Tag Archives: update


I know its been awhile since I’ve posted on here.  About a month ago, I got a new job where I’m working overnights so its been tough getting programming as a hobby in and especially writing as it while I adjust to the new work shift.  Some projects I’ve been working on:

1. I’ve gotten real heavy into using microprocessors.  Recently, I’ve gone to programming on the Arduino to using the ATMega in its own circuit (programmed while on the Arduino board for testing and then once ready to complete, finishing it on its own circuit.)

2. As usual, working on an XFDL for Linux project.  The GUI in WXWidgets is coming along, working out using libxml2 to parse the file, which is taking awhile but its beginning to flow.  Keep checking back for updates as they happen.

3. Finally got a Mac OSX running with xCode in Virtual Box.  I’m going to get back into Objective C and iPhone apps as I get it working more smoothly.

Thank you for checking in, I’ll be posting more regularly from here on out.

Fern Screensaver : Part 4

I’ve now completed the Fern Screensaver in Objective-C for the Mac!  Surprisingly, using Objective-C was not that far from C/C++.  In fact, much of my code could be pasted directly in.  That includes the variables, math functions, etc.  Also, Mac has done a good job of documenting it’s libraries so using the NSObjects was not that difficult between Google and a quick reference search along with the example screensaver code.  I’m going to hit a few key differences and then post the entire file I edited.  XCode does the templating pretty well.

First, all the variables are at the top of the code so they don’t change as the program advances frames.

float mat[4][7] = {

@implementation ZackScreenSaverView

Secondly, I had to use implement my NSObjects at the start of the -(void)animateOneFrame method.  The size = [self bounds].size; calls the screensize.  It’ll take some time to get used to the method calls in Objective-C!

- (void)animateOneFrame
	NSRect dot;
	NSSize size;
	NSColor *color;
	NSBezierPath *path;
	float red,green,blue,alpha;

	size = [self bounds].size;

The framework has some good methods for getting random floats, or any integer type!

	// random number
	p = SSRandomFloatBetween(0.0,1.0);

Finally, it took some new methods to draw my dots to the screen.

	// set dot
	dot = NSMakeRect(jx,jy,1.0,1.0);

	// make dot
	path = [NSBezierPath bezierPathWithRect:dot];

	// draw dot
	[path stroke];

Other than that, the rest is pretty much the same.  I encourage those more used to Objective-C and programming for Mac products to comment about the use of this code and correct any bad assumptions!  Here is the code in it’s entirety (note that I’ve taken out the redraw at this time)…

//  ZackScreenSaverView.m
//  ZackScreenSaver
//  Created by Zachary D. Skelton on 5/30/10.
//  Copyright (c) 2010, Skelton Networks. All rights reserved.

#import "ZackScreenSaverView.h"

float mat[4][7] = {
// constant sets
float xa = -5.5;
float xb = 6.5;
float ya = -0.5;
float yb = 10.5;
// x and y to be altered
float x = 0.0;
float y = 0.0;
// screen/image size
int ix = 512;
int iy = 512;
// floats for math fulction
float p = 0.0;
float x0 = 0;
float jx = 0;
float jy = 0;
// variables to control function
int i = 0;
int k = 1;
int end = 10000;

@implementation ZackScreenSaverView

- (id)initWithFrame:(NSRect)frame isPreview:(BOOL)isPreview
    self = [super initWithFrame:frame isPreview:isPreview];
    if (self) {
        [self setAnimationTimeInterval:1/30.0];
    return self;

- (void)startAnimation
    [super startAnimation];

- (void)stopAnimation
    [super stopAnimation];

- (void)drawRect:(NSRect)rect
    [super drawRect:rect];

- (void)animateOneFrame
	NSRect dot;
	NSSize size;
	NSColor *color;
	NSBezierPath *path;
	float red,green,blue,alpha;

	size = [self bounds].size;

	ix = size.width;
	iy = size.height;
	dot = NSMakeRect(ix/2,iy/2,1.0,1.0);

	red = 255.0;
	green = 255.0;
	blue = 255.0;
	alpha = 255.0;
	color = [NSColor colorWithCalibratedRed: red
									  green: green
									   blue: blue
									  alpha: alpha];

	[color set];

	// random number
	p = SSRandomFloatBetween(0.0,1.0);

	// find random i
	if(p <= mat[0][6])
		i = 0;
	else if(p <= (mat[0][6] + mat[1][6]))
		i = 1;
	else if(p <= (mat[0][6] + mat[1][6] + mat[2][6]))
		i = 2;
		i = 3;

	// super math function
	x0 = ((x*mat[i][0])+(y*mat[i][1])+mat[i][4]);
	y = (x*mat[i][2]+y*mat[i][3]+mat[i][5]);
	x = x0;
	jx = ((x-xa)/(xb-xa)*(ix-1));
	jy = (iy-1)-(y-ya)/(yb-ya)*iy-1;

	// set dot
	dot = NSMakeRect(jx,jy,1.0,1.0);

	// make dot
	path = [NSBezierPath bezierPathWithRect:dot];

	// draw dot
	[path stroke];

	if(k == end) {
		k = 0;
	} else
		k += 1;

- (BOOL)hasConfigureSheet
    return NO;

- (NSWindow*)configureSheet
    return nil;


Ubuntu 10.04 – Fixing Title Bar Buttons (Place on the right)

After downloading Ubuntu 10.04 Lucid Lynx, I noticed that the biggest user interface change is the title bar buttons.  Unlike Windows or Mac, the buttons are located on the left side.  This is not too bad if you can get used to it, but I found several complaints online.  So, for those who are not used to gconf-editor, here are instructions to fixing the title bar.

  1. Open a terminal or use Alt+F2 and type ‘gconf-editor’.
  2. In the tree menu on the left side go to: apps -> metacity -> general
  3. On the options menu (right side of the editor) find the option midway down for ‘button_layout’.
  4. Editing these options can let you customize the menu, here’s how:
    • The colon ‘ : ‘ sets the middle, so anything on the left of the colon is on the left of the title bar.
    • Settings are comma separated values of menu, minimize, maximize, close, separator
      • Duplicates and unknown values are silently ignored.
    • Example #1: menu:minimize,maximize,close
    • Example #2: close,minimize,maximize:
    • Example #3: minimize,maximize,close:

See, one of the great things with Linux is that these configurations are available.  If you take a moment to look around your gconf-editor, you’ll see how powerful this tool is to your user interface customization.  Feel free to contact me or comment here with questions regarding this process.

XFDL in Linux :: Part 2

More for the ongoing series of producing an XFDL viewer in Linux.  In the previous tutorial, we decompressed an XFDL file, although I have had trouble recompressing the file.  It turns out that I need to do some experimentation and find the exact compression method used in gzip to be able to make the form readable.  That will be for the next update though.  I thought I would give a short preview of what’s next on this.

An XFDL file is an XML (xform) by IBM meant to run through their interpreter. IBM has some great documentation on this format.  PureEdge works much like a browser does to decompress the file by Mime-type and to then parse and read the file, including embedded binaries (for pictures, files, etc) and embedded coding (custom functions).  My interpreter will have a long ways to go so I’ll be happy to just be able to place my values in the correct fields.  I’m re-reading XML parsing within Python to make this an easy function, so be patient on that part.  But for those eager to see what I’m talking about, I’ve pasted a small section of XML from a decompressed XFDL.

      <field sid="NAME">
            <ae>Times New Roman</ae>
         <acclabel>d ay form 46 44-r, december 19 82.
ay p d. p e version 1.00.
edition of 1 august 19 77 is obsolete.
army reserve reenlistment data.
for use of this form, see ay r 1 40-1 11, the proponent agency is r c p ay c.
item 1. enter name using last name comma first name comma middle initial format.</acclabel>
As you can see, there is a <value> tag for these nodes.  For my next post, I’ll write some python code to break this xml to an object that can print the label and insert a value into the xml.  There is a lot of work to interpret the embedded items, code and other tags, but this will be a start!


So for anyone reading this blog, I am still here, just have not added anything this week.  I’m working and have not been able to update the blog but I will soon have links and information to my linux Cribbage game.  This is near completion and I have written it using pygtk.  It is using card and game modules that I had designed for a text based run of the program and figuring no one would want to use the text based, I’ve switched to a GTK interface, which is obviously, much better.