Finding character positions

October 12th, 2008 by Hans Wichman

Also known as:

  • finding the position of a character in a dynamic textfield with embedded fonts using actionscript 2
  • One of current projects involves some texteffects and I am loath to do anything on the timeline that can be done quicker by code. So my basic idea was (keeping the designer in me happy):

    Doing the design stuff at design time on stage:

  • put a dynamic textfield on stage
  • apply a font, fontsize, color, anti-aliasing
  • apply effects such as dropshadow, glow etc to make it look good
  • Doing the animate stuff at runtime through code:

  • break apart the stage textfield into little textfields that I could animate
  • At this point I was already thinking about converting the stage textfields to bitmaps but found I was thinking about optimising things too early, so back to KISS, basic principles first.

    Silly me, I thought it would be easy in actionscript 2 to get the position of a character in a dynamic textfield. As in:

    textfield.getCoordsOfChar (pIndex:Number)

    but apparently no such thing exists. Ofcourse if you have a monospaced font, there are other ways to accomplish this, but this solution works for both monospaced and other fonts.

    Although in actionscript 3 there is something like getCharIndexAtPoint, that is not quite what I needed.

    Using a trick I managed to implement it in actionscript 2. Note that this is still under development, being researched etc, so it’s not a general I-will-work-everytime-approach. Anyway the basic principle is this:

  • create a bitmap as large as your textfield
  • create two textformats derivatives of your textfield’s textformat and set the textcolor of one to white, the other to black
    now loop over the characters in your textfield (i = 0 to textfield.length), and:
    • apply first the white textformat to everything, then applying the black textformat to the range (i, i+1)
      (basically in every iteration of the loop you set everything to white except the character whose position you are looking for)
    • copy the textfield to the bitmap
    • perform a getColorBoundsRect on the bitmap and voila an approximation of the character position

    And I say approximation since it’s seems to be off by a couple of pixels, but close enough to be usuable. In addition large amounts of text will slow down the process considerably and small font sizes wreak havoc, but it’s good enough:

    Download the prototype here, it includes the Greensock Tween classes, but you can use anything you like.

    Iterating properties creates unwanted side-effects

    October 12th, 2008 by Hans Wichman

    Also known as:

  • iterating properties in actionscript 2 causes getter setter to execute
  • I was working on our AS2 logger today. In particular I was creating a setup where you could simply drop in a couple components in your fla and ‘tada’, you would have a reflecting logger at your disposal.

    I’ll go into the reflecting logger and component creation in another post, because what happened was that during a test run I ran into the dreaded 256 levels recursion problem.

    Some research indicated that the problem lay with getters and setters.

    Imagine you have a class:

    class TestClass {
        public function get id1 () {
            trace ("hello world");
        }
    
        public function id2() {
            trace ("goodbye world");
        }
    }
    

    Now do:

    _global.ASSetPropFlags(TestClass.prototype, null, 0, 7);
    for (var i:String in TestClass.prototype) {
        trace (
             "Property:"+i+" is function ? "+
             (TestClass.prototype[i] instanceof Function)
        );
    }
    

    Ok, truth be told, you will not do this every day. In fact building a reflection package is probably the only time this issue shows up. However I like to document stuff for posterity’s sake, so here we are.

    Executing the code above will show something like:
    hello world
    Property:id1 is function ? false
    Property:id2 is function ? true
    Property:__get__id1 is function ? true
    Property:__proto__ is function ? false
    Property:constructor is function ? true

    The _global.ASSetPropFlags is used to unprotect all the prototypes properties, in order to force them to show up. In a real situation, you should always make sure you keep track of the original settings of an object’s properties and revert the object back to those settings after you are done with it.

    Anyway what is really interesting is that testing the id1 property to see whether it is a function or not, causes the underlying method (the ‘get’ method) to execute.

    Luckily I never use getters and setters. But other people do. This is not to say that getters and setters are bad, just that I ran into a situation which I hadn’t anticipated :) .

    In most situation this will not cause a problem either, but you never know. The getter might go into a recursive loop if no parameters are passed. A class might update it’s properties unintentionally, who knows? I don’t. I do know that if those side effects do happen, you will lose hours of precious time bughunting.

    So how to circumvent these special properties of woe?
    If you look closely at the output again, you’ll see something like __get__id1 in there as well.
    These kind of methods will only be created by flash if you use getters and setters.

    So how can you detect if obj[i] refers to a getter/setter and should not be executed?

    Test for the existence of __set__i and __get__i.

    As the saying goes, you’ll find the solution in the last place you look.

    More information on ASSetPropFlags:
    http://objectpainters.com/blog/2007/06/21/assetpropflags-explained/

    Wedding gift

    August 10th, 2008 by Hans Wichman

    As mentioned in my previous post, we’ve just gotten back from the UK where my sister Corine got married to Rob. It was a wonderful party at which we enjoyed ourselves very much. I pondered long and hard on what to get them, thinking about doing something on the guitar, but I didn’t think it was the right kind of party for that. I thought about doing a speech, but I knew there were already going to be a few very good ones and didn’t want to bore them with mine, although I do regret for passing on the chance to say something to a special person who made all the difference for me in getting through some rough days at school when we were young. Instead I chose to draw/paint something. They say a picture says more than a thousand words, but then again ‘they’ haven’t heard the great speeches so I’ll never trust that statement again ;). Anywayz, this is my way of saying ‘guyz we love you very much and wish you all the best together!’.

    And the sketch which I created first:

    Silence! You infidel!

    August 10th, 2008 by Hans Wichman

    Sooo it has been kind of silent around here lately. It’s annoying really. Although I normally keep these kind of post to myself, I thought I’d make an exception. Silence may give you the wrong impression that nothing is going on here, while the truth is quite the opposite. So what’s causing it?
    Well first of all, I’ve been working on the same project for the past few years, and it’s gonna stay in AS2. Although the project is great, I feel AS2 is .. well .. so last year (for a few years already). On the other hand except for performance reasons I’m not jumping up and down to move to AS3. We’ve come up with a lot of ‘fixes’ for problems in AS2, which are now mostly standard features people are praising in AS3, such as solid error handling, reflection, logging, dictionaries etc and in addition nothing beats MTASC as a compiler:). Besides that I’m still not too sure about migrating the project to AS3, although I myself feel I might need to move on or miss the last rowing AS3 boat entirely.

    So what is going on on that front is that AS2 development continues, while I’m turning to AS3 as well, for example by developing new stuff with Gaia (Steven Sacks’ framework), doing some tutorial work, and I’ll probably do the next NeuroFlasher game in AS3. Migrating the current project is kinda hard because of the 30 or so people involved and the 1000+ fla’s that have to be migrated as well (although AS2 to AS3 communication might help us out there, the garbage collection problems in the current FP9 player will not).

    One of the other causes of radio silence is… truth be told.. family & social life. Yep I know if you are a workaholic this will sound sad :). Roan just turned 1, Leon is almost 5 and we share many a happy hour which couldn’t be further from the concept of silence than it is already. Besides that I enjoy playing AD&D, AT43, and a lot of other computerbased games such as starcraft, diablo, warcraft, with a bunch of friends where I live and online… and yes once you start …. :) Although this only happens about one night in a week, if one night is all you got to do something extra, it diminishes the output by about well yes a 100%! But of course that is entirely my own fault.

    So what else is there? Ah yes, exercise woohoo. I set myself a goal to gain (yes you are reading it correctly) some kilograms, and up to now it’s working quite well, although the muscle/fat gain ratio could be improved :). In addition I’m working on a tattoo for Jeremy from New Jersey for his son Aidan, like I have one for mine. Up to now it’s going nicely, although there is still a certain amount of work left to be done. I’ll post some pictures of it. Which brings me to my most recent painting, a work I did for my sister Corine’s wedding in the UK, from which we just got home. An awesome party with a very nice family, but I won’t go into details here (but I’ll post the painting and some pictures). Last but not least, the beta version of NeuroPuzzles 1.3 is close to completion, and I’m very excited about it’s release (and yes I’ll post some pictures and more info about that too!).
    So here I am, on Sunday morning, with a few hours of holiday to spare, before I’m getting back to work to tomorrow, full of plans for improving the frequency of my blogposts with the images & words promised above!

    FLfile.listFolder archive bit bug

    May 7th, 2008 by Hans Wichman

    Today I ran into a nasty ‘feature’ of FLfile.listFolder in Flash 8 on Windows XP.

    FLfile.listFolder doesn’t list files that don’t have the archive flag enabled.

    Workaround: none except enabling the archive flag for all files you are searching for.

    :(

    Consuming webservices in Flash 8

    May 5th, 2008 by Hans Wichman

    During a partial refactoring process of the Behrloo client system, one of the items on my list was the backend webservice result processing. Without going into a lot of detail how these services are wrapped, it suffices to say that somewhere in the application a couple of webservices are being initialized and utilized through the macromedia webservice classes.

    You might be familiar with them, they come in several flavours, for example the WebServiceConnector and the Webservice class. Personally I don’t like to use the WebServiceConnector, mostly since the Webservice class is simple enough to use and tends to give you more control over what is happening.

    Basic example

    As a simple example of using this Webservice class, paste the following code onto the first frame of the timeline in a new fla document (on a sidenote, REAL applications are not written on a timeline, but for example purposes/quick proof of concepts, this will do just fine):

    //example 1
    import mx.services.*;
    
    var lLog:Log = new Log (Log.VERBOSE, "myLog");
    var lWebService:WebService =
         new WebService ("http://www.flash-mx.com/mm/tips/tips.cfc?wsdl", lLog);
    

    You’ll note some log information passing by in your output window, showing you the progress during the initialization process and such. Somewhere at the end you’ll see a line like:

    4/23 13:14:32 [INFO] myLog: Made SOAPCall for operation getTipByProduct

    This means the webservice supports an operation called getTipByProduct. Other than that you don’t really know much about it. This is the first step in handling webservices, getting a grip on what your dealing with. Although there are different methods for doing so, I’ll mention two:
    1. the webservice panel in flash, this allows you to enter a webservice url, and check the methods including the required parameters and expected return types in flash.
    2. WebServiceStudio, a neat little tool. You might need to disable your proxy if it is giving you the same headaches as ours, but other than that, this tool will let you open, inspect and interrogate webservices.

    Looking through Flash’s helpfiles you’ll find an example where the getTipByProduct is called with a string argument of “Flash”, so let’s try that one by extending our example.

    Webservices are asynchronous

    First thing to realize is that, just like most things in flash, a webservice is asynchronous, meaning that code following the instantiation of a webservice will execute before the webservice is actually instantiated. An example that demonstrates this fact extends the previous example:

    //example 1
    import mx.services.*;
    
    var lLog:Log = new Log (Log.VERBOSE, "myLog");
    var lWebService:WebService =
        new WebService ("http://www.flash-mx.com/mm/tips/tips.cfc?wsdl", lLog);
    
    //example 2 addition
    trace ("*** You'll see me before the log output has completed ***");
    

    This ofcourse means that if you try to call a method on the webservice before it has been instantiated the call will fail. In other words: we will have to wait till it has been successfully instantiated. Without too much further explanation, we’ll just show the complete process of calling a method on the webservice and showing the results and then continue to the result processing part, since the process itself is explained in enough detail in the Flash Manual:

    //example 1
    import mx.services.*;
    
    var lLog:Log = new Log (Log.VERBOSE, "myLog");
    var lWebService:WebService = new WebService ("http://www.flash-mx.com/mm/tips/tips.cfc?wsdl", lLog);
    
    //example 2 addition
    trace ("*** You'll see me before the log output has completed ***");
    
    //example 3 addition
    import mx.utils.Delegate;
    
    lWebService.onFault = function () { trace ("WHOOPS!"); }
    lWebService.onLoad = Delegate.create (this, _performExampleCall);
    
    function _performExampleCall() {
       trace("\n\nPerforming example call...");
       var lPendingCall:PendingCall = lWebService.getTipByProduct("Flash");
       lPendingCall.onResult = Delegate.create (this, _parseResult);
    }
    
    function _parseResult (pResults:Object) {
       trace ("\n\nResults:\n"+pResults);
    }
    

    Decoding webservices results

    The thing to note in this example is that the result is a simple string. However, and that is were we get to the interesting part of this post: that is not always the case. The result could be an array, a predefined class, or some other complex object. This is were a couple of other settings/flags come into play:

    - doDecoding
    - doLazyDecoding

    The Flash manual has this to say with respect to these two flags:

    SOAPCall.doDecoding-description:
    Turns decoding of the XML response on (true) or off (false). By default, the XML response is converted (decoded) into ActionScript objects. If you want just the XML, set SOAPCall.doDecoding to false.

    SOAPCall.doLazyDecoding-description:
    Turns “lazy decoding” of arrays on (true) or off (false). By default, a “lazy decoding” algorithm is used to delay turning SOAP arrays into ActionScript objects until the last moment; this makes functions execute much more quickly when returning large data sets. This means any arrays you receive from the remote location are ArrayProxy objects. Then when you access a particular index (foo[5]), that element is automatically decoded if necessary. You can turn this behavior off (which causes all arrays to be fully decoded) by setting SOAPCall.doLazyDecoding to false.

    Let’s look into doDecoding first:

    Although the description is pretty clear, the actual results I got when interpreting webservice results in Behrloo (which uses a .Net webservice backend), were kind of puzzling. When I turned decoding off, I still got an xml object as a result (while I was expecting a large string of some sort), and when I turned decoding on, I got an object which consisted of nodes of type String, Boolean, Array but also of XmlNode (so part of the result was still xml).

    In the first implementation of the Behrloo backend, I had decoding turned on, and I dealt with both ‘decoded’ nodes, and xml nodes, which I decoded myself using several xml parsing mechanisms. However triggered by the testresults above, I decided to dive a bit deeper into the WebService class source code, and I found that under the hood the Webservice class is already an XML object to execute any calls to a webservice. This means that WHATEVER you do, the result is always already an XML object. With or without decoding.
    With decoding turned on, it goes on to try and decode your object, EXCEPT for the nodes with an xsi:type=”…” attribute, which unfortunately most of my nodes had. I found no way to override this behavior, which means that the default decoding mechanism didn’t do a lot to help me.

    Disabling the default decoding

    By default, the result is decoded. This takes time, and is kind of useless if you are not using this feature anyway. However disabling the decoding cannot be done on a pendingcall since in order to get a reference to a pendingcall, you need to execute it first, so we disable the decoding through:

    _myWebService.getCall ("<operation name here").doDecoding = false;

    If you want to do this automatically for all calls defined on a webservice use something like:

    for (var lOperationName:String in _myWebService.stub.activePort) {
    	myWebService.getCall (lOperationName).doDecoding = false;
    }
    

    So what about doLazyDecoding?

    LazyDecoding only kicks in if you have doDecoding enabled, after all if we do not decode anything, setting it to lazy has no effect.

    Parsing the webservice result with decoding turned off

    Well assuming you still want to use webservice and don’t want to switch to something like remoting, we use a simple XmlUtil class that converts XML objects to complete actionscript objects. In our project we need to interpret the complete result from the webservice, so this is feasible (in other words, we don’t spend time decoding object we don’t use anyway).

    The source for our XmlUtil can be found here (save as XmlUtil.as in nl/trimm/util):
    XmlUtil.as

    Flash HitArea quirks

    May 5th, 2008 by Hans Wichman

    Also known as:

  • dynamically drawn hitarea bug
  • filter applied hitarea bug
  • hitarea no longer works
  • hitarea stops working
  • I recently noticed two weird bugs while handling hitArea’s in Flash (I say bug you might say feature).

    Situation 1:

    - you have a clip on the timeline, let’s call it dialog
    - you have a large hitarea below the dialog, let’s call it largeHitArea
    - you have connected the hitarea to the dialog: dialog.hitArea = largeHitArea
    - you have set the onPress of the dialog to anything but null

    Everything works fine up to this point, the large hitarea makes the dialog act as a modal dialog, since you cannot trigger any mouse events below it.

    Now the following happens:
    - during a graphical redesign you think you are smart, fast and furious YEAH BABY and you apply a DropShadow to the dialog clip on the timeline.

    Next thing you know, your hitArea has died and gone forever, dramatic ain’t it?

    Cause: no idea, but I think cacheAsBitmap has to do with it.
    Workaround: set the dropshadow on the dialog clip through code.

    Situation 2:

    - you have a clip on the timeline to which you want to attach a dynamically drawn hitarea

    Everything works fine up to this point.

    Now the following happens:
    - during a graphical redesign you think you are smart, fast and furious YEAH BABY and you apply a glow filter to the dynamically drawn hitArea.

    Next thing you know, your hitArea has died and gone forever, dramatic ain’t it?

    Cause: no idea, but I think cacheAsBitmap has to do with it (again)
    Workaround: create a bitmap from the dynamicall drawn hitArea first, attach it to a clip, set THAT clip as hitArea and apply the glow filter to it.

    Skinning the v2 Alert component

    April 19th, 2008 by Hans Wichman

    I ran into some trouble today that after skinning a v2 Alert component, none of my changes showed up when I implemented it in my main fla. My main fla ofcourse had it’s class export frame set to something different than export in first frame, and I knew that was the problem, but not quite how to fix it.

    Normally you set the class export frame to something like 2 or 20 or whatever, disable the ‘export in first frame flag’ on all your content by running a jsfl like:

    //
    // DisableExport
    //
    // Sets the linkage identifiers for all items to false

    var items = fl.getDocumentDOM().library.items;
    var item;
    for (var i=0; i item = items[i];
    if (item.linkageExportForAS == true) {
    fl.trace (item.name);
    item.linkageExportInFirstFrame = false;
    }
    }

    and then you make sure that somewhere after your class export frame you have a movieclip on the timeline containing all the stuff for which you disabled the first frame export.

    Apparently there is an order to that content as well, and I had never encountered that before. In my case I had overridden the TitleBackground clip, the ActivatorSkin and ButtonSkin, and you have to make sure these are loaded before the components that use them.

    So imagine you have a ‘all_my_content’ clip, simply put 2 frames in it, put the overriding clips on the first frame and all the components on the second with a nice stop(); to go along.

    Problem solved.

    Alive tattoo

    March 6th, 2008 by Hans Wichman

    It seems I’m posting more artwork than flash related stuff nowadays, and I love it ;) .

    Anyway here is a sketch for a tattoo that comes alive and digs its little claws in.

    I overbleached it a bit, but it’s a rough anyway to paint over, which will bring back the detail (I hope:))

    Luis Royo Fanart

    February 29th, 2008 by Hans Wichman

    Although I wish I could learn to draw by the book, at this point in my life I don’t see it happening anytime soon. Assuming I’m not too tired to draw, I’m almost always too tired to do repetitive exercises (that’s why I’ll never be a great guitar player either :) ). Although drawing in general helps you improve, it’s not the same as studying art. Ah well I decided that that is how it is for now, I’m sure it’ll change someday and I can invest more time in the foundations of drawing instead of simply just reproducing what others drew before me.

    That said, beautiful women and scary beasties ofcourse remain my favourite subject, and luckily there’s a lot of them to go around, so I can keep this up for years:). Here is some more Luis Royo fanart, just a quick sketch, but I liked it nonetheless.