) to crop and rotate images. Because of that, all credits belong to these libraries.

uCrop - Yalantis

This project aims to provide an ultimate and flexible image cropping experience. Made in Yalantis

TOCropViewController - Tim Oliver

TOCropViewController is an open-source UIViewController subclass to crop out sections of UIImage objects, as well as perform basic rotations. It is excellent for things like editing profile pictures, or sharing parts of a photo online. It has been designed with the iOS Photos app editor in mind, and as such, behaves in a way that should already feel familiar to users of iOS.

Cropper.js - Fengyuan Chen

JavaScript image cropper.

How to install

Android

Add UCropActivity into your AndroidManifest.xml

<activity
    android:name="com.yalantis.ucrop.UCropActivity"
    android:screenOrientation="portrait"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar"/>

Note:

From v1.2.0, you need to migrate your android project to v2 embedding (detail)

iOS

No configuration required

Web

Add following codes inside <head> tag in file web/index.html:

<head>
  ....

  <!-- cropperjs -->
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/cropperjs/1.6.2/cropper.css" />
  <script src="https://cdnjs.cloudflare.com/ajax/libs/cropperjs/1.6.2/cropper.min.js"></script>

  ....
</head>

Usage

Required parameters

sourcePath: the absolute path of an image file.

Optional parameters

maxWidth: maximum cropped image width.
maxHeight: maximum cropped image height.
aspectRatio: controls the aspect ratio of crop bounds. If this values is set, the cropper is locked and user can't change the aspect ratio of crop bounds.
compressFormat: the format of result image, png or jpg (default is ImageCompressFormat.jpg).
compressQuality: number between 0 and 100 to control the quality of image compression. Note: this field is ignored on Web.
uiSettings: controls UI customization on specific platform (android, ios, web,...)
- Android: see Android customization.
- iOS: see iOS customization.
- Web: see Web customization.

Note

The result file is saved in NSTemporaryDirectory on iOS and application Cache directory on Android, so it can be lost later, you are responsible for storing it somewhere permanent (if needed).
The implementation on Web is much different compared to the implementation on mobile app. It causes some configuration fields not working (compressQuality) on Web.
WebUiSettings is required for Web.

Customization

Android

Click to view detail

Image Cropper provides a helper class called AndroidUiSettings that wraps all properties can be used to customize UI in uCrop library.

Property	Description	Type
`toolbarTitle`	desired text for Toolbar title	String
`toolbarColor`	desired color of the Toolbar	Color
`statusBarColor`	desired color of status	Color
`toolbarWidgetColor`	desired color of Toolbar text and buttons (default is darker orange)	Color
`backgroundColor`	desired background color that should be applied to the root view	Color
`activeControlsWidgetColor`	desired resolved color of the active and selected widget and progress wheel middle line (default is white)	Color
`dimmedLayerColor`	desired color of dimmed area around the crop bounds	Color
`cropFrameColor`	desired color of crop frame	Color
`cropGridColor`	desired color of crop grid/guidelines	Color
`cropFrameStrokeWidth`	desired width of crop frame line in pixels	int
`cropGridRowCount`	crop grid rows count	int
`cropGridColumnCount`	crop grid columns count	int
`cropGridStrokeWidth`	desired width of crop grid lines in pixels	int
`showCropGrid`	set to true if you want to see a crop grid/guidelines on top of an image	bool
`lockAspectRatio`	set to true if you want to lock the aspect ratio of crop bounds with a fixed value (locked by default)	bool
`hideBottomControls`	set to true to hide the bottom controls (shown by default)	bool
`initAspectRatio`	desired aspect ratio is applied (from the list of given aspect ratio presets) when starting the cropper	CropAspectRatioPreset
`cropStyle`	controls the style of crop bounds, it can be rectangle or circle style (default is `CropStyle.rectangle`).	CropStyle
`aspectRatioPresets`	controls the list of aspect ratios in the crop menu view.	List

iOS

Click to view detail

Image Cropper provides a helper class called IOUiSettings that wraps all properties can be used to customize UI in TOCropViewController library.

Property	Description	Type
`minimumAspectRatio`	The minimum croping aspect ratio. If set, user is prevented from setting cropping rectangle to lower aspect ratio than defined by the parameter	double
`rectX`	The initial rect of cropping: x.	double
`rectY`	The initial rect of cropping: y.	double
`rectWidth`	The initial rect of cropping: width.	double
`rectHeight`	The initial rect of cropping: height.	double
`showActivitySheetOnDone`	If true, when the user hits 'Done', a `UIActivityController` will appear before the view controller ends	bool
`showCancelConfirmationDialog`	Shows a confirmation dialog when the user hits 'Cancel' and there are pending changes (default is false)	bool
`rotateClockwiseButtonHidden`	When disabled, an additional rotation button that rotates the canvas in 90-degree segments in a clockwise direction is shown in the toolbar (default is false)	bool
`hidesNavigationBar`	If this controller is embedded in `UINavigationController` its navigation bar is hidden by default. Set this property to false to show the navigation bar. This must be set before this controller is presented	bool
`rotateButtonsHidden`	When enabled, hides the rotation button, as well as the alternative rotation button visible when `showClockwiseRotationButton` is set to YES (default is false)	bool
`resetButtonHidden`	When enabled, hides the 'Reset' button on the toolbar (default is false)	bool
`aspectRatioPickerButtonHidden`	When enabled, hides the 'Aspect Ratio Picker' button on the toolbar (default is false)	bool
`resetAspectRatioEnabled`	If true, tapping the reset button will also reset the aspect ratio back to the image default ratio. Otherwise, the reset will just zoom out to the current aspect ratio. If this is set to false, and `aspectRatioLockEnabled` is set to true, then the aspect ratio button will automatically be hidden from the toolbar (default is true)	bool
`aspectRatioLockDimensionSwapEnabled`	If true, a custom aspect ratio is set, and the `aspectRatioLockEnabled` is set to true, the crop box will swap it's dimensions depending on portrait or landscape sized images. This value also controls whether the dimensions can swap when the image is rotated (default is false)	bool
`aspectRatioLockEnabled`	If true, while it can still be resized, the crop box will be locked to its current aspect ratio. If this is set to true, and `resetAspectRatioEnabled` is set to false, then the aspect ratio button will automatically be hidden from the toolbar (default is false)	bool
`title`	Title text that appears at the top of the view controller.	String
`doneButtonTitle`	Title for the 'Done' button. Setting this will override the Default which is a localized string for "Done"	String
`cancelButtonTitle`	Title for the 'Cancel' button. Setting this will override the Default which is a localized string for "Cancel"	String
`cropStyle`	controls the style of crop bounds, it can be rectangle or circle style (default is `CropStyle.rectangle`).	CropStyle
`aspectRatioPresets`	controls the list of aspect ratios in the crop menu view.	List

Web

Click to view detail

Image Cropper provides a helper class called WebUiSettings that wraps all properties can be used to customize UI in cropperjs library.

Property	Description	Type
`size`	Display size of the cropper. Default = `{ width: 500, height: 500 }`	CropperSize
`viewwMode`	Define the view mode of the cropper. Details of available options in View Mode. Default = `0`	WebViewMode
`dragMode`	Define the dragging mode of the cropper. Details of available options in Drag Mode. Default = `crop`	WebDragMode
`initialAspectRatio`	Define the initial aspect ratio of the crop box. By default, it is the same as the aspect ratio of the canvas (image wrapper). Note: Only available when the aspectRatio option is set to NaN.	num
`checkCrossOrigin`	Check if the current image is a cross-origin. Default = `true` image.	bool
`checkOrientation`	Check the current image's Exif Orientation information. Note that only a JPEG image may contain Exif Orientation information. Requires to set both the rotatable and scalable options to true at the same time. Default = `true`	bool
`modal`	Show the black modal above the image and under the crop box. Default = `true`	bool
`guides`	Show the dashed lines above the crop box. Default = `true`	bool
`center`	Show the center indicator above the crop box. Default = `true`	bool
`highlight`	Show the white modal above the crop box (highlight the crop box). Default = `true`	bool
`background`	Show the grid background of the container. Default = `true`	bool
`movable`	Enable to move the image. Default = `true`	bool
`rotatable`	Enable to rotate the image. Default = `true`	bool
`scalable`	Enable to scale the image. Default = `true`	bool
`zoomable`	Enable to zoom the image. Default = `true`	bool
`zoomOnTouch`	Enable to zoom the image by dragging touch. Default = `true`	bool
`zoomOnWheel`	Enable to zoom the image by mouse wheeling. Default = `true`	bool
`wheelZoomRatio`	Define zoom ratio when zooming the image by mouse wheeling. Default = `0.1`	num
`cropBoxMovable`	Enable to move the crop box by dragging. Default = `true`	bool
`cropBoxResizable`	Enable to resize the crop box by dragging. Default = `true`	bool
`toggleDragModeOnDblclick`	Enable to toggle drag mode between "crop" and "move" when clicking twice on the cropper. Default = `true`	bool
`minContainerWidth`	The minimum width of the container. Default = `200`	num
`minContainerHeight`	The minimum height of the container. Default = `100`	num
`minCropBoxWidth`	The minimum width of the crop box. Default = `0`	num
`minCropBoxHeight`	The minimum height of the crop box. Default = `0`	num
`presentStyle`	Presentation style of cropper, either a dialog or a page (route). Default = `dialog`	WebPresentStyle
`context`	Current BuildContext. The context is required to show cropper dialog or route	BuildContext
`customDialogBuilder`	Builder to customize the cropper `Dialog`	WebDialogBuilder
`customRouteBuilder`	Builder to customize the cropper `PageRoute`	WebRouteBuilder
`barrierColor`	Barrier color for displayed `Dialog`	Color
`translations`	Translations to display	WebTranslations
`themeData`	Control UI customization	WebThemeData

View Mode:

0: no restrictions
1: restrict the crop box not to exceed the size of the canvas.
2: restrict the minimum canvas size to fit within the container. If the proportions of the canvas and the container differ, the minimum canvas will be surrounded by extra space in one of the dimensions.
3: restrict the minimum canvas size to fill fit the container. If the proportions of the canvas and the container are different, the container will not be able to fit the whole canvas in one of the dimensions.

If you set viewMode to 0, the crop box can extend outside the canvas, while a value of 1, 2, or 3 will restrict the crop box to the size of the canvas. viewMode of 2 or 3 will additionally restrict the canvas to the container. There is no difference between 2 and 3 when the proportions of the canvas and the container are the same.

Drag Mode:

crop: create a new crop box
move: move the canvas
none: do nothing

Note:

If using WebDialogBuilder and WebRouteBuilder to customize cropper dialog and route, the customization codes must to call following functions:

initCropper() to initialize Cropper object.
crop() to trigger crop feature and then returning the cropped result data to the plugin by using Navigator.of(context).pop(result).


  class CropperDialog extends StatefulWidget {
    ...
  }  

  class _CropperDialogState extends State<CropperDialog> {
    @override
    void initState() {
      super.initState();
      /// IMPORTANT: must to call this function
      widget.initCropper();
    }

    @override
    Widget build(BuildContext context) {
      Dialog(
        child: Column(
          children: [
            ...
            cropper,
            ...
            TextButton(
              onPressed: () async {
                /// IMPORTANT: to call crop() function and return
                /// result data to plugin, for example:
                final result = await crop();
                Navigator.of(context).pop(result);
              },
              child: Text('Crop'),
            )
          ]
        ),
      );
    }
  }

  WebUiSettings(
    ...
    customDialogBuilder: (cropper, initCropper, crop, rotate, scale) {
      return CropperDialog(
        cropper: cropper,
        initCropper: initCropper,
        crop: crop,
        rotate: rotate,
        scale: scale,
      );
    },
    ...
  )

Example


import 'package:image_cropper/image_cropper.dart';

CroppedFile croppedFile = await ImageCropper().cropImage(
    sourcePath: imageFile.path,
    uiSettings: [
      AndroidUiSettings(
        toolbarTitle: 'Cropper',
        toolbarColor: Colors.deepOrange,
        toolbarWidgetColor: Colors.white,
        aspectRatioPresets: [
          CropAspectRatioPreset.original,
          CropAspectRatioPreset.square,
          CropAspectRatioPresetCustom(),
        ],
      ),
      IOSUiSettings(
        title: 'Cropper',
        aspectRatioPresets: [
          CropAspectRatioPreset.original,
          CropAspectRatioPreset.square,
          CropAspectRatioPresetCustom(), // IMPORTANT: iOS supports only one custom aspect ratio in preset list
        ],
      ),
      WebUiSettings(
        context: context,
      ),
    ],
  );

class CropAspectRatioPresetCustom implements CropAspectRatioPresetData {
  @override
  (int, int)? get data => (2, 3);

  @override
  String get name => '2x3 (customized)';
}

Credits

Android: uCrop created by Yalantis
iOS: TOCropViewController created by Tim Oliver
Web: Cropper.js created by Fengyuan Chen

Image Cropper

Introduction

uCrop - Yalantis

TOCropViewController - Tim Oliver

Cropper.js - Fengyuan Chen

How to install

Android

Note:

iOS

Web

Usage

Required parameters

Optional parameters

Note

Customization

Android

iOS

Web

View Mode:

Drag Mode:

Note:

Example

Credits

Libraries

image_cropper package