Opera's Unwanted Functionality

I was just doing a bit of work in the Opera web browser, typing some information into a web app's text box, when I accidentally de-selected the input box in the process of jumping between applications. On my next keystroke the interface suddenly went to an archaic layout. It looked like something rendered in Netscape 3.

I had no idea how I did this, it was completely unwanted, and the impact was extremely disruptive. Closing and restarting the application didn't remove this sticky setting, and randomly (and systematically) selecting what I thought would be the accidental shortcut keys yielded no solution.

Now I had to waste time finding, and then turning off, a feature that I didn't want in the first place.

This brings to mind a couple of user interface issues:

• All applications should have an undo stack (a transaction log, of sorts) that clearly logs and lists every notable app change - minimizing, maximizing, resizing, or changing options like rendering mode. If there was such an undo stack, I could jump to it, see the "Switch to User Stylesheet Rendering" transaction just occurred moments ago - maybe even with a help link to see what that event type was and how I triggered it - and I could roll it back. This is something I've wanted for years (neigh...decades) but of course have never had the time or resources to implement such a non-standard technique in my own apps.
• Having options like this - switching rendering modes - configured for a standard key (in this case Shift-G) is questionable, and given the severity of the change it should really ask for a confirmation of use. "You have selected the shortcut to switch to User stylesheet mode (Shift-G). Are you sure?" (with a checkbox allowing brave users to avoid the confirmation in the future). It's a bit of education and avoidance wrapped up in one.
• Opera doesn't indicate the shortcuts on many of their menu items, including the style mode menu item (the culprits in this case), making it difficult to investigate possible causes.

While there is a minority of users who override site stylesheets with their own, justifying the feature in Opera (though I'm not convinced that it should be an everyday keystroke like Shift-G by default), this brings me to another user interface observation.

Highly Configurable Interfaces are Usually Detrimental

Drawing from personal experience, I worked on a project quite a few years back where one developer insisted upon absolute flexibility in the user interface - Every toolbar had to be movable and dockable anywhere, every sidebar item drag and droppable, every menu item configurable, every UI skinnable. It was a nice cop out for us because we didn't really have to put too much thought into the interface, and could always justify it with the stock "the user can configure it how they want". Stick some more toolbars, statusbars, and panels in there because the user can clean it up according to their own needs, the logic went.

In the field, about 99.9% (more likely 100%) of the time that people discovered this functionality it was to their detriment. Like the taskbar-stuck-perilously-on-the-side-of-the-screen on your Aunt's Windows 95 computer, it was just something that happened by accident, and they didn't know how to get it back the way it was: No one (or very few) did it on purpose, but there it was terrorizing every computer user.

The first step of any support call for our app was to determine in what innovative ways the user managed to mess up their user interface. After getting a visualization of the sidebar on the bottom, the icons all on the background, the toolbar on the right, some critical toolbars hidden, with the menus all jumbled and the icons all removed, the cleanup began.

On the next release a menu item to reset the interface to the initial defaults was added, and on further releases most interface flexibility was removed (or alternately made much more difficult to do - you had to be dedicated and informed if you really wanted to change things. Someone is much more likely to unintentionally hit Shift-G with no input box focused than they are to accidentally go into the advanced preferences and set an option).

The moral of the story is that customizable interfaces are seldom beneficial, and instead function as a lazy, non-committal cop-out by the developers and designers of the application.

Even the most fundamental element of our user experience - windowing - merits some analysis: Apart from Winamp and Media Player, how often are apps in any configuration other than maximized or minimized? I run with dual-monitors, and 99% of the time one or both of them has a full screen application on them. My "windowing" is alt-tabbing through full-screen windows, and I copy data between apps using copy/paste, or, where dragging is necessary, via the taskbar.

Tagged: [Software Development], [Programming], [Software-Development], [Usability]

Came across an old project where I had to solve this need, and thought I'd archive it on here for search engine purposes. This can be useful for scenarios like corporate training video directories, where you let the trainers upload videos and it automatically creates a thumbnail for clients to browse in a webapp, for example.

The first thing you'll need is an interop assembly to allow you to use the DirectShow COM objects from within .NET. You could either add a COM reference to your project, or better still use the command line tlbimp.exe framework utility to create the interop - the latter is preferred, as you'll want a strongly named interop assembly, which you can accomplish by specifying a keyfile with the tlbimp.exe /keyfile: parameter (specifying a key file that you created with the sn.exe framework utility). Add the newly created interop assembly as a reference in your project - barring specifying parameters otherwise, it'll be called Interop.DexterLib.dll, and once referenced will appear in the references as, of course, Interop.DexterLib.

There are a couple of structures that we need to define as we'll need them to communicate with DirectShow.

  [StructLayout(LayoutKind.Sequential)]
  struct element_RECT
  {
    public int left;
    public int top;
    public int right;
    public int bottom;
  }

  [StructLayout(LayoutKind.Sequential)]
  struct element_VideoHeaderInfo
  {
    public element_RECT rcSource;
    public element_RECT rcTarget;
    public UInt32 dwbitrate;
    public UInt32 dwbiterrorrate;
  }

The following code presumes that a couple of variables exist (for instance as parameters to a function)

• videoFilename (string) - The string full path and filename of the source video
• videoOffset (float) - How many seconds from the beginning of the video to pull the frame
• bitmapDestination (string) - The full path of where to store the extracted file. The MediaDet object requires that the extracted file be stored as a file

In your extraction function, create a MediaDet instance, set the source video file path via the Filename property, and search for a video stream (there can be multiple streams. We search for a video stream by looking for one identified by the GUID 05589f80-c356-11ce-bf01-00aa0055595a). The following presumes that the unit has a using Interop.DexterLib; in it.

MediaDet mediaInt = new Interop.DexterLib.MediaDet();
mediaInt.Filename = videoFilename;
   
bool videoStreamFound=false;
_AMMediaType oMediaType = mediaInt.StreamMediaType;

System.Guid videoHeader = new
                  System.Guid("05589f80-c356-11ce-bf01-00aa0055595a");
   
int streamCount = mediaInt.OutputStreams;
for (int counter=0;counter< mediaInt.streamCount; counter++)
{
 mediaInt.CurrentStream = counter;
 oMediaType = mediaInt.StreamMediaType;
 if (oMediaType.formattype == videoHeader)
 {
  videoStreamFound= true;
  break;
 }
}

Notice that we're setting the CurrentStream property on each iteration, so when a video stream is found, the MediaDet object will already have it selected as the active stream.

If we found a video stream in the file, retrieve the properties of the video frame so we can grab a full frame, and then direct it to save a frame at the specified time offset to our specified destination file. 

if (videoStreamFound)
{
 element_VideoHeaderInfo *header =
          (element_VideoHeaderInfo *)(oMediaType.pbFormat.ToPointer());
 mediaInt.WriteBitmapBits(
                    videoOffset,
                    oHeader->rcSource.right-oHeader->rcSource.left,
                    oHeader->rcSource.bottom-oHeader->rcSource.top,
                    bitmapDestination);
 Marshal.FreeCoTaskMem((System.IntPtr)oHeader);
}

Now ensure that the COM object is predictably freed now.

Marshal.FinalReleaseComObject(mediaInt);

Note that there are pointers (scary!) used above, so this code needs to be compiled with /unsafe. Don't worry - It's safe.

This technique works for pretty much any non-DRM multimedia file that contains a video stream, for which there is a DirectShow compatible codec installed on the system.

One note about this entry - I would use the PRE element and layout the code better, however Radio Userland exhibits a trait that drives me nuts with software: It is too clever, in a way that is often very detrimental. From removing attribute formatting, to completely reformatting PRE blocks, to auto-linking links that it shouldn't link, I seem to spend too much time trying to avoid it's "helpful" logic. This seems to be the case with too much software out there.

"It appears that you're writing a letter..."

Tagged: [.NET], [NET], [Software Development], [Programming], [Software-Development]

Back on September 13th I declared that SVG was a dead technology. Since then, the release of Firefox 1.5, along with the free-as-in-beer state of Opera - both featuring native SVG rendering engines - has really spurred SVG activity. I've been getting dozens of SVG related search hits here a day, and that's for an old article that I wrote back in 2002. It could be that the community finally caught onto this fantastic technology.

SVG might not be dead afterall.

Tagged: [SVG], [Programming], [Software-Development]

One of the benefits of being in the industry for a few years (I've been professionally developing and providing system consulting services for 12 years now, and of course was in the amateur ranks for a decade before that) is that you get to see history revised firsthand. This is especially true in the web app world, where the history of the platform is being rewritten by people who want to change it for their own gain, or who simply weren't involved in the industry and thus have incomplete knowledge, rewriting it purely out of ignorance.

A frequent loser in this rewriting is Microsoft: Whether it's imagining Microsoft to be a web app laggard (I was developing for the Microsoft technology stack, making web apps that blow away what people are amazed by today...6 and 7 years ago. Microsoft was a web technology superstar, but because most shops remained committed to fat apps, or wanted cross platform capabilities, few embraced their innovations), or having no influence (a lot of the current platform was either invented or implemented first by Microsoft. From IFRAMEs to most of CSS to XMLHTTP. Others like behaviors and filters died an ignoble death). While Microsoft is far from a perfect netizen, a lot of what they did has significantly and positively affected the web that we use today.

Rumor has it, and I am prone to believing it, that the web app platform was getting so powerful that the Internet Explorer team was disbanded: It was becoming capable enough that many corporations were switching many of their in-house applications to web apps, and the worry was that even with IE-only web apps, tied to IE-specific functionality, it was just a short jump to making them cross-platform (or allowing for parallel, slightly less capable cross platform options), dramatically reducing the lock-in of the Windows platform.

In any case, one Microsoft technology that is being particularly maligned is the infamous ActiveX.

Of course the term itself is a bit of a mess, and offers a classic example of Microsoft marketing gone awry (just like the disaster of naming that was .NET. If people weren't fired over that debacle, then justice wasn't served) - According to some Microsoft sources, ActiveX was a set of interfaces that could be added to a COM (Component Object Model) object to allow it to interact with the interface of an application. Generally encapsulated in .OCX files (Ole Custom Controls), these provided a replacement to the venerable VBX controls of yesteryear, providing a binary, language-neutral visual control that could be used in any ActiveX environment: Whether a Visual Basic app, a Delphi app, a MS Access form, an Excel worksheet, or a Visual C++ app, you could make use of a single ActiveX control. At one gig we needed two synchronized animated graphs showing engine performance for a tradeshow presentation - one quick Delphi ActiveX control later, and it was in the presentation (integrated right in the PowerPoint) and working great. That was the power of ActiveX.

ActiveX was also the technology behind plug-ins in Internet Explorer - Instead of begging the Netscape cabal to let them into the inner circle of Netscape plug-ins, ActiveX controls could be created by anyone and used in web pages (presuming some security hurdles were jumped, such as getting the controls signed). It was a free and open world for web extensions, and of course they proliferated by the thousands, though only a few remained when the dust settled.

Another definition is that ActiveX refers simply to COM controls themselves - if it's a COM control, then it's an ActiveX control. Another variant is that ActiveX refers to COM controls marked "Safe For Scripting".

In any case, COM was a great advance for the platform. It provided high performance, binary, language neutral, object-oriented controls that could be used throughout the system in a truly modular fashion. They could even be proxied across systems, or hosted in service modules (MTS which became component services).

Seeing the value of this powerful, extensible, system-wide technology, the Internet Explorer team decided to implement a lot of its functionality via this mechanism - So long as you configured it with the proper registry entries, and optionally implemented an interface stating its safety level, these components were usable from scripting in Internet Explorer. An obvious, and incredibly powerful, example was the use of the XMLHTTP component (a part of the MSXML library, which itself is a variety of COM controls) from within Internet Explorer. Independently both sides could be upgraded and changed, automatically benefitting the other side where desired. If you implemented visual controls, you could implement specific functionality that couldn't be handled with traditional web technologies in something like Delphi or MFC/C++, and gain all of the advantages of the web model (such as the document flow layout) alongside extremely rich controls.

It helped a lot of shops start transitioning to web applications long before the web platform could do it on its own.

The problem with ActiveX, and the main reason why it's maligned (apart from the platform lock-in), is that several controls that were marked safe for scripting were not, in fact, safe for scripting: Either they were programmed sloppily, and opened holes for buffer overflow and other nefarious activities, or they had dangerous operations that should never have been allowed from within Internet Explorer. Whatever the case, they opened holes that shouldn't have been opened.

Specific implementations gave the whole technology - a modular, high-performance and highly extensible system - a bad name. It could be said that it deserved it, given that it didn't sandbox the operations of the scripted object, but that's an implementation detail: At the core it really is a fantastic foundation.

Tagged: [Software Development], [Programming], [Software-Development], [ActiveX]

A classic, forever repeating quandary when designing applications that store large numbers of data files (images, user files, supporting documents, etc) is whether to store the files in the database, or to store them in the filesystem with pointers in the database.

Consider a web application that tracks support tickets, where users can add supporting documents to their tickets. In many implementations the files are uploaded and stored in a filesystem location with a unique name or directory (often a GUID), and that unique filename is stored in the database correlated with the record. This means that record access necessitates both file system access along with the database access.

There are significant disadvantages to this, including the lack of transactional integrity of the filesystem objects, the difficulty of management (trying to coordinate file system and database backups to be able to restore to a consistent state), the security issues, the lack of relational integrity (files could be deleted, records could be deleted without cleaning up the related files, and so on), among others.

On the flip side, the advantage of this technique is reduced load on the database server (e.g. you could offload file storage to a very large scale NAS device), as well as immediate file system access where appropriate (e.g. an administrator needs no special tools to browse the files, although this could be considered a detriment as well). Many developers find it an easier model to implement using the file system for supporting files.

For those who prefer the file system in such scenarios, the transactional integrity deficiency of this technique will be fixed in Windows Vista (formerly Longhorn) and related technologies - It is introducing a transaction-capable variant of NTFS (TxF). NTFS is already a journaled and reliable filesystem, however TxF will add the ability of the filesystem to participate in distributed transactions - both intra-machine, and inter-machine - with standard two-phase commit functionality. This means, for instance, that when the user is adding the record that includes a supporting document, the file and record could be created under a shared transaction in the middle tier (or even in the database if you use it as a conduit, storing and retrieving filesystem objects in the database logic), and if either fail they both fail (avoiding dirty data). Add this with the easy ability to add complex database logic to probe and validate the correlating file system (now that SQL Server 2005 can host .NET functionality, meaning that your trigger can more robustly check for file existance when records are created, and delete them when they are removed), and it becomes a much more credible option.

(As an aside - Distributed transactions - transactions across heterogenous resource managers - have traditionally been very, very slow. This new file-system transaction functionality most certainly isn't free, but where the reliability is critical - which is almost always given the cost and uselessness of dirty data - it can represent a great improvement. Registry changes will also be boundable in distributed transactions)

Supporting Links
MSDN Page
Channel 9 Video on TxF (Given that the long form name is the correctly descriptive Transactional NTFS, shouldn't the abbreviation be TxNTFS? Longer to say, but it seems superior to me)

Tagged: [Software Development], [Programming], [Software-Development], [Vista]

It always surprizes me that large domains don't configure common mistypes of their subdomains in their DNS. For instance

w.microsoft.com
ww.microsoft.com
wwww.microsoft.com

For that website it only works as http://www.microsoft.com, or http://microsoft.com. It seems logical that they should add the common derivatives in, point them to a multi-host-header site that does nothing but redirect to http://www.microsoft.com, and voila - A lot of sloppy-typing users save a bit of time and avoid a bit of frustration.

Microsoft actually makes use of a lot of their subdomains (e.g. research.microsoft.com, msdn.microsoft.com), however for smaller sites it could simply be a wildcard entry. Even if there are lots of subdomains, the redirect logic could do some analysis of the typed in entry and figure out the likely destination. e.g. madn.microsoft.com probably wanted msdn.microsoft.com, and resrch.microsoft.com probably wanted research.microsoft.com.

Of course yafla.com isn't configured like that - I don't control the DNS in this case so I didn't have the option.

User measurement and tuning of computer hardware and components is largely a lost art - we buy high performance hardware within our budget, and it is what it is. When we require more speed, or more likely just buy to keep up with technological advances, we buy something new.

This came to mind as I was evaluating why the media performance between a couple of home PCs was relatively poor: For whatever reason, streaming media files were stuttering, and photo replication was taking far too long given the quantities of data involved. While I just lived with this for a while (it is just a couple of home PCs), I finally decided to get some real metrics to know what I was dealing with. I decided to look at the numbers from the file system level (rather than measuring just the network itself to catch any high-level issues). Off I went with the fantastic application iozone (which also doubles as an excellent test utility to gauge the performance of various segregated storage systems, which will be another entry coming very soon), analyzing both the wired network and the wireless network.

To make a boring entry even more boring, it turns out that the source computer - running on an nvidia nforce motherboard - was using the nforce chipset networking adapter, with the secondary Marvell adapter disabled. All with stock settings. After running the first set of tests, seeing that the network performance over the 100Mbps network was yielding about 800KB/second of actual transfer (despite the links all reporting a 100Mbps signalling speed), I disabled that network adapter and enabled the Marvell, switching the ethernet cable over.

With that simple action, network throughput suddenly jumped to 12MB/second (the theoretical limit of 100Mbps ethernet). A 15x performance improvement just because I finally decided to measure it and do something about it. Now I think I'll play with the buffer settings to see what further benefits can be gained. Then I'll probably upgrade to 1000Mbps and start again (amazing how inexpensive 1Gbps networking equipment is now).

I always enjoy these exercises because inevitably you go down a path and learn more about a fringe - yet still important - element of our computing world. For instance some interesting details about the file cache of Windows 2000 (which was largely unchanged for Windows 2003).