Rename git branch locally and remotely

In case you have created a branch with a wrong name and pushed your branch to the remote git repository you can follow these steps to change the name of your branch.

git branch -m old_branch new_branch # Rename branch locally
git push origin :old_branch # Delete the old branch
git push –set-upstream origin new_branch # Push the new branch, set local branch to track the new remote

Please note, if you use the name of the branch somewhere in your build scripts or somewhere else like SonarQube you have to change it there also.

Get rotation from its “natural” orientation on your android device

Up to API Level 7 you can use android.view.Display.getOrientation() to get the rotation of the screen from its default orientation. But this method was deprecated in API level 8.

But now you can use

The returned value is:

  • Surface.ROTATION_0 (no rotation)
  • Surface.ROTATION_90
  • Surface.ROTATION_180
  • Surface.ROTATION_270
  • If your device has a naturally portrait screen, and the user has turned it on its side to go into a landscape orientation, the value returned here may be either Surface.ROTATION_90 or Surface.ROTATION_270 depending on the direction it was turned.

    With this simple line of code you can get the information about the screen orientation related to the default. This could be helpful, if you want to deal with your Sensor.

    Android Activity without UI

    Is it possible to create a Android activity without UI?

    Yes it is. Android provides a theme for this requirement. Add the following line to your AndroidManifest.xml and call finish() at the end of the Activity’s onCreate() method.



    public static final class – Added in API level 3
    int Theme_NoDisplay
    Default theme for activities that don’t actually display a UI; that is, they finish themselves before being resumed.

    Constant Value: 16973909 (0x01030055)

    How to know if the app goes to Background

    With API Level 14 – Android 4.0, there is a Method in Application which is called onTrimMemory. The onTrimMemory is executed by the system with different levels ( TRIM_MEMORY_COMPLETE, TRIM_MEMORY_MODERATE, TRIM_MEMORY_BACKGROUND, TRIM_MEMORY_UI_HIDDEN, TRIM_MEMORY_RUNNING_CRITICAL, TRIM_MEMORY_RUNNING_LOW, or TRIM_MEMORY_RUNNING_MODERATE). The interesting level is “TRIM_MEMORY_UI_HIDDEN”. This level can be used to know that the app is going to background.

    The following example is a demonstration of the Application.onTrimMemory Method:

    public class MyApplication extends Application {
    // ...
    public void onTrimMemory(int level) {
    if (level == TRIM_MEMORY_UI_HIDDEN) {
    // ...

    With this simple piece of code, you can check if your app is being sent to the background!

    How to Format cells in Excel for Android

    Not a snippet, but a needed Information when using Microsoft Android Calc

    How to Format cells in Excel for Android. (Sceenshot made on a german device)

    Some more informations are available in the video at Excel for Android is very similar to Microsoft Excel for Windows. But some differences can confuse sometimes. The short video shows you how to get up and running with Microsoft Calc for Android.

    Recompiling objects in oracle

    A pl/sql script to recompile all invalid objects in oracle. Simple but powerfull.


    How To use landscape and reverseLandscape in AndroidManifest.xml

    If you develope a app or activity which is only available in landscape mode, you can enhance the app by adding the reverseLandscape mode (Landscape orientation in the opposite direction from normal landscape. Added in API level 9.) via editing the android:screenOrientation attribute of your activity in AndroidManifest.xml. Instead of using the “landscape” value, you can use “sensorLandscape” (Landscape orientation, but can be either normal or reverse landscape based on the device sensor. Added in API level 9.).

    This is a simple solution and your users will enjoy the possibility of using the device even if it is rotated by 180 degrees. The same solution is possible for portrait apps and activities. In this case you have to use sensorPortrait instead of sensorLandscape in AndroidManifest.xml.

    How to sort an ArrayList in Java

    If you want to sort any ArrayList in java, you need to make sure, your objects in the arrylist are comparable. This is done by using implements Comparable and implementing the abstract method compareTo (T cmp). For example if you want to sort some highscores you can do it like this.

    This is a simple, but powerfull solution to sort an ArrayList.

    How to execute a shell command from android app

    To execute a shell command from your android app you can grab the standard input of the su process just launched by Runtime.getRuntime().exec(“su”) and write down the command there, otherwise you are running the commands with the current UID.

    With the following code you can excute the screenrecord command to grab your screen to a mp4 video file (Works on Android 4.4 API level 19 and higher). There are many othe commands you can execute. You can find some of them at


    How to turn on/off (enable/disable) GPS in Android

    If you want to develop an Android app to turn on/off GPS you can use the following code snippets.