Program a graphing function using the Android SDK for eclipse?

Question

I'm new to the Android SDK, but am pretty well versed in Java. I need to create a graphing function for a class, but I'm not entirely sure how to do it without using swing and in XML. Any suggestions?

Answer 1

If you are talking about displaying a graph such as a bar or line graph I would suggest using a library to help you out. Have a look here:

https://stackoverflow.com/questions/424752/any-good-graphing-packages-for-android?lq=1

Answer 2

You don't have to use XML. Its just the default way eclipse wants you to create your UI. The best way to do what you want is to create a class that extends view and override the ondraw method. Then you call setContentView(yourclass);

Here is an example of some code that simply draws a line on the screen that should be enough to get you started.

The main Activity:

package com.example.myexample;

import android.os.Bundle;
import android.app.Activity;


public class MainActivity extends Activity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //Create class that extends view
    Example myexample = new Example(this);

    setContentView(myexample);
}

}

And the Example class would look like this:

package com.example.myexample;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;

public class Example extends View{

    //You will need to declare a variable of paint to draw
    Paint mypaint = new Paint();


    //constructor
    public Example(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
    }

    //This is the function where you draw to the screen
    @Override
    public void onDraw (Canvas canvas){


        canvas.drawLine(25, 25, 25, 50, mypaint);   
    }

}