Re: Drawing line on ImageIcon on panel after getting data

From:
 bH <bherbst65@hotmail.com>
Newsgroups:
comp.lang.java.help
Date:
Thu, 01 Nov 2007 18:05:38 -0700
Message-ID:
<1193965538.489542.51940@o80g2000hse.googlegroups.com>
On Oct 25, 11:13 pm, "Andrew Thompson" <u32984@uwe> wrote:

bH wrote:

..

public class IconMapShoScale extends JPanel{


This example might have been an SSCCE except for:
a) line wrap, which had to be fixed before it compiled
b) lack of images locally.

For the first, you might try <http://www.physci.org/twc.jnlp>
This little tool shows the width of the source/text pasted
in the text area. I recommned limiting it to '62 chars' for
usenet posts.

For the second, try obtaining images that are small (in bytes),
but large enough (in width/height) to show the problem,
directly off the net. If you have a site of your own, upload
some examples to use, otherwise the code might get them
off another site.

Here is one image search..
<http://images.google.com.au/images?q=+filetype:jpg&as_st=y&svnum=10&h...

That search locates images that are 'small' in width/height.

As to the technical side of the problem, I suspect it is
non-optimal to create an ImageIcon. I would tend to use
a JPanel, override paintComponent and draw the Image
directly (Graphics.drawImage()). Once the points are
obtained, it is a simple matter to Graphics.drawLine()
(obviously, draw the lines *after* the image itself is drawn).

--
Andrew Thompsonhttp://www.athompson.info/andrew/

Message posted viahttp://www.javakb.com


Hi Andrew,

Thanks for the text width checker.
Taking your suggestions and making revisions using your suggestions,
This is supplied below.
bH

import javax.swing.*;
import java.awt.*;
import javax.swing.border.BevelBorder;
import java.awt.event.*;
import java.net.*;

/* Notes for use....
 * Map scale enter number to be used; i.e. 600
 * Click points requried
 * [0] Click point Map Location of City 1
 * [1] Click point Map Location of City 2
 * [3] Click on the point Scale Chart at the 0 Minimum Value
 * [4] Click on the point Scale Chart at the Maximum Value
 */

public class IconMapShoScaleImgs extends JFrame{
  int deltaAddrX = 0;
  int deltaAddrY = 0;
  int points = 4;
  int dataPointX[]= new int[points];
  int dataPointY[]= new int[points];
  int distanceResult = 0;
  double distanceCalc = 0;
  double deltaScaleX = 0;
  int scale = 0;
  Point clickPoint = null;
  int ptCounter = 0;
  JPanel infoPanel = new JPanel();
  JLabel scaleLbl = new JLabel("Show Scale Larger NUMBER Used");
  JLabel distLbl = new JLabel("After 4 Clicks The mi/km Between Points
Are");
  JTextField scaleFld;
  JTextField mileFld;

// Constructor
  public IconMapShoScaleImgs() {
    super("Distances Calculated by Click Points on Map");
    this.setLayout(new BorderLayout());
    Image img = null ;
    try
    {
      img = java.awt.Toolkit.getDefaultToolkit().
        getDefaultToolkit().createImage(new
        URL("http://www.lib.utexas.edu/maps/cia07/
australia_sm_2007.gif" ));
      // utexas.edu: good site for maps with other scale charts
    } catch (Exception e)
    {
      e.printStackTrace( System.out ) ;
    }
    JLabel label = new JLabel(new ImageIcon(img) ) ;
    getContentPane().setSize(400,400);
    getContentPane().add( label ) ;
    BevelBorder loweredBevelBorder = (BevelBorder)BorderFactory.
      createLoweredBevelBorder();
    this.addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent event){
        clickPoint = event.getPoint();
        dataPointX[ptCounter] = clickPoint.x;
        dataPointY[ptCounter] = clickPoint.y;
        repaint();
        ptCounter++;

        if (ptCounter > 3){
          //taking it in steps first between two cities.
          deltaAddrX = dataPointX[1] - dataPointX[0];
          deltaAddrY = dataPointY[1] - dataPointY[0];
          distanceCalc = Math.pow(((deltaAddrX * deltaAddrX) +
                                   (deltaAddrY * deltaAddrY)), 0.5);

          //From the scale chart is horizontal .. Y is not needed
          double deltaScaleX = Math.abs(dataPointX[3] -
dataPointX[2]);

          scale = (int)(Double.parseDouble(scaleFld.getText()));
          distanceCalc = distanceCalc/deltaScaleX * scale;
          distanceResult = (int)distanceCalc;

          mileFld.setText(String.valueOf(distanceResult));
          // making possible other measurements from the same map
          deltaScaleX = 0;
          distanceCalc = 0;
          ptCounter = 0;
        }

      }
    }
    );
// infoPanel re: map scale, resultant of clicks measure.
    this.add(infoPanel, BorderLayout.SOUTH);
    infoPanel.add(scaleLbl);
    scaleFld = new JTextField(6);
    infoPanel.add(scaleFld);
    infoPanel.add(distLbl);
    mileFld = new JTextField(6);
    infoPanel.add(mileFld);

    pack() ;
    setLocationRelativeTo(null) ;
    setVisible(true);
  }

  public void paint(Graphics g){
    super.paint(g);
    if (ptCounter > 1){
      g.setColor(Color.red);
 
g.drawLine(dataPointX[0],dataPointY[0],dataPointX[1],dataPointY[1]);
    }
  }
  public static void main(String[] args) {

    IconMapShoScaleImgs IconMapShoScaleImgs1 = new
IconMapShoScaleImgs();
  }
}

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