[android help] Drawing on Canvas and refresginh (Sea Battle)

Drawing on Canvas and refresginh (Sea Battle)

I'm new to Android programming and now I'm trying to make a simple Sea Battle game for one person. Ships are places, player hits the field and see whether the shot hit or not. Basically, the field looks like this:

The code is:

public void onDraw(Canvas canvas) {

    if (getWidth() > getHeight()) { 
         rebro = getHeight(); 
    } else {
        rebro = getWidth();  // the smaller size of screen is "rebro"
    }
    rebro_piece = rebro / 10; // divide the screen by 10 (to get 10x10 field)

    Paint background = new Paint();
    background.setColor(getResources().getColor(R.color.game_background));
    canvas.drawRect(0, 0, rebro, rebro, background);  // draw background

    Paint divider = new Paint();
    divider.setColor(getResources().getColor(R.color.divider_black));

    // drawing divider lines
    for (int i=0; i<11; i++) {
        canvas.drawLine(0, i*rebro_piece, rebro, i*rebro_piece, divider);  // horizontal
        canvas.drawLine(i*rebro_piece, 0, i*rebro_piece, rebro, divider);  // vertical
    }

canvas.drawLine(rebro-1, 0, rebro-1, rebro, divider);
}

That's how I make the "field."

In another class I have a method that collects numbers x and y of a 10×10 array that represents where the ships are placed. For debugging, I need to draw them on my field. Ship coordinates are retrieved in a cycle.

So I wrote a drawShip(int x, int y) method.

On Stack Overflow I've founded a question about "Why I can't paint outside onDraw()?" and I've changed my method to this:

public void drawShip(int x, int y) {
myX = x; //global
myY = y; //global
needToPaintShip = true; //boolean
invalidate(); // refreshibg?
needToPaintShip = false;
}

Here needToPaintShip decides whether the redrawing of canvas is needed or not.

Also I've edited the onDraw(Canvas canvas) method:

if(needToPaintShip == true) {
        Paint ship = new Paint();
        ship.setColor(getResources().getColor(R.color.ship_color));
        Log.d(TAG, "onDraw(): rebro_piece = " + rebro_piece + " , myX = "+ myX + " , myY = " + myY); // I only get the last coordinates! 
        Rect r = new Rect(myX*(rebro_piece),myY*rebro_piece, myX*(rebro_piece+1), myY*(rebro_piece+1));
        canvas.drawRect(r, ship);
    }

but the result is awful:

Guys, I'm desperate. How can I fix this and make "ships" be drawn on the field?

.

stackoverflow.comm