DrawingCanvas.java

//   Copyright 2011 Palantir Technologies
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.
package com.palantir.ptoss.cinch.example.demo;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;

import javax.swing.JComponent;

import com.palantir.ptoss.cinch.core.Bindings;
import com.palantir.ptoss.cinch.core.CallOnUpdate;
import com.palantir.ptoss.cinch.example.demo.DrawingCanvasModel.Mode;

public class DrawingCanvas extends JComponent {
    private static final long serialVersionUID = 1L;

    private final DrawingCanvasModel model;
    private final Bindings bindings = new Bindings();

    public DrawingCanvas(DrawingCanvasModel model) {
        this.model = model;
        initializeListeners();
        bindings.bind(this);
    }

    private void initializeListeners() {
        addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                processPoint(e);
            }
        });

        addMouseMotionListener(new MouseMotionAdapter() {
            @Override
            public void mouseDragged(MouseEvent e) {
                if (model.isAllowDrag()) {
                    processPoint(e);
                }
            }
        });
    }

    private void processPoint(MouseEvent e) {
        if (model.getMode() == Mode.POINT) {
            model.addPoint(e.getPoint());
        } else if (model.getMode() == Mode.LINE) {
            if (model.getCursor() != null) {
                model.addLine(new Line2D.Double(
                        model.getCursor().getX(), model.getCursor().getY(), e.getX(), e.getY()));
            }
            model.setCursor(e.getPoint());
        }
    }

    @CallOnUpdate(model = "model")
    @Override
    public void repaint() {
        super.repaint();
    }

    @Override
    protected void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D)g;
        g2.setColor(Color.WHITE);
        g2.fillRect(0, 0, getWidth(), getHeight());
        g2.setColor(Color.BLACK);
        for (Line2D line : model.getLines()) {
            g2.draw(line);
        }
        for (Point2D point : model.getPoints()) {
            g2.fillOval((int)point.getX(), (int)point.getY(), 5, 5);
        }
    }
}