Thursday , November 7 2024

Android Working with XML Animations

Adding animations to your app interface will give high quality feel to your android applications. Animations can be performed through either XML or android code. In this tutorial i explained how to do animations using XML notations. I will explain how to do the same using android java code in future tutorials.
Here i covered basic android animations like fade in, fade out, scale, rotate, slide up, slide down etc.

In this project i wrote saperate activity and xml file for each animation.

Step 1: Create xml that defines the animation

Create an xml file which defines type of animation to perform. This file should be located under anim folder under res directory (res ⇒ anim ⇒ animation.xml). If you don’t have anim folder in your res directory create one. Following is example of simple fade in animation.

screen1

fade_in.xml

<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true” >

<alpha
android:duration=”1000″
android:fromAlpha=”0.0″
android:interpolator=”@android:anim/accelerate_interpolator”
android:toAlpha=”1.0″ />

</set>

Step 2: This is the final code of java file.

FadeInActivity.java

package info.w2class.androidanimations;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.Animation.AnimationListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class FadeInActivity extends Activity implements AnimationListener {

TextView txtMessage;
Button btnStart;

// Animation
Animation animFadein;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fadein);

txtMessage = (TextView) findViewById(R.id.txtMessage);
btnStart = (Button) findViewById(R.id.btnStart);

// load the animation
animFadein = AnimationUtils.loadAnimation(getApplicationContext(),
R.anim.fade_in);

// set animation listener
animFadein.setAnimationListener(this);

// button click event
btnStart.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
txtMessage.setVisibility(View.VISIBLE);

// start the animation
txtMessage.startAnimation(animFadein);
}
});

}

@Override
public void onAnimationEnd(Animation animation) {
// Take any action after completing the animation

// check for fade in animation
if (animation == animFadein) {
Toast.makeText(getApplicationContext(), “Animation Stopped”,
Toast.LENGTH_SHORT).show();
}

}

@Override
public void onAnimationRepeat(Animation animation) {
// TODO Auto-generated method stub

}

@Override
public void onAnimationStart(Animation animation) {
// TODO Auto-generated method stub

}

}

Some useful animations:

Following i am giving xml code to perform lot of useful animations. Try to assign different values to xml attributes to see change in animations.

1. Fade In
2. Fade Out
3. Cross Fading
4. Blink
5. Zoom In
6. Zoom Out
7. Rotate
8. Move
9. Slide Up
10. Slide Down
11. Bounce
12. Sequential Animation
13. Together Animation

Fade In
For fade in animation you can use <alpha> tag which defines alpha value. Fade in animation is nothing but increasing alpha value from 0 to 1.

fade_in.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true” >

<alpha
android:duration=”1000″
android:fromAlpha=”0.0″
android:interpolator=”@android:anim/accelerate_interpolator”
android:toAlpha=”1.0″ />

</set>
Fade Out
Fade out is exactly opposite to fade in, where we need to decrease the alpha value from 1 to 0

fade_out.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true” >

<alpha
android:duration=”1000″
android:fromAlpha=”1.0″
android:interpolator=”@android:anim/accelerate_interpolator”
android:toAlpha=”0.0″ />

</set>
Cross Fading
Cross fading is performing fade in animation while other element is fading out. For this you don’t have to create separate animation file, you can just use fade_in.xml and fade_out.xml files.

In the following code i loaded fade in and fade out, then performed them on two different UI elements.

TextView txtView1, txtView2;
Animation animFadeIn, animFadeOut;
.
.
// load animations
animFadeIn = AnimationUtils.loadAnimation(getApplicationContext(),
R.anim.fade_in);
animFadeOut = AnimationUtils.loadAnimation(getApplicationContext(),
R.anim.fade_out);
.
.
// set animation listeners
animFadeIn.setAnimationListener(this);
animFadeOut.setAnimationListener(this);

.
.
// Make fade in elements Visible first
txtMessage2.setVisibility(View.VISIBLE);

// start fade in animation
txtMessage2.startAnimation(animFadeIn);

// start fade out animation
txtMessage1.startAnimation(animFadeOut);
Blink
Blink animation is animating fade out or fade in animation in repetitive fashion. For this you will have to set android:repeatMode=”reverse” and android:repeatCount attributes.

blink.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”>
<alpha android:fromAlpha=”0.0″
android:toAlpha=”1.0″
android:interpolator=”@android:anim/accelerate_interpolator”
android:duration=”600″
android:repeatMode=”reverse”
android:repeatCount=”infinite”/>
</set>
Zoom In
For zoom use <scale> tag. Use pivotX=”50%” and pivotY=”50%” to perform zoom from the center of the element. Also you need to use fromXScale, fromYScale attributes which defines scaling of the object. Keep these value lesser than toXScale, toYScale

zoom_in.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true” >

<scale
xmlns:android=”http://schemas.android.com/apk/res/android”
android:duration=”1000″
android:fromXScale=”1″
android:fromYScale=”1″
android:pivotX=”50%”
android:pivotY=”50%”
android:toXScale=”3″
android:toYScale=”3″ >
</scale>

</set>
Zoom Out
Zoom out animation is same as zoom in but toXScale, toYScale values are lesser than fromXScale, fromYScale

zoom_out.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true” >

<scale
xmlns:android=”http://schemas.android.com/apk/res/android”
android:duration=”1000″
android:fromXScale=”1.0″
android:fromYScale=”1.0″
android:pivotX=”50%”
android:pivotY=”50%”
android:toXScale=”0.5″
android:toYScale=”0.5″ >
</scale>

</set>
Rotate
Rotate animation uses <rotate> tag. For rotate animation required tags are android:fromDegrees and android:toDegrees which defines rotation angles.

Clock wise – use positive toDegrees value
Anti clock wise – use negative toDegrees value

rotate.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”>
<rotate android:fromDegrees=”0″
android:toDegrees=”360″
android:pivotX=”50%”
android:pivotY=”50%”
android:duration=”600″
android:repeatMode=”restart”
android:repeatCount=”infinite”
android:interpolator=”@android:anim/cycle_interpolator”/>

</set>
Move
In order to change position of object use <translate> tag. It uses fromXDelta, fromYDelta for X-direction and toXDelta, toYDelta attributes for Y-direction.

move.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set
xmlns:android=”http://schemas.android.com/apk/res/android”
android:interpolator=”@android:anim/linear_interpolator”
android:fillAfter=”true”>

<translate
android:fromXDelta=”0%p”
android:toXDelta=”75%p”
android:duration=”800″ />
</set>
Slide Up
Sliding animation uses <scale> tag only. Slide up can be achieved by setting android:fromYScale=”1.0″ and android:toYScale=”0.0″

slide_up.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true” >

<scale
android:duration=”500″
android:fromXScale=”1.0″
android:fromYScale=”1.0″
android:interpolator=”@android:anim/linear_interpolator”
android:toXScale=”1.0″
android:toYScale=”0.0″ />

</set>
Slide Down
Slide down is exactly opposite to slide down animation. Just interchange android:fromYScale and android:toYScale values.

slide_down.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true”>

<scale
android:duration=”500″
android:fromXScale=”1.0″
android:fromYScale=”0.0″
android:interpolator=”@android:anim/linear_interpolator”
android:toXScale=”1.0″
android:toYScale=”1.0″ />

</set>
Bounce
Bounce is just an animation effect where animation ends in bouncing fashion. For this set android:interpolator value to @android:anim/bounce_interpolator. This bounce can be used with any kind animation. Following slide down example uses bounce effect.

bounce.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true”
android:interpolator=”@android:anim/bounce_interpolator”>

<scale
android:duration=”500″
android:fromXScale=”1.0″
android:fromYScale=”0.0″
android:toXScale=”1.0″
android:toYScale=”1.0″ />

</set>
Sequential Animation
If you want to perform multiple animation in a sequential manner you have to use android:startOffset to give start delay time. The easy way to calculate this value is to add the duration and startOffset values of previous animation. Following is a sequential animation where set of move animations performs in sequential manner.

sequential.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true”
android:interpolator=”@android:anim/linear_interpolator” >

<!– Use startOffset to give delay between animations –>

<!– Move –>
<translate
android:duration=”800″
android:fillAfter=”true”
android:fromXDelta=”0%p”
android:startOffset=”300″
android:toXDelta=”75%p” />
<translate
android:duration=”800″
android:fillAfter=”true”
android:fromYDelta=”0%p”
android:startOffset=”1100″
android:toYDelta=”70%p” />
<translate
android:duration=”800″
android:fillAfter=”true”
android:fromXDelta=”0%p”
android:startOffset=”1900″
android:toXDelta=”-75%p” />
<translate
android:duration=”800″
android:fillAfter=”true”
android:fromYDelta=”0%p”
android:startOffset=”2700″
android:toYDelta=”-70%p” />

<!– Rotate 360 degrees –>
<rotate
android:duration=”1000″
android:fromDegrees=”0″
android:interpolator=”@android:anim/cycle_interpolator”
android:pivotX=”50%”
android:pivotY=”50%”
android:startOffset=”3800″
android:repeatCount=”infinite”
android:repeatMode=”restart”
android:toDegrees=”360″ />

</set>
Together Animation
Performing all animation together is just writing all animations one by one without using android:startOffset

together.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<set xmlns:android=”http://schemas.android.com/apk/res/android”
android:fillAfter=”true”
android:interpolator=”@android:anim/linear_interpolator” >

<scale
xmlns:android=”http://schemas.android.com/apk/res/android”
android:duration=”4000″
android:fromXScale=”1″
android:fromYScale=”1″
android:pivotX=”50%”
android:pivotY=”50%”
android:toXScale=”4″
android:toYScale=”4″ >
</scale>

<!– Rotate 180 degrees –>
<rotate
android:duration=”500″
android:fromDegrees=”0″
android:pivotX=”50%”
android:pivotY=”50%”
android:repeatCount=”infinite”
android:repeatMode=”restart”
android:toDegrees=”360″ />

</set>

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