android app demotouch homework

MainActivity.java



package com.example.demotouch;

import android.support.v7.app.ActionBarActivity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;

public class MainActivity extends ActionBarActivity {

private LinearLayout ll;
private myview mv;
private Button btnBlack;
private Button btnBlue;
private Button btnred;
private Button btnclear;
private SeekBar sb;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

ll=(LinearLayout) findViewById(R.id.LinearLayout1);

btnclear=new Button(this);
btnclear.setText("Clear");
ll.addView(btnclear);
btnclear.setOnClickListener(l);
sb = new SeekBar(this);
sb.setMax(50);
ll.addView(sb);
//black
btnBlack=new Button(this);
btnBlack.setText("black");
ll.addView(btnBlack);
//blue
btnBlue=new Button(this);
btnBlue.setText("blue");
ll.addView(btnBlue);
//red
btnred=new Button(this);
btnred.setText("red");
ll.addView(btnred);

mv=new myview(this);
ll.addView(mv);
btnBlack.setOnClickListener(l);
btnBlue.setOnClickListener(l);
btnred.setOnClickListener(l);



sb.setOnSeekBarChangeListener(sk);

}

private SeekBar.OnSeekBarChangeListener sk =new SeekBar.OnSeekBarChangeListener() {

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub

}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub

}

@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
// TODO Auto-generated method stub
mv.w=progress;
mv.invalidate();
}
};


private Button.OnClickListener l=new Button.OnClickListener(){

@Override
public void onClick(View v) {

// TODO Auto-generated method stub
if(((Button)v).getText().toString().equalsIgnoreCase("black")) mv.color=Color.BLACK;
else if(((Button)v).getText().toString().equalsIgnoreCase("blue")) mv.color=Color.BLUE;
else if(((Button)v).getText().toString().equalsIgnoreCase("red")) mv.color=Color.RED;
mv.invalidate();
}

};


@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}

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myview.java

package com.example.demotouch;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Path;

import android.graphics.PointF;

import android.view.MotionEvent;

import android.view.View;

public class myview extends View {

int color  =  Color.BLUE;

int w = 10; 

private Path  path = new Path();

private Paint paint = new Paint();

private PointF p;

public myview(Context context) {

super(context);

// TODO Auto-generated constructor stub

paint.setColor(color);

paint.setStyle(paint.getStyle().STROKE);

paint.setStrokeWidth(10);

paint.setAntiAlias(true);

}

@Override

public boolean onTouchEvent(MotionEvent event) {

PointF p=new PointF();

p.x=event.getX();

p.y=event.getY();

switch(event.getAction())

{

case MotionEvent.ACTION_DOWN:

path.moveTo(p.x, p.y);

return true;

case MotionEvent.ACTION_MOVE:

path.lineTo(p.x, p.y);

break;

case MotionEvent.ACTION_UP:

break;

default:

return false;

}

invalidate();

return true;

}

@Override

public void onDraw(Canvas canvas) {

paint.setColor(color);

paint.setStrokeWidth(w);

canvas.drawPath(path, paint);

super.onDraw(canvas);

}

}

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