I'm downloading files with my app via an API (this is working perfectly). Later in my app I'm doing a call to my database to get the file info: id, name, location and return it as a HashMap:
HashMap<Integer, ArrayList<String>> imgTitle;
I take the returned HashMap, extract the ArrayList and use that to populate some buttons. the array list holds the filename and file location. When the page loads the names display correctly but the images don't always load or one loads. If I go back and reenter the activity (via a button press) I'll get different images showing up. I've sent my array to the log and the file location is present and correct for all arrays. Why are only some image showing?
for (Map.Entry<Integer, ArrayList<String>> e : imgTitle.entrySet()) {
...
ArrayList<String> catList = e.getValue();
final String catTitle = catList.get(0);
File indexImage = new File(catList.get(1));
// add images
ImageButton imgButton = new ImageButton(this);
imgButton.setImageURI(Uri.fromFile(indexImage));
...
}
The above is inside a method called on the onCreate. My assumption is maybe the setImageURI is too slow? Any ideas?
Prior to using the setImageURI I used
imgButton.setImageResource(R.drawable.test_vehicle);
as a placeholder it was working fine. However, now I have to use a file that was downloaded and saved locally.
You could try to decode a Bitmap from a stream, like this:
File indexImage = new File(catList.get(1));
InputStream imageStream = new FileInputStream(indexImage);
Bitmap backgroundImage = null;
try {
backgroundImage = BitmapFactory.decodeStream(imageStream);
}
catch(Exception e) {
e.printStackTrace();
}
finally {
try {
//Dispose of the temporary resources
imageStream.close();
imageStream = null //So that the stream is deleted on next GC
}
catch(IOException e) {
e.printStackTrace();
}
}
if (backgroundImage != null) {
ImageButton imgButton = new ImageButton(this);
imgButton.setImageBitmap(backgroundImage);
backgroundImage.recycle();
}
Note: This is pure speculation, I haven't tested any of this. It's simply the first solution that came to my mind
Related
I am displaying all apps installed in a gridView. When loading a lot of apps, lets say 30 or more, the icons will display at the default Android icon and then several seconds later update to the correct icon. I am wondering about improvements I can make to my code to make the icon images display faster.
Load the following with: new LoadIconsTask().execute(mApps.toArray(new AppsInstalled[]{}));
Here is what I do.
private class LoadIconsTask extends AsyncTask<AppsInstalled, Void, Void>{
#Override
protected Void doInBackground(AppsInstalled... params) {
// TODO Auto-generated method stub
Map<String, Drawable> icons = new HashMap<String, Drawable>();
PackageManager manager = getApplicationContext().getPackageManager();
// match package name with icon, set Adapter with loaded Map
for (AppsInstalled app : params) {
String pkgName = app.getAppUniqueId();
Drawable ico = null;
try {
Intent i = manager.getLaunchIntentForPackage(pkgName);
if (i != null) {
ico = manager.getActivityIcon(i);
}
} catch (NameNotFoundException e) {
Log.e(TAG, "Unable to find icon match based on package: " + pkgName
+ " : " + e.getMessage());
}
icons.put(app.getAppUniqueId(), ico);
}
mAdapter.setIcons(icons);
return null;
}
Also populate my listing of apps before I loadIconsTask() with
private List<App> loadInstalledApps(boolean includeSysApps) {
List<App> apps = new ArrayList<App>();
// the package manager contains the information about all installed apps
PackageManager packageManager = getPackageManager();
List<PackageInfo> packs = packageManager.getInstalledPackages(0); // PackageManager.GET_META_DATA
for (int i = 0; i < packs.size(); i++) {
PackageInfo p = packs.get(i);
ApplicationInfo a = p.applicationInfo;
// skip system apps if they shall not be included
if ((!includeSysApps)
&& ((a.flags & ApplicationInfo.FLAG_SYSTEM) == 1)) {
continue;
}
App app = new App();
app.setTitle(p.applicationInfo.loadLabel(packageManager).toString());
app.setPackageName(p.packageName);
app.setVersionName(p.versionName);
app.setVersionCode(p.versionCode);
CharSequence description = p.applicationInfo
.loadDescription(packageManager);
app.setDescription(description != null ? description.toString()
: "");
apps.add(app);
}
return apps;
}
In regards to my Adapter class it is standard. My getView() looks like the following:
#Override
public View getView(int position, View convertView, ViewGroup parent) {
AppViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row, null);
// creates a ViewHolder and stores a reference to the children view
// we want to bind data to
holder = new AppViewHolder();
holder.mTitle = (TextView) convertView.findViewById(R.id.apptitle);
holder.mIcon = (ImageView) convertView.findViewById(R.id.appicon);
convertView.setTag(holder);
} else {
// reuse/overwrite the view passed assuming that it is castable!
holder = (AppViewHolder) convertView.getTag();
}
App app = mApps.get(position);
holder.setTitle(app.getTitle());
if (mIcons == null || mIcons.get(app.getPackageName()) == null) {
holder.setIcon(mStdImg);
} else {
holder.setIcon(mIcons.get(app.getPackageName()));
}
return convertView;
}
Is there a better way? Can I somehow store the images of the icons in a data structure and when I return back to this Activity I can skip the loadIconsTask? Is that possible? Thank you in advance.
You can use Picasso library with a custom RequestHandler to load the icons in the background.
First create a RequestHandler which will handle the specific case where an app icon needs to be loaded.
public class AppIconRequestHandler extends RequestHandler {
/** Uri scheme for app icons */
public static final String SCHEME_APP_ICON = "app-icon";
private PackageManager mPackageManager;
public AppIconRequestHandler(Context context) {
mPackageManager = context.getPackageManager();
}
/**
* Create an Uri that can be handled by this RequestHandler based on the package name
*/
public static Uri getUri(String packageName) {
return Uri.fromParts(SCHEME_APP_ICON, packageName, null);
}
#Override
public boolean canHandleRequest(Request data) {
// only handle Uris matching our scheme
return (SCHEME_APP_ICON.equals(data.uri.getScheme()));
}
#Override
public Result load(Request request, int networkPolicy) throws IOException {
String packageName = request.uri.getSchemeSpecificPart();
Drawable drawable;
try {
drawable = mPackageManager.getApplicationIcon(packageName);
} catch (PackageManager.NameNotFoundException ignored) {
return null;
}
Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
return new Result(bitmap, Picasso.LoadedFrom.DISK);
}
}
In your adapter, create a Picasso instance and add your RequestHandler.
// field variable
private Picasso mPicasso;
// in constructor
Picasso.Builder builder = new Picasso.Builder(context);
builder.addRequestHandler(new AppIconRequestHandler(context));
mPicasso = builder.build();
In your adapter's getView() load the icon using Picasso.
mPicasso.load(AppIconRequestHandler.getUri(app.packageName)).into(holder.mIcon);
it's surprising the system takes that much time in getting these lists, you may want to add some logs with timestamping to see which one is the demanding operation.
I don't know if that procedure can be further optimized, I haven't used these system API's very much, but what you can certainly do is to cache this list
Create it in onResume / onCreate as a static list, and (for the sake of correctness) destroy it in onPause / onStop if you want to consider the case where the user may install an application while in your app (onPause will be called), but you can certainly skip this step.
You may want to also permanently cache the list in the sdcard and find some simple and fast heuristic to decide if the list has changed in order to recreate it. Something like maybe the number of installed packages together with something else (to discard the case when the user uninstalls 3 apps and install 3 different apps, the number of packages will be the same and you have to detect this somehow).
EDIT- To recommend a caching mechanism, you should identify which one is the slow operation. Just guessing, and from your question "the icons take some seconds to appear" it looks like that the slow operation is:
ico = manager.getActivityIcon(i);
but I might be wrong. Let's suppose I'm right, so a cheap caching can be:
1) Move the Map<String, Drawable> icons = new HashMap<String, Drawable>(); outside of doInBackground to the root of the class and make it static, like:
private static Map<String, Drawable> sIcons = new HashMap<String, Drawable>()
2) In your loadIconsTask consider the case you already have this icon:
for (AppsInstalled app : params) {
String pkgName = app.getAppUniqueId();
if (sIcons.containsKey(pkgName) continue;
.
.
.
}
This is because sIcons is now static and will be alive as long as your application is alive.
3) As a classy thing, you may want to change sIcons from Drawable to Bitmap. Why? Because a Drawable may keep inside references to Views and Context and it's a potential memory leak. You can get the Bitmap from a Drawable very easily, calling drawable.getBitmap() , (Assuming drawable is a BitmapDrawable, but it will obviously be because it's an app icon), so suming up you'll have:
// the static icon dictionary now stores Bitmaps
static Map<String, Bitmap> sIcons = new HashMap<String, Bitmap>();
.
.
// we store the bitmap instead of the drawable
sIcons.put(app.getAppUniqueId(), ((BitmapDrawable)ico).getBitmap());
.
.
// when setting the icon, we create the drawable back
holder.setIcon(new BitmapDrawable(mIcons.get(app.getPackageName())));
This way your static hashmap will never leak any memory.
4) You may want to check if it's worth to store those bitmaps on disk. Mind this is some additional work and it might not be worth if the time to load the icon from disk is similar to the time to load the icon calling ico = manager.getActivityIcon(i);. It may be (i don't know if manager.getActivityIcon() extracts the icon from the APK) but it certainly may be not.
If you check out it's worth, when you create the list, you can save the bitmaps to the sdcard like this:
// prepare a file to the application cache dir.
File cachedFile=new File(context.getCacheDir(), "icon-"+app.getPackageName());
// save our bitmap as a compressed JPEG with the package name as filename
myBitmap.compress(CompressFormat.JPEG, quality, new FileOutputStream(cachedFile);
... then when loading the icons, check if the icon exists and load from the sdcard instead:
String key=app.getPackageName();
File localFile=new File(context.getCacheDir(), "icon-"+key);
if (localFile.exists()) {
// the file exists in the sdcard, just load it
Bitmap myBitmap = BitmapFactory.decodeStream(new FileInputStream(localFile));
// we have our bitmap from the sdcard !! Let's put it into our HashMap
sIcons.put(key, myBitmap)
} else {
// use the slow method
}
Well as you see it's just a matter of identifying the slow operation. If our above assumption is correct, your stored bitmaps will survive your application destroy and it will hopefully optimize the icon loading.
You can use Glide for automatic loading and caching and the URI of each application icon:
final RequestManager mGlide = Glide.with(activity);
final Uri appIconUri = applicationInfo.icon != 0 ?
Uri.parse("android.resource://" + packageName + "/" + applicationInfo.icon) :
null;
if (appIconUri != null) mGlide.load(appIconUri).into(holder.appIconImgView);
else {
mGlide.clear(holder.appIconImgView); // as suggested here: https://bumptech.github.io/glide/doc/getting-started.html
mGlide.load(android.R.drawable.sym_def_app_icon).into(holder.appIconImgView);
}
The reason I suggest Glide and not other image loading libraries is that Glide supports XML drawable (or dynamic/adaptive or vector icons) loading while others don't (see https://github.com/facebook/fresco/issues/2173)
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 have an image url I parse form json that I want to load into an android widget onto the homescreen. Right now I am trying to do it this way but its wrong:
ImageDownloadTask imageD = new ImageDownloadTask(image);
views.setImageViewBitmap(R.id.image, imageD.execute(image));
image is a string holding a url to an image that needs to be downloaded and I am trying to set it to R.id.image
I found another stack question and tried this as a result:
views.setBitmap(R.id.image, "setImageBitmap",BitmapFactory.decodeStream(new URL(image).openStream()));
And when I use that nothing in the app loads at all, none of the text views get set.
My third try was this:
//get beer data
JSONObject o = new JSONObject(result);
String name = getName(o);
String image = getImage(o);
String abv = getABV(o);
String ibu = getIBU(o);
String glass = getGlass(o);
String beerBreweryName = getBreweryName(o);
String beerBreweryStyle = getBreweryStyle(o);
String beerDescription = getDescription(o);
InputStream in = new java.net.URL(image).openStream();
Bitmap bitmap = BitmapFactory.decodeStream(in);
views.setTextViewText(R.id.beerTitle, name);
views.setTextViewText(R.id.beerBreweryName, beerBreweryName);
views.setTextViewText(R.id.beerStyleName, beerBreweryStyle);
views.setImageViewBitmap(R.id.image, bitmap);
This gave the same result as the last attempt, it would not even set any text views....
Just tried another attempt after one of the answers posted below:
RemoteViews views = new RemoteViews(c.getPackageName(), R.layout.widget_test);
//get beer data
JSONObject o = new JSONObject(result);
String name = getName(o);
String imageURL = getImage(o);
String abv = getABV(o);
String ibu = getIBU(o);
String glass = getGlass(o);
String beerBreweryName = getBreweryName(o);
String beerBreweryStyle = getBreweryStyle(o);
String beerDescription = getDescription(o);
Log.d("widgetImage" , imageURL);
views.setImageViewUri(R.id.image, Uri.parse(imageURL));
views.setTextViewText(R.id.beerTitle, name);
views.setTextViewText(R.id.beerBreweryName, beerBreweryName);
views.setTextViewText(R.id.beerStyleName, beerBreweryStyle);
mgr.updateAppWidget(appWidgetIds, views);
This attempt lets all the text views load, but no image ever shows up.
The way to do this reliably is to use setImageViewURI on the remote ImageView. The trick is that the URI you give it is a content:// URI which then points back to a content provider that you export from your application. In your content provider you can do anything you need to do to supply the image bytes.
For example, in your manifest:
<provider android:name=".ImageContentProvider" android:authorities="com.example.test" android:exported="true" />
And your provider:
public class ImageContentProvider extends ContentProvider {
// (Removed overrides that do nothing)
#Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
List<String> segs = uri.getPathSegments();
// Download the image content here, get the info you need from segs
return ParcelFileDescriptor.open(new File(path), ParcelFileDescriptor.MODE_READ_ONLY);
}
}
And then your URL is something like:
content://com.example.test/something-you-can-define/here
This is necessary because your remote image view is not running in your process. You are much more limited in what you can do because everything must be serialized across the process boundary. The URI can serialize just fine but if you try to send a megabyte of image data with setImageViewBitmap, it's probably going to fail (depending on available device memory).
Got a lot of help from multiple sources for this question. The big problem for me why a bunch of the attempts I tried listed above seemed to lock the widget app and not load anything is because I can not download the image and set it in a UI thread.
To accomplish this I had to move everything to the do in background of my async task and not in the onPostExecute.
here i want to display a image logo which i am receiving from a sqlite as blob database when i dont have internet, though i know its a not a good practice but i want to make it simpler this way.
Problem i am facing is i am able to receive image in log but some warning (link below) is coming because of which it is not loading it into imageView.
Here's the warning i am getting in log !!
I am unable to figure out why it still running DownloadImageTask which is a async task even when not online that is isOnline()==false !!
ImageView logo = (ImageView)findViewById(R.id.Logo);
Bundle extras = getIntent().getExtras();
if(isOnline(this)==true);
{
String link = extras.getString("Logo1");
new DownloadImageTask(logo).execute(link);
}
if(isOnline(this)==false){
Log.d("offline","image");
Log.d("offline",extras.getByteArray("Logo2").toString());
//getting these ^^ in log
byte[] outImage=(byte[]) extras.getByteArray("Logo2");
if(outImage!=null)
{
ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
Bitmap theImage = BitmapFactory.decodeStream(imageStream);
logo.setImageBitmap(theImage);
}
}
}
if(isOnline(this)==true)//you Superfluous add a ";" in this
{
String link = extras.getString("Logo1");
new DownloadImageTask(logo).execute(link);
}
i am a newbie,hope can help you
I put in 2 texts then pressed save and saving internal storage. Press List button reading List.java there are saving data's in list. so I pressed MainActivity button and i put in 2 texts again. But this time List.java's previous data has lost. Only one row data's in listview. How can i fix this problem. I want to dynamically add 2 items in internal storage in listview.
https://stackoverflow.com/questions/16940672/how-to-save-internal-storage-via-custom-adapter-in-android-list
Thanks for help.
Try to use Custom view for List row and implement that view into List View.
Here are some of the links for Custom List
Example-1
Example-2
You could try saving the array list to Internal Storage as a file. Check this answer or code below,
For writing to file,
try {
//Modes: MODE_PRIVATE, MODE_WORLD_READABLE, MODE_WORLD_WRITABLE
FileOutputStream output = openFileOutput("lines.txt",MODE_WORLD_READABLE);
DataOutputStream dout = new DataOutputStream(output);
dout.writeInt(text_lines.size()); // Save line count
for(String line : text_lines) // Save lines
dout.writeUTF(line);
dout.flush(); // Flush stream ...
dout.close(); // ... and close.
}
catch (IOException exc) { exc.printStackTrace(); }
For reading it,
FileInputStream input = openFileInput("lines.txt"); // Open input stream
DataInputStream din = new DataInputStream(input);
int sz = din.readInt(); // Read line count
for (int i=0;i<sz;i++) { // Read lines
String line = din.readUTF();
text_lines.add(line);
}
din.close();