Question

How can i draw a set of rectangles on a canvas Using DrawRect method? I am trying to generate a dynamic indoor map by just passing the coordinates of the blocks.

I want to know.. how to use the drawRect method inside a for loop..!

I made two classes by the help of Luke Taylor.(Thank you..! 🙂 )

One is coordinate and the other one is main class called DrawMapActivity..
Now i need to know how to fill up the coordinates Array???

package itgsm.drawmap;

import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Bundle;

public class DrawMapActivity extends Activity {
/** Called when the activity is first created. */

static Coordinates[] coordinates = new Coordinates[10]; // 10 is just an example

//    public void onCreate(Bundle savedInstanceState) {
//        super.onCreate(savedInstanceState);
//        setContentView(R.layout.main);
//     
//    }

public void onDraw(Canvas canvas) {

    Paint myPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    myPaint.setStrokeWidth(8/*1 /getResources().getDisplayMetrics().density*/);
    myPaint.setColor(0xffff0000);   //color.RED

    for(int i = 0; i < coordinates.length; i++) {
        canvas.drawRect(new Rect(coordinates[i].getX(), coordinates[i].getY(),   coordinates[i].getX() + 10,coordinates[i].getY() + 10), myPaint); // 10 is the dimension of your block
        }


}
}

Answer 1

You could create a method that takes an array of objects that contain coordinates:

This would be the class called “Coordinate” that contains the coordinates.

public class Coordinate {

int x;
int y;

public void setX(int x) {
this.x = x;
}

public void setY(int y) {
this.y = y;
}

public int getX() {
return this.x;
}

public int getY() {
return this.y;

}

}

You can create an array of these objects containing the individual coordinates:

Coordinates[] coordinates = new Coordinates[10]; // 10 is just an example

In your rendering method, you can now render the individual blocks.

public void drawMap(Coordinates[] coordinates) {
for(int i = 0; i < coordinates.length; i++) {
canvas.drawRect(new Rect(coordinates[i].getX, coordinates[i].getY, coordinates[i].getX + 10,coordinates[i].getY + 10), paint); // 10 is the dimension of your block
}
}

I hope this helps.

Update:

This is how you could fill one index of the array with an Coordinate object:

coordinates[1] = new Coordinate();
coordinates[1].setX(0);
coordinates[1].setY(0);