A example of custom widget view

MyWidgetView.java, our custom widget view.

package com.exercise.AndroidWidgetView;



import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.util.AttributeSet;

import android.view.View;



public class MyWidgetView extends View {

	

	final int MIN_WIDTH = 200;

	final int MIN_HEIGHT = 50;

	final int DEFAULT_COLOR = Color.WHITE;

	int _color;

	

	final int STROKE_WIDTH = 2;



	public MyWidgetView(Context context) {

		super(context);

		// TODO Auto-generated constructor stub

		init();

	}



	public MyWidgetView(Context context, AttributeSet attrs) {

		super(context, attrs);

		// TODO Auto-generated constructor stub

		init();

	}



	public MyWidgetView(Context context, AttributeSet attrs, int defStyle) {

		super(context, attrs, defStyle);

		// TODO Auto-generated constructor stub

		init();

	}

	

	private void init(){

		setMinimumWidth(MIN_WIDTH);

		setMinimumHeight(MIN_HEIGHT);

		_color = DEFAULT_COLOR;

	}



	@Override

	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

		// TODO Auto-generated method stub

		super.onMeasure(getSuggestedMinimumWidth(), getSuggestedMinimumHeight());

	}



	@Override

	protected void onDraw(Canvas canvas) {

		// TODO Auto-generated method stub

		

		Paint paint = new Paint();

		paint.setColor(_color);

		paint.setStrokeWidth(STROKE_WIDTH);

		canvas.drawRect(5, 5, getWidth()-5, getHeight()-5, paint);

	}

	

	public void setColor(int color){

		_color = color;

	}

	

}

main.xml, the layout with our custom widget view

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

   android:orientation="vertical"

   android:layout_width="fill_parent"

   android:layout_height="fill_parent"

   >

<TextView 

   android:layout_width="fill_parent"

   android:layout_height="wrap_content"

   android:text="@string/hello"

   />

<com.exercise.AndroidWidgetView.MyWidgetView

	android:id = "@+id/mywidget_01"

   android:layout_width="fill_parent"

   android:layout_height="wrap_content"

   android:layout_margin="5dp"

   />

<com.exercise.AndroidWidgetView.MyWidgetView

	android:id = "@+id/mywidget_02"

   android:layout_width="50dp"

   android:layout_height= "50dp"

   android:layout_margin="5dp"

   />

<com.exercise.AndroidWidgetView.MyWidgetView

	android:id = "@+id/mywidget_03"

   android:layout_width="50dp"

   android:layout_height= "50dp"

   android:layout_margin="5dp"

   />

</LinearLayout>

main code

package com.exercise.AndroidWidgetView;



import android.app.Activity;

import android.graphics.Color;

import android.os.Bundle;



public class AndroidWidgetViewActivity extends Activity {

	

	MyWidgetView myWidget_01, myWidget_02, myWidget_03;

	

   /** Called when the activity is first created. */

   @Override

   public void onCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.main);

      

       myWidget_01 = (MyWidgetView)findViewById(R.id.mywidget_01);

       myWidget_02 = (MyWidgetView)findViewById(R.id.mywidget_02);

       myWidget_03 = (MyWidgetView)findViewById(R.id.mywidget_03);

       myWidget_02.setColor(Color.RED);

       myWidget_03.setBackgroundColor(Color.GREEN);

       myWidget_03.setColor(Color.BLUE);

   }

}

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