An Android widget to fit an ImageView to the screen bounds of a device without affecting it's aspect ratio.

FittedImageView.java

package com.company.sample.widgets;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;

/** 
 * FittedImageView
 * @extends ImageView
 * 
 * Provides a display for an image in such as way that it is able
 * to stretch to fill the width of the screen without stretching the image
 * out of aspect ratio.
 * 
 * @author joshmcarthur
 *
 */
public class FittedImageView extends ImageView {
	
	/** 
	 * Constructor.
	 * 
	 * @param context (required) the context to pass to the superclass ImageView
	 */
	public FittedImageView(Context context) {
		super(context);
    }

	/**
	 * Constructor.
	 * 
	 * @param context (required) the context to pass to the superclass ImageView
	 * @param attrs (optional) the attributes to pass to the superclass ImageView
	 */
    public FittedImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /** 
     * Constructor.
     * 
     * @param context (required) the context to pass to the superclass ImageView
     * @param attrs (optional) the attributes to pass to the superclass ImageView
     * @param defStyle (optional) the style ID to pass to the superclass ImageView
     */
    public FittedImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }


    /**
     * Override of onMeasure to resize the drawable to retain it's aspect ratio.
     * 
     * @param widthMeasureSpec (required) the width measure to derive size from
     * @param heightMeasureSpec (required) the height measure required by superclass 
     * 		  method definition.
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = width * getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth();
        setMeasuredDimension(width, height);
    }
}

layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <com.company.sample.widgets.FittedImageView
        android:id="@+id/capturedImageView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:adjustViewBounds="true"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />

</RelativeLayout>