Small pieces of code that can be copy/paste-ed on your project
Figuring out how to pull the current flavor from gradle While working on an update for one of our games, I needed to figure out how to get the current flavor and use it in code. Since there are a lot of ways to do this, I chose to create a custom build config parameter and…
The following snippet will help you generate a random number in Java that is between 2 numbers (min and max).
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static Random random = new Random(); /** * Min is inclusive and max is exclusive in this case **/ public static int randomBetween(int min, int max) { return random.nextInt(max - min) + min; } |
Please note that the min variable is inclusive in the results of this method while max is exclusive.
So if you ever need the screen width and height on Android, you can use the following snippet:
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/** * Returns the size of the screen in pixels (width and height) * * @return a Point that has the screen width stored in x and height in y */ public Point getScreenSize(Activity context) { Display display = context.getWindowManager().getDefaultDisplay(); Point size = new Point(); if (android.os.Build.VERSION.SDK_INT >= 13) { display.getSize(size); } else { //noinspection deprecation size.set(display.getWidth(), display.getHeight()); } return size; } |
If you are working with HttpURLConnection on Android then you might encounter strange InputStream outputs like when you have a strange character encoding even though on the server side everything seems ok. A problem I was encountered lately was when I needed to parse a RSS/Atom feed on Android. I was getting the following error:…
If you ever want to get the SHA, MD5 or the signing key used to sign your app for example you can use the following snippet:
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private void printSHA() { try { // get the package info that contains the key you want to print PackageInfo info = getPackageManager().getPackageInfo(getPackageName(), PackageManager.GET_SIGNATURES); for (Signature signature : info.signatures) { // you can use other algorithms like MD5, SHA-1 or SHA-256 MessageDigest sha = MessageDigest.getInstance("SHA-256"); sha.update(signature.toByteArray()); // print the signing key SHA hash byte[] output = sha.digest(); Log.e("MY KEY HASH:", Base64.encodeToString(output, Base64.DEFAULT)); Log.e("MY KEY HASH Hex:", bytesToHex(output)); } } catch (PackageManager.NameNotFoundException notFoundException) { Log.e("My tag", notFoundException.getMessage()); } catch (NoSuchAlgorithmException noSuchAlgorithmException) { Log.e("My tag", noSuchAlgorithmException.getMessage()); } } |
And the converter method that outputs a hexa string from an array of bytes:
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public static String bytesToHex(byte[] bytes) { final StringBuilder builder = new StringBuilder(); for(byte aByte : bytes) { builder.append(String.format("%02x", aByte)); } return builder.toString(); } |
Using this you can implement validation systems between your app and backend. This…
Maybe you need to add links to a TextView on Android but you don't want to use Linkify for some reasons and you also want that link to be opened when the user taps it. Here is a simple solution:
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yourTextView.setText(Html.fromHtml( "Text with a " + "<a href=\"http://www.myandroidsolutions.com/\">link to My Android Solutions</a> ")); // this is important as well !! yourTextView.setMovementMethod(LinkMovementMethod.getInstance()); |
Note that I used the fromHtml() method from the Html class to generate a Spanned…
If you need to set a smaller hint for your edit text, you can set the hint this way:
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myEditText.setHint(Html.fromHtml( "<small><small><small>" + getString(R.string.hint) + "</small></small></small>")); |
Also, you can set the size in the string resource file where is the string for the hint.
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<string name="edit_text_hint"><font size="15">My hint string</font></string> |
and in the xml file just set the hint as usual:
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android:hint="@string/edit_text_hint" |
If you ever need to get the version of the OS on which your app runs, you can try this out:
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android.os.Build.VERSION.SDK_INT |
And you can use it against(for more check this out):
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android.os.Build.VERSION_CODES.[BASE-KITKAT] |
Finally you end up with something like:
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if(android.os.Build.VERSION.SDK_INT == android.os.Build.VERSION_CODES.HONEYCOMB){ // do whatever you want here } |
You might notice the new CardView widget on Android L preview presentation. The view can be used to display text or images and has a nice shadow. You can add that view into your project even if you don't have the minimum API level to "L"... to do that, follow the steps below: 1. Edit your gradle.build…