android - How to rotate a Bitmap on Canvas center

MainActivity.java

package com.cfsuman.androidtutorials;

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.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    private Resources mResources;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the Resources
        mResources = getResources();

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(view -> {
            // Get the source bitmap to draw on canvas
            Bitmap srcBitmap = BitmapFactory.decodeResource(
                    mResources,
                    R.drawable.rose_small
            );

            // Initialize a new Bitmap
            Bitmap bitmap = Bitmap.createBitmap(
                    1400, // Width
                    1000, // Height
                    Bitmap.Config.ARGB_8888 // Config
            );

            // Initialize a new Canvas instance
            Canvas canvas = new Canvas(bitmap);

            // Draw a solid color on the canvas as background
            canvas.drawColor(Color.LTGRAY);

            // Initialize a new Paint instance to draw on canvas
            Paint paint = new Paint();
            paint.setAntiAlias(true);
            paint.setDither(true);
            paint.setFilterBitmap(true);

            // Initialize a new Matrix instance
            Matrix matrix = new Matrix();

            // Set rotation on matrix
            matrix.setRotate(
                    45, // degrees
                    (float) srcBitmap.getWidth() / 2, // px
                    (float)srcBitmap.getHeight() / 2 // py
            );

            // Draw the bitmap at the center position of the canvas
            // both vertically and horizontally
            matrix.postTranslate(
                    (float) canvas.getWidth() / 2
                            - (float) srcBitmap.getWidth() / 2, // dx
                    (float) canvas.getHeight() / 2
                            - (float) srcBitmap.getHeight() / 2 // dy
            );


            // Finally, draw the bitmap on canvas as a rotated bitmap
            canvas.drawBitmap(
                    srcBitmap, // Bitmap
                    matrix, // Matrix
                    paint // Paint
            );

            // Display the newly created bitmap on app interface
            imageView.setImageBitmap(bitmap);
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - How to rotate a Canvas

MainActivity.java

package com.cfsuman.androidtutorials;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(view -> {
            // Initialize a new Bitmap
            Bitmap bitmap = Bitmap.createBitmap(
                    1200, // Width
                    600, // Height
                    Bitmap.Config.ARGB_8888 // Config
            );

            // Initialize a new Canvas instance
            Canvas canvas = new Canvas(bitmap);

            // Draw a solid color on the canvas as background
            canvas.drawColor(Color.LTGRAY);

            // Initialize a new Paint instance to draw on canvas
            Paint paint = new Paint();
            paint.setStyle(Paint.Style.FILL);
            paint.setColor(Color.parseColor("#676767"));
            paint.setAntiAlias(true);

            // Set an offset value in pixels to draw rectangle on canvas
            int offset = 200;

            // Save the canvas state
            canvas.saveLayer(
                    0, // left
                    0, // top
                    canvas.getWidth(),
                    canvas.getHeight(),
                    null // paint
            );

            // Rotate the canvas
            canvas.rotate(
                    25, // degrees
                    (float) canvas.getWidth() / 2, // px, center x
                    (float) canvas.getHeight() / 2 // py, center y
            );

            // Draw the rounded corners rectangle object on the canvas
            // The rectangle will be drawn as a 25 degrees rotated rectangle
            canvas.drawRect(
                    offset, // left
                    offset, // top
                    canvas.getWidth() - offset, // right
                    canvas.getHeight() - offset, // bottom
                    paint // Paint
            );

            // Finally, restore the canvas state
            canvas.restore();

            // Display the newly created bitmap on app interface
            imageView.setImageBitmap(bitmap);
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - How to draw Rounded Rectangle on Canvas

MainActivity.java

package com.cfsuman.androidtutorials;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Bundle;
import android.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(view -> {
            // Initialize a new Bitmap
            Bitmap bitmap = Bitmap.createBitmap(
                    1200, // Width
                    600, // Height
                    Bitmap.Config.ARGB_8888 // Config
            );

            // Initialize a new Canvas instance
            Canvas canvas = new Canvas(bitmap);

            // Draw a solid color on the canvas as background
            canvas.drawColor(Color.LTGRAY);

            // Initialize a new Paint instance to
            // draw the rounded rectangle
            Paint paint = new Paint();
            paint.setStyle(Paint.Style.FILL);
            paint.setColor(Color.parseColor("#676767"));
            paint.setAntiAlias(true);

            // Set an offset value in pixels to draw
            // rounded rectangle on canvas
            int offset = 75;

            // Initialize a new RectF instance
            RectF rectF = new RectF(
                    offset, // left
                    offset, // top
                    canvas.getWidth() - offset, // right
                    canvas.getHeight() - offset // bottom
            );

            // Define the corners radius of rounded rectangle
            int cornersRadius = 50;

            // Finally, draw the rounded corners
            // rectangle object on the canvas
            canvas.drawRoundRect(
                    rectF, // rect
                    cornersRadius, // rx
                    cornersRadius, // ry
                    paint // Paint
            );

            // Display the newly created bitmap on app interface
            imageView.setImageBitmap(bitmap);
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw Rounded Rectangle"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - How to draw a Bitmap on a Canvas

MainActivity.java

package com.cfsuman.androidtutorials;

import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.os.Bundle;
import android.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    private Resources mResources;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the Resources
        mResources = getResources();

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(view -> {
            // Bitmap to draw on the canvas
            Bitmap bitmap = BitmapFactory.decodeResource(
                    mResources,
                    R.drawable.flower
            );

            // Define an offset value between canvas and bitmap
            int offset = 100;

            // Initialize a new Bitmap to hold the source bitmap
            Bitmap dstBitmap = Bitmap.createBitmap(
                    bitmap.getWidth() + offset * 2, // Width
                    bitmap.getHeight() + offset * 2, // Height
                    Bitmap.Config.ARGB_8888 // Config
            );

            // Initialize a new Canvas instance
            Canvas canvas = new Canvas(dstBitmap);

            // Draw a solid color on the canvas as background
            canvas.drawColor(Color.LTGRAY);

            //Finally, Draw the source bitmap on the canvas
            canvas.drawBitmap(
                    bitmap, // Bitmap
                    offset, // Left
                    offset, // Top
                    null // Paint
            );

            // Display the newly created bitmap on app interface
            imageView.setImageBitmap(dstBitmap);
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw Bitmap"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - How to draw a Line on Canvas

MainActivity.java

package com.cfsuman.androidtutorials;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(view -> {
            // Initialize a new Bitmap object
            Bitmap bitmap = Bitmap.createBitmap(
                    1200, // Width
                    600, // Height
                    Bitmap.Config.ARGB_8888 // Config
            );

            // Initialize a new Canvas instance
            Canvas canvas = new Canvas(bitmap);

            // Draw a solid color on the canvas as background
            canvas.drawColor(Color.LTGRAY);

            // Initialize a new Paint instance to draw the line
            Paint paint = new Paint();
            // Line color
            paint.setColor(Color.parseColor("#676767"));
            paint.setStyle(Paint.Style.STROKE);
            // Line width in pixels
            paint.setStrokeWidth(12);
            paint.setAntiAlias(true);

            // Set a pixels value to offset the line from canvas edge
            int offset = 50;

            // Draw a line on canvas at the center position
            canvas.drawLine(
                    offset, // startX
                    (float) canvas.getHeight() / 2, // startY
                    canvas.getWidth() - offset, // stopX
                    (float) canvas.getHeight() / 2, // stopY
                    paint // Paint
            );

            // Display the newly created bitmap on app interface
            imageView.setImageBitmap(bitmap);
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw Line"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - How to draw a Rectangle on a Canvas

MainActivity.java

package com.cfsuman.androidtutorials;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Bundle;
import android.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(view -> {
            // Initialize a new Bitmap object
            Bitmap bitmap = Bitmap.createBitmap(
                    1200, // Width
                    600, // Height
                    Bitmap.Config.ARGB_8888 // Config
            );

            // Initialize a new Canvas instance
            Canvas canvas = new Canvas(bitmap);

            // Draw a solid color to the canvas background
            canvas.drawColor(Color.LTGRAY);

            // Initialize a new Paint instance to draw the Rectangle
            Paint paint = new Paint();
            paint.setStyle(Paint.Style.FILL);
            paint.setColor(Color.parseColor("#676767"));
            paint.setAntiAlias(true);

            // Set a pixels value to padding around the rectangle
            int padding = 50;

            // Initialize a new Rect object
            Rect rectangle = new Rect(
                    padding, // Left
                    padding, // Top
                    canvas.getWidth() - padding, // Right
                    canvas.getHeight() - padding // Bottom
            );

            // Finally, draw the rectangle on the canvas
            canvas.drawRect(rectangle,paint);

            // Display the newly created bitmap on app interface
            imageView.setImageBitmap(bitmap);
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw Rectangle"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - How to draw a circle on a Canvas

MainActivity.java

package com.cfsuman.androidtutorials;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the widgets reference from XML layout
        Button button = findViewById(R.id.button);
        ImageView imageView = findViewById(R.id.imageView);


        // Set a click listener for Button widget
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // Initialize a new Bitmap object
                Bitmap bitmap = Bitmap.createBitmap(
                        1200, // Width
                        600, // Height
                        Bitmap.Config.ARGB_8888 // Config
                );

                // Initialize a new Canvas instance
                Canvas canvas = new Canvas(bitmap);

                // Draw a solid color to the canvas background
                canvas.drawColor(Color.LTGRAY);

                // Initialize a new Paint instance to draw the Circle
                Paint paint = new Paint();
                paint.setStyle(Paint.Style.FILL);
                paint.setColor(Color.RED);
                paint.setAntiAlias(true);

                // Calculate the available radius of canvas
                int radius = Math.min(
                        canvas.getWidth(),canvas.getHeight()/2);

                // Set a pixels value to padding around the circle
                int padding = 5;

                // Finally, draw the circle on the canvas
                canvas.drawCircle(
                        (float)canvas.getWidth() / 2, // cx
                        (float)canvas.getHeight() / 2, // cy
                        radius - padding, // Radius
                        paint // Paint
                );

                // Display the newly created bitmap on app interface
                imageView.setImageBitmap(bitmap);
            }
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw Circle"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

android - Draw border and shadow around a bitmap

activity_main.xml

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFF"
    android:padding="24dp"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Draw Border"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/iv"
        android:layout_width="0dp"
        android:layout_height="250dp"
        android:layout_marginTop="24dp"
        android:scaleType="fitCenter"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.cfsuman.androidtutorials;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Bundle;
import android.app.Activity;
import android.widget.Button;
import android.widget.ImageView;


public class MainActivity extends Activity {
        private ImageView mImageView;
        private Context mContext;
        private Resources mResources;
        private Bitmap mBitmap;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_main);

                // Get the application context
                mContext = getApplicationContext();

                // Get the Resources
                mResources = getResources();

                // Get the widgets reference from XML layout
                Button btn = findViewById(R.id.button);
                mImageView = findViewById(R.id.iv);

                // Get the bitmap resource id
                final int bitmapResourceID =R.drawable.flower;

                // Set an image to ImageView
                mImageView.setImageBitmap(
                        BitmapFactory.decodeResource(
                                mResources, bitmapResourceID
                        )
                );

                btn.setOnClickListener(v -> {
                        // Get the bitmap from drawable resources
                        mBitmap = BitmapFactory.decodeResource(
                                mResources, bitmapResourceID
                        );

                        // Add a border around the bitmap
                        mBitmap = addBorderToBitmap(
                                mBitmap, 50,
                                Color.parseColor("#F0F8FF")
                        );

                        // Add a border around the bitmap as shadow
                        mBitmap = addBorderToBitmap(
                                mBitmap, 10,
                                Color.LTGRAY
                        );

                        // Set the ImageView image as drawable object
                        mImageView.setImageBitmap(mBitmap);
                });
        }


        // Custom method to add a border around bitmap
        protected Bitmap addBorderToBitmap(
                Bitmap srcBitmap, int borderWidth, int borderColor){

                // Initialize a new Bitmap to make it bordered bitmap
                Bitmap dstBitmap = Bitmap.createBitmap(
                        srcBitmap.getWidth() + borderWidth*2, // Width
                        srcBitmap.getHeight() + borderWidth*2, // Height
                        Bitmap.Config.ARGB_8888 // Config
                );

                // Initialize a new Canvas instance
                Canvas canvas = new Canvas(dstBitmap);

                // Initialize a new Paint instance to draw border
                Paint paint = new Paint();
                paint.setColor(borderColor);
                paint.setStyle(Paint.Style.STROKE);
                paint.setStrokeWidth(borderWidth);
                paint.setAntiAlias(true);

                Rect rect = new Rect(
                        borderWidth / 2,
                        borderWidth / 2,
                        canvas.getWidth() - borderWidth / 2,
                        canvas.getHeight() - borderWidth / 2
                );

                // Draw a rectangle as a border/shadow on canvas
                canvas.drawRect(rect,paint);

                // Draw source bitmap to canvas
                canvas.drawBitmap(
                        srcBitmap, borderWidth, borderWidth, null
                );

                srcBitmap.recycle();

                // Return the bordered bitmap
                return dstBitmap;
        }
}

android - How to create rounded corners ImageView

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="24dp"
    tools:context=".MainActivity"
    android:background="#F8F8FF">

    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Rounded It"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/iv"
        android:layout_width="match_parent"
        android:layout_height="250dp"
        android:layout_marginTop="24dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btn" />

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.cfsuman.androidtutorials;

import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import androidx.core.graphics.drawable.RoundedBitmapDrawable;
import androidx.core.graphics.drawable.RoundedBitmapDrawableFactory;


public class MainActivity extends Activity {
    private Context mContext;
    private Resources mResources;
    private Button mBTN;
    private ImageView mImageView;
    private Bitmap mBitmap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get the application context
        mContext = getApplicationContext();

        // Get the Resources
        mResources = getResources();

        // Get the widgets reference from XML layout
        mImageView = (ImageView) findViewById(R.id.iv);
        mBTN = (Button) findViewById(R.id.btn);

        // Get the bitmap from drawable resources
        mBitmap = BitmapFactory.decodeResource(
                mResources,
                R.drawable.flower
        );

        // Display the bitmap in ImageView
        mImageView.setImageBitmap(mBitmap);

        // Set a click listener for Button widget
        mBTN.setOnClickListener(view -> {
            // Define the ImageView corners radius
            float cornerRadius = 80.0f;

            // Initialize a new RoundedBitmapDrawable
            RoundedBitmapDrawable roundedBitmapDrawable
                    = RoundedBitmapDrawableFactory.create(
                    mResources,
                    mBitmap
            );

            // Set the RoundedBitmapDrawable corners radius
            roundedBitmapDrawable.setCornerRadius(cornerRadius);

            roundedBitmapDrawable.setAntiAlias(true);

            // Set the ImageView image as drawable object
            mImageView.setImageDrawable(roundedBitmapDrawable);
        });
    }
}