Develop Reference

JPG image shows from phone but not from server - android

In my app I am able to pick up a picture from the Gallery and show it on my phone. The picture has extension JPG. But when I email it to myself, save it on the server and then try to display it on my phone, it does not display. I even tried to downsize it to 30% using my email app on the phone, so now it is 220KB instead of 1.4MB but it still does not display.
In both cases I use the method
imageView.setImageBitmap(BitmapFactory.decodeFile(personPicture))
What do I need to do to overcome this problem?
BTW: the name of the picture was changed when I saved it on the server. I do not think it matters but I mentioned it anyway.
EDIT
The above is all the code I am using. Just to complete the issue here is the code that handles both jpg and png and it works if the picture is renamed to png.
if (url.contains("jpg")) {
imageView.setImageBitmap(BitmapFactory.decodeFile(url));
} else {
Drawable drw = LoadImageFromWebOperations(url);
if (drw != null) {
imageView.setImageDrawable(drw);
}
}
Note: the 1.4MB PNG file worked fine on the emulator but gave Out of memory exception on the device. When I re-sized the PNG file to 350KB it displayed properly on the device also.
If needed here is the url used in the above code (a picture of a cat)/
http://212.150.56.58:8080/feedback/pictures/56.png

When you try to load image from server into app, load it using Picasso library like as below:
Picasso.with(MainActivity.this).load("image_to_be_loaded").into(profile_image);
Edit
If you don't want to use third party library then try the following code:
public Drawable loadImageFromURL(String url, String name) {
try {
InputStream is = (InputStream) new URL(url).getContent();
Drawable d = Drawable.createFromStream(is, name);
return d;
} catch (Exception e) {
return null;
}
}

Use Picasso to load server images to your app image view it also supports caching and lot many features.
Use is like this
Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);
checkout Picasso Library for more details.

I do not understand why, but if I renamed the picture on my server to extension PNG the picture displays, in all sizes.

android + access remote drawables - best practices

Im developing an app which is a product catalogue. Users can search for and view products (books). It's all read only and just so allow user's to view products. When the user clicks on a product, the next screen displays
- book title
- book author
- picture of front cover.
It's the picture part that I've a question about. I know one way to present drawables is to have them in the "drawable" direction in my android project and access them (in my xml file) as android:src="#drawable/name".
Only problem is that new products will be added so I can't store drawables in the APK file when I release it. I'll need to read them at runtime. I'm wondering what the best way to approach this is.
I'm thinking of upon (very first) launch of the app executing an AsyncTask which would call
openConnection of HttpURLConnection and would grab down all drawable (from a particular remote directory on a website) and would then store them in the sqllite db (as a blob). Each product in the db could easily be associated with it's specific drawable.
Not sure if there's a better approach to this ? or should I save them to the internal storage of the device (I know the size is an issue with this option). Trying to grab the drawable on demand can take 2-4secs (i.e. to get from remote server). Is there a way to download drawables in an efficent way ?
Update: The only problem with the above approach is the time it takes to grab the remote drawable and render it on the device (between 2-7 seconds). So I can't go with that approach for performance reasons. When the user launches the app for the very first time, it (using an ASynch task) grabs all products (in a csv remotely) and stores it's contents in an SQLLite db. So they've a small acceptable wait on very first launch of the app but none after that. I'd like to do something similiar (i.e. get the drawables too) but not sure should should I store them in internal storage or persist them as BLOB into the db. There max size of 2-3kb each in size but there could be 300 products in total
Any help would be great. I'm developing on Android 4.0.3.
Thanks - Ro

The method you described is the best way to perform such a task. Grab them directly from online so that any time you change the picture it is changed on your phone. Also an easier way, you can directly display images to user no need for storing them into database but before you have to check internet connection.
Function for retrieving images:
public static Bitmap getBitmapFile(String str)
{
Bitmap bmImg=null;
URL myFileUrl;
try {
myFileUrl = new URL(str);
HttpURLConnection conn= (HttpURLConnection)myFileUrl.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
bmImg = BitmapFactory.decodeStream(is);
} catch (Exception e) {
e.printStackTrace();
}
return bmImg;
}
For checking Internet connection:
// declaring variable for holding Internet connection state
boolean connected = false;
// checking connectivity to the Internet through mobile network or WIFI
ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED ||
connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) {
// Internet connection
connected = true;
}
else
// no Internet connection
connected = false;
Example:
// grab image to display
try {
// Bitmap bmp1;
// String url1;
// ImageView img1;
// in case there is Internet connection display image from online url
if(connected == true)
{
bmp1=MainActivity.getBitmapFile(url1);
img1.setImageBitmap(bmp1);
}
else
{
img1.setImageResource(R.drawable.not_connected);
}
} catch(Exception e) {
e.printStackTrace();
}

Downloading just the icon of an application from Google Play (Market)

Is there a way to download just the icons that are stored in a particular application from Google Play/Market without downloading the entire APK and installing it?

You can do this but it would require downloading he page source and then parsing it.
What you could do is first download the webpage, i like JSoup. Like
Document d = null;
try {
d = Jsoup.connect("https://play.google.com/store/apps/details?id=" + packageName).get();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Then you should parse that document for the following tag ""
Elements div = d.getElementsByAttributeValueContaining("class", "doc-banner-icon");
String path = div.get(0).attr("src");
This path variable should be the path for the image to download. I have not tested this.

Nope
There is no official API for market content. Be it to retrieve icons or anything else.
If you are just interested in getting the image files you can download them manually via the web front end to the Market. But I wouldn't write code to do this, as it is very likely that they will make a change to the web front end that will result in your code breaking. p.s. I am no lawyer, but also I don't think there is very much that you would be "allowed" to do with these images even if you did download them (without permission from each developer of course)

The answer by Jug6ernaut will no longer work. This works as of November 2016:
#WorkerThread public static String scrapeGooglePlayIcon(#NonNull String packageName) throws IOException {
return Jsoup.connect("https://play.google.com/store/apps/details?id=" + packageName).get()
.select("div[class=details-info] > div[class=cover-container] > img[class=cover-image]")
.attr("abs:src");
}
I created a small library that web scrapes the Google Play store. If this stops working in the future, please comment or create an issue on the GitHub project: https://github.com/jaredrummler/GooglePlayScraper

You could create a Yahoo Pipes like this http://kcy.me/hylg it will parse the page for you and extract a JSON in wich you could read the sinlge image URL.
http://kcy.me/hylj
You can parameterize the pipe in order to receive the link to the app you want to extract the image.

The simple solution is that just right click on the icon of the app from Chrom browser and save image as, this will save the icon with webp extension, now use this Conver webp to png
to convert the icon to PNG.

Android resource loading (icons and strings) at runtime

I'm stuck with the following scenario and appreciate any help/advice..
Requirement
I have number of categories and subcatergories in my application. Say for example, I have a category "Food" and under which I have subcategories: Mexican, Chinese, Italian etc.. I have around 20 categories and each category has around 30 subcategories.
Each subcategory/category has an Icon associated with it
User would be able to select one or more of these sub-categories, so the UI would be a seectable list view.
Questions:
What's the best way to store and retrieve this data (Strings and Icons), serverside or client side ?
Is there a way to load icons dynamically at runtime, when I show the subcategories? (using http?)
Thanks in advance !

Why would you fetch icon-data from a server? 20 * 30 = 600 icons.
You probably will save hard drive space with respect to the installation. But personally I wouldn't go for that solution.
If you're not in need of a client/server - approach then don't use it. What if the server for example breaks down, or you don't have an internet connection?. The application will then be useless :)

You can load images dynamically as:
BitmapFactory.Options options = new BitmapFactory.Options();
options.outWidth= IMAGE_WIDTH;
options.outHeight= IMAGE_HEIGHT;
Bitmap bm = BitmapFactory.decodeFile("icon image file path", options);
imageView.setImageBitmap(bm);
In your case, you can download all the required icons on mobile's sdcard. So in future,if sub categories increases then you can download new icons for that and can dynamically render on UI.

How to Set Background Image from asset folder in android?

I am facing problem while setting the backGround Image of LinearLayout from asset folder.
String filePath="file:///android_asset/images/test.png";
Drawable d = Drawable.createFromPath(filePath);
frontTextView.setBackgroundDrawable(d);
Can someone help me out.

First you create a Drawable object from the asset file:
Drawable d = Drawable.createFromStream(getAssets().open(path_in_assets), null);
and then set it to some View that only supports Drawables as a background.

As far as I'm aware, you cannot access assets directly like you are trying to. You'll need to use the AssetManager class to get at your data if you want to store it as an asset. Here's a pretty decent blog post explaining a bit about resources and assets, though the official documentation is also a good resource, of course.
I'll also add, though, that things like background images are typically best stored in res/drawable and accessed using the R.drawable.* style (the blog post linked above also discusses this) whenever possible. It's not really clear why you need to do it this way from your provided code sample, though, so I suppose that's ultimately your call.

EDIT: added create image from InputStream...
I had the similar problem using ImageButton. I figured it out by loading bitmap from assets and using it as image for ImageButton. Probably not a good approach, but is working and solved my problem - unability to have subfolders in drawable dir and not allowed characters in file names.
(Yes, I can use prefix instead of subdir, and rename files to match the pattern (lowercase only and numbers) and I probably will do it later.)
InputStream is = null;
try {
is = this.getResources().getAssets().open("Images/Fruits/Apple.png");
} catch (IOException e) {
Log.w("EL", e);
}
Bitmap image = BitmapFactory.decodeStream(is);
ImageButton ib2 = (ImageButton) findViewById( R.id.imageButton2);
ib2.setImageBitmap( image);