Question

I’m developing a simple game like BSD robots. This game contains a rather large board (over 40 cells) and it doesn’t look nice even at 10 inch tablet. My decision was to scroll (move) surface view and not to scale each figure which size is like finger spot.
I’ve read tons articles about surface view but I cannot understand how to move it?

My activity code:

package ru.onyanov.robots;
public class MainActivity extends Activity {

public BoardView board;

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

    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    board = new BoardView(this);
    setContentView(board);
}
}

Class Board:

package ru.onyanov.robots;
public class BoardView extends SurfaceView {
private GameThread mThread;
private boolean running = false;
public final int sizeX = 50;
public final int sizeY = 35;
public final int cellSize = 64;

private int robotCount = 4;

public ArrayList<Cell> cells = new ArrayList<Cell>();
private ArrayList<Robot> robots = new ArrayList<Robot>();
private Hero hero;
public Bitmap imageCell;
public Bitmap imageRobot;
public Bitmap imageHero;

public BoardView(Context context) {
    super(context);     

    makeGraphic();
    constructCells();
    constructRobots();      
    hero = new Hero(this, 3, 2, imageHero);

    mThread = new GameThread(this);

    getHolder().addCallback(new SurfaceHolder.Callback() {
        public void surfaceDestroyed(SurfaceHolder holder) {
            boolean retry = true;
            mThread.setRunning(false);
            while (retry) {
                try {
                    mThread.join();
                    retry = false;
                } catch (InterruptedException e) {
                }
            }
        }

        public void surfaceCreated(SurfaceHolder holder) {
            mThread.setRunning(true);
            mThread.start();
        }

        public void surfaceChanged(SurfaceHolder holder, int format,
                int width, int height) {


        }
    });
}

private void makeGraphic() {
    Bitmap cellImageSource = BitmapFactory.decodeResource(getResources(),
            R.drawable.cell);
    imageCell = Bitmap.createScaledBitmap(cellImageSource, cellSize,
            cellSize, false);
    imageRobot = BitmapFactory.decodeResource(getResources(),
            R.drawable.robot);
    imageHero = BitmapFactory.decodeResource(getResources(),
            R.drawable.hero);

}

private void constructRobots() {
    Robot robot;
    Random rand = new Random();
    for (int r = 0; r < robotCount; r++) {
        int x = rand.nextInt(sizeX);
        int y = rand.nextInt(sizeY);
        robot = new Robot(this, x, y, imageRobot);
        robots.add(robot);
    }
    return;
}

private void constructCells() {
    Cell cell;
    for (int y = 0; y < sizeY; y++) {
        for (int x = 0; x < sizeX; x++) {
            cell = new Cell(this, x, y, imageCell);
            cells.add(cell);
        }
    }
    return;
}

protected void onDraw(Canvas canvas) {
    canvas.drawColor(Color.WHITE);
    Cell cell;
    for (int c = 0; c < cells.size(); c++) {
        cell = cells.get(c);
        cell.onDraw(canvas);
    }
    Robot robot;
    for (int r = 0; r < robots.size(); r++) {
        robot = robots.get(r);
        robot.onDraw(canvas);
    }
    hero.onDraw(canvas);
}

public boolean onTouchEvent(MotionEvent e) {
    int shotX = (int) e.getX();
    int shotY = (int) e.getY();

    if (e.getAction() == MotionEvent.ACTION_MOVE){
        //TODO move board
        showToast("move Board");
    } else if (e.getAction() == MotionEvent.ACTION_UP) {
        showToast("touchPoint: " + shotX + ", "+shotY);
        hero.moveByDirection(shotX, shotY);
        this.scrollTo(shotX, shotY);
    }
    return true;
}

public void showToast(String mes) {
    Toast toast = Toast.makeText(getContext(), mes, Toast.LENGTH_LONG);
    toast.show();
}

public class GameThread extends Thread {
    private BoardView view;

    public GameThread(BoardView view) {
        this.view = view;

    }

    public void setRunning(boolean run) {
        running = run;
    }

    public void run() {
        while (running) {
            Canvas canvas = null;
            try {
                canvas = view.getHolder().lockCanvas();
                synchronized (view.getHolder()) {
                    onDraw(canvas);                     
                }
                canvas.scale(300, 300);
            } catch (Exception e) {
            } finally {
                if (canvas != null) {
                    view.getHolder().unlockCanvasAndPost(canvas);
                }
            }
        }
    }
}
}

Some magic digits here are temporary. Now I just want to move BoardView;

Answer 1

The issue was to add x and y fields to SurfaceView, change them at onTouchEvent and draw all the elements in canvas with x- and y-offset. It’s strange that I didn’t recieved any answers…