Android: Fading between two Activities

Here's the code to do a nice smooth fade between two Activities..

Create a file called fadein.xml in res/anim

<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
   android:interpolator="@android:anim/accelerate_interpolator"
   android:fromAlpha="0.0" android:toAlpha="1.0" android:duration="2000" />

Create a file called fadeout.xml in res/anim

<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
   android:interpolator="@android:anim/accelerate_interpolator"
   android:fromAlpha="1.0" android:toAlpha="0.0" android:duration="2000" />

If you want to fade from Activity A to Activity B, put the following in the onCreate method for Activity B before setContentView.

overridePendingTransition(R.anim.fadein, R.anim.fadeout);

If the fades are too slow for you, change android:duration in the xml files above to something smaller

Android: Adding a new Activity using Eclipse

To add a new screen to your android app you'll want to add a new activity. This is a slightly manual process however, so I've noted down here for future reference.

This example will add a new activity called 'Foo'.

Step 1 - Add the activity class

• In the Package Explorer, right click your main package (e.g. com.calvium.myApp) and select New / Class
• Set the new class Name (e.g. Foo.java), and set it the superclass to android.app.Activity
• Add an override for the onCreate method.
• Easy method: Open the new file and place your cursor inside the main { } block. Press CTRL-SPACE and up pops a list of possibilities. Type 'onCreate' and hit enter to generate the method stub.
• After super.onCreate add:

setContentView(R.layout.foo);

Step 2 - Create the Activity Layout File

• Back in the package explorer, right-click res / layout.
• Select New / Other / Android / Android XML File
• Call the new file foo.xml
• Add whatever controls you want to the xml file using the designer tool in eclipse, or by typing stuff manually.

Step 3 - Register the new activity in the AndroidManifest.xml file

• Open AndroidManifest.xml
• Just before the closing tag insert:

<activity android:name=".Foo">activity>