In my case, I want to write a TextView with an animation in its left side.
ImageView + TextView could work but it’s not frugal enough.
TextView with drawableLeft would be the best option.
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<TextView
… …
android:drawablePadding=”10dip”
android:drawableLeft=”@drawable/loadingicon” />
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But above implementation just show a icon in the left of TextView, not an animation.
How to show an animation instead of a icon?
Assume you have 4 pictures which would be an animation if display them one after one. Then define animation xml in res/anim folder in your project.
loading_animation.xml:
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<animation-list xmlns:android=”http://schemas.android.com/apk/res/android”
android:oneshot=”false” >
<item
android:drawable=”@drawable/loading_1″
android:duration=”500″>
</item>
<item
android:drawable=”@drawable/loading_2″
android:duration=”500″>
</item>
<item
android:drawable=”@drawable/loading_3″
android:duration=”500″>
</item>
</animation-list>
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“android:oneshot” determines whether or not play the animation just once.
“android:duration” determines the duration of pictures switching.
Then in layout xml, use above animation like this:
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<TextView
… …
android:drawablePadding=”10dip”
android:drawableLeft=”@anim/loading_animation” />
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Bingo? no, no, no, the animation can not switching yet.
You need to do more.
In java/Activity code, you must get the animation drawable and start it.
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Drawable[] draws = locateAreaTextView.getCompoundDrawables();
if (draws != null && draws.length > 0 && draws[0] instanceof AnimationDrawable) {
loadingAnimation = (AnimationDrawable) draws[0];
loadingAnimation.start();
}
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In above, we get index 0 of the drawable array since drawableLeft is in 0 position of the array.
Now, the animation works. But there is one more trap.
If you put above codes in onCreate() of Activity, draws will be a [null, null, null, null] array.
You must put it in onResumse() of Activity.