Scary Symbian

I’m not really in the mood to revise writing communication scripts… So I will just blog about Symbian to conclude the assignment I submitted yesterday.

Symbian started as a collaborative Effort between Nokia, Sony Erricson, Samsung and several other mobile phone manufacturers to create an operating system that work for their devices. It’s certainly not the first OS, Palm OS existed long before that. The fact that Symbian collaborated development started in 1998 and got wide attention around 2000 may make you expect a modern operating system with good design while maintaining compatibility.

It’s simply scary for me.

Looking at the sheer amount of features and headers would make you confused, the documentation seems to be machine – generated with very very very few example what each function do. It’s a good thing that a single operating system support all functionality that normally only available on separate devices: media player, digital camera, gaming device… But that is a burden for the developers :(. They will have to get familiar with a multitude of data structures… You think int is just int? No, for Symbian there are 8 bit int, 16 bit int and 32 bit int, and the developer will have to decide what to write both when they design (write the header) and when they code (using the function). Failing to match the two declaration can be fatal and that lead to debug…

To debug you’ll have to install Nokia’s tool: Carbide; which in turn will require you to install

  • Perl
  • Java
  • GNU C++
  • MingW in case you use Windows
  • Phone SDK for simulation; and they install a complete set of files for each SDK

Three languages just to program in one language for one operating system! Even so, if they worked smoothly then there weren’t this post: the SDK installation has a screen in which you can choose where to install, even though you can click the button and change it; and the documentation didn’t recommend otherwise, don’t change it. It will mess up with itself! Installing the SDK in a drive different from the IDE, or different from your workspace drive would results in dumb error messages like “file not found” which unless you are familiar with *nix system, you’ll just went mad! (And even if you have the skill to fix it, are you ready to fix tens of thousands of lines of Perl code just to write a C++ hello world!?)

Expecting the resource editor? It depends on whether you've been nice or naughty…

If you have installed stuff on Windows Mobile before, and ever think to yourself “why must I bring my phone to phone shops, I can do this, piece of cake!”, try using Symbian! Each program throws resource in multiple directories, together with system applications. While this is a good thing on some aspects, a developer just can’t find where his resource file is in the big mess called “sys”. If you think Windows’s window directory on windows mobile is messy because it’s full of dll and executables, have a look at Symbian’s system directory. You’ll see types of files have never seen. Open your eyes and embrace r01, l01, mbm… And because the OS is that complex, OS’s native file structures is complex, to do something as simple as replacing a bitmap, the developer will have to wait for the tools to rebuild it, and then deploy it to the phone, which is not a fast process at all…

And possibly for the same reason why you must rely on shops when your phone has problem, the documentation doesn’t have any mention for any error and how to fix it… Sometimes if you are in luck you may found it in some corner of the Internet. For example a common problem for the 3rd SDK FP1 emulator is it display a kernel failure every time it start. If you google the error, you’ll see several discussion on forum nokia (and several copy of those discussion), most of which will tell you “leave it there, it doesn’t hurt”. It’s not until one beautiful day searching for another kernel problem that I found this KB article: NCNList KERN-EXEC 3 panic when starting the S60 3rd Edition, FP1 emulator. There you go, download the file, install it, and if your phone is happy, it won’t spit a list panic =))

Small community size, clueless forum posts is what you are going to face searching for help with Symbian. I wonder how could they able write so many stuff for their phone? Magic happens among Nokia-employed developers? =))

Some part in their documentation, they mention about how Symbian is so different from normal C, it was designed before the current C++ standards were born. Oh really? How come you can design a new interface for acceleration sensor and can’t even wrap the compiler to use the approrate kind of number and character instead of forcing the developers write clueless stuff like Tint, Tbuf, Tdes, TPtr!? C++ is complex enough already! Keep in mind that you inherited that together with the language next time! Or is it just too hard to let the compiler do exception handling the C++ way instead of some “simple leaves” which make the developer throws away most of their knowledge about constructors to do the so-called “2 phase contruction” like

CBanCo::CBanCo()
{
}
CBanCo::CBanCo(TRect aRect)
{
	iRect=aRect;
	iSize=15;
	iNum=0;
	TRgb color(102,255,255);
	iColor=color;
    iWidth = aRect.Width();
	iHeight = aRect.Height();
	iSwitch = EFalse;
}
void CBanCo::ConstructL()
{
	CSettings* settings = CSettings::NewL();

	iSize = settings->iBoardSize;
	iRow = iHeight/iSize;
	iCol = iWidth/iSize;
	iFlag = false;
	iColCur = iRowCur = 0;
	iArray = NULL; // The following line may fail
	iArray = new (ELeave) CArrayFixFlat(iRow*iCol);
		for(TInt i=0 ; i < iRow ; i++)
			for(TInt j=0 ; j < iCol ; j++)
				iArray->AppendL(-1);
	if (settings->iPlayerSymbol == 0)
		iSwitch = EFalse;
	else
		iSwitch = ETrue;
	iImageX = AknIconUtils::CreateIconL(BitmapStore, (iSwitch == EFalse? 2 : 3));
	iImageO = AknIconUtils::CreateIconL(BitmapStore, (iSwitch == EFalse? 3 : 2));

	delete settings;
}
CBanCo::~CBanCo()
{
	if (iArray != NULL)
		delete iArray;
	if (iImageX != NULL)
		delete iImageX;
	if (iImageO != NULL)
		delete iImageO;
	iArray = NULL;
	iImageX = NULL;
	iImageO = NULL;
}
CBanCo* CBanCo::NewL(TRect aRect)
{
	CBanCo* myObj = CBanCo::NewLC(aRect);
	CleanupStack::Pop(myObj);
	return myObj;
}
CBanCo* CBanCo::NewLC(TRect aRect)
{
	CBanCo* myObj = new (ELeave) CBanCo(aRect);
	CleanupStack::PushL(myObj);
	myObj->ConstructL();
	return myObj;
}

While it could be

CBanCo::CBanCo()
{
	;
}
CBanCo::CBanCo(TRect aRect)
{
	iRect=aRect;
	iSize=15;
	iNum=0;
	TRgb color(102,255,255);
	iColor=color;
    iWidth = aRect.Width();
	iHeight = aRect.Height();
	iSwitch = EFalse;
	CSettings* settings = new CSettings();
	iSize = settings->iBoardSize;
	iRow = iHeight/iSize;
	iCol = iWidth/iSize;
	iFlag = false;
	iColCur = iRowCur = 0;
	iArray = NULL; // The following line may fail
	iArray = new (ELeave) CArrayFixFlat(iRow*iCol);
		for(TInt i = 0; i < iRow ; i++)
			for(TInt j=0 ; j < iCol ; j++)
				iArray->AppendL(-1);
	if (settings->iPlayerSymbol == 0)
		iSwitch = EFalse;
	else
		iSwitch = ETrue;
	iImageX = AknIconUtils::CreateIconL(BitmapStore, (iSwitch == EFalse? 2 : 3));
	iImageO = AknIconUtils::CreateIconL(BitmapStore, (iSwitch == EFalse? 3 : 2));
	delete settings;
}
CBanCo::~CBanCo()
{
	if (iArray != NULL)
		delete iArray;
	if (iImageX != NULL)
		delete iImageX;
	if (iImageO != NULL)
		delete iImageO;
	iArray = NULL;
	iImageX = NULL;
	iImageO = NULL;
}

See it? my code hilighter can’t parse Symbian C++ as C++ :))… I stray too far from the debug part, didn’t I? Yes, the debugger does not allow code view, and because it stops immediately when some error happens, you can’t see the values you are tracking at that time. Proved you are clever enough to have the debug work while winscw’s configuration just won’t start.

Guess that when the phone is sold to the rich, its developers should also be rich and have a lot of spare time to think like the rich then. At least the OS have a nice interface after all

Symbian gomoku, thanks to my instructor

Strangely, I can’t help noticing Nokia still has the largest market share in the smartphone market according to canalysis (51% in 2007). I just can’t find a nice chart to match smartphone sales to dumb phone’s so I can’t just conclude that most of the rich people uses an inextricably complex operating system 😛

Nevertheless, iPhone is steadily gaining its part and the first dream phone (as what Google calls it) appeared a couple of months ago also with quite a lot of function. Both of which could be interesting factors to facilitate Symbian in the future.

Splash screen in C#

How come every time I build something small, no matter how trivial it could be, I wanted to share it? :-/

This afternoon, i was asked on how to do a splash screen in C#. The guy already tried threads to display they screen and and that threw an ugly exception at the user’s face. I guess it is not that simple to guess 😛

The splash screen is just a form. You can either show it on the foreground and allow your application to load on the background with thread, or just build another application and execute it with some function in the System.Diagnostic namespace, I will demo how to make a splash screen for the later since it’s easier to debug and you can show as many of them as once as you like 😛

First, you need a form, splash screen doesn’t have title bar and stuff, so change the FormBorderStyle property to none, insert a picture box and fill-docking it to the form. Why a picture box and not just the form’s background you ask? Well, the picture box is designed to host pictures and you can scale it, provide an error image for it etc. If you simply use the form itself, you’ll have to scale the picture by hand.

Next change the image attribute of the picture box to your splash bitmap. Alternatively, if you want to reuse the program without having to recompile the project, have it read the splash bitmap in the application’s directory with:

String strPath = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().CodeBase).Substring(6);
Bitmap img = new Bitmap(strPath + System.IO.Path.DirectorySeparatorChar + "splash.bmp");
pictureBox1.Image = img;

Put that in the Form_Load() event. The first line get the application’s directory; the Substring() is there to remove the file:// part form the returned path. The second line’s Bitmap constructor doesn’t like that 🙂

For the final touch, add a timer, set it to enabled, set your desired splash duration for interval, add a Tick event and type in

this.Close();

That’s it, F5 and you have a Splash screen to go

Splash screen

Download the source (dynamically load a bitmap)
Download the source (embedded bitmap in picturebox)

PS: That’s my actual Eclipse splash, I photoshopped it for personal use since I can’t stand the stock splash xD. But since I’m releasing this I guess I’ll have to add the source: I took it from here.

PPS: Argh, byet hosts are not compatible with WordPress’s integrated picture management T__T

Building a PHP file browser

This week’s assignment that I gave to another group member, but the result turned out unsatisfactory. It can’t even delete a folder, move a file or copy them. Yes, it’s pretty easy to build a PHP file browser, it’s just a matter of calling file_* functions, but combining them together can be tricky. For example, this guy used GET to pass data and operation between screens. What happen if a file name contains & or =, the characters that make the GET themselves? It has to be revamped (and I have to do this -__-)

About code style, they claim to have done it in procedural style, but… I don’t know what kind of programming is that to name. Well, it worked on some aspects nevertheless, so I decided to move straight to fix the interface. I just can’t bear to see that pile of mumble-jumble ><; and the result…

Interface

Icons are from famfamfam. Thanks James! You may notice that it looks familiar. Yes, it resembles Vista’s explorer. I love Mac in overall but for the interface alone, explorer looks better than finder. I also tested some css pseudo-class: the rows will be highlighted when you move over them. A breadcumb would be trivial to implement too, but that’s something I can work with already 🙂

The code

Basically, this is just a directory list with more function added at the beginning so that it will execute the required operation before listing. The original code used scandir() to get the files in the directory, which is a php5 function (the only thing PHP5 specific in the project); I decided to fall back to its PHP4 equivalent so it can run on older servers (the code is from PHP manual)

$dh  = opendir($newPath);
while (false !== ($filename = readdir($dh))) {
	$files[] = $filename;
}
sort($files);

I know, most host have upgraded to PHP5 and PHP6 is at the horizon, but when it’s so easy to make it compatible, why not?

For most online file browser I’ve seen, they will only allow clicking on the filenames to open them; while on your familiar explorer, nautilus or finder you can click anywhere on the row, so I decided to move the onclick to the row <tr>.
It worked! But then another problem rises: whenever the checkbox is ticked, the view changes to the corresponding file / directory without waiting for the user to choose what to do with the file!. This is possibly the reason why online file browsers does not allow this 😉 After some research, I found a way to stop the event from bubbling (Internet Explorer terminology) or propagating (W3C terminology) from the checkbox to the row (i.e. after you check the checkbox the browser will stop and forget the fact that you clicked inside the row)

function doSomething(e)
{
	if (!e) var e = window.event;
	e.cancelBubble = true;
	if (e.stopPropagation) e.stopPropagation();
}

The code above do fine if you set the event with attachEvent(), but for the code I have the event is attached in the traditional way (onclick=”js”). And trying to put an anonymous function in is no use, “e” would be undefined in all of the browsers 🙁

The secret? In IE the window.event could be accessed but firefox does not seems to have it. Instead, it have “event” (duh) and the following code work (I wrote it together in one line to put to the onclick)

if(!e){var e = window.event;if(!e){e = event;if(e.stopPropagation)e.stopPropagation();}e.cancelBubble = true;}

Coding this, just to know that directory browsing can be tricky. There are functions, like that there’s a rmdir, but It just won’t delete non-empty directories and unlike the command you know from popular OSes, it doesn’t have /s to –-recursive to force delete the directory. That’s when you have to write your own function to get the job done.

function recursiveDel($dir) {
		if ($dir[strlen($dir) - 1] != "/")
			$dir = $dir."/";
		$mydir = opendir($dir);
		while(($file = readdir($mydir)) !== false) {
			if($file != "." && $file != "..") {
				// Unix compat
				chmod($dir.$file, 0777);
				if(is_dir($dir.$file)) {
					chdir('.');
					recursiveDel($dir.$file.'/');
					rmdir($dir.$file);
				}
				else
					unlink($dir.$file);
			}
		}
		closedir($mydir);
		rmdir($dir);
	}

Now that most directories can be deleted, what about directories that contains special characters mentioned above? Well, you may notice when browsing that sometimes your Address bar contains something like %2f%ac; they are ASCII characters, they can be embedded in an URL and then retrived later thanks to urlencode() and urldecode(). A better solution is instead of using GET, use POST or a hidden field.

About security, the guy didn’t even check what the user put in. The only check there is the firectory name check “Invalid directory name. It can’t contains . .. /”. Anyone could just put in path =/ etc / passwd in the address bar at any time. What a common beginner pitfall! A couple of str_replace() wouldn’t hurt…

Below is the code to this moment. Note that its capability is limited to navigating, creating directories and Upload file, but at least it have done those quite good and if one’s only need is somewhere to occasionally throw one or two file in; or to study how file managers work, this script is a good choice 🙂

Download the source

Gotta OOP-rize it and clean it up…

4 hours later edit: Phew, done! ^^ You can have a peek over here. This is a stripped down version, so you can’t upload and edit / preview the file for obivous reasons 😛 other than that, all functions displayed on screen is working now.