Develop Reference

Draw Circle in Preview in CameraX describing TapToFocus

I am trying to implement TapToFocus feature using the CameraX Api .I have implemented it successfully but not able to know how to draw a circle on the preview describing the Location pressed by the user .
I want to have a circle in the preview like the image has

The are many ways to draw and animate a focus ring around a tap position on PreviewView, some fancier than others. One simple way of doing so is to:
Create a Drawable of the ring, something like this for instance.
Layout an ImageView containing the Drawable on top of PreviewView, and initially hide it.
<FrameLayout ...>
<androidx.camera.view.PreviewView
... />
<ImageView
android:id="#+id/focusRing"
android:src="#drawable/focus_ring"
android:visibility="invisible"
... />
</FrameLayout>
Set up a touch listener on PreviewView. On a touch event, use the event's coordinates to show the ring around it.
private void animateFocusRing(float x, float y) {
ImageView focusRing = findViewById(R.id.focusRing);
// Move the focus ring so that its center is at the tap location (x, y)
float width = focusRing.getWidth();
float height = focusRing.getHeight();
focusRing.setX(x - width / 2);
focusRing.setY(y - height / 2);
// Show focus ring
focusRing.setVisibility(View.VISIBLE);
focusRing.setAlpha(1F);
// Animate the focus ring to disappear
focusRing.animate()
.setStartDelay(500)
.setDuration(300)
.alpha(0F)
.setListener(new Animator.AnimatorListener() {
#Override
public void onAnimationEnd(Animator animator) {
focusRing.setVisibility(View.INVISIBLE);
}
// The rest of AnimatorListener's methods.
});
}

MPAndroidChart PieChart Animations

I set 2 values on piechart. I want to animate it. But I want to change animation way. All animations do right to left angle. I want to do left to right angle. How can I change animation direction?
Edit 1: Library: MPAndroidChart
Edit 2: Althought it is not very relevant, I add following code here.
mButton_AvailableLimit.setOnClickListener( new View.OnClickListener() {
#Override
public void onClick(View v) {
// fromAngle and toAngle is a float variables that less then 360
mPieChart.spin( 500,fromAngle,360 - toAngle, Easing.EasingOption.EaseInOutQuad );
}
} );

It's very simple in fact,
//for rotating anti-clockwise
mPieChart.spin( 500,0,-360f, Easing.EasingOption.EaseInOutQuad);

pieChart.animateX(1000); this is work fine

How to rotate ImageView by clockwise

I have sliding up panel and in the titlebar of that panel I have ImageView as in the picture. How to rotate to 180* by clockwise that ImageView when user slide panel up and anti-clockwise when slide down.
For sliding that panel I have method:
#Override
public void onPanelSlide(View panel, float slideOffset) {
Log.i(TAG, "onPanelSlide, offset " + slideOffset);
//Animation here
}
Thanks for any help!

If you want to rotate a view without animation:
view.setRotation(float) sets the degrees that the view is
rotated around the pivot point. Increasing values result in clockwise
rotation.
view.setRotationX(float) sets the degrees that the view is
rotated around the horizontal axis through the pivot point.
Increasing values result in clockwise rotation from the viewpoint of
looking down the x axis. When rotating large views, it is recommended to adjust the camera distance accordingly.
view.setRotationY(float) sets the degrees that the view is
rotated around the vertical axis through the pivot point. Increasing
values result in counter-clockwise rotation from the viewpoint of
looking down the y axis. When rotating large views, it is recommended to adjust the camera distance accordingly.
If you want to use animation:
https://github.com/daimajia/AndroidViewAnimations (recommended)
https://github.com/castorflex/FlipImageView
https://github.com/florent37/ViewAnimator
https://github.com/alexvasilkov/GestureViews
https://gist.github.com/simon-heinen/9795036
https://gist.github.com/methodin/5678214
https://www.google.com/ :D

I didn't want to mark this as an answer but I can't leave comments yet, I was able to get Apurva's solution working correctly but I had to use this instead of getApplicationContext(), I had to use this because of where I was setting the animation from, the code in my application where I am attaching the animation looks like this...
ImageView billysArm = (ImageView) findViewById(R.id.imageView6);
Animation rotate = AnimationUtils.loadAnimation(this, R.anim.rotate);
billysArm.startAnimation(rotate);
hope this helps

You should try this out, setting an animation for your e.g. ImageView
#Override
public void onPanelSlide(View panel, float slideOffset) {
Log.i(TAG, "onPanelSlide, offset " + slideOffset);
// Locate view
ImageView iv= (ImageView) findViewById(R.id.iv);
// Create an animation instance
Animation an = new RotateAnimation(0.0f, 180.0f, 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
iv.setAnimation(an);
}

ScaleAnimation in custom View getting clipped

I have a custom View where I implement onDraw and it successfully draws the background as well as a small overlay image at the top right. I animate that overlay image (AnimationSet with a ScaleAnimation and Rotate Animation) manually by doing:
final AnimationSet animationSet = new AnimationSet(false);
animationSet.addAnimation(scaleAnimation);
animationSet.addAnimation(rotationAnimation);
animationSet.setFillAfter(true);
post(new Runnable() {
#Override
public void run () {
animationSet.start();
new Handler().post(getAnimationRunnable(animationSet));
}
private Runnable getAnimationRunnable (final AnimationSet animationSet) {
return new Runnable() {
#Override
public void run () {
final Transformation outTransformation = new Transformation();
if (animationSet.getTransformation(System.currentTimeMillis(), outTransformation)) {
// store matrix for applying in onDraw
mMatrix = outTransformation.getMatrix();
// THIS INVALIDATE DOESN'T WORK
parent.invalidate(new Rect(getParentInvalidateRect()));
post(getAnimationRunnable(animationSet));
}
}
};
}
});
If I invalidate the custom View like this ...
// THIS INVALIDATE DOES WORK
invalidate(getOverlayClientRect());
then the animation happens and all is great, except that the animated image now gets clipped - because it's being scaled up, beyond the top and right bounds.
But when I pass a Rect to parent.invalidate() that intersects the custom View's top right corner area, it does not trigger an onDraw for the custom View.
So ...
will this approach work?
if so, is there any other factor than the Rect passed to parent.invalidate() that determines whether it will call the custom Views onDraw method?

After a lot of searching, the answer was obvious. I just had to set the clipChildren property of the parent to false. Didn't need to invalidate the parent, just the custom View.
That worked fine on a 4.0.3 tablet. However, on a Galaxy Nexus (4.2.2), not only did it render outside of the bounds during the animation, it actually only cleared the background of the Rect passed to invalidate. So, when the animation was done some remnants of the image were still visible outside the Rect. The solution there was to pass a Rect large enough to cover the largest of the drawn bitmaps during animation.

Rotating a view in Android

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" />