/extended_image

A powerful extended official image for Flutter, which support placeholder(loading)/ failed state,cache network,zoom pan image,photo view,slide out page,crop,save,paint etc.

Primary LanguageDartMIT LicenseMIT

extended_image

pub package

Language: English | 中文简体

A powerful extended official image for Dart, which support placeholder(loading)/ failed state,cache network,zoom pan image,photo view,slide out page,crop,save,paint etc.

Table of contents

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()

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 ture for network and others are false) to ture

img

/// 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 ture, return widget which from LoadStateChanged fucntion 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 -
abstract class ExtendedImageState {
  void reLoadImage();
  ImageInfo get extendedImageInfo;
  LoadState get extendedImageLoadState;

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

  ImageProvider get imageProvider;

  bool get invertColors;

  Object get imageStreamKey;
}

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;
      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

img

ExtendedImage

parameter description default
mode image mode (none,gestrue) none
initGestureConfigHandler init GestureConfig when image is ready,for example, base on image width/height -
onDoubleTap call back of double tap under ExtendedImageMode.Gesture -

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
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);
  },
)

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();
},

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)

img

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.

img

enable slide out page

ExtendedImage

parameter description default
enableSlideOutPage whether enable slide out page false

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 custom 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 -
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)),
),

img

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 {

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 netwrok 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 != "";
}

Crop

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

ExtendedRawImage soureRect is which you want to show image rect.

img

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

crop image demo

Paint

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

img

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

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 ture, image will reload in next time. true