92 lines
2.6 KiB
Java
92 lines
2.6 KiB
Java
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Draw or Delete lines from JPanel
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import java.awt.*;
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import java.awt.event.*;
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import java.awt.geom.Line2D;
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import javax.swing.*;
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public class LineUnder extends JFrame
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{
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LinePanel linePanel = new LinePanel();
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LineUnder()
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{
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setDefaultCloseOperation(EXIT_ON_CLOSE);
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initContentPane();
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pack();
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setLocationRelativeTo(null);
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setVisible(true);
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}
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private void initContentPane()
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{
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linePanel.line.setLine(0d, 0d, 300d, 300d);
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getContentPane().add(linePanel);
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}
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class LinePanel extends JPanel
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{
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Point lineStart = new Point(0, 0);
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Point lineEnd = new Point(0, 0);
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Line2D line = new Line2D.Double(lineStart, lineEnd);
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//width of line
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private Stroke stroke = new BasicStroke(2.0f);
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private LineListener lis = null;
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LinePanel()
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{
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super();
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addMouseListener(lis = new LineListener(this, line));
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}
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//draw and delete line
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public void paintComponent(Graphics g)
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{
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super.paintComponent(g);
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Graphics2D g2 = (Graphics2D) g;
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g2.setStroke(stroke);
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if (lis.deleteLine)
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{
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g2.setColor(getBackground());
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lis.deleteLine = false;
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}
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else
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g2.setColor(Color.RED);
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//draw shape of line
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g2.draw(line);
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}
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//define panel's size
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public Dimension getPreferredSize()
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{
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return new Dimension(400, 350);
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}
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}
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class LineListener extends MouseAdapter
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{
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private Line2D line = null;
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private JComponent parent = null;
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boolean deleteLine = false;
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LineListener(JComponent parent, Line2D line)
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{
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this.parent = parent;
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this.line = line;
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}
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public void mouseClicked(MouseEvent e)
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{
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Point p = e.getPoint();
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//this does it!
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if (line.ptSegDist(p) == 0.0)
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{
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System.out.println("Hit!");
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deleteLine = true;
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}
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else
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System.out.println("Point: " + p + "\nDistance: " + line.ptSegDist(p));
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parent.repaint();
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}
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}
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public static void main(String[] args)
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{
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new LineUnder();
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}
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}
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