TermApp/app/src/main/java/com/xypower/mpapp/v2/AutoFitGLView.java

package com.xypower.mpapp.v2;

import android.content.Context;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class AutoFitGLView extends GLSurfaceView implements View.OnTouchListener {

    private int mRatioWidth = 0;
    private int mRatioHeight = 0;

    public AutoFitGLView(Context context) {
        this(context, null);
    }

    public AutoFitGLView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setOnTouchListener(this);
    }

    private TouchListener touchListener;

    /**
     * Sets the aspect ratio for this view. The size of the view will be measured based on the ratio
     * calculated from the parameters. Note that the actual sizes of parameters don't matter, that
     * is, calling setAspectRatio(2, 3) and setAspectRatio(4, 6) make the same result.
     *
     * @param width  Relative horizontal size
     * @param height Relative vertical size
     */
    public void setAspectRatio(int width, int height) {
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException("Size cannot be negative.");
        }
        mRatioWidth = width;
        mRatioHeight = height;
        post(() -> requestLayout());
    }


    @Override
    public boolean onTouch(View v, MotionEvent event) {
        final int actionMasked = event.getActionMasked();
        if (actionMasked != MotionEvent.ACTION_DOWN) {
            return false;
        }

        if (touchListener != null) {
            touchListener.onTouch(event, v.getWidth(), v.getHeight());
        }
        return false;
    }

    public interface TouchListener {
        void onTouch(MotionEvent event, int width, int height);
    }

    public void setTouchListener(TouchListener touchListener) {
        this.touchListener = touchListener;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        if (0 == mRatioWidth || 0 == mRatioHeight) {
            setMeasuredDimension(width, height);
        } else {
            if (width < height * mRatioWidth / mRatioHeight) {
                setMeasuredDimension(width, width * mRatioHeight / mRatioWidth);
            } else {
                setMeasuredDimension(height * mRatioWidth / mRatioHeight, height);
            }
        }
    }
}