i want to access the child of Object!
for instance:
we a have child(that name is a1) in k1 object.
how can i access it(my means a1 which in the k1)
var k1:keypad=new keypad();
k1.x=7.05;
k1.y=229.20;
add Child(k1);
this.k1.a1.addEventListener(Mouse Event.CLICK,ts);
function ts(event:Mouse Event):void{
trace("OK");
};
thank you.
event has a property target. this one is the child which was clicked.
function ts(event:MouseEvent):void{
trace(event.target);
};
You are doing it wrong. You declare a local variable k1:
var k1:keypad
which is not a member of this object, you cannot access it
this.k1
So your code will probably work this way:
// Bad class name: lowercase.
var k1:keypad = new keypad;
k1.x = 7.05;
k1.y = 229.20;
// This is addChild() method, it is spelled without space.
addChild(k1);
// Then you access k1 just as you did above, without this.
// This will work if you designed your keypad with
// Adobe Flash IDE on default publish settings.
k1.a1.addEventListener(Mouse Event.CLICK, onA1);
// This will work too if a1's instance name is a1:
// k1.getChildByName("a1").addEventListener(Mouse Event.CLICK, onA1);
// Event handler. MouseEvent is a class name,
// it has no space inside.
function onA1(e:MouseEvent):void
{
trace("OK");
}
// Normally you don't need ; after function body.
Related
I have a MovieClip inside library, linkaged to MyObject and it contains a textField.
I don't know how I can access this textField without using the getChildByName method.
Apparently, the 3rd section works when object is on stage (without using addChild). But when using addChild I think there has to be some kind of casting; which I don't know how.
var childElement: MyObject = new MyObject();
childElement.name = "theChildElement";
container.addChild(childElement);
btn.addEventListener(MouseEvent.CLICK, changeText);
function changeText(event: MouseEvent): void
{
var targetBox:MovieClip = container.getChildByName(childElement.name) as MovieClip;
targetBox.textField.text = "hello"; // THIS WORKS
// This works too:
// MovieClip(container.getChildByName("theChildElement"))["textField"].text = "hello"; // THIS WORKS TOO.
// THIS DOESN'T WORK. why?
// container["theChildElement"]["textField"].text = "hello";
}
As confusing as it may seem, instance name, and name are not the same. From your code you should always be able to get to your MC by it's variable name. To get your last like to work you could just use this.
childElement["textField"].text = "hello";
There is a difference between Symbols created by the Flash IDE, which aggregate other DisplayObjects and programmatically created DisplayObjects.
When a DisplayObject is created in the Flash IDE, it's instance name can be used to resolve the instance as a property - which means it can be accessed via []. The [] can be used to access properties or keys of dynamic declared classes - like MovieClip. This necessary because you'll most likely down cast to MovieClip instead of using the symbol class created by Flash. That is not possible when simply using addChild, addChildAt or setChildAt from the DisplayObjectContainer API.
It is always the save way to access it via getChildByNameand check for null because otherwise your app, website or whatever is doomed for 1009 errors as soon as someone is changing the symbols.
I'd create a bunch of helper methods, like
// not tested
function getChildIn(parent:DisplayObjectContainer, names:Array):DisplayObject {
var child:DisplayObject, name:String;
while (names.length > 0) {
name = names.shift();
child = parent.getChildByName(name);
if (!child) {
// log it
return null;
}
if (names.length == 0) {
return child;
}
}
// log it
return null;
}
function getTextFieldIn(parent:DisplayObjectContainer, names:Array):TextField {
return getChildIn(parent, names) as TextField;
}
function getMovieClipIn(parent:DisplayObjectContainer, names:Array):MovieClip {
return getChildIn(parent, names) as MovieClip;
}
Your third method doesn't work because you are trying to call the ChildElement by it's name
without using getChildByName method. On the other hand, you shouldn't call your textField textField, because that's already an actionScript property.
Your should rather call it 'displayText' for example.
For a textField called 'displayText' contained in childElement :
function changeText(event:MouseEvent): void
{
childElement.displayText.text = "hello";
}
Is there any way in Actionscript 3 to add an event listener for any event, in order to do something like trace it? There is a very complicated library that I'm trying to figure out and going through and adding an event listener for every constant in the file would take up more lines of script than the rest of the project.
You may want to prepare the file with the constants first, embed it into the project, get array of strings out of it and add a listener per string, like this:
[Embed(source = 'yourFile.txt', mimeType='application/octet-stream')]
public static const EmbeddedFile:Class; // name accordingly
....
var ba:ByteArray=new EmbeddedFile();
var a:Array = ba.toString.split('\n');
for each (var e:String in a) addEventListener(e,yourFunction);
...
function yourFunction(e:Event):void {
trace(e.type);
trace(flash.utils.describeType(e));
// more if you like
}
I want to add listeners to google map events, but not using anonymous functions but named, external functions as this happens inside a loop, I do not want to define an anonymous function right there, but instead use a named, external function:
Not:
for (...) {
googleMap.event.addListener(instance, eventName, function() {...});
}
But rather sth. like:
doSomething = function(parameter1, parameter2...) {
...
}
for (...) {
googleMap.event.addListener(instance, eventName, params, doSomething);
}
When "instance" is a google map marker, I can add the parameter(s) to the marker using marker.set(paramName, paramValue) and then access the parameters inside the event handler function via this.paramName, but is there any other way to pass values to the event handler function when I don't want to use an anonymous one?
Any advice welcome, Roman.
I had the same problem. Here is a solution. It genuinely avoids the create function in a loop problem, by using the pattern described here
In JavaScript, what are specific reasons why creating functions within a loop can be computationally wasteful?
Which I call the "function factory" pattern.
The other ingredients are that inside the function "this" refers to the object which raised the function (the thing on the map which was clicked, or whatever), and because JavaScript is completely dynamic, you can attach additional properties at will to the thing which was clicked, and query them by calling this.blah inside the function
function doSomethingHandlerFactory(){
var f = function(event){
//do something, for example call a method on a property we attached to the object which raised the event
this.blah.clicked(event);
};
return f;
}
//add a property to the google overlay object (for example a polyline which we've already set up)
thePolyline.blah = ...;
//get a handle for a function, attach the event (in this case to a polyline), and keep
//a reference to the event (in case we want to call removeListener later). The latter
//is optional.
var f = doSomethingHandlerFactory();
var ev = google.maps.event.addListener(thePolyline, 'click', f);
I hope this helps someone out.
How about wrapping your named function in an anonymous function:
google.maps.event.addListener(instance, eventName, function() { doSomething(parameter1, parameter2,...) });
Im trying to understan a function that I found on the web.
Iknow what the function does, It get the information about the webcam in your computer and post it on the textArea,
But the individual line are just a bit confused.
Any help ?
Thanks
private var camera:Camera;
private function list_change(evt:ListEvent):void {
var tList:List = evt.currentTarget as List;
var cameraName:String = tList.selectedIndex.toString();
camera = Camera.getCamera(cameraName);
textArea.text = ObjectUtil.toString(camera);
}
private var camera:Camera;
This line creates a variable of the class type Camera. It does not create an instance of the variable.
private function list_change(evt:ListEvent):void {
This line is a standard function heading. Because the argument is a ListEvent, it makes me think that this function is probably written as an event handler. Because of the name of the function, it is most like listening to the change event on a list.
var tList:List = evt.currentTarget as List;
This line creates a reference to the list that dispatched the event, which caused this handler to be executed.
var cameraName:String = tList.selectedIndex.toString();
This line converts the selectedIndex to a string. It's a bit odd to convert an index to a string, as opposed to some value. But the reason they do that looks to be on the next line..
camera = Camera.getCamera(cameraName);
This uses that camera variable (defined back in line 1) and actually gets an instance of the camera. It uses the "cameraName" which makes me think that the list that dispatched this change event contains a list of cameras available on the system.
textArea.text = ObjectUtil.toString(camera);
This converts the camera object to a string and displays it in a text area. Normally you wouldn't try to do this as it provides no valuable data. A default object will display strings as [Object object] or something similar. Perhaps the camera object has a custom string function; I don't have experience with that. Normally, you'd want to access properties of the object to get useful information, not try this on the object itself.
}
This line is the end of the function. The open bracket was in the 2nd line of code in the function definition.
I have the following functions:
private function createContent(slideData:Object):void
{
transitions = new Transitions();
if (slide){
transitions.applyTransition(slide);
transitions.addEventListener(Transitions.TRANSITION_COMPLETE, completeHandler);
}
slide = new Slide(slideData);
addChild(slide);
transitions.applyTransition(slide);
}
private function completeHandler(e:Event):void{
removeChild(slide);
}
I dispatch an event in the first function and when it comes to the completehandler i would like to delete the slide from the first function but it isnt recognized. How can i pass the slide with the eventlistener so i can remove it in the completeHandler?(i have several instances from slide so i have to pass it through to have the right instance).
Anyone who can help me?
Here are a couple of ways to pass the slide to the event listener.
1/ As a property of the event
//Assuming that:
// 1/ you create a custom Event class that takes two parameters
// type: String
// slide:Slide
// 2/ that you have assigned the slide object to a variable in the
// applyTransition method , which you can then assign to the event
transitions.dispatchEvent( new TransitionEvent(
Transitions.TRANSITION_COMPLETE , slide ) );
2/ As a property of the dispatcher
//Assuming that:
// you assign the slide object to a variable in the
// applyTransition method
private function completeHandler(e:Event):void{
var target:Transitions = event.currentTarget as Transitions;
removeChild(target.slide);
}
You can use the name property of the slide if you wish.
(Though you have not described how & where slide is actually declared - sprite, mc, etc)
Using name property :
Set slide as slide.name = "instanceName" (In your first function)
Get slide as getChildByName("instanceName") (In your second function)
Alternatively you can also:
Set the slide as class member,
accessible by all the function of
the class.
Add reference of every slide to
an array available as class
member to all its functions.
If the variable is not dynamic, you could probably use an anonymous function to pass the variable.
transitions.addEventListener(Transitions.TRANSITION_COMPLETE, function (evt:Event) {
completeHandler(evt, variable1, variable2);
});
function completeHandler(evt, catch1, catch2) {
//do stuff
}