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>