I want to make an ImageButton rotate when the device orientation changes. It should rotate for 90, 180, 270 and 360 angles and its relative layout should remain steady so only the buttons move. How can this be done? I've done some research but found nothing that could help me.
You can detect an orientation change by Overriding onConfigurationChanged() like this:
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
//call your rotate method here
}
Then once you detect the orientation change event, you can perform an animated rotation on a Button like this:
public void rotateView(View view) {
Button button = (Button) view.findViewById(R.id.some_button);
RotateAnimation rotateAnimation = new RotateAnimation(0, 360);
rotateAnimation.setDuration(2000);
button.startAnimation(rotateAnimation);
}
You can set the starting and ending angle in the constructor of RotateAnimation, then set the duration for how long the animation should take (in milliseconds). Then you simply call startAnimation() on the view you want to animate.
Related
So for example I use an object animator to change the alpha of a button to 0 and then I rotate the screen, then it's back to pre animated state because onCreate is called again. I was thinking I should implement something like an animation listener and at the end of the animation I should change the properties of the button, but I am not sure how to do that. For example if I have a constraint layout and I moved a button by 100 pixels up, what code should I have in the animation listener so that the change stays after the animation is over. I read something about setting the fill after tag to be true but I believe that is for view animations.
Thank You for the help.
For the application you've described, you could use a ValueAnimator and set an AnimatorUpdateListener on it to record the state after each animation frame.
To listen for orientation changes and persist the state of the animation, you should first include android:configChanges="orientation" within the <activity> tag of your Manifest. This will ensure that your activity is not recreated on orientation change and that onCreate() won't be called again. Whenever an orientation change occurs, onConfigurationChanged() will be called, so you should override it to persist the animation state.
So, in your onCreate() you could do something like:
ValueAnimator valueAnimator = ValueAnimator.ofObject(new IntEvaluator(),
initialPosition, finalPosition);
valueAnimator.setDuration(duration);
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator animation) {
// mCurrentPosition should be a member variable
mCurrentPosition = (int)animation.getAnimatedValue();
// Update the position of your button with currentPosition
}
}
valueAnimator.start();
and your onConfigurationChanged() should look like:
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
setContentView(R.layout.your_layout);
// Set the position of your button with mCurrentPosition
}
For more info, please refer to https://developer.android.com/reference/android/animation/ValueAnimator.html and https://developer.android.com/guide/topics/resources/runtime-changes.html.
I am trying to rotate an image by 360 degree using AccelerateDecelerateInterpolator. I have included the code to rotate the image in an onclickfunction of a button. When i press the button for the first time, the image rotates. However, when i press it the next time, nothing happens.
public void displaySpinResult_Spinner(View view) {
arrow.animate().rotation(360).setInterpolator(new AccelerateDecelerateInterpolator()).start();
}
This is probably because the rotation value is retained. When you specify rotation(360) for the second time, the View is already rotated by 360degrees, so nothing happens.
You can either try rotation(arrow.getRotation() + 360), or use the rotationBy() method instead.
I think this is the solution:
public void displaySpinResult_Spinner(View view) {
arrow.animate().rotation(360).setInterpolator(new AccelerateDecelerateInterpolator()).start();
arrow.animate().rotation(360).setInterpolator(new AccelerateDecelerateInterpolator()).reset();
}
I have a LinearLayout, I'm applying a translation animation to it. I'm filling the animation before and after. Visually it works fine. The animation ends by translating the view off screen. But if I click an x,y coordinate on screen that happens to be where the view was at some point during its animation, a button on the view has its click listener fire.
The only solution I've found is to add an animation listener, and when the animation ends, mark the buttons on the (now out of view) layout to visibility=gone, enabled=false. This seems bizarre - the view is no longer on screen, but it's still responding to click events. Is this a known thing, I'm probably not setting the animation up correctly?
Thanks
----- Update --------
I refactored my animation a little. Instead of using animation.setFillAfter(true), I set the layout's visibility to GONE when the animation is complete. Now it doesn't register clicks when off-screen. Still interested to know if this is a known thing, as it'd be easier to simply not have to add an animation listener etc.
Translate Animations on lower level API( below honey comb) changes where the button is drawn, but not where the button physically exists within the container. So, you are on your own to handle this situation. For more information about this you can refer to this link. One way is to actually change the location of the button in the layout(not by animation). Here is how you can achieve this:
params = (LayoutParams) mBtn.getLayoutParams();
TranslateAnimation animation = new TranslateAnimation(0, 0, 0, 400);
animation.setDuration(2000);
animation.setAnimationListener(mAnimationListener);
mBtn.startAnimation(animation);
....
....
private AnimationListener mAnimationListener = new AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {
}
#Override
public void onAnimationRepeat(Animation animation) {
}
#Override
public void onAnimationEnd(Animation animation) {
params.topMargin = params.topMargin + 400;
mButton.setLayoutParams(params);
}
};
Here by changing the layout params we are changing the physical position of the button.
In your case as view is going off the screen so you just need to change the visibility of the button(View.GONE) on animation end.
I want to rotate an imageview from 30 degrees on each click on a button.
On the first clic, i can set the animation properly but i can't succeed to update the imageview position after the animation. When i clicked again on the button, the animation start from the original position of the imageview and not from the final position after the first animation.
Here is my code :
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
turnImg = (ImageView) findViewById(R.id.imageViewturnImg );
Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.imgTurn);
// Getting width & height of the given image.
int w = bmp.getWidth();
int h = bmp.getHeight();
turnImg .setImageBitmap(bmp);
Button buttonok = (Button) findViewById(R.id.buttonok);
buttonok.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
turn();
}
});
}
public void turn()
{
float degrees = 30;
RotateAnimation anim = new RotateAnimation(0, degrees,Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,0.5f);
anim.setInterpolator(new LinearInterpolator());
anim.setDuration(300);
anim.setFillEnabled(true);
anim.setFillAfter(true);
anim.setAnimationListener(new AnimationListener() {
#Override
public void onAnimationEnd(Animation arg0) {
Matrix mat = turnImg.getImageMatrix();
mat.postRotate(30,turnImg.getWidth()/2, turnImg.getHeight()/2);
turnImg.setScaleType(ScaleType.MATRIX);
turnImg.setImageMatrix(mat);
}
#Override
public void onAnimationRepeat(Animation animation) {}
#Override
public void onAnimationStart(Animation animation) {}
});
turnImg.startAnimation(anim);
}
I think the problem came from the way i actualize the position in the onAnimationEnd().
ps : sorry for my bad english...
The problem is that your animation is not affecting the same object as your matrix rotation. That is, you are animating the rotation of the ImageView object, but then you are setting the rotation of the image that is within that ImageView object. So, for example, the first time you rotate it, the ImageView rotates from 0 to 30 degrees, and then remains at a rotation of 30 degrees due to the call to setFillAfter(true). Then the onAnimationEnd() handler runs, which rotates the internal image by 30 degrees. This effectively jumps the image to a rotation of 60 degrees, as seen by the user (30 for the View, 30 for the bitmap). Then the next time the animation runs, it rotates the view from 0 to 30 degrees, with the internal image still at its rotation of 30 degrees. This makes it look to the user like it's rotating from 30 to 60 degrees. Then you apply another rotation on the internal image when that animation finishes, ending up with the image rotated to 60 degrees and the view rotated (again) to 30 degrees, so the image is now visually rotated to 90 degrees.
And so on.
There are different ways to handle this problem, but one simple way is to avoid affecting the two different objects - just work with the ImageView. Instead of rotating from 0 to 30 each time, rotate from whatever the current rotation is to that value plus 30 degrees. You can remove the onAnimationEnd() handler, because you will no longer need to rotate the image inside the view.
The resulting code for turn() is much simpler:
public void turn()
{
RotateAnimation anim = new RotateAnimation(currentRotation, currentRotation + 30,
Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,0.5f);
currentRotation = (currentRotation + 30) % 360;
anim.setInterpolator(new LinearInterpolator());
anim.setDuration(1000);
anim.setFillEnabled(true);
anim.setFillAfter(true);
turnImg.startAnimation(anim);
}
This code assumes an instance variable of currentRotation, which is used to track the last degrees the view was rotated to.
Its a bit more involved if you allow the user to click mid-animation, but not too difficult.
By the way, this is much simpler in the animation system in 3.0; there is now a 'rotation' property on View, and you can run an animation on that property and it can track its own current value. But the approach above should work for older releases.
I have a button that I want to put on a 45 degree angle. For some reason I can't get this to work.
Can someone please provide the code to accomplish this?
API 11 added a setRotation() method to all views.
You could create an animation and apply it to your button view. For example:
// Locate view
ImageView diskView = (ImageView) findViewById(R.id.imageView3);
// Create an animation instance
Animation an = new RotateAnimation(0.0f, 360.0f, pivotX, pivotY);
// Set the animation's parameters
an.setDuration(10000); // duration in ms
an.setRepeatCount(0); // -1 = infinite repeated
an.setRepeatMode(Animation.REVERSE); // reverses each repeat
an.setFillAfter(true); // keep rotation after animation
// Aply animation to image view
diskView.setAnimation(an);
Extend the TextView class and override the onDraw() method. Make sure the parent view is large enough to handle the rotated button without clipping it.
#Override
protected void onDraw(Canvas canvas) {
canvas.save();
canvas.rotate(45,<appropriate x pivot value>,<appropriate y pivot value>);
super.onDraw(canvas);
canvas.restore();
}
I just used the simple line in my code and it works :
myCusstomView.setRotation(45);
Hope it works for you.
One line in XML
<View
android:rotation="45"
... />
Applying a rotation animation (without duration, thus no animation effect) is a simpler solution than either calling View.setRotation() or override View.onDraw method.
// substitude deltaDegrees for whatever you want
RotateAnimation rotate = new RotateAnimation(0f, deltaDegrees,
Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
// prevents View from restoring to original direction.
rotate.setFillAfter(true);
someButton.startAnimation(rotate);
Rotating view with rotate() will not affect your view's measured size. As result, rotated view be clipped or not fit into the parent layout. This library fixes it though:
https://github.com/rongi/rotate-layout
Joininig #Rudi's and #Pete's answers. I have created an RotateAnimation that keeps buttons functionality also after rotation.
setRotation() method preserves buttons functionality.
Code Sample:
Animation an = new RotateAnimation(0.0f, 180.0f, mainLayout.getWidth()/2, mainLayout.getHeight()/2);
an.setDuration(1000);
an.setRepeatCount(0);
an.setFillAfter(false); // DO NOT keep rotation after animation
an.setFillEnabled(true); // Make smooth ending of Animation
an.setAnimationListener(new AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {}
#Override
public void onAnimationRepeat(Animation animation) {}
#Override
public void onAnimationEnd(Animation animation) {
mainLayout.setRotation(180.0f); // Make instant rotation when Animation is finished
}
});
mainLayout.startAnimation(an);
mainLayout is a (LinearLayout) field
As mentioned before, the easiest way it to use rotation available since API 11:
android:rotation="90" // in XML layout
view.rotation = 90f // programatically
You can also change pivot of rotation, which is by default set to center of the view. This needs to be changed programatically:
// top left
view.pivotX = 0f
view.pivotY = 0f
// bottom right
view.pivotX = width.toFloat()
view.pivotY = height.toFloat()
...
In Activity's onCreate() or Fragment's onCreateView(...) width and height are equal to 0, because the view wasn't measured yet. You can access it simply by using doOnPreDraw extension from Android KTX, i.e.:
view.apply {
doOnPreDraw {
pivotX = width.toFloat()
pivotY = height.toFloat()
}
}
if you wish to make it dynamically with an animation:
view.animate()
.rotation(180)
.start();
THATS IT
#Ichorus's answer is correct for views, but if you want to draw rotated rectangles or text, you can do the following in your onDraw (or onDispatchDraw) callback for your view:
(note that theta is the angle from the x axis of the desired rotation, pivot is the Point that represents the point around which we want the rectangle to rotate, and horizontalRect is the rect's position "before" it was rotated)
canvas.save();
canvas.rotate(theta, pivot.x, pivot.y);
canvas.drawRect(horizontalRect, paint);
canvas.restore();
fun rotateArrow(view: View): Boolean {
return if (view.rotation == 0F) {
view.animate().setDuration(200).rotation(180F)
true
} else {
view.animate().setDuration(200).rotation(0F)
false
}
}
That's simple,
in Java
your_component.setRotation(15);
or
your_component.setRotation(295.18f);
in XML
<Button android:rotation="15" />