Only change the code in onCreate() of AndroidViewUI.java
package com.exercise.AndroidViewUI;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
public class AndroidViewUI extends Activity {
public class MyView extends View {
private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
private float initX, initY, radius;
private boolean drawing = false;
public MyView(Context context) {
super(context);
// TODO Auto-generated constructor stub
init();
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
init();
}
public MyView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
init();
}
private void init(){
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
paint.setColor(Color.WHITE);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec),
MeasureSpec.getSize(heightMeasureSpec));
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
if(drawing){
canvas.drawCircle(initX, initY, radius, paint);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
int action = event.getAction();
if (action==MotionEvent.ACTION_MOVE){
float x = event.getX();
float y = event.getY();
radius = (float) Math.sqrt(Math.pow(x-initX, 2) + Math.pow(y-initY, 2));
}
else if (action==MotionEvent.ACTION_DOWN){
initX = event.getX();
initY = event.getY();
radius = 1;
drawing = true;
}
else if (action==MotionEvent.ACTION_UP){
drawing = false;
}
invalidate();
return true;
}
}
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.main);
LinearLayout mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
MyView myView1 = new MyView(this);
LayoutParams myView1Params = new LayoutParams(200, 200);
myView1.setLayoutParams(myView1Params);
myView1.setBackgroundColor(Color.GREEN);
MyView myView2 = new MyView(this);
LayoutParams myView2Params = new LayoutParams(300, 200);
myView2.setLayoutParams(myView2Params);
myView2.setBackgroundColor(Color.BLUE);
mainLayout.addView(myView1);
mainLayout.addView(myView2);
setContentView(mainLayout);
}
}
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