An implementation of ImageView for Android that restricts the image to a given aspect ratio, if possible. This is a more generalised way of doing SquareImageView, just set both the width and height ratios to 1 for a square image.

ratio_image_view_attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="RatioImageView">
        <attr name="width_ratio" format="float"/>
        <attr name="height_ratio" format="float"/>
    </declare-styleable>
</resources>

RatioImageView.java

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

public class RatioImageView extends ImageView {

    private static final float DEFAULT_WIDTH_RATIO = 1;
    private static final float DEFAULT_HEIGHT_RATIO = 1;

    private float widthRatio = DEFAULT_WIDTH_RATIO;
    private float heightRatio = DEFAULT_HEIGHT_RATIO;

    public RatioImageView(Context context) {
        super(context);
        init(context, null, 0);
    }

    public RatioImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    public RatioImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs, defStyle);
    }

    private void init(Context context, AttributeSet attrs, int defStyle) {
        if(attrs == null)
            return; // Nothing to do here

        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.RatioImageView, 0, 0);

        try {
            widthRatio = a.getFloat(R.styleable.RatioImageView_width_ratio, DEFAULT_WIDTH_RATIO);
            heightRatio = a.getFloat(R.styleable.RatioImageView_height_ratio, DEFAULT_HEIGHT_RATIO);
        } finally {
            a.recycle();
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);

        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);

        if(widthMode == MeasureSpec.EXACTLY && heightMode != MeasureSpec.EXACTLY) {
            // Use the width
            int width = widthSize;
            int height = (int)Math.round(widthSize / widthRatio * heightRatio);

            setMeasuredDimension(width, height);
        } else if(heightMode == MeasureSpec.EXACTLY && widthMode != MeasureSpec.EXACTLY) {
            // Use the height
            int width = (int)Math.round(heightSize / heightRatio * widthRatio);
            int height = heightSize;

            setMeasuredDimension(width, height);
        } else {
            //  ¯\(°_o)/¯
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }
}

sample_usage.xml

<!-- Fixes the image into a 4:3 ratio based on the width, also crops -->
<full.class.name.of.RatioImageView
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:src="@drawable/image"
  android:scaleType="centerCrop"
  app:width_ratio="4"
  app:height_ratio="3"/>