extended_image

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A powerful official extension library of images, which supports placeholder(loading)/ failed state, cache network, zoom pan image, photo view, slide-out page, editor (crop, rotate, flip), paint custom etc.

Web demo for ExtendedImage

Table of contents

• extended_image
  • Table of contents
  • Import
  • Cache Network
    • Simple use
    • Use ExtendedNetworkImageProvider
  • Load State
    • demo code
  • Zoom Pan
    • double tap animation
  • Editor
    • crop aspect ratio
    • crop layer painter
    • crop,flip,reset
    • crop data
      • dart library(stable)
      • native library(faster)
  • Photo View
  • Slide Out Page
    • enable slide out page
    • include your page in ExtendedImageSlidePage
    • make sure your page background is transparent
    • push with transparent page route
  • Border BorderRadius Shape
  • Clear Save
    • clear
    • save network
  • Show Crop Image
  • Paint
  • Notch
  • MemoryUsage
  • Other APIs

Import

• null-safety

environment:
  sdk: '>=2.12.0 <3.0.0'
  flutter: '>=2.0'
dependencies:
  extended_image: ^4.0.0

• non-null-safety

1.22.6 to 2.0, Flutter Api has breaking change，please use non-null-safety if you under 1.22.6.

environment:
  sdk: '>=2.6.0 <2.12.0'
  flutter: '>1.17.0 <=1.22.6'
dependencies:
  extended_image: ^3.0.0-non-null-safety

Cache Network

Simple use

You can use ExtendedImage.network as Image Widget

ExtendedImage.network(
  url,
  width: ScreenUtil.instance.setWidth(400),
  height: ScreenUtil.instance.setWidth(400),
  fit: BoxFit.fill,
  cache: true,
  border: Border.all(color: Colors.red, width: 1.0),
  shape: boxShape,
  borderRadius: BorderRadius.all(Radius.circular(30.0)),
  //cancelToken: cancellationToken,
)

Use ExtendedNetworkImageProvider

ExtendedNetworkImageProvider

   ExtendedNetworkImageProvider(
      this.url, {
      this.scale = 1.0,
      this.headers,
      this.cache: false,
      this.retries = 3,
      this.timeLimit,
      this.timeRetry = const Duration(milliseconds: 100),
      CancellationToken cancelToken,
    })  : assert(url != null),
          assert(scale != null),
          cancelToken = cancelToken ?? CancellationToken();

parameter	description	default
url	The URL from which the image will be fetched.	required
scale	The scale to place in the [ImageInfo] object of the image.	1.0
headers	The HTTP headers that will be used with [HttpClient.get] to fetch image from network.	-
cache	whether cache image to local	false
retries	the time to retry to request	3
timeLimit	time limit to request image	-
timeRetry	the time duration to retry to request	milliseconds: 100
cancelToken	token to cancel network request	CancellationToken()

you can create new provider and extends it with ExtendedProvider, and override instantiateImageCodec method. so that you can handle image raw data here (compress image).

Load State

Extended Image provide 3 states(loading,completed,failed), you can define your state widget with loadStateChanged call back.

loadStateChanged is not only for network, if your image need long time to load, you can set enableLoadState(default value is true for network and others are false) to true

Notice:

• if you don't want to override any state, please return null in this case

• if you want to override size or sourceRect, you can override it with ExtendedRawImage at completed state

• if you want to add something (like animation) at completed state, you can override it with ExtendedImageState.completedWidget

• ExtendedImageState.completedWidget is include gesture or editor, so that you would't miss them

/// custom load state widget if you want
    final LoadStateChanged loadStateChanged;

enum LoadState {
  //loading
  loading,
  //completed
  completed,
  //failed
  failed
}

  ///whether has loading or failed state
  ///default is false
  ///but network image is true
  ///better to set it's true when your image is big and take some time to ready
  final bool enableLoadState;

ExtendedImageState(LoadStateChanged call back)

parameter/method	description	default
extendedImageInfo	image info	-
extendedImageLoadState	LoadState(loading,completed,failed)	-
returnLoadStateChangedWidget	if this is true, return widget which from LoadStateChanged function immediately(width/height/gesture/border/shape etc, will not effect on it)	-
imageProvider	ImageProvider	-
invertColors	invertColors	-
imageStreamKey	key of image	-
reLoadImage()	if image load failed,you can reload image by call it	-
completedWidget	return completed widget include gesture or editor	-
loadingProgress	return the loading progress for network image (ImageChunkEvent )	-

abstract class ExtendedImageState {
  void reLoadImage();
  ImageInfo get extendedImageInfo;
  LoadState get extendedImageLoadState;

  ///return widget which from LoadStateChanged function immediately
  bool returnLoadStateChangedWidget;

  ImageProvider get imageProvider;

  bool get invertColors;

  Object get imageStreamKey;

  Widget get completedWidget;
}

demo code

ExtendedImage.network(
  url,
  width: ScreenUtil.instance.setWidth(600),
  height: ScreenUtil.instance.setWidth(400),
  fit: BoxFit.fill,
  cache: true,
  loadStateChanged: (ExtendedImageState state) {
    switch (state.extendedImageLoadState) {
      case LoadState.loading:
        _controller.reset();
        return Image.asset(
          "assets/loading.gif",
          fit: BoxFit.fill,
        );
        break;

      ///if you don't want override completed widget
      ///please return null or state.completedWidget
      //return null;
      //return state.completedWidget;
      case LoadState.completed:
        _controller.forward();
        return FadeTransition(
          opacity: _controller,
          child: ExtendedRawImage(
            image: state.extendedImageInfo?.image,
            width: ScreenUtil.instance.setWidth(600),
            height: ScreenUtil.instance.setWidth(400),
          ),
        );
        break;
      case LoadState.failed:
        _controller.reset();
        return GestureDetector(
          child: Stack(
            fit: StackFit.expand,
            children: <Widget>[
              Image.asset(
                "assets/failed.jpg",
                fit: BoxFit.fill,
              ),
              Positioned(
                bottom: 0.0,
                left: 0.0,
                right: 0.0,
                child: Text(
                  "load image failed, click to reload",
                  textAlign: TextAlign.center,
                ),
              )
            ],
          ),
          onTap: () {
            state.reLoadImage();
          },
        );
        break;
    }
  },
)

Zoom Pan

ExtendedImage

parameter	description	default
mode	image mode (none, gesture, editor)	none
initGestureConfigHandler	init GestureConfig when image is ready，for example, base on image width/height	-
onDoubleTap	call back of double tap under ExtendedImageMode.gesture	-
extendedImageGestureKey	you can handle zoom/pan by using this key manually	-

GestureConfig

parameter	description	default
minScale	min scale	0.8
animationMinScale	the min scale for zooming then animation back to minScale when scale end	minScale _ 0.8
maxScale	max scale	5.0
animationMaxScale	the max scale for zooming then animation back to maxScale when scale end	maxScale _ 1.2
speed	speed for zoom/pan	1.0
inertialSpeed	inertial speed for zoom/pan	100
cacheGesture	save Gesture state (for example in ExtendedImageGesturePageView, gesture state will not change when scroll back),remember clearGestureDetailsCache at right time	false
inPageView	whether in ExtendedImageGesturePageView	false
initialAlignment	init image rect with alignment when initialScale > 1.0	InitialAlignment.center
hitTestBehavior	How to behave during hit tests	HitTestBehavior.deferToChild

ExtendedImage.network(
  imageTestUrl,
  fit: BoxFit.contain,
  //enableLoadState: false,
  mode: ExtendedImageMode.gesture,
  initGestureConfigHandler: (state) {
    return GestureConfig(
        minScale: 0.9,
        animationMinScale: 0.7,
        maxScale: 3.0,
        animationMaxScale: 3.5,
        speed: 1.0,
        inertialSpeed: 100.0,
        initialScale: 1.0,
        inPageView: false,
        initialAlignment: InitialAlignment.center,
        );
  },
)

double tap animation

onDoubleTap: (ExtendedImageGestureState state) {
  ///you can use define pointerDownPosition as you can,
  ///default value is double tap pointer down postion.
  var pointerDownPosition = state.pointerDownPosition;
  double begin = state.gestureDetails.totalScale;
  double end;

  //remove old
  _animation?.removeListener(animationListener);

  //stop pre
  _animationController.stop();

  //reset to use
  _animationController.reset();

  if (begin == doubleTapScales[0]) {
    end = doubleTapScales[1];
  } else {
    end = doubleTapScales[0];
  }

  animationListener = () {
    //print(_animation.value);
    state.handleDoubleTap(
        scale: _animation.value,
        doubleTapPosition: pointerDownPosition);
  };
  _animation = _animationController
      .drive(Tween<double>(begin: begin, end: end));

  _animation.addListener(animationListener);

  _animationController.forward();
},

Editor

    ExtendedImage.network(
      imageTestUrl,
      fit: BoxFit.contain,
      mode: ExtendedImageMode.editor,
      extendedImageEditorKey: editorKey,
      initEditorConfigHandler: (state) {
        return EditorConfig(
            maxScale: 8.0,
            cropRectPadding: EdgeInsets.all(20.0),
            hitTestSize: 20.0,
            cropAspectRatio: _aspectRatio.aspectRatio);
      },
    );

ExtendedImage

parameter	description	default
mode	image mode (none,gestrue,editor)	none
initEditorConfigHandler	init EditorConfig when image is ready.	-
extendedImageEditorKey	key of ExtendedImageEditorState to flip/rotate/get crop rect	-

EditorConfig

parameter	description	default
maxScale	max scale of zoom	5.0
cropRectPadding	the padding between crop rect and image layout rect.	EdgeInsets.all(20.0)
cornerSize	size of corner shape (DEPRECATED! Use cornerPainter)	Size(30.0, 5.0)
cornerColor	color of corner shape (DEPRECATED! Use cornerPainter)	primaryColor
lineColor	color of crop line	scaffoldBackgroundColor.withOpacity(0.7)
lineHeight	height of crop line	0.6
editorMaskColorHandler	call back of editor mask color base on pointerDown	scaffoldBackgroundColor.withOpacity(pointerDown ? 0.4 : 0.8)
hitTestSize	hit test region of corner and line	20.0
animationDuration	auto center animation duration	Duration(milliseconds: 200)
tickerDuration	duration to begin auto center animation after crop rect is changed	Duration(milliseconds: 400)
cropAspectRatio	aspect ratio of crop rect	null(custom)
initialCropAspectRatio	initial aspect ratio of crop rect	null(custom: initial crop rect will fill the entire image)
initCropRectType	init crop rect base on initial image rect or image layout rect	imageRect
cornerPainter	corner shape	ExtendedImageCropLayerPainterNinetyDegreesCorner()
hitTestBehavior	How to behave during hit tests	HitTestBehavior.deferToChild

crop aspect ratio

it's a double value, so it's easy for you to define by yourself. following are official values

class CropAspectRatios {
  /// no aspect ratio for crop
  static const double custom = null;

  /// the same as aspect ratio of image
  /// [cropAspectRatio] is not more than 0.0, it's original
  static const double original = 0.0;

  /// ratio of width and height is 1 : 1
  static const double ratio1_1 = 1.0;

  /// ratio of width and height is 3 : 4
  static const double ratio3_4 = 3.0 / 4.0;

  /// ratio of width and height is 4 : 3
  static const double ratio4_3 = 4.0 / 3.0;

  /// ratio of width and height is 9 : 16
  static const double ratio9_16 = 9.0 / 16.0;

  /// ratio of width and height is 16 : 9
  static const double ratio16_9 = 16.0 / 9.0;
}

crop layer painter

you can define your crop layer by override [EditorConfig.editorCropLayerPainter].

class EditorCropLayerPainter {
  const EditorCropLayerPainter();
  void paint(Canvas canvas, Size size, ExtendedImageCropLayerPainter painter) {
    paintMask(canvas, size, painter);
    paintLines(canvas, size, painter);
    paintCorners(canvas, size, painter);
  }

  /// draw crop layer corners
  void paintCorners(
      Canvas canvas, Size size, ExtendedImageCropLayerPainter painter) {
  }

  /// draw crop layer lines
  void paintMask(
      Canvas canvas, Size size, ExtendedImageCropLayerPainter painter) {
  }
  

  /// draw crop layer lines
  void paintLines(
      Canvas canvas, Size size, ExtendedImageCropLayerPainter painter) {
  } 
}

crop,flip,reset

• add key for ExtendedImageEditorState

  final GlobalKey<ExtendedImageEditorState> editorKey =GlobalKey<ExtendedImageEditorState>();

• rotate right

  editorKey.currentState.rotate(right: true);

• rotate left

  editorKey.currentState.rotate(right: false);

• flip

  editorKey.currentState.flip();

• reset

  editorKey.currentState.reset();

crop data

dart library(stable)

• add Image library into your pubspec.yaml, it's used to crop/rotate/flip image data

dependencies:
  image: any

• get crop rect and raw image data from ExtendedImageEditorState

  ///crop rect base on raw image
  final Rect cropRect = state.getCropRect();

  var data = state.rawImageData;

• convert raw image data to image library data.

  /// it costs much time and blocks ui.
  //Image src = decodeImage(data);

  /// it will not block ui with using isolate.
  //Image src = await compute(decodeImage, data);
  //Image src = await isolateDecodeImage(data);
  final lb = await loadBalancer;
  Image src = await lb.run<Image, List<int>>(decodeImage, data);

• crop,flip,rotate data

  //clear orientation
  src = bakeOrientation(src);

  if (editAction.needCrop)
    src = copyCrop(src, cropRect.left.toInt(), cropRect.top.toInt(),
        cropRect.width.toInt(), cropRect.height.toInt());

  if (editAction.needFlip) {
    Flip mode;
    if (editAction.flipY && editAction.flipX) {
      mode = Flip.both;
    } else if (editAction.flipY) {
      mode = Flip.horizontal;
    } else if (editAction.flipX) {
      mode = Flip.vertical;
    }
    src = flip(src, mode);
  }

  if (editAction.hasRotateAngle) src = copyRotate(src, editAction.rotateAngle);

• convert to original image data

output is raw image data, you can use it to save or any other thing.

  /// you can encode your image
  ///
  /// it costs much time and blocks ui.
  //var fileData = encodeJpg(src);

  /// it will not block ui with using isolate.
  //var fileData = await compute(encodeJpg, src);
  //var fileData = await isolateEncodeImage(src);
  var fileData = await lb.run<List<int>, Image>(encodeJpg, src);

native library(faster)

• add ImageEditor library into your pubspec.yaml, it's used to crop/rotate/flip image data

dependencies:
  image_editor: any

• get crop rect and raw image data from ExtendedImageEditorState

  ///crop rect base on raw image
  final Rect cropRect = state.getCropRect();

  var data = state.rawImageData;

• prepare crop option

  final rotateAngle = action.rotateAngle.toInt();
  final flipHorizontal = action.flipY;
  final flipVertical = action.flipX;
  final img = state.rawImageData;

  ImageEditorOption option = ImageEditorOption();

  if (action.needCrop) option.addOption(ClipOption.fromRect(rect));

  if (action.needFlip)
    option.addOption(
        FlipOption(horizontal: flipHorizontal, vertical: flipVertical));

  if (action.hasRotateAngle) option.addOption(RotateOption(rotateAngle));

• crop with editImage

output is raw image data, you can use it to save or any other thing.

  final result = await ImageEditor.editImage(
    image: img,
    imageEditorOption: option,
  );

more detail

Photo View

ExtendedImageGesturePageView is the same as PageView and it's made for show zoom/pan image.

if you have cache the gesture, remember call clearGestureDetailsCache() method at the right time.(for example,page view page is disposed)

ExtendedImageGesturePageView

parameter	description	default
cacheGesture	whether should move page	true

GestureConfig

parameter	description	default
cacheGesture	save Gesture state (for example in ExtendedImageGesturePageView, gesture state will not change when scroll back),remember clearGestureDetailsCache at right time	false
inPageView	whether in ExtendedImageGesturePageView	false

ExtendedImageGesturePageView.builder(
  itemBuilder: (BuildContext context, int index) {
    var item = widget.pics[index].picUrl;
    Widget image = ExtendedImage.network(
      item,
      fit: BoxFit.contain,
      mode: ExtendedImageMode.gesture,
      gestureConfig: GestureConfig(
        inPageView: true, initialScale: 1.0,
        //you can cache gesture state even though page view page change.
        //remember call clearGestureDetailsCache() method at the right time.(for example,this page dispose)
        cacheGesture: false
      ),
    );
    image = Container(
      child: image,
      padding: EdgeInsets.all(5.0),
    );
    if (index == currentIndex) {
      return Hero(
        tag: item + index.toString(),
        child: image,
      );
    } else {
      return image;
    }
  },
  itemCount: widget.pics.length,
  onPageChanged: (int index) {
    currentIndex = index;
    rebuild.add(index);
  },
  controller: PageController(
    initialPage: currentIndex,
  ),
  scrollDirection: Axis.horizontal,
),

Slide Out Page

Extended Image support to slide out page as WeChat.

enable slide out page

ExtendedImage

parameter	description	default
enableSlideOutPage	whether enable slide out page	false
heroBuilderForSlidingPage	build Hero only for sliding page, the transform of sliding page must be working on Hero,so that Hero animation wouldn't be strange when pop page	null

include your page in ExtendedImageSlidePage

take care of onSlidingPage call back, you can update other widgets' state as you want. but, do not setState directly here, image state will changed, you should only notify the widgets which are needed to change

    return ExtendedImageSlidePage(
      child: result,
      slideAxis: SlideAxis.both,
      slideType: SlideType.onlyImage,
      onSlidingPage: (state) {
        ///you can change other widgets' state on page as you want
        ///base on offset/isSliding etc
        //var offset= state.offset;
        var showSwiper = !state.isSliding;
        if (showSwiper != _showSwiper) {
          // do not setState directly here, the image state will change,
          // you should only notify the widgets which are needed to change
          // setState(() {
          // _showSwiper = showSwiper;
          // });

          _showSwiper = showSwiper;
          rebuildSwiper.add(_showSwiper);
        }
      },
    );

ExtendedImageGesturePage

parameter	description	default
child	The [child] contained by the ExtendedImageGesturePage.	-
slidePageBackgroundHandler	build background when slide page	defaultSlidePageBackgroundHandler
slideScaleHandler	customize scale of page when slide page	defaultSlideScaleHandler
slideEndHandler	call back of slide end,decide whether pop page	defaultSlideEndHandler
slideAxis	axis of slide(both,horizontal,vertical)	SlideAxis.both
resetPageDuration	reset page position when slide end(not pop page)	milliseconds: 500
slideType	slide whole page or only image	SlideType.onlyImage
onSlidingPage	call back when it's sliding page, change other widgets state on page as you want	-
slideOffsetHandler	customize offset when slide page	-

Color defaultSlidePageBackgroundHandler(
    {Offset offset, Size pageSize, Color color, SlideAxis pageGestureAxis}) {
  double opacity = 0.0;
  if (pageGestureAxis == SlideAxis.both) {
    opacity = offset.distance /
        (Offset(pageSize.width, pageSize.height).distance / 2.0);
  } else if (pageGestureAxis == SlideAxis.horizontal) {
    opacity = offset.dx.abs() / (pageSize.width / 2.0);
  } else if (pageGestureAxis == SlideAxis.vertical) {
    opacity = offset.dy.abs() / (pageSize.height / 2.0);
  }
  return color.withOpacity(min(1.0, max(1.0 - opacity, 0.0)));
}

bool defaultSlideEndHandler(
    {Offset offset, Size pageSize, SlideAxis pageGestureAxis}) {
  if (pageGestureAxis == SlideAxis.both) {
    return offset.distance >
        Offset(pageSize.width, pageSize.height).distance / 3.5;
  } else if (pageGestureAxis == SlideAxis.horizontal) {
    return offset.dx.abs() > pageSize.width / 3.5;
  } else if (pageGestureAxis == SlideAxis.vertical) {
    return offset.dy.abs() > pageSize.height / 3.5;
  }
  return true;
}

double defaultSlideScaleHandler(
    {Offset offset, Size pageSize, SlideAxis pageGestureAxis}) {
  double scale = 0.0;
  if (pageGestureAxis == SlideAxis.both) {
    scale = offset.distance / Offset(pageSize.width, pageSize.height).distance;
  } else if (pageGestureAxis == SlideAxis.horizontal) {
    scale = offset.dx.abs() / (pageSize.width / 2.0);
  } else if (pageGestureAxis == SlideAxis.vertical) {
    scale = offset.dy.abs() / (pageSize.height / 2.0);
  }
  return max(1.0 - scale, 0.8);
}

make sure your page background is transparent

if you use ExtendedImageSlidePage and slideType =SlideType.onlyImage, make sure your page background is transparent

push with transparent page route

you should push page with TransparentMaterialPageRoute/TransparentCupertinoPageRoute

  Navigator.push(
    context,
    Platform.isAndroid
        ? TransparentMaterialPageRoute(builder: (_) => page)
        : TransparentCupertinoPageRoute(builder: (_) => page),
  );

Slide Out Page Demo Code 1

Slide Out Page Demo Code 2

Border BorderRadius Shape

ExtendedImage

parameter	description	default
border	BoxShape.circle and BoxShape.rectangle,If this is [BoxShape.circle] then [borderRadius] is ignored.	-
borderRadius	If non-null, the corners of this box are rounded by this [BorderRadius].,Applies only to boxes with rectangular shapes; ignored if [shape] is not [BoxShape.rectangle].	-
shape	BoxShape.circle and BoxShape.rectangle,If this is [BoxShape.circle] then [borderRadius] is ignored.	-

ExtendedImage.network(
  url,
  width: ScreenUtil.instance.setWidth(400),
  height: ScreenUtil.instance.setWidth(400),
  fit: BoxFit.fill,
  cache: true,
  border: Border.all(color: Colors.red, width: 1.0),
  shape: boxShape,
  borderRadius: BorderRadius.all(Radius.circular(30.0)),
),

Clear Save

clear

to clear disk cached , call clearDiskCachedImages method.

// Clear the disk cache directory then return if it succeed.
///  <param name="duration">timespan to compute whether file has expired or not</param>
Future<bool> clearDiskCachedImages({Duration duration})

to clear disk cached with specific url, call clearDiskCachedImage method.

/// clear the disk cache image then return if it succeed.
///  <param name="url">clear specific one</param>
Future<bool> clearDiskCachedImage(String url) async {

get the local cached image file

Future<File> getCachedImageFile(String url) async {

to clear memory cache , call clearMemoryImageCache method.

///clear all of image in memory
 clearMemoryImageCache();

/// get ImageCache
 getMemoryImageCache() ;

save network

call saveNetworkImageToPhoto and save image with image_picker_saver

///save network image to photo
Future<bool> saveNetworkImageToPhoto(String url, {bool useCache: true}) async {
  var data = await getNetworkImageData(url, useCache: useCache);
  var filePath = await ImagePickerSaver.saveFile(fileData: data);
  return filePath != null && filePath != "";
}

Show Crop Image

get your raw image by [Load State](#Load State), and crop image by sourceRect.

ExtendedRawImage sourceRect is which you want to show image rect.

ExtendedRawImage(
  image: image,
  width: num400,
  height: num300,
  fit: BoxFit.fill,
  sourceRect: Rect.fromLTWH(
      (image.width - width) / 2.0, 0.0, width, image.height.toDouble()),
)

Paint

provide BeforePaintImage and AfterPaintImage callback, you will have the chance to paint things you want.

ExtendedImage

parameter	description	default
beforePaintImage	you can paint anything if you want before paint image.	-
afterPaintImage	you can paint anything if you want after paint image.	-

  ExtendedImage.network(
    url,
    width: ScreenUtil.instance.setWidth(400),
    height: ScreenUtil.instance.setWidth(400),
    fit: BoxFit.fill,
    cache: true,
    beforePaintImage: (Canvas canvas, Rect rect, ui.Image image) {
      if (paintType == PaintType.ClipHeart) {
        if (!rect.isEmpty) {
          canvas.save();
          canvas.clipPath(clipheart(rect, canvas));
        }
      }
      return false;
    },
    afterPaintImage: (Canvas canvas, Rect rect, ui.Image image) {
      if (paintType == PaintType.ClipHeart) {
        if (!rect.isEmpty) canvas.restore();
      } else if (paintType == PaintType.PaintHeart) {
        canvas.drawPath(
            clipheart(rect, canvas),
            Paint()
              ..colorFilter =
                  ColorFilter.mode(Color(0x55ea5504), BlendMode.srcIn)
              ..isAntiAlias = false
              ..filterQuality = FilterQuality.low);
      }
    },
  );

see paint image demo and push to refresh header which is used in crop image demo

Notch

By setting layoutInsets, you can ensure the image is positioned outside of obstructing elements such as the phone notch or home indicator if displayed in full screen. This will still allow the image margin to show underneath the notch if zoomed in.

ExtendedImage

parameter	description	default
layoutInsets	Amount to inset from the edge during image layout	EdgeInsets.zero

  ExtendedImage.network(
    url,
    fit: BoxFit.contain,
    layoutInsets: MediaQuery.of(context).padding
  );

MemoryUsage

You can reduce memory usage with following settings now.

• ExtendedResizeImage

parameter	description	default
[ExtendedResizeImage.compressionRatio]	The images size will resize to original * [compressionRatio].It's ExtendedResizeImages first pick.The compressionRatio`s range is from 0.0 (exclusive), to 1.0 (exclusive).	null
[ExtendedResizeImage.maxBytes]	[ExtendedResizeImage] will compress the image to a size that is smaller than [maxBytes]. The default size is 50KB. It's actual bytes of Image, not decode bytes	50 << 10
[ExtendedResizeImage.width]/[ExtendedResizeImage.height]	The width/height the image should decode to and cache. It's same as [ResizeImage],	null

    ExtendedImage.network(
      'imageUrl',  
      compressionRatio: 0.1,
      maxBytes: null,
      cacheWidth: null,
      cacheHeight: null,  
    )

    ExtendedImage(
      image: ExtendedResizeImage(
        ExtendedNetworkImageProvider(
          'imageUrl',  
        ),
        compressionRatio: 0.1,
        maxBytes: null,
        width: null,
        height: null,
      ),
    )

• clearMemoryCacheWhenDispose

parameter	description	default
clearMemoryCacheWhenDispose	It's not good enough after Flutter 2.0, it seems that we can't release memory usage if this image is not completed(fluttercandies#317). It will release memory usage only for completed image now.	false

   ExtendedImage.network(
     'imageUrl',     
     clearMemoryCacheWhenDispose: true,
   )

• imageCacheName

parameter	description	default
imageCacheName	The name of [ImageCache], you can define custom [ImageCache] to store this image. In this way you can work with them without affecting other [ImageCache]	null

   ExtendedImage.network(
     'imageUrl',  
     imageCacheName: 'MemoryUsage',
   )
     
  /// clear when this page is disposed   
  @override
  void dispose() {
    // clear ImageCache which named 'MemoryUsage'
    clearMemoryImageCache(imageCacheName);
    super.dispose();
  }   

Other APIs

ExtendedImage

parameter	description	default
enableMemoryCache	whether cache in PaintingBinding.instance.imageCache)	true
clearMemoryCacheIfFailed	when failed to load image, whether clear memory cache.if true, image will reload in next time.	true
clearMemoryCacheWhenDispose	when image is removed from the tree permanently, whether clear memory cache.	false