Question

I’m trying to make and android app with some dynamically drawn views. Currently, the only thing the views draw is a circle in the middle of the view.

The views are inside a grid view, but it doesn’t seem to be drawing them right.

This is what happens when I load the screen:

The orange block is the view in the grid view that has the focus.

However, if I use my finger (or mouse) to drag along the view, it gets painted correctly:

Why is this?

How can I make it draw the second image all the time.

Here is the code I’m using:

public class ChooseTablePanel extends GamePanel {
    TableAdapter adapter;

    public ChooseTablePanel(Context context, GamePanel nextPanel,
            GamePanel failurePanel) {
        super(context, nextPanel, failurePanel);
        initialize();
    }

    public ChooseTablePanel(Context context, AttributeSet attrs,
            GamePanel nextPanel, GamePanel failurePanel) {
        super(context, attrs, nextPanel, failurePanel);
        initialize();
    }

    private void initialize() {     
        adapter = new TableAdapter(getContext());
        adapter.setTables(new int[] {5,4,3,2,1,6});

        GridView gridView = new GridView(getContext());
        gridView.setAdapter(adapter);
        gridView.setNumColumns(adapter.getCount()/3);

        this.addView(gridView);
        this.invalidate();
    }


    class TableAdapter extends BaseAdapter {
        private Context context;
        private TableView[] tables;

        public TableAdapter(Context context) {
            this.context = context;
        }

        public void setTables(int[] tables) {
            this.tables = new TableView[tables.length];

            for(int i = 0; i < tables.length; i++){
                this.tables[i] = new TableView(tables[i], context);
            }
        }

        public int getCount() {
            return tables.length;
        }

        public Object getItem(int position) {
            return tables[position];
        }

        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            TableView tableView;
            if (convertView == null) {  // if it's not recycled, initialize some attributes
                tableView = new TableView(1, this.context);
                tableView.setLayoutParams(new GridView.LayoutParams(85, 85));
                tableView.setPadding(8, 8, 8, 8);
            } else {
                tableView = (TableView) convertView;
            }

            tableView.invalidate();
            return tableView;
        }
    }

    class TableView extends View {
        private int seats;

        public TableView(int Seats, Context context) {
            super(context);
            this.seats = Seats;

            if(seats < 1){
                throw new IllegalArgumentException("Number of seats must be greater than one.");
            }
        }

        public int getSeats() {
            return seats;
        }

        @Override
        protected void onDraw(Canvas canvas){
            int tableWidth = canvas.getWidth() / 2;
            ShapeDrawable tableShape = new ShapeDrawable(new OvalShape());          
            tableShape.setBounds(canvas.getWidth()/2 - tableWidth/2, canvas.getHeight()/2 - tableWidth/2, canvas.getWidth()/2 + tableWidth/2, canvas.getHeight()/2 + tableWidth/2 );

            tableShape.draw(canvas);
            canvas.drawText(seats + "", 0, 0, new Paint());
        }


    }

}

Answer 1

Instead of using canvas.getWidth() and canvas.getHeight() try using this.getWidth() and this.getHeight().