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Android: Rotate image in imageview by an angle


Question

I am using the following code to rotate a image in ImageView by an angle. Is there any simpler and less complex method available.

ImageView iv = (ImageView)findViewById(imageviewid);
TextView tv = (TextView)findViewById(txtViewsid);
Matrix mat = new Matrix();
Bitmap bMap = BitmapFactory.decodeResource(getResources(),imageid);
mat.postRotate(Integer.parseInt(degree));===>angle to be rotated
Bitmap bMapRotate = Bitmap.createBitmap(bMap, 0, 0,bMap.getWidth(),bMap.getHeight(), mat, true);
iv.setImageBitmap(bMapRotate);
2016/07/03
1
155
7/3/2016 8:51:58 AM

Accepted Answer

Another simple way to rotate an ImageView:
UPDATE:
Required imports:

import android.graphics.Matrix;
import android.widget.ImageView;

Code: (Assuming imageView, angle, pivotX & pivotY are already defined)

Matrix matrix = new Matrix();
imageView.setScaleType(ImageView.ScaleType.MATRIX);   //required
matrix.postRotate((float) angle, pivotX, pivotY);
imageView.setImageMatrix(matrix);

This method does not require creating a new bitmap each time.

NOTE: To rotate an ImageView on ontouch at runtime you can set onTouchListener on ImageView & rotate it by adding last two lines(i.e. postRotate matrix & set it on imageView) in above code section in your touch listener ACTION_MOVE part.

2015/08/18
195
8/18/2015 10:56:06 AM


If you're supporting API 11 or higher, you can just use the following XML attribute:

android:rotation="90"

It might not display correctly in Android Studio xml preview, but it works as expected.

2015/04/03

There are two ways to do that:

1 Using Matrix to create a new bitmap:

imageView = (ImageView) findViewById(R.id.imageView);
Bitmap myImg = BitmapFactory.decodeResource(getResources(), R.drawable.image);

Matrix matrix = new Matrix();
matrix.postRotate(30);

Bitmap rotated = Bitmap.createBitmap(myImg, 0, 0, myImg.getWidth(), myImg.getHeight(),
        matrix, true);

imageView.setImageBitmap(rotated);

2 use RotateAnimation on the View you want to Rotate, and make sure the Animation set to fillAfter=true, duration=0, and fromDegrees=toDgrees

 <?xml version="1.0" encoding="utf-8"?>
<rotate
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:fromDegrees="45"
  android:toDegrees="45"
  android:pivotX="50%"
  android:pivotY="50%"
  android:duration="0"
  android:startOffset="0"
/>

and Inflate the Animation in code:

Animation rotation = AnimationUtils.loadAnimation(this, R.anim.rotation);
myView.startAnimation(rotation);
2012/01/25

I know this is insanely late, but it was helpful for me so it may help others.

As of API 11, you can set the absolute rotation of an ImageView programmatically by using the imageView.setRotation(angleInDegrees); method.

By absolute, I mean you can repeatedly call this function without having to keep track of the current rotation. Meaning, if I rotate by passing 15F to the setRotation() method, and then call setRotation() again with 30F, the image's rotation with be 30 degrees, not 45 degrees.

Note: This actually works for any subclass of the View object, not just ImageView.

2016/10/25

This is my implementation of RotatableImageView. Usage is very easy: just copy attrs.xml and RotatableImageView.java into your project and add RotatableImageView to your layout. Set desired rotation angle using example:angle parameter.

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:example="http://schemas.android.com/apk/res/com.example"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <com.example.views.RotatableImageView
        android:id="@+id/layout_example_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:scaleType="fitCenter"
        android:src="@drawable/ic_layout_arrow"
        example:angle="180" />
</FrameLayout>

If you have some problems with displaying image, try change code in RotatableImageView.onDraw() method or use draw() method instead.

2012/09/24

Can also be done this way:-

imageView.animate().rotation(180).start();

got from here.

2018/10/27

Source: https://stackoverflow.com/questions/8981845
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