Develop Reference

How to get the Uri path from a ImageView?

I am trying to create a wallpaper application. All images will come from internet.
Before of set as background, I need to crop the image. And for this, I am using an API named AndroidImageCropper. This API need of a URI object to execute the crop.
How can I get the Uri from ImageView? Because my image is from internet. The image is not on drawable folder. I am confusing. Maybe you guys can help me.
public class MainActivity extends AppCompatActivity {
private NetworkImageView imageView;
private Uri mCropImageUri;
public static final String URL_PHOTO = "http://cdn.wonderfulengineering.com/wp-content/uploads/2016/02/iron-man-wallpaper-42-610x1084.jpg";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = (NetworkImageView) findViewById(R.id.image_view);
// Singleton for Volley API, Load image from internet
ImageLoader loader = MySingleton.getInstance(this).getImageLoader();
loader.get(URL_PHOTO, ImageLoader.getImageListener(imageView, R.drawable.temp_picture, android.R.drawable.ic_dialog_alert));
imageView.setImageUrl(URL_PHOTO, loader);
// Put the image on URI object
// #################################
// ### mCropImageUri = <-- ###
// #################################
}
// Action for my button
public void cropImage(View view) {
// API to crop an image
CropImage.activity(mCropImageUri)
.start(this);
}
}
Do you have any suggestion to me?
Thanks.

So you're using Volley? I'm not very familiar with Volley, both just some of my thoughts.
After image is downloaded to Android device, try to find the absolute path of the file and use android.net.Uri.fromFile to get a uri from the image.
Or else, can you use Bitmap object directly, instead of an uri.
OK, after some investigation, I think you have two solutions.
Using volley to download image as file, without using ImageLoader. In this way it's easy to get file uri of the image.
For Android-Image-Cropper, you can use Activity or use View(refer here). You can get the Bitmap object of the image in method onLoadingComplete of ImageLoadingListener. Then use com.theartofdev.edmodo.cropper.CropImageView to crop the image.

Image Manager - convert a URI from Google Play Game Services to a Drawable

I am getting the URI from google with this method:
Player me = Games.Players.getCurrentPlayer(mGoogleApiClient);
Uri uri = me.getHiResImageUri();
I read in various posts that because of Google's security restrictions I need to use the ImageManager class.
This class only provides voids which directly set the URI as the drawable for the ImageView I provide. This is the method: loadImage(ImageView imageView, Uri uri);
The problem is that I need to get a variable of the Drawable class from this Uri and use that. Having the Uri set as the drawable of the image does not work in my specific case.
I don't know if there is a class similar to ImageManager or if there is a workaround to get the drawable.
Thanks for all replies in advance!

One approach is to use HttpURLConnection and call the URL, you'll then get the InputStream and use it to instantiate a BitMap by decoding it thru BitmapFactory.decodeStream. As indicated by #señor-reginold-francis in his answer, don't forget to add the "User-agent" property as it may be denied access if its absent (considering you're getting it from a google domain)

You still have to determine yourself what you want to do with the image.
final ImageView imgView = (ImageView) findViewById(R.id.imageView);
ImageManager.create(context)
.loadImage(new ImageManager.OnImageLoadedListener() {
#Override
public void onImageLoaded(Uri uri, Drawable drawable, boolean b) {
imgView.setImageDrawable(drawable);
}
}, participant.getHiResImageUri(), R.drawable.placeholder);

Android + Volley: how to get image bitmap using ImageLoader?

I'm trying to get images for list view using Volley Library. I created simple HTTP helper with the following method.
/**
* Processing Image request and gets the image with given URL
*/
public Bitmap makeImageRequest(String url) {
ImageLoader il = new ImageLoader(queue, new BitmapLruCache());
il.get(url, new ImageLoader.ImageListener() {
#Override
public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) {
mBitmap = processImageResponse(response);
}
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(Constants.Global.ERROR, "Error: " + error.getMessage());
mBitmap = null;
}
});
return mBitmap;
}
But problem is that:
new BitmapLruCache()
Method is not recognized.
So i tried to create ImageLoader using the following code which i found on the URL:
http://www.androidhive.info/2014/05/android-working-with-volley-library-1/
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
But in thos code i cannot find out where to get
AppController
Because the method code is triggered from the custom
public class HttpHelperClass
And called from the activity using the:
// Try to load remote image from URL
Bitmap bm = http.makeImageRequest("http://camranger.com/wp-content/uploads/2014/10/Android-Icon.png");
ImageView iv = (ImageView) findViewById(R.id.imageView);
iv.setImageBitmap(bm);
Is it the right approach how to load images and how can i repair my code to make succcessfull request?
Many thanks for any advice.

I think your makeImageRequest method will always return null because it takes some time for the onResponse or onErrorResponse listeners to get called but you return the mBitmap immidately!
If you want to use Volley's ImageLoader you'd better get image inside your activity or ... not from another class like your HttpHelperClass.
Also AppController is a class that extends Application and you should create it yourself. (It's in your AndroidHive link. Section 3. Creating Volley Singleton class)
And also for caching images you should not create a new ImageLoader everytime because in this way the caching gets meaningless. You should get that from your AppController class.
Furthermore I suggest you using Picasso because it's way better that Volley in image loading and a lot easier!
With Picasso you only need to call the following line to load an image from web into an ImageView:
Picasso.with(context).load(urlString).to(imageView);

Loading an ImageView from an URL in a widget

I'm trying to do a dynamic widget that has an ImageView. I'm trying to download an image from an URL using AsyncTask and then trying to apply the newly downloaded bitmap on to the ImageView, but nothing appears in the widget.
Here's the Java code going on in the widget:
public class MyWidget extends AppWidgetProvider
{
private static RemoteViews remoteViews;
private static String thumbnailUrl = "..."; // The image I'd like to show
// Async task for downloading an image and setting it to the ImageView
class DownloadImageTask extends AsyncTask<String, Void, Bitmap>
{
#Override
protected Bitmap doInBackground(String... urls)
{
String url = urls[0];
Bitmap icon = null;
try
{
InputStream in = new java.net.URL(urldisplay).openStream();
icon = BitmapFactory.decodeStream(in);
}
catch(Exception e)
{
e.printStackTrace();
}
return icon;
}
#Override
protected void onPostExecute(Bitmap bitmap)
{
if(bitmap == null)
{
System.out.println("Bitmap is null!");
return;
}
remoteViews.setImageViewBitmap(R.id.thumbnailView, bitmap);
}
}
#Override
public void onUpdate(Context context, AppWidgetManager manager, int[] widgetIds)
{
if(remoteViews == null)
{
remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);
}
new DownloadImageTask().execute(thumbnailUrl);
}
} // End of MyWidget
The widget does work, because if I put a static TextView there, it shows up. However, this ImageView does not. The view's ID is correct, and the URL is valid. The bitmap is not null when onPostExecute() is called. Why doesn't the bitmap show up?

First, replace the AsyncTask with an IntentService. There is every possibility that your process will be terminated before you get your work done. Have your AppWidgetProvider delegate to the IntentService.
Second, use better code for downloading the image than what you have, as it will not deal well with typical mobile issues like sporadic connectivity. There are plenty of image-loading libraries available (Picasso, Universal Image Loader, etc.) that will be more resilient in the face of problems.
Third, you actually have to do something with the RemoteViews. Right now, you call setImageViewBitmap()... and then drop the RemoteViews on the floor. You need to use AppWidgetManager to tell Android to update the app widget with the RemoteViews.
And, as Ashish points out, bear in mind that there is a 1MB limit on IPC transactions, which will cap how big your Bitmap can be. Many of those image-loading libraries also have resampling logic built in to scale your image to an appropriate size, so you can aim to avoid this limit.

check you logcat output, are you getting something like -
ERROR/JavaBinder(20204): !!! FAILED BINDER TRANSACTION !!!
If yes, then you are hitting the file size limit :P

Caching Images - Bitmap not collected after different bitmap was loaded or ImageView's activity closed

I am trying to implement something that is very similar to UrlImageViewHelper (https://github.com/koush/UrlImageViewHelper) where you can easily using a simple one line of code, load images from a url, and if the image was already downloaded it is loaded from the cache instead. The major difference is that I want the same effect but instead of downloading it from a url, I want to receive the images from my own server using my own client-server communication. Every image on my server can be uniquely identified by a string, and I use this as the id for the image.
My main idea was this: Use an LRU Cache to hold the images, but instead of holding the Bitmaps (that are very large) I want to hold the raw image data binary, so I can use the same image to build bitmaps of different sizes and qualities on demand depending on the specific situation.
This is my implementation so far:
public class ImageHandler {
private static class BitmapCache extends LruCache<String, byte[]>
{
public WigoBitmapCache(int maxSize) {
super(maxSize);
}
#Override
protected int sizeOf(String key, byte[] value) {
return value.length;
}
}
private static class ImageHandlerThread extends Thread
{
/* THIS THREAD WILL DECODE THE IMAGE AND SET THE BITMAP TO THE IMAGEVIEW IN THE BACKGROUND */
Activity activity;
ImageView imageView;
byte[] imageBytes;
public ImageHandlerThread(Activity activity, ImageView imageView, byte[] imageBytes)
{
this.activity=activity;
this.imageView=imageView;
this.imageBytes=imageBytes;
}
public void run() {
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length, o);
int factor1=o.outHeight/height;
int factor2=o.outWidth/width;
/* height and width are for now constant */
o = null;
o = new BitmapFactory.Options();
if (factor1>factor2)
o.inSampleSize=factor1;
else
o.inSampleSize=factor2;
Bitmap bit = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length,o);
setBitmap(bit);
bit = null;
}
private void setBitmap(final Bitmap bit) {
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
imageView.setImageBitmap(bit);
}
});
}
}
private static class QueueItem
{ /*USED TO HOLD INFO ABOUT THE IMAGE REQUEST UNTIL THE IMAGE GETS FROM THE SERVER */
String imageName;
Activity activity;
ImageView imageView;
public QueueItem(String imageName, Activity activity, ImageView imageView)
{
this.imageName=imageName;
this.activity = activity;
this.imageView = imageView;
}
}
private BitmapCache cache; // this cache holds the image binaries
private ArrayList<QueueItem> queue; // this queue holds the info about the request, until the server sends the image
public ImageHandler(int maxSize)
{
cache=new BitmapCache(maxSize);
queue = new ArrayList<QueueItem>();
}
public synchronized void setBitmap(Activity activity, ImageView imageView, String imageName)
{
byte[] imageBytes = cache.get(imageName);
if (imageBytes==null)
{
QueueItem item = new QueueItem(imageName, activity, imageView);
queue.add(item);
/* HERE IS THE CODE TO RETRIEVE THE IMAGE BINARY FROM MY SERVER, THIS CODE WORKS FINE, SO THERE IS NO REASON TO BOHER YOU WITH IT */
}
else
{
ImageHandlerThread thread = new ImageHandlerThread(activity, imageView, imageBytes);
thread.start();
}
}
public synchronized void insert (String imageName, byte[] imageBytes)
{
/* THIS METHOD IS THE CALLBACK THAT IS CALLED WHEN THE IMAGE BINARY IS RECEIVED FROM THE SERVER */
cache.put(imageName, imageBytes);
for (QueueItem item: queue)
{
if (item.imageName.equals(imageName))
{
ImageHandlerThread thread = new ImageHandlerThread(item.activity, item.imageView, imageBytes);
thread.start();
queue.remove(item);
}
}
}
}
Basically, the main method here is setBitmap(), it gets the activity, the imageView that needs the bitmap, and the name of the image name. If the image is already in the cache, a new thread is started to decode the bytes into the proper size bitmap and set the bitmap to the imageView. If the image is not present in the cache, the request is put in a queue until the image is received, the image is retrieved from the server and then the same thread as before is started.
All this works absolutely fine, the problem is that when the imageView is set another bitmap for the image or even when the activity is destroyed, the bitmap is still resident in memory and is not collected by the GC.
At first I though that it is because I was keeping a reference to the activity, and that reference keeps the activity alive, but it seems not to be the case, my reference to an activity is very short lived, and once the image arrives from the server this reference is cleared.
I am running out of memory fast with this implementation, and I have no idea why or what to do to fix it. The bitmaps I create are not collected although I keep no references to them. Could this be an artifact of the way I decode the images? or do the threads keep references that are not collected properly? Anyone has any ideas?

Ok, so I misunderstood the problem, what was happening is that the GC was not collecting the finished thread objects because I was running this in debug mode, and not in run mode. When I ran this in run mode, the memory usage of my app did not go above 8MB at all, while when it was in debug mode I got to the 25MB+ area.
Conclusion: Do not trust the GC and memory usage info in debug mode, especially if you have many short term threads running.