moonlight-android/app/src/main/java/com/limelight/ui/StreamView.java

package com.limelight.ui;

import android.annotation.TargetApi;
import android.content.Context;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.SurfaceView;

public class StreamView extends SurfaceView {
    private double desiredAspectRatio;
    private InputCallbacks inputCallbacks;

    public void setDesiredAspectRatio(double aspectRatio) {
        this.desiredAspectRatio = aspectRatio;
    }

    public void setInputCallbacks(InputCallbacks callbacks) {
        this.inputCallbacks = callbacks;
    }

    public StreamView(Context context) {
        super(context);
    }

    public StreamView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public StreamView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @TargetApi(21)
    public StreamView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // If no fixed aspect ratio has been provided, simply use the default onMeasure() behavior
        if (desiredAspectRatio == 0) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            return;
        }

        // Based on code from: https://www.buzzingandroid.com/2012/11/easy-measuring-of-custom-views-with-specific-aspect-ratio/
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);

        int measuredHeight, measuredWidth;
        if (widthSize > heightSize * desiredAspectRatio) {
            measuredHeight = heightSize;
            measuredWidth = (int)(measuredHeight * desiredAspectRatio);
        } else {
            measuredWidth = widthSize;
            measuredHeight = (int)(measuredWidth / desiredAspectRatio);
        }

        setMeasuredDimension(measuredWidth, measuredHeight);
    }

    @Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        // This callbacks allows us to override dumb IME behavior like when
        // Samsung's default keyboard consumes Shift+Space. We'll process
        // the input event directly if any modifier keys are down.
        if (inputCallbacks != null && event.getModifiers() != 0) {
            if (event.getAction() == KeyEvent.ACTION_DOWN) {
                if (inputCallbacks.handleKeyDown(event)) {
                    return true;
                }
            }
            else if (event.getAction() == KeyEvent.ACTION_UP) {
                if (inputCallbacks.handleKeyUp(event)) {
                    return true;
                }
            }
        }

        return super.onKeyPreIme(keyCode, event);
    }

    public interface InputCallbacks {
        boolean handleKeyUp(KeyEvent event);
        boolean handleKeyDown(KeyEvent event);
    }
}