My problem is the following: I try to load images to a text view like this:
URLImageParser p = new URLImageParser(textView, this);
Spanned htmlSpan = Html.fromHtml(textWithImages, p, null);
textView.setText(htmlSpan);
I followed this example https://stackoverflow.com/a/7442725/1835251
If I load images from the web it works perfectly.
I modified to code a bit to load certain images from SDCard as well.
In the "doInBackground" Method of the async task I implemented this:
#Override
protected Drawable doInBackground(String... params) {
String source = params[0];
Drawable d = null
if(source != null) {
if(source.startsWith("/myApp/images/")) {
localImage = true;
}
}
if(localImage) {
String sdcard = Environment.getExternalStorageDirectory().getAbsolutePath();
d = Drawable.createFromPath(sdcard+source);
d.setBounds(0, 0, 0 + (int)(d.getIntrinsicWidth()), 0
+ (int) (d.getIntrinsicHeight()));
localImage = false;
} else {
// load images from internet
}
return d;
localImage is a boolen which is set to determine if the current source "points" to an
image from the internet or a local image.
As stated before: Loading images from the internet works perfectly.
BUT when I load images from the SDCard it sometimes happens that not all images are displayed.
The whole text (including the images) gets cut as if it hasn't been loaded correctly.
I figured out that this happens much more often on a Samsung Galaxy S3 than on a Samsung S Plus.
On the S3 I sometimes load only 1 or 1.5 images and the rest gets cut.
The S Plus always loads all 4 images but rarely cuts the last 2 or 3 sentences of the text.
I think that it is a sort of a timing problem with the AsyncTask but I never worked with it before.
I know this is a really large post but I hope that someone still can help me.
Best regards
Siggy
Ok I am stupid... I solved it!
I forgot that I only need the AsyncTask if I load images from the internet. For local images I don't need that.
Solution for the interested:
ImageGetter imgGetter = new ImageGetter() {
#Override
public Drawable getDrawable(String source) {
String sdcard = Environment.getExternalStorageDirectory().getAbsolutePath();
Drawable d = Drawable.createFromPath(sdcard+source);
d.setBounds(0, 0, 0 + (int)(d.getIntrinsicWidth()), 0
+ (int) (d.getIntrinsicHeight()));
return d;
}
};
Spanned htmlSpan = Html.fromHtml(textAndImage, imgGetter, null);
textView.setText(htmlSpan);
Related
I am working on an app that uses a Recyclerview to display mp3 files, providing its cover art image along with other info. It works but is slow once it starts dealing with a dozen or more cover arts to retrieve, as I am currently doing this from the id3 on the main thread, which I know is not a good idea.
Ideally, I would work with placeholders so that the images can be added as they become available. I've been looking into moving the retrieval to a background thread and have looked at different options: AsyncTask, Service, WorkManager. AsyncTask seems not to be the way to go as I face memory leaks (I need context to retrieve the cover art through MetadataRetriever). So I am leaning away from that. Yet I am struggling to figure out which approach is best in my case.
From what I understand I need to find an approach that allows multithreading and also a means to cancel the retrieval in case the user has already moved on (scrolling or navigating away). I am already using Glide, which I understand should help with the caching.
I know I could rework the whole approach and provide the cover art as images separately, but that seems a last resort to me, as I would rather not weigh down the app with even more data.
The current version of the app is here (please note it will not run as I cannot openly divulge certain aspects). I am retrieving the cover art as follows (on the main thread):
static public Bitmap getCoverArt(Uri medUri, Context ctxt) {
MediaMetadataRetriever mmr = new MediaMetadataRetriever();
mmr.setDataSource(ctxt, medUri);
byte[] data = mmr.getEmbeddedPicture();
if (data != null) {
return BitmapFactory.decodeByteArray(data, 0, data.length);
} else {
return null;
}
}
I've found many examples with AsyncTask or just keeping the MetaDataRetriever on the main thread, but have yet to find an example that enables a dozen or more cover arts to be retrieved without slowing down the main thread. I would appreciate any help and pointers.
It turns out it does work with AsyncTask, as long as it is not a class onto itself but setup and called from a class with context. Here is a whittled down version of my approach (I am calling this from within my Adapter.):
//set up titles and placeholder image so we needn't wait on the image to load
titleTv.setText(selectedMed.getTitle());
subtitleTv.setText(selectedMed.getSubtitle());
imageIv.setImageResource(R.drawable.ic_launcher_foreground);
imageIv.setAlpha((float) 0.2);
final long[] duration = new long[1];
//a Caching system that helps reduce the amount of loading needed. See: https://github.com/cbonan/BitmapFun?files=1
if (lruCacheManager.getBitmapFromMemCache(selectedMed.getId() + position) != null) {
//is there an earlier cached image to reuse? imageIv.setImageBitmap(lruCacheManager.getBitmapFromMemCache(selectedMed.getId() + position));
imageIv.setAlpha((float) 1.0);
titleTv.setVisibility(View.GONE);
subtitleTv.setVisibility(View.GONE);
} else {
//time to load and show the image. For good measure, the duration is also queried, as this also needs the setDataSource which causes slow down
new AsyncTask<Uri, Void, Bitmap>() {
#Override
protected Bitmap doInBackground(Uri... uris) {
MediaMetadataRetriever mmr = new MediaMetadataRetriever();
mmr.setDataSource(ctxt, medUri);
byte[] data = mmr.getEmbeddedPicture();
Log.v(TAG, "async data: " + Arrays.toString(data));
String durationStr = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
duration[0] = Long.parseLong(durationStr);
if (data != null) {
InputStream is = new ByteArrayInputStream(mmr.getEmbeddedPicture());
return BitmapFactory.decodeStream(is);
} else {
return null;
}
}
#Override
protected void onPostExecute(Bitmap bitmap) {
super.onPostExecute(bitmap);
durationTv.setVisibility(View.VISIBLE);
durationTv.setText(getDisplayTime(duration[0], false));
if (bitmap != null) {
imageIv.setImageBitmap(bitmap);
imageIv.setAlpha((float) 1.0);
titleTv.setVisibility(View.GONE);
subtitleTv.setVisibility(View.GONE);
} else {
titleTv.setVisibility(View.VISIBLE);
subtitleTv.setVisibility(View.VISIBLE);
}
lruCacheManager.addBitmapToMemCache(bitmap, selectedMed.getId() + position);
}
}.execute(medUri);
}
I have tried working with Glide for the caching, but I haven't been able to link the showing/hiding of the TextViews to whether there is a bitmap. In a way though, this is sleeker as I don't need to load the bulk of the Glide-library. So I am happy with this for now.
I'm trying to free memory when I don't need it any more but that doesn't seem to be easy. I create a ListView containing some images (Bitmaps). Every time I do that, the memory monitor shows increase of memory used by my app. This is how I do it:
private ArrayList<ImgMdl> populateList(){
ArrayList<ImgMdl> list = new ArrayList<>();
File folder = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + settingsFileDir + "/" + imgLogFileDir);
if(folder.exists()) {
File[] listOfFiles = folder.listFiles();
listOfFiles = sortFileList(listOfFiles);
for (int i = 0; i < listOfFiles.length; i++) {
String imgFilePath = listOfFiles[i].toString();
Bitmap bmp = BitmapFactory.decodeFile(imgFilePath);
ImgMdl imgMdl = new ImgMdl();
imgMdl.set_itm_txt(getDateString(listOfFiles[i].getName()));
imgMdl.set_itm_img(bmp);
list.add(imgMdl);
}
}
return list;
}
public class MainGate_ImgMdl {
private String itm_txt;
private Bitmap itm_img;
public String get_itm_txt() {
return itm_txt;
}
public void set_itm_txt(String itm_txt) {
this.itm_txt = itm_txt;
}
public Bitmap get_itm_img() {
return itm_img;
}
public void set_itm_img(Bitmap itm_img) {
this.itm_img = itm_img;
}
}
If I open the activity containing that list several times, I'll sometime get an outOfMemoryException. How can I free memory if I don't need it any more? finish() doesn't help.
First, do not load images until they are needed. Suppose that you have 100 images in that directory. Most likely, the user cannot see all 100 on the screen — they would have to scroll to do that. If the user does not scroll, you have loaded the unseen images for no reason.
Second, do not load images that you already loaded. If you "open the activity containing that list several times", and you are loading all of the images each time, that is a waste, as you loaded many of those images previously.
Overall, do not load images yourself. There are plenty of image-loading libraries that are available, such as Picasso and Glide. A decent image-loading library will have a configurable cache (addressing my second point) and know how to load images on-demand in the background, even from rows in a ListView or RecyclerView (addressing my first point).
I have an array of ParseObjects that are being displayed in a list view. Three text views are loaded into my custom cell, and then there's an image in a ParseFile that should also be loaded. The code I have gets the first cell to load correctly, but in every other cell the image doesn't load. Here's my code:
this.origImage = (ParseFile) posts.get(position).get("image");
try {
Log.d("MyMessage", "Gonna convert image");
this.imageData = this.origImage.getData();
this.options = new BitmapFactory.Options();
this.options.inDither = true;
this.options.inPreferredConfig = Bitmap.Config.ARGB_8888;
this.options.inSampleSize = 8;
this.notConvertedYet = BitmapFactory.decodeByteArray(this.imageData, 0, this.imageData.length, this.options);
if (this.notConvertedYet != null)
this.myBitmap = rotateImage(90, this.notConvertedYet);
else
this.myBitmap = this.notConvertedYet;
mHolder.picImageView.setImageBitmap(this.myBitmap);
Log.d("MyMessage", "Converted image");
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
What is happening that's messing it up?
when its bound to a list adapter, what does the
posts.get(position).get("image");
do actually? Is the parse SDK calling a series of AsyncTasks for the network Http GET on the actual URL in parse's file CDN?
You may have to find out more about what its doing because , as is, it may not be very efficient as used by the Adapter.getView()...
Any image loader framework like Volley, like Universal Image Loader, like AQuery will work like an api where you make a call providing the ImageView and the CDN URL for the image as parms. The framework will handle multithreading, pooled Parse.com connections , memCache and fileCache for all images. When using parse to store bitmaps in the file CDN you can still use any of the image loading frameworks.
AQuery sample in an adapter...
ImageView thumbnail=(ImageView)vi.findViewById(R.id.imageView1); // thumb image
mAquery.id(thumbnail).width(110).image($thumbUrl_CDN,
true, true, 0, R.drawable.default_video, null, 0, mAspectRatio);
Your code looks ok.. maybe the reason all the imageViews are black is that the adapter did not have time to get the files loaded across the network and the loop statement did not block the UI thread??
I am trying to create a thumbnail from video. I use the following line:
Bitmap thumb = ThumbnailUtils.createVideoThumbnail(selectedVideoPath, MediaStore.Images.Thumbnails.MICRO_KIND);
It works great when I select an existing video from the gallery, but returns NULL when recording a new video and then trying to get the thumbnail, although the path is valid (/storage/emulated/0/airImagePicker/1394007123308.3gp).
I am on HTC One Android 4.2.2.
Thanks!
I faced the same problem and noticed that it worked when there was a delay between taking the video and creating the bitmap. A workaround that worked for me was to retry creating the bitmap with busy waiting until it wasn't null( it took a few seconds). It's clearly not a clean solution but it seems to do the job.
example of use (in c# xamarin android)
try {
Bitmap bitmap = null;
for (int time = 0; time < 6000; time += timeInterval) {
bitmap = ThumbnailUtils.CreateVideoThumbnail (videoFile.Path, ThumbnailKind.MiniKind);
if (bitmap != null)
break;
await Task.Delay (timeInterval);
}
return bitmap;
I hope it helps.
The problem
Hi there,
I'm developing an application where the user specifies some pictures and how long they are going to be on the screen.So sometimes he wants to create something like a small animation or viewing the images for a small amount of time.The problem is that after some time the images are not previewed when they should and we have a few ms of error.In the application that i'm developing time matters so I would like some help on what the problem might be.
The code
So let me explain how it works.I take the pictures from my web app and then I save them in a HashMap
Bitmap image = ImageOperations(url,String.valueOf(frameNum) + ".jpg");
ImageMap.put(String.valueOf(frameNum), image);
where the mathod ImageOperations is like that:
private Bitmap ImageOperations(String url, String saveFilename) {
try {
Display display = getWindowManager().getDefaultDisplay();
InputStream is = (InputStream) this.fetch(url);
Bitmap theImage = BitmapFactory.decodeStream(is);
if (theImage.getHeight() >= 700 || theImage.getWidth() >= 700) {
theImage = Bitmap.createScaledBitmap(theImage,
display.getWidth(), display.getHeight() - 140, true);
}
return theImage;
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
So later I run a thread that updates the UI when the user specified.The method that updates it is this one.
public void setPictures(int NumOfFrame) {
if (frameArray.get(NumOfFrame - 1).frame_pic.contains("n/a") != true) {
ImagePlace.setImageBitmap(ImageMap.get(String.valueOf(NumOfFrame)));
} else {
ImagePlace.setImageDrawable(null);
}
}
After we update the image we put the thread for sleep and when runs again it updates the thread.Is there something that creates the problem?Does it have to do with Garbage collection?
Thank you in advance
Probably the issue is in increasing heap size when it loads additional images. I would suggest You to do some profiling so things will be much clearer and You'll get full picture of timings for the app.
First you are missing a null check at here:
ImageMap.get(String.valueOf(NumOfFrame))
And you do not recycle the old bitmap at here:
theImage.recycle(); // missing line
theImage = Bitmap.createScaledBitmap(theImage,
display.getWidth(), display.getHeight() - 140, true);
It may lead to outofmemory exceptions, with is most likely from your description of the problem.
Also I am not sure if BitmapFactory.decodeStream throw exception when he fails. You need to add a null point check there too.