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bitmap – Android: Rotate image in imageview by an angle

Posted by: admin March 10, 2020 Leave a comment

Questions:

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);
How to&Answers:

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.

Answer:

mImageView.setRotation(angle) with API>=11

Answer:

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.

Answer:

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);

Answer:

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.

Answer:

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.

Answer:

Also, if you want to rotate an ImageView by 180 degrees vertically or horizontally, you can use scaleY or scaleX properties and set them to -1f. Here is a Kotlin example:

imageView.scaleY = -1f
imageView.scaleX = -1f

1f value is used to return an ImageView to its normal state:

imageView.scaleY = 1f
imageView.scaleX = 1f

Answer:

I have a solution to this.
Actually it is a solution to a problem that arises after rotation(Rectangular image doesn’t fit ImagView)
but it covers your problem too..
Although this Solution has Animation for better or for worse

    int h,w;
    Boolean safe=true;

Getting the parameters of imageView is not possible at initialisation of activity
To do so please refer to this solution
OR set the dimensions at onClick of a Button Like this

    rotateButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(imageView.getRotation()/90%2==0){
                h=imageView.getHeight();
                w=imageView.getWidth();

            }
        .
        .//Insert the code Snippet below here 
       }

And the code to be run when we want to rotate ImageView

if(safe)     
imageView.animate().rotationBy(90).scaleX(imageView.getRotation()/90%2==0?(w*1.0f/h):1).scaleY(imageView.getRotation()/90%2==0?(w*1.0f/h):1).setDuration(2000).setInterpolator(new LinearInterpolator()).setListener(new Animator.AnimatorListener() {
                @Override
                public void onAnimationStart(Animator animation) {
                      safe=false;
                }

                @Override
                public void onAnimationEnd(Animator animation) {
                      safe=true;

                }

                @Override
                public void onAnimationCancel(Animator animation) {

                }

                @Override
                public void onAnimationRepeat(Animator animation) {

                }
            }).start();
        }
    });

This solution is sufficient for the Problem above.Although it will shrink the imageView even if it is not necessary(when height is smaller than Width).If it bothers you,you can add another ternary operator inside scaleX/scaleY.

Answer:

I think the best method 🙂

int angle = 0;
imageView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            angle = angle + 90;
            imageView.setRotation(angle);
        }
    });

Answer:

Can also be done this way:-

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

got from here.

Answer:

Rotate an image in android with delay:

imgSplash.animate().rotationBy(360f).setDuration(3000).setInterpolator(new LinearInterpolator()).start();

Answer:

try this on a custom view

public class DrawView extends View {


    public DrawView(Context context,AttributeSet attributeSet){
        super(context, attributeSet);
    }

    @Override
    public void onDraw(Canvas canvas) {
        /*Canvas c=new Canvas(BitmapFactory.decodeResource(getResources(), R.drawable.new_minute1)    );

        c.rotate(45);*/

        canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.new_minute1), 0, 0, null);
        canvas.rotate(45);
    }
}

Answer:

here’s a nice solution for putting a rotated drawable for an imageView:

Drawable getRotateDrawable(final Bitmap b, final float angle) {
    final BitmapDrawable drawable = new BitmapDrawable(getResources(), b) {
        @Override
        public void draw(final Canvas canvas) {
            canvas.save();
            canvas.rotate(angle, b.getWidth() / 2, b.getHeight() / 2);
            super.draw(canvas);
            canvas.restore();
        }
    };
    return drawable;
}

usage:

Bitmap b=...
float angle=...
final Drawable rotatedDrawable = getRotateDrawable(b,angle);
root.setImageDrawable(rotatedDrawable);

another alternative:

private Drawable getRotateDrawable(final Drawable d, final float angle) {
    final Drawable[] arD = { d };
    return new LayerDrawable(arD) {
        @Override
        public void draw(final Canvas canvas) {
            canvas.save();
            canvas.rotate(angle, d.getBounds().width() / 2, d.getBounds().height() / 2);
            super.draw(canvas);
            canvas.restore();
        }
    };
}

also, if you wish to rotate the bitmap, but afraid of OOM, you can use an NDK solution i’ve made here

Answer:

If you only want to rotate the view visually you can use:

iv.setRotation(float)

Answer:

Sadly, I don’t think there is. The Matrix class is responsible for all image manipulations, whether it’s rotating, shrinking/growing, skewing, etc.

http://developer.android.com/reference/android/graphics/Matrix.html

My apologies, but I can’t think of an alternative. Maybe someone else might be able to, but the times I’ve had to manipulate an image I’ve used a Matrix.

Best of luck!

Answer:

Another possible solution is to create your own custom Image view(say RotateableImageView extends ImageView )…and override the onDraw() to rotate either the canvas/bitmaps before redering on to the canvas.Don’t forget to restore the canvas back.

But if you are going to rotate only a single instance of image view,your solution should be good enough.

Answer:

without matrix and animated:

{
    img_view = (ImageView) findViewById(R.id.imageView);
    rotate = new RotateAnimation(0 ,300);
    rotate.setDuration(500);
    img_view.startAnimation(rotate);
}

Answer:

just write this in your onactivityResult

            Bitmap yourSelectedImage= BitmapFactory.decodeFile(filePath);
            Matrix mat = new Matrix();
            mat.postRotate((270)); //degree how much you rotate i rotate 270
            Bitmap bMapRotate=Bitmap.createBitmap(yourSelectedImage, 0,0,yourSelectedImage.getWidth(),yourSelectedImage.getHeight(), mat, true);
            image.setImageBitmap(bMapRotate);
            Drawable d=new BitmapDrawable(yourSelectedImage);
            image.setBackground(d); 

Answer:

Try this code 100% working;

On rotate button click write this code:

        @Override
        public void onClick(View view) {
            if(bitmap==null){
                Toast.makeText(getApplicationContext(), "Image photo is not yet set", Toast.LENGTH_LONG).show();
            }
            else {
                Matrix matrix = new Matrix();
                ivImageProduct.setScaleType(ImageView.ScaleType.MATRIX);   //required
                matrix.postRotate(90,ivImageProduct.getDrawable().getBounds().width()/2,ivImageProduct.getDrawable().getBounds().height()/2);
                Bitmap bmp=Bitmap.createBitmap(bitmap, 0, 0,bitmap.getWidth(), bitmap.getHeight(), matrix, true);
                bitmap.recycle();
                bitmap=bmp;
                ivImageProduct.setImageBitmap(bitmap);
            }
        }

Answer:

Rather than convert image to bitmap and then rotate it try to rotate direct image view like below code.

ImageView myImageView = (ImageView)findViewById(R.id.my_imageview);

AnimationSet animSet = new AnimationSet(true);
animSet.setInterpolator(new DecelerateInterpolator());
animSet.setFillAfter(true);
animSet.setFillEnabled(true);

final RotateAnimation animRotate = new RotateAnimation(0.0f, -90.0f,
    RotateAnimation.RELATIVE_TO_SELF, 0.5f, 
    RotateAnimation.RELATIVE_TO_SELF, 0.5f);

animRotate.setDuration(1500);
animRotate.setFillAfter(true);
animSet.addAnimation(animRotate);

myImageView.startAnimation(animSet);

Answer:

Follow the below answer for continuous rotation of an imageview

int i=0;

If rotate button clicked

imageView.setRotation(i+90);
i=i+90;

Answer:

if u want to rotate an image by 180 degrees then put these two value in imageview tag:-

android:scaleX="-1"
android:scaleY="-1"

Explanation:- scaleX = 1 and scaleY = 1 repesent it’s normal state but if we put -1 on scaleX/scaleY property then it will be rotated by 180 degrees

Answer:

Matrix matrix = new Matrix();
imageView.setScaleType(ImageView.ScaleType.MATRIX); //required
matrix.postRotate((float) 20, imageView.getDrawable().getBounds().width()/2, imageView.getDrawable().getBounds().height()/2);
imageView.setImageMatrix(matrix);

how to use?

public class MainActivity extends AppCompatActivity {
   int view = R.layout.activity_main;
   TextView textChanger;
   ImageView imageView;
   @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(view);
      textChanger = findViewById(R.id.textChanger);
      imageView=findViewById(R.id.imageView);
      textChanger.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            roateImage(imageView);
         }
      });
   }
   private void roateImage(ImageView imageView) {
      Matrix matrix = new Matrix();
      imageView.setScaleType(ImageView.ScaleType.MATRIX); //required
      matrix.postRotate((float) 20, imageView.getDrawable().getBounds().width()/2,    imageView.getDrawable().getBounds().height()/2);
      imageView.setImageMatrix(matrix);
   }
}

Answer:

For Kotlin,

mImageView.rotation = 90f //angle in float

This will rotate the imageView rather than rotating the image

Also, though its a method in View class. So you can pretty much rotate any view using it.