Android fade in and fade out with ImageView
I'm having some troubles with a slideshow I'm building.
I've created 2 animations in xml for fade in and fade out:
fadein.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="2000"/>
</set>
fadeout.xml
<?xml version="1.0" encoding="UTF-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha android:fromAlpha="1.0" android:toAlpha="0.0"
android:interpolator="@android:anim/accelerate_interpolator"
android:duration="2000"/>
</set>
What Im'trying to do, is to change images from an ImageView using the fade effect, so the currently displayed image will fade out, and another one will fade in. Considering that I have an image already set, I can fadeout this Image without problem, with this:
Animation fadeInAnimation = AnimationUtils.loadAnimation(this, R.anim.your_fade_in_anim);
imageView.startAnimation(fadeoutAnim);
But then, I set the next image to be displayed:
imageView.setImageBitmap(secondImage);
It just shows up in the imageView, and when i set the animation it hides the image, the fade it in... Is there any way to fix that, I mean, when I do imageView.setImageBitmap(secondImage); command, the image do not shows up immediately, and only when the fade in animation is executed?
I wanted to achieve the same goal as you, so I wrote the following method which does exactly that if you pass it an ImageView and a list of references to image drawables.
ImageView demoImage = (ImageView) findViewById(R.id.DemoImage);
int imagesToShow[] = { R.drawable.image1, R.drawable.image2,R.drawable.image3 };
animate(demoImage, imagesToShow, 0,false);
private void animate(final ImageView imageView, final int images[], final int imageIndex, final boolean forever) {
//imageView <-- The View which displays the images
//images[] <-- Holds R references to the images to display
//imageIndex <-- index of the first image to show in images[]
//forever <-- If equals true then after the last image it starts all over again with the first image resulting in an infinite loop. You have been warned.
int fadeInDuration = 500; // Configure time values here
int timeBetween = 3000;
int fadeOutDuration = 1000;
imageView.setVisibility(View.INVISIBLE); //Visible or invisible by default - this will apply when the animation ends
imageView.setImageResource(images[imageIndex]);
Animation fadeIn = new AlphaAnimation(0, 1);
fadeIn.setInterpolator(new DecelerateInterpolator()); // add this
fadeIn.setDuration(fadeInDuration);
Animation fadeOut = new AlphaAnimation(1, 0);
fadeOut.setInterpolator(new AccelerateInterpolator()); // and this
fadeOut.setStartOffset(fadeInDuration + timeBetween);
fadeOut.setDuration(fadeOutDuration);
AnimationSet animation = new AnimationSet(false); // change to false
animation.addAnimation(fadeIn);
animation.addAnimation(fadeOut);
animation.setRepeatCount(1);
imageView.setAnimation(animation);
animation.setAnimationListener(new AnimationListener() {
public void onAnimationEnd(Animation animation) {
if (images.length - 1 > imageIndex) {
animate(imageView, images, imageIndex + 1,forever); //Calls itself until it gets to the end of the array
}
else {
if (forever){
animate(imageView, images, 0,forever); //Calls itself to start the animation all over again in a loop if forever = true
}
}
}
public void onAnimationRepeat(Animation animation) {
// TODO Auto-generated method stub
}
public void onAnimationStart(Animation animation) {
// TODO Auto-generated method stub
}
});
}
To implement this the way you have started, you'll need to add an AnimationListener so that you can detect the beginning and ending of an animation. When onAnimationEnd() for the fade out is called, you can set the visibility of your ImageView object to View.INVISIBLE, switch the images and start your fade in animation - you'll need another AnimationListener here too. When you receive onAnimationEnd() for your fade in animation, set the ImageView to be View.VISIBLE and that should give you the effect you're looking for.
I've implemented a similar effect before, but I used a ViewSwitcher with 2 ImageViews rather than a single ImageView. You can set the "in" and "out" animations for the ViewSwitcher with your fade in and fade out so it can manage the AnimationListener implementation. Then all you need to do is alternate between the 2 ImageViews.
Edit: To be a bit more useful, here is a quick example of how to use the ViewSwitcher. I have included the full source at https://github.com/aldryd/imageswitcher.
activity_main.xml
<ViewSwitcher
android:id="@+id/switcher"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:inAnimation="@anim/fade_in"
android:outAnimation="@anim/fade_out" >
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="fitCenter"
android:src="@drawable/sunset" />
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="fitCenter"
android:src="@drawable/clouds" />
</ViewSwitcher>
MainActivity.java
// Let the ViewSwitcher do the animation listening for you
((ViewSwitcher) findViewById(R.id.switcher)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ViewSwitcher switcher = (ViewSwitcher) v;
if (switcher.getDisplayedChild() == 0) {
switcher.showNext();
} else {
switcher.showPrevious();
}
}
});
Have you thought of using TransitionDrawable instead of custom animations? https://developer.android.com/reference/android/graphics/drawable/TransitionDrawable.html
One way to achieve what you are looking for is:
// create the transition layers
Drawable[] layers = new Drawable[2];
layers[0] = new BitmapDrawable(getResources(), firstBitmap);
layers[1] = new BitmapDrawable(getResources(), secondBitmap);
TransitionDrawable transitionDrawable = new TransitionDrawable(layers);
imageView.setImageDrawable(transitionDrawable);
transitionDrawable.startTransition(FADE_DURATION);
I used used fadeIn animation to replace new image for old one
ObjectAnimator.ofFloat(imageView, View.ALPHA, 0.2f, 1.0f).setDuration(1000).start();