How to create Image Reflection in Android?

By | January 8, 2012

Reflection in Android

This simple Activity creates a reflection of the provided image.

[java]
package com.coderzheaven.imagereflection;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Shader.TileMode;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;

public class ImageReflection extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_image_reflection);

Bitmap originalImage = BitmapFactory.decodeResource(getResources(),
R.drawable.coderzheaven_logo);

// Create an Image view and add our bitmap with reflection to it
ImageView imageView = new ImageView(this);
imageView.setImageBitmap(getRefelection(originalImage));

// Add the image to a linear layout and display it
LinearLayout linLayout = new LinearLayout(this);
linLayout.addView(imageView, new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));

linLayout.setBackgroundColor(Color.BLACK);
// set LinearLayout as ContentView
setContentView(linLayout);
}

public Bitmap getRefelection(Bitmap image) {
// The gap we want between the reflection and the original image
final int reflectionGap = 4;

// Get you bit map from drawable folder
Bitmap originalImage = image;

int width = originalImage.getWidth();
int height = originalImage.getHeight();

// This will not scale but will flip on the Y axis
Matrix matrix = new Matrix();
matrix.preScale(1, -1);

// Create a Bitmap with the flip matix applied to it.
// We only want the bottom half of the image
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
height / 2, width, height / 2, matrix, false);

// Create a new bitmap with same width but taller to fit reflection
Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
(height + height / 2), Config.ARGB_8888);

// Create a new Canvas with the bitmap that’s big enough for
// the image plus gap plus reflection
Canvas canvas = new Canvas(bitmapWithReflection);
// Draw in the original image
canvas.drawBitmap(originalImage, 0, 0, null);
//Draw the reflection Image
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

// Create a shader that is a linear gradient that covers the reflection
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0,
originalImage.getHeight(), 0, bitmapWithReflection.getHeight()
+ reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
// Set the paint to use this shader (linear gradient)
paint.setShader(shader);
// Set the Transfer mode to be porter duff and destination in
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
// Draw a rectangle using the paint with our linear gradient
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
+ reflectionGap, paint);
return bitmapWithReflection;
}

}

[/java]

Download the complete source code for above example from here.

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