ActionScript 3.0 :: Overriding Event Listeners - Scrollbar Class
Mar 1, 2012
I am working on a Flash demo (all AS3) that requires a scrollbar. I wanted to create my own so on searching I found this Kirupa tutorial. I learned it an incorporated everything (also went well beyond) and the end product works nicely. There is one aspect of the code provided in this tutorial that has me very confused and, although my code includes it and everything works, it bugs me to not understand it. It's this part of the Scrollbar class:
Can event listeners only be added to the class which dispatched the event? I ask because I want to have the logic for the listener on the main class, and the action is dispatched on click from a thumb which is instantiated in a scroller class. Kinda like this:
ActionScript Code: pseudo code: class main { main() {
[code]....
This doesn't work. Why can't the main class listen for an event on the thumb class?
I have many buttons in Main.mxml. I'm trying to move the button functionality into a Class and have Event Listeners inside the class respond to Click and call other functions. I have written:
I'm creating a class for a game, and I'm having a problem removing event listeners from movieclips in that class.In the class file I have an enterFrame event which puts the movieclips into motion - I want to remove that event listener when the movieclip is removed from the stage.I made the function 'public' in the class file and tried to target it as follows (animal is the movieclip)animal.removeEventListener(Event.ENTER_FRAME, animal.onEnterFrameHandler)
i am making a simple game i want to be able to add an keyboard event lisnter within the class constructor. However i am having trouble. i undertsand you have to pass the stage through a listed display object property stage? anyway i am getting errors that do not recognise my event listener keyboard event.
how do I use mouse event listeners outside of my document class. I have the following simplified document class:
public class Main extends Sprite { public var realMain:State1 = new State1();
[Code].....
However, this doesn't work in its current state; "State1" isn't outputted. I have seen references to the use of the Event.ADDED_TO_STAGE event, but am not sure if that is what I need to do, or how to use it.
I want to make a little game. What I need is to add event listeners to all of Tank objects inside the Battlefield instance. I just can seem to figure out how.
I came in to flash on ActionScript 3 and when I was starting out just over a year ago I realised how much of a bother finding keyCodes was and changing controls was just as long as had to look up the new one I wanted to use. My solution was to (eventually) write a class that handles all of my key presses and event listeners attached to that stuff. instead of using keyCodes, the functions use strings for their arguments making it easier to see what keys you want to do what. Initially the class only worked for letters and numbers but I managed to make it easily customisable and includes the arrow keys, numpad numbers, space, enter, shift and control keys.
The reason why I wrote this thread was because: I plan on making it a public class (available to anyone who wnats to use it) and b) to see if there were any specific functions that people think may be useful. So far there are the standard key-down and onRelease type functions as well as a function that only returns true once for the duration that a key is down - difference between pressing and holding.
I would like to make a little app to test out the Accelerometer class. I was thinking of using a Loader to load the swf, and replacing the Accelerometer with my own copy. Is there any way to do this? If it's not possible, how could I do this with a custom client?
I am defining this function in one of my classes:public function onUse():void {};Then in another of my classes (let's call it "class2"), I create a object of this class, and then want to override this function with another one. After some Google-Fu, I have found this, and used it...
The problem is I get Error: Error #2094: Event dispatch recursion overflow. Why does removechild keep getting called if this.parent does not exist? Why doesn't removing event listeners work?
I hsve a setp where a couple of classes inherit from a base class (events, plus common math). All derived classes implement the same set of methods. Another part of the program wants to instantiate any of these classes. So far I was creating empty functions in the base class and overriding them. Could an interface improve on that? I tried to list the common functions in an interface and use that as a datatype, but that would not let me use functions that the base class already inherits, in particular event dispatcher. Would I need to add these to the interface?
I have two SWFs: main.swf and external.swf. main.swf needs to access some methods in external.swf, so it loads external.swf into itself and uses getDefinitionByName("package.Class") to access the class and one of its methods:
var ExternalClass = getDefinitionByName("package.Class") as Class; var ClassInstance = new ExternalClass(); var NeededFunction:Function = ClassInstance["NeededFunction"] as Function; var response:String = NeededFunction(param);
Now, I need to extend the functionality of NeededFunction (which is a public method)... I know it's possible to override public methods, but how would I go about this with a dynamically loaded class?
I was thinking I could do something like this, but it doesn't work:
var ClassInstance["NeededFunction"] = function(param1:uint):String { var newString = "Your number is: "+param1.toString(); //New functionality return newString; }
I want to know how to make class instances into listeners and broadcasters, from inside each class. Here is what I am trying specifically... part of the Proj class... (projectiles, as a matter of fact)
Code: private function listen():Void { u.register(this); onUpdate = function(){ step(); // a function I have which makes the projectile move (not shown) } }
where "u" is another class, the Updater class with this code...
Code: class Updater { // const. --- make this a broadcaster public function Updater(){
[code]....
PS: What is the syntax for using AS2 code tags instead of just "[CODE|"?
So I've gotten into using my own as Classes, and have an interesting question. My main swf calls a php script that gets data from a mysql database which is returned as XML. Part of that data that is retrieved is a filepath to a jpg image. It then takes that filepath and other information, and passes it to my external class, the "news story" class.
All fine and good. Then, the "news story" class uses a loader to load that image along with some text, organize it, and voila, you've got your own very pretty "news story". (I'm extending the MovieClip class here, though I suppose it doesnt matter)
Now, my main swf uses this component to load multiple of these "news stories". The problem is, theres that load time for the image. The main swf is loading them all one at a time, because they are putting each one together on their own.
The key here is that it be dynamic. So, since we don't know how much text is in each "news story", we also therefore don't know it's height. What I'm doing is creating each story in the main swf, pushing it into a "news story" array, adding an event listener to each ones' loader, and when the event listener is triggered, I want it to go to the 'add content' function where it sets the news story's Y value based off the position and height of the previous story that was added (stacking them, obviously). This makes sense, because otherwise it'd add them all on top of each other and it'd be a jumbled mess.
The problem is, the event listener is on the loader object INSIDE the component actionscript. So, how do I figure out which news story to set the Y value for? Because the eventlistener is listening to the loader, not the class. I hope this makes sense AT ALL. Here is the code:
Quote:
while (fancy shmantzy conditions) { /*creates the news story and passes xml data to it (filepath, etc)*/ storyBlock = new StoryBlock(a bunch of parameters); subCBArray.push(storyBlock); //array that stores each news story info
I have made an event listener:text0_mc.addEventListener(MouseEvent.CLICK, showMe);showMe is a function, but I need it to call more than 1 function at once i.e. -ext0_mc.addEventListener(MouseEvent.CLICK, showMe1, showMe2, showMe3, showMe4, showMe5, showMe6, showMe7);Each function contains an if statment as below.
function showMe1(event:MouseEvent):void { if (shuffledArray[1]==orderArray[1]){
Lately I've been twitching in the back of my head wondering just how many references to objects that I'm making, and whether or not they are getting GC'd or not.My question in this sense refers to event listeners and whether or not they are removed in certain cases where you get rid of an object. Two examples:
First, and I think this one is an easy one... when you create an object that adds an event listener to itself INSIDE it's own methods (e.g. this.addEventListener(e:Event, function)), when you REMOVE that object (this), do it's event listeners disappear too? I can only say yes, because they are referencing THAT object and are INSIDE that object.
So I think that question answers itself (but I'd love to know if the truth says otherwise).
But secondly, if you add an event listener to an object from a sibling or parent object, and then remove the object, does that event listener stick around, therefore maintaining a reference to that object and keeping it in memory? And is that the concept that people keep referring to of 'weak' event listeners? E.g. someChildObject.addEventListener(e:Event, function)Also, are event listeners by default strong or weak?
And I am assuming that 'yes', it DOES keep the reference. Which, if you are a n00b programmer like me, you probably are all like, 'aww sh*t damn, how am I supposed to make sure that my objects are getting thrown in the garbage collector's mouth of goodness every once in a while?
I found this code for a contact form at[url]...and it dynamically creates input fields and buttons. I didn't like the dynamically drawn submit and reset buttons, so I added my own MCs(my 'buttons') to the stage.I tried modifying the code and took out the dynamically drawn buttons..However, I cant figure out how to add Event Listeners to the buttons which exist on the stage--Im getting undefined errors...[code]...
I have a movielcip (A) class in which I have used a Tween class effect on a child movieclip (B) scrollRect. The (B) Movieclip in turn has several movieclips whose have tween class effect being executed on thier child movieclips.the tweens are all unique to each movieclip and the event listeners are taken off once completed.This works all well and good in FLASH IDE..My problem arises when I try to view this in a browser on a Windows XP.[code]
What is happening in most cases it that the animation appears to "stick" but i think what may be happening is the listening or removal of the event listeners. The animations are left incompleted.Is there any rule of thumb when using multiple event listeners?[code]the effect disables and re-enables the buttons when its done.... then the listeners are removed.each one with the exception cretes its own unique tween (obviously this is a custom class built as each clip)
I have an array that returns multidimensional data from an mysql database, when this is collected the createNews function creates the user interface. The problem I am having is the loop is iterating quicker than the UI is being created, is there a way to use event listeners with loops so it only continues after my function has completed its work?
In my Flash project I have a movieclip that has 2 keyframes. Both frames contain 1 movieclip each.
frame 1 - Landing frame 2 - Game
The flow of the application is simple:
User arrives on landing page (frame 1) User clicks "start game" button User is brought to the game page (frame 2) When the game is over, the user can press a "play again" button which brings them back to step 1
Both Landing and Game movieclips are linked to separate classes that define event listeners. The problem is that when I end up back at step 1 after playing the game, the Game event listeners fire twice for their respective event. And if I go through the process a third time, the event listeners fire three times for every event. This keeps happening, so if I loop through the application flow 7 times, the event listeners fire seven times. I don't understand why this is happening because on frame 1, the Game movieclip (and I would assume its related class instance) does not exist - but I'm clearly missing something here.
I've run into this problem in other projects too, and tried fixing it by first checking if the event listeners existed and only defining them if they didn't, but I ended up with unexpected results that didn't really solve the problem.
How do you know when you should remove event listeners? For example, I know that if I have a TimerEvent listener, I can safely remove that event when I have stopped and / or deleted my timer. Or, if I have a display object on the stage, and I remove it, I can safely remove any event listeners associated with the display object.
Im sure this has been asked a million times, so forgive me but I cannot seem to find an answer or my search query is wrong. I am using Tweener for animation.
I have 2 MC's on my stage. I have an event listener for my main MC (MOUSE_OVER, MOUSE_OUT) that triggers Tweener to animate another MC on top of the main clip. The problem is that when it overlaps the listener no longer works, and tried to execute the MOUSE_OUT. I understand why its not working, I just cant find a solution. Here is the code and a simple FLA.
