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POJava 6: how to drag/move a line?
 

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  1. POJava 6: how to drag/move a line?
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    <p>I have this piece of code, which is supposed to move some pixels on release of mousebutton:</p> <pre><code>if (selected != -1) { Point to = e.getPoint(); int dx = start.x - to.x; int dy = start.y - to.y; for (Point p: store.get(selected)) { int px = (int) p.getX(); int py = (int) p.getY(); p.move(px - dx, py - dy); } validate(); </code></pre> <p>Use of debugger shows that Point p's indeed get a new value, but visuals don't get updated. Please help me out. </p> <p>Below is the whole code of my program. </p> <pre><code>public class Pisi extends JFrame implements MouseMotionListener, MouseListener { ArrayList&lt;ArrayList&lt;Point&gt;&gt; store = new ArrayList&lt;ArrayList&lt;Point&gt;&gt;(); ArrayList&lt;Point&gt; pts = new ArrayList&lt;Point&gt;(); Point start; static int xsize = 450; static int ysize = 300; int listNumber = 0; int selected = -1; public static void main(String[] args) { Pisi d = new Pisi(); d.setSize(xsize, ysize); d.setLocationRelativeTo(null); d.addMouseMotionListener(d); d.addMouseListener(d); d.setResizable(false); d.setVisible(true); } @Override public void update(Graphics g) { paint(g); } @Override public void paint(Graphics g) { Point last = null; for (Point p : pts) { if (last == null) { last = p; continue; } g.drawLine(last.x, last.y, p.x, p.y); last = p; } } @Override public void mouseDragged(MouseEvent e) { if (e.getButton() == MouseEvent.BUTTON1) { pts.add(e.getPoint()); repaint(); } } @Override public void mouseMoved(MouseEvent e) { //To change body of implemented methods use File | Settings | File Templates. } @Override public void mouseClicked(MouseEvent e) { //To change body of implemented methods use File | Settings | File Templates. } @Override public void mousePressed(MouseEvent e) { Point point = e.getPoint(); start = null; selected = -1; for (ArrayList&lt;Point&gt; points: store) { for (Point p : points) { double dist = point.distanceSq(p); if (dist &lt; 10) { selected = store.indexOf(points); } } } if (selected != -1) { start = e.getPoint(); } System.out.println(selected); } @Override public void mouseReleased(MouseEvent e) { if (selected != -1) { Point to = e.getPoint(); int dx = start.x - to.x; int dy = start.y - to.y; for (Point p: store.get(selected)) { int px = (int) p.getX(); int py = (int) p.getY(); p.move(px - dx, py - dy); } validate(); } else if (e.getButton() == MouseEvent.BUTTON1 &amp;&amp; pts.size() != 0) { store.add(new ArrayList&lt;Point&gt;(listNumber)); for (int i = 0; i &lt; pts.size(); i++) { store.get(listNumber).add(pts.get(i)); } listNumber++; } pts.clear(); } @Override public void mouseEntered(MouseEvent e) { //To change body of implemented methods use File | Settings | File Templates. } @Override public void mouseExited(MouseEvent mouseEvent) { //To change body of implemented methods use File | Settings | File Templates. } } </code></pre>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USPriidu Kull
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
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      1. PTAnswer
    2. PO
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      1. PTAnswer
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      1. POJava 6: how to drag/move a line?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYou should not be drawing directly on a JFrame in the first place. Have you gone through any Swing graphics tutorials yet? If not, I recommend that you do so.
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      1. POJava 6: how to drag/move a line?
      1. USHovercraft Full Of Eels
 

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