I have trouble finding the right workflow to load images into cache.
What I want to do:
Show Progress bar
Get data from REST service and load it into SQLite database
Some objects contain urls in JSON > load these images in cache so
they are quickly loaded when needed
Dismiss Progress bar
I have all the data loaded from rest and stored in a DB,
but I'm new to caching images.
What I go so far:
- Inserted Universal Image Loader into my project
(https://github.com/nostra13/Android-Universal-Image-Loader)
- I tried
imageLoader.loadImage(url of an image, new SimpleImageLoadingListener() {
#Override
public void onLoadingStarted(String imageUri, View view) {
super.onLoadingStarted(imageUri, view);
//notify me the image started loading
}
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
super.onLoadingComplete(imageUri, view, loadedImage);
//notify me the image is loaded
}
}
But when I check:
int size = MemoryCacheUtils.findCachedBitmapsForImageUri(url from that image, ImageLoader.getInstance().getMemoryCache()).size();
//show me the size
it's always zero.
My question is the following: am I going in the right direction or do I need to fix this someother way?
I found a better solution: ShutterBug (Android alternative for SDWebImage for iOs). It's easy to add urls to the ShutterbugManager and when I want to fill an ImageView (FetchableImageView in Shutterbug) with an image, it grabs the image from cache.
Related
I am using RecyclerView and volley's NetworkImageView to render images once they are downloaded. The view consists of an author image, some text fields and a picture. Following is the code snippet to populate the view:
// vh is the viewholder
vh.picture.setDefaultImageResId(R.drawable.default_image);
vh.picture.setImageUrl(post.getImageUrl(), mImageLoader);
The problem I am facing is when scrolling, out of say 20 images, mostly ~18 show up. I see from the logs that all images are downloaded and are in the cache, but some are not rendered. Even the default image is not displayed for those views. If the view is invalidated (scroll up and down again), the images show up.
Funny thing is, for the views where the picture is not displayed, even the author pic is not displayed, even if I can see the same author pic in a post just above it. Its as if the entire view has a problem displaying images.
Is there any way to call invalidate() or postInvalidate() on NetworkImageView manually once the images are downloaded? Or any other ideas?
This was also asked here. I finally got around to this problem by not using NetworkImageView at all. I started using the regualar ImageView, am still fetching the images through volley through a custom image request and onResponse() applying the image on the view. This seems to work pretty well.
public void getImage(String url, final ImageView v) {
if (TextUtils.isEmpty(url)) return; // don't fetch a null url
ImageRequest imageRequest = new ImageRequest(url, new Response.Listener<Bitmap>() {
#Override
public void onResponse(Bitmap response) {
v.setImageBitmap(response);
}
}, 0, 0, null, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Error- " + error.getMessage());
}
});
mRequestQueue.addToRequestQueue(imageRequest);
}
Iam getting some image URLs in my JSON which I parse and show in my image view. So if the Url is null, I show a default image. But in some cases the Urls are specified but the images are corrupted. In this case nothing displays in the ImageView only a white space shows. Is there any way I can handle this scenario.
Any help will be useful.
You can use ImageLoader to check this case. Example:
private ImageLoader imageLoader = new ImageLoader();
private ImageView Iv;
private String URL =null;
private DisplayImageOptions mDio;
URL = "URL you get from your JSON";
if (URL != null) {
imageLoader.displayImage(URL, Iv, mDio, new SimpleImageLoadingListener() {
#Override
public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
// check corrupt images on here
view.setImageResource(R.drawable.iv_fail)
}
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
if (loadedImage != null) {
view.setImageBitmap(loadedImage);
}
}
}, new ImageLoadingProgressListener() {
#Override
public void onProgressUpdate(String imageUri, View view, int current,
int total) {
}
});
} else Iv.setImageResource(R.drawable.iv_default);
Hope this helps
Use picasso bro
A very easy image handling library for android
Picasso supports both download and error placeholders as optional features.
Picasso.with(context)
.load(url)
.placeholder(R.drawable.user_placeholder)
.error(R.drawable.user_placeholder_error)
.into(imageView);
http://square.github.io/picasso/
and yes,its that easy
The Best way to do it easily is to use proper lib - Use picasso or UIL or something else. Advantages is that this libs are well maintained and is stable. Your empty image will be treated as an error and default will be shown
I am trying to set background for the image view. But not got luck to set background using universal image loader.
I am using following code.
DisplayImageOptions options = new DisplayImageOptions.Builder()
.showStubImage(R.drawable.mo_no_image)
.showImageForEmptyUri(R.drawable.mo_no_image)
.cacheInMemory().cacheOnDisc()
.displayer(new RoundedBitmapDisplayer(0))
.imageScaleType(ImageScaleType.EXACTLY).build();
ImageLoader.getInstance().displayImage("url_to_load_image", imgView, options);
By using above code I am able to set image resource which check aspect ratio and using that modifying image size.
I want to set downloaded image to the background of image view.
I can recommend a different way that works like a charm: Android Query.
You can download that jar file from http://code.google.com/p/android-query/downloads/list
AQuery androidAQuery=new AQuery(this);
As an example:
androidAQuery.id(YOUR IMAGEVIEW).image(YOUR IMAGE TO LOAD, true, true, getDeviceWidth(), ANY DEFAULT IMAGE YOU WANT TO SHOW);
It's very fast and accurate, and using this you can find many more features like Animation when loading; getting a bitmap, if needed; etc.
In your case you need to fetch Bitmap, so for it, use below code
androidAQuery.ajax(YOUR IMAGE URL,Bitmap.class,0,new AjaxCallback<Bitmap>(){
#Override
public void callback(String url, Bitmap object, AjaxStatus status) {
super.callback(url, object, status);
//You will get Bitmap from object.
}
});
Use this bitmap to set your background resource of ImageView using method.
Universal Image Loader also provide to use the Background functionality.Please check the below coed for it:-
Here Uri is the path of the folder image OR the url of the image.
imageLoader.loadImage(YOUR_URL, new SimpleImageLoadingListener() {
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
super.onLoadingComplete(imageUri, view, loadedImage);
layout.setBackgroundDrawable(new BitmapDrawable(loadedImage));
}
});
I want to load multiple image(list view or gridview) of specified size (i need to change height and width of image at run time) .Can anyone suggest me for any library which support this functionality ?
imageloader.loadimage(imageview,"imageurl",height,width);
Check out UniversalImageLoader. I think this is the best library for loading images. In its loading listener you can resize the loaded image before display it.
Try by this one : and check this for refrence https://github.com/nostra13/Android-Universal-Image-Loader
ImageSize targetSize = new ImageSize(120, 80); // result Bitmap will be fit to this size
imageLoader.loadImage(imageUri, targetSize, displayOptions, new SimpleImageLoadingListener() {
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
// Do whatever you want with Bitmap
}
});
I am using the Android-Universal-Image-Loader library to loading/caching remote images, and have been digging through the source for quite a while trying to find a way to retrieve the original image size (width and height) for my ImageLoadingListener.
The sample code below is just give you an idea of what I'm trying to do.
protected class ViaImageLoadingListener implements ImageLoadingListener {
final SelectableImageView selectableImageView ;
protected ViaImageLoadingListener(SelectableImageView selectableImageView) {
this.selectableImageView = selectableImageView;
}
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
selectableImageView.setImageBitmap(loadedImage);
// loadedImage.getWeight() will not return the original
// dimensions of the image if it has been scaled down
selectableImageView.setOriginalImageSize(width, height);
selectableImageView.invalidate();
}
I have tried extending the ImageDecoder class and the ImageLoader class to find a round-about way to linking the decoder (from which I can get the original image size in the #prepareDecodingOptions method) to my custom ImageLoadingListener. But the configuration object is private and the fields (including the decoder) are inaccessible from subclasses (and feels like an overly hacky way of solving the problem anyways).
Have I overlooked a simple "built-in" way of getting the original image size without losing the benefit of the UIL's scaling/memory management?
There is no way to pass original image size from ImageDecoder to listener through params.
I think the solution for you is following.
Extend BaseImageDecoder and create map in it for keeping image sizes:
Map<String, ImageSize> urlToSizeMap = new ConcurrentHashMap<String, ImageSize>();
Then override defineImageSizeAndRotation(...):
protected ImageFileInfo defineImageSizeAndRotation(InputStream imageStream, String imageUri) throws IOException {
ImageFileInfo info = super.defineImageSizeAndRotation(imageStream, imageUri);
urlToSizeMap.put(imageUri, info.imageSize); // Remember original image size for image URI
return info;
}
Note: info.imageSize won't compile because imageSize isn't visible. I'll fix it in next version (1.8.5) but you can use reflection for now.
Set this decoder into configuration and keep reference to this decoder anywhere (or you can make urlToSizeMap static to access from listener).
Then in your listener:
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
selectableImageView.setImageBitmap(loadedImage);
ImageSize imageSize = decoder.urlToSizeMap.get(imageUri);
selectableImageView.setOriginalImageSize(imageSize.getWidth(), imageSize.getHeight());
selectableImageView.invalidate();
}
It seems that you do not have to implement own ImageLoadingListener if you want to get original size of loaded image. I use loadImage method and it seems recieved bitmap has origin sizes.
UIL v1.8.6
loader.loadImage(pin_url, option, new SimpleImageLoadingListener() {
#Override
public void onLoadingFailed(String imageUri, View view,
FailReason failReason) {
showErrorLayout();
}
#Override
public void onLoadingComplete(String imageUri, View view,
Bitmap loadedImage) {
// width - device width
// height - OpenGl maxTextureSize
if (width < loadedImage.getWidth() || height < loadedImage.getHeight()) {
// handle scaling
}
iv.setImageBitmap(loadedImage);
}
});