How to swing bitmap drawable resource folder image to any specified given Angle-Degrees above canvas on button click.

In this tutorial we are simply rotating the bitmap image which is called from drawable folder and rotate that image to 45° angle. So here is the complete step by step tutorial for Rotate Bitmap image on Canvas in android programmatically.

Note : Please download sample image form below and put inside drawable-hdpi folder.

 

Below is the demo image download this image and copy into drawable-hdpi folder :

How to Rotate Bitmap image on Canvas in android programmatically.

Code for MainActivity.java file.

 package com.rotatebitmaponcanvas_android_examples.com;
import android.app.Activity;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {

 ImageView imageview;
 Button button;
 Bitmap bitmap1,bitmap2;
 Canvas canvas;
 Paint paint;
 Resources resources;
 Matrix matrix;
 int bitmap1Width, bitmap1Height, CanvasWidth,CanvasHeight;
 int degreesAngle = 45 ;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 imageview = (ImageView)findViewById(R.id.imageView1);
 button = (Button)findViewById(R.id.button1);
 
 resources = getResources();
 
 matrix = matrix = new Matrix();
 
 button.setOnClickListener(new View.OnClickListener() {
 
 @Override
 public void onClick(View v) {
 // TODO Auto-generated method stub
 
 CreateBitmap();
 
 bitmap2 = Bitmap.createBitmap(
 400,
 300,
 Bitmap.Config.RGB_565
 );
 
 CreateCanvas();
 
 GetWidthHeight();
 
 matrix.setRotate(
 degreesAngle,
 bitmap1Width,
 bitmap1Height
 );
 
 
 
 matrix.postTranslate(
 CanvasWidth - bitmap1Width,
 CanvasHeight - bitmap1Height
 );
 
 DrawCanvas();
 
 imageview.setImageBitmap(bitmap2);
 
 }
 });
 }
 
 public void CreateBitmap(){
 
 bitmap1 = BitmapFactory.decodeResource(
 resources,
 R.drawable.demo_image
 );
 
 }
 
 public void CreateCanvas(){
 
 canvas = new Canvas(bitmap2);
 
 canvas.drawColor(Color.CYAN);
 }
 
 public void GetWidthHeight(){
 
 bitmap1Width = bitmap1.getWidth() / 2 ;
 bitmap1Height = bitmap1.getHeight() / 2 ;
 
 CanvasWidth = canvas.getWidth() / 2 ;
 CanvasHeight = canvas.getHeight() / 2 ;
 
 }
 
 public void DrawCanvas(){
 
 canvas.drawBitmap(
 bitmap1,
 matrix,
 paint
 );
 
 }
}

Code for activity_main.xml layout file.

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:paddingBottom="@dimen/activity_vertical_margin"
 android:paddingLeft="@dimen/activity_horizontal_margin"
 android:paddingRight="@dimen/activity_horizontal_margin"
 android:paddingTop="@dimen/activity_vertical_margin"
 tools:context="com.rotatebitmaponcanvas_android_examples.com.MainActivity" >

 <ImageView
 android:id="@+id/imageView1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignParentTop="true"
 android:layout_centerHorizontal="true"
 />

 <Button
 android:id="@+id/button1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_centerHorizontal="true"
 android:layout_centerVertical="true"
 android:text="Click here to Rotate a Bitmap image on Canvas in android programmatically" />

</RelativeLayout>

Screenshot: