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 21:43:55 -0700

Message-ID:

<1193978635.508388.60930@o38g2000hse.googlegroups.com>

On Nov 1, 10:54 pm, Lew <l...@lewscanon.com> wrote:

bH wrote:

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{

Probably better to have a JFrame than to be one, but no matter ...

[snip]
    pack() ;
    setLocationRelativeTo(null) ;
    setVisible(true);
  }

Shouldn't all this be happening on the EDT?

  public static void main(String[] args) {

    IconMapShoScaleImgs IconMapShoScaleImgs1 = new
IconMapShoScaleImgs();
  }
}

Wise writers on matters Java advise not to run everything from the
constructor. Bad Things can happen. Constructors are for construction - you
have a JFrame running in an incompletely-constructed object. Strangely, you
didn't in your first post.

Summary:
- Run Swing / AWT actions on the EDT.
- Constructors should only construct.
- Prefer composition to inheritance. (Joshua Bloch, /Effective Java/)

--
Lew- Hide quoted text -

- Show quoted text -

Hi Lew,

Using the original design I was really puzzled
how to draw the line connecting the two points
(cities on the map) AFTER I had used the protected
paint to display the image. That was the intent of my
original Q. I tried a lot of ways to make it happen.
Each time I tried to adjust the initial design something
else weird would happen, i.e. couldn't get the lower panel to show.
That is why the "pack();" where it is.

This solution even lacks my initial intent to make
the line joining the cities to remain after the presentation
of the miles between the cities. Now it disappears before.

I recall that others say not to include a great deal of acticity into
the
public static void main(String[] args) {....

Too many constraints. Grr!!

My apologies to those that who are getting the shudders over this
bad bit of code: The lights come on but the wiring is screwed up.

I need(ed) help with the original design.... if it was worth your
notice here.

bH