[netrexx-course] Re: Netrexx class question

[dIon Gillard/Multitask Consulting/AU]

You need to run this class using:

     java nrxbeans.lab.NrxLED

from the directory *above*  your nrxbeans directory.

Note the package statement, which effectively adds the package name onto the
class name (qualifies it).

--
dIon Gillard, Multitask Consulting
Work:      http://www.multitask.com.au
Play:        http://www.trongus.com


This is the sample from the NrxRedbk\nrxbeans\lab directory of the IBM
Redbook samples.
I have a directory called NetRexx and I copied the nrxbeans and
subdirectories to it to give me a NetRexx\nrxbeans\lab structure.  I tried
to set up my classpath to run from their directory, but I ran out of
environment space.  Windows only gives you so much room.  Here is the code
for NrxLED.

/* nrxbeans\lab\NrxLED.nrx

   A simple LED display bean, with numbers, colon, point, minus, blank */

package nrxbeans.lab   -- if you change the package name you also need to
modify
                       -- the path to the LED GIF files

import java.awt.
import java.beans.

class NrxLED binary extends Canvas implements Serializable

  properties private static
    DIGIT_WIDTH  = int 7
    DIGIT_HEIGHT = int 16
    MAX_DIGITS   = int 14
    DIGIT_BLANK  = byte 10
    DIGIT_COLON  = byte 11
    DIGIT_DOT    = byte 12
    DIGIT_MINUS  = byte 13

  properties private
    digits = Image[]

  properties indirect
    numberOfDigits = int
    text           = String

  method NrxLED() public
    super()
    ------------------------------ load the digit images
    digits = Image[MAX_DIGITS]
    loop i = 0 to MAX_DIGITS-1
      imageName = "/nrxbeans/lab/LED" || i || ".gif"    -- must be in same
path as class
      digits[i] = loadImage(imageName)
      if digits[i] = null then
        System.err.println("Couldn't load image" imageName)
    end
    ------------------------------ set properties
    setNumberOfDigits(8)
    setText("88:88:88")
    setBackground(Color.black)
    setForeground(Color.green)

  method loadImage(imageName = String) private returns Image
    imgUrl = this.getClass().getResource(imageName)
    return Toolkit.getDefaultToolkit().getImage(imgUrl)

  method getPreferredSize() returns Dimension
    return Dimension((2+DIGIT_WIDTH)*numberOfDigits+4, -
                      DIGIT_HEIGHT + 6)

  method paint(g = Graphics) protect
    width = getSize().width
    height = getSize().height
    g.setColor(getBackground())
    g.fillRect(1, 1, width-2, height-2)
    g.setColor(Color.black)
    g.draw3DRect(0, 0, width-1, height-1, 0)
    paintDigits(g)

  method paintDigits(g = Graphics)
    loop i = 0 to text.length()-1
      c = text.charAt(i)
      select
        when c >= char '0' & c <= char '9' then idx = byte c - '0'
        when c = ':' then idx = DIGIT_COLON
        when c = '.' then idx = DIGIT_DOT
        when c = '-' then idx = DIGIT_MINUS
        otherwise         idx = DIGIT_BLANK
      end
      g.drawImage(digits[idx], 3+i*(2+DIGIT_WIDTH), 3, this)
    end

  method setNumberOfDigits(n = int)
    numberOfDigits = Math.max(0, Math.min(12, n))
    sizeToFit()

  method setText(aText = String)
    if aText.length() <= numberOfDigits then text = aText
    repaint()

  method sizeToFit()
    d = getPreferredSize()
    setSize(d.width, d.height)
    p = getParent()
    if p \= null then do
      p.invalidate()
      p.doLayout()
    end

Thanks,
Thom Stone
[hidden email]


-----Original Message-----
From: [hidden email] <[hidden email]>
To: [hidden email] <[hidden email]>
Date: Monday, April 19, 1999 10:39 PM
Subject: [netrexx-course] Re: Netrexx class question


>
>
>Java classes are case sensitive. NetRexx usually isn't. Sounds like the
NrxLED

>should be called nrxLED or NRXLed or something similar....can you post some
>snippet of source code for the NrxLed class definition?
>
>--
>dIon Gillard, Multitask Consulting
>Work:      http://www.multitask.com.au
>Play:        http://www.trongus.com
>
>
>
>
>I seem to have the course installed ok and most examples seem to compile

and
>run ok, but I found this NrxLED that looked interesting to me and no matter
>what I do with it I get the same error when I try to run it.  I have no
idea
>what it means. Any help would appreciated.
>Error loading class NrxLED : Wrong name
>This comes after either :
>NRC -RUN NrxLED
>which compiles ok, or once I have the class file after
>JAVA NrxLED
>Here is my classpath statement:
>SET
>CLASSPATH=C:\jdk1.1.8\LIB\NetRexxC.zip;C:\NetRexx;C:\jdk1.1.8\bin;C:\jdk1.1
.

>8\LIB\xclasses.jar;C:\Data\NetRexx
>My directory structure is:
>C:\NetRexx\NrxLED.nrx
>C:\NetRexx\NrxLED.java
>C:\NetRexx\NrxLED.class
>C:\NetRexx\nrxbeans\lab\........the package files
>So far this OO stuff leaves me feeling like I'm missing a really important
>point somewhere.
>Thanks,
>Thom
>

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