AS3 Accessing frame without using gotoAndStop - actionscript-3

Is there a way to access the image data (children/transformation info) of a particular frame in a MovieClip without having to use the gotoAndStop methods.
These methods are part of a rendering pipeline, all I want is access to the data, not to start a chain of asynchronous events that were developed to render things on screen, call multiple event listeners and execute frame actions.

Not only can you not do that, but gotoAndStop() doesn't even immediately make that data available. The contents of a frame aren't code accessible until the FRAME_CONSTRUCTED Event is dispatched when that frame is reached, so what you would actually have to do is more like:
var lastFrame:int = currentFrame;
function ready(e:Event):void
{
if(currentFrame !== lastFrame)
{
// In this example, frame 15 is where some image
// data we want is.
if(currentFrame === 15)
{
// Get image data.
//
}
lastFrame = currentFrame;
}
}
addEventListener(Event.FRAME_CONSTRUCTED, ready);
Needless to say; storing data you need across frames is not a viable way to structure an application.

Related

How do you share a variable between scripts using the MovieClip variable?

I'm currently trying to code an interactive timeline for my Uni project (keep in mind im a new coder) and we go over basic actionscript stuff. I was taught to communicate between scripts using a movieclip variable and declaring this.parent.
I have 3 scripts, one that controls the button that is used to move forward in the timeline, one is main, and the other controls the text box which displays the timeline. I placed a number variable in main, initialised at 0(timeCount). In the button script, i have it linked to main using refToMain, my movieclip variable. Within the button script, if the user clicks on the button, it rises the number variable from main using refToMain(refToMain.timeCount). It was my ambition to have the text box script track the number and each number has a different bit of the timeline on. However, when I trace timeCount in the button script, the number seems fine and raises accordingly, however it doesnt change the number in any other script. How can I fix this using basic as3 code?
In Main:
var timeCount:Number = 0;
In Button:
public function mDown (mDown:MouseEvent){
refToMain.timeCount += 1;
if(refToMain.timeCount >= 10){
refToMain.timeCount = 10;
}
trace(refToMain.timeCount);
In timeline:
if(refToMain.timeCount == 0){
timelineText.text = "welcome"
}
if(refToMain.timeCount == 1){
timelineText.text = "hello"
}
Are you expecting the code in your timeline to run continuously instead of just once? A frame script will only run once each time the timeline reaches that frame. And if you only have one frame, the timeline won't advance at all. If that's the case, a simple fix would be to add another frame to your timeline with F5, and then your timeline will alternate between your two frames forever so that your script on frame 1 will execute every other frame.
A better option would be to call the script that updates the timeline text directly every time the button is clicked. So you would move the code from your timeline script to your button script like this:
public function mDown (mDown:MouseEvent) {
refToMain.timeCount += 1;
if(refToMain.timeCount >= 10) {
refToMain.timeCount = 10;
}
trace(refToMain.timeCount);
if(refToMain.timeCount == 0) {
MovieClip(root).timelineText.text = "welcome";
}
if(refToMain.timeCount == 1) {
MovieClip(root).timelineText.text = "hello";
}
}
There are several ways and approaches to access objects and variables across your application.
1) Traversing. The (probably) older and the most straightforward one is fully understanding and controlling the display list tree. If you understand where your current script is and where your target script is, you just traverse this tree with root to go straight to the top, parent to go level up and getChildByName or [] or dot notation to go level down.
Pros: it's simple. Contras: The weak point of this approach is its inflexibility. Once you change the structure of display list tree, the access would presumably be broken. Also, this way you might not be able to access things that are not on the display list. Also, there are cases the dot notation would not work, and there are cases getChildByName would not work. Not that simple, after all.
2) Bubbling events. These are events that bubble from the depths of display list to the root. Mouse events are bubbling: you can catch it anywhere from the deepest object that had some mouse event then all its parents right up to the stage. You can read about them here. So, you can send bubbles from whatever depth you want then intercept them at the any parent of the event target:
// *** TextEvent.as class file *** //
package
{
import flash.events.Event;
public class TextEvent extends Event
{
static public const TEXT_EVENT:String = "text_event";
public var text:String;
// Although it is not a very good practice to leave the basic Event
// parameters out of it, but it will do for this example.
public function TextEvent(value:String)
{
// Set type = "text_event" and bubbles = true.
super(TEXT_EVENT, true);
text = value;
}
}
}
// *** Button script *** //
import TextEvent;
// Dispatch the event.
dispatchEvent(new TextEvent("welcome"));
// *** Main timeline *** //
import TextEvent;
// Subscribe to catch events.
addEventListener(TextEvent.TEXT_EVENT, onText);
function onText(e:TextEvent):void
{
// Extract the passed text value.
timelineText.text = e.text;
}
Pros: it is good in an app architecture terms. Contras: you cannot catch the bubbling event at the point that is not parent of event source.
3) Static class members. Or singleton pattern, its basically the same. You can devise a class that shares certain values and references over the whole application:
// *** SharedData.as class file *** //
package
{
import flash.display.MovieClip;
public class SharedData
{
static public var MainTimeline:MovieClip;
}
}
// *** Main timeline *** //
import SharedData;
// Make root accessible from anywhere.
SharedData.MainTimeline = this;
// *** Button script *** //
import SharedData;
// You can access main timeline via shared reference.
SharedData.MainTimeline.timelineText.text = "welcome";
Pros: you are not limited by display list structure any more, you can also share non-visual instances this way, anything. Contras: careful with timelines, they tend to destroy and create timeline instances as playhead moves, so it is not impossible to end up with a reference to a removed object while timeline holds a new instance that is no longer shared.

AS3: how do i stop two of the same function from playing at once?

i am using AS3 to create a function that will automatically play a movieclip all the way through and then remove it. my project is going to have a lot of animated cutscenes, so id like to be able to call this function, use the cutscene id like as a parameter, and then move on to the next. the problem is, im trying to use the function multiple times in a row to play clips sequentially, but they're all playing at the same time. is there a fix, or a better way to do this altogether?
playClip(new a_walk); //find a way to make these stop playing at the same time
playClip(new a_door);
//a_walk and a_door are the AS linkage class names for the movieclips im referring to
function playClip (clip:MovieClip):void {
addChildAt(clip, 0);
clip.mask = myMask;
clip.x=412.4;
clip.y=244.5;
clip.addEventListener(Event.ENTER_FRAME, checkframes);
function checkframes(event:Event) {
if (clip.currentFrame == clip.totalFrames) {
//trace("wow! youre an idiot!");
if (clip.parent) {
clip.parent.removeChild(clip);
trace (100);
return;
}
}
}
}
Sounds like you want a mechanism to play a queue of MovieClips? If so, here is a way you can accomplish this:
//create an array with the clips you want to play (in order), in my example here, the items can be a MovieClip derived Class, or a MovieClip instance
var playQueue:Array = [a_walk, a_door];
//create a var to store the currently playing clip
var currentClip:MovieClip;
playNext(); //call this when you want the queue of clips to start playing
function playNext():void {
//if there was an item previously playing (currentClip has a value), stop it and remove it/dispose of it
if(currentClip){
currentClip.stop(); //stop it from playing
currentClip.addFrameScript(currentClip.totalFrames-1, null); //remove the frame script that was added
currentClip.parent.removeChild(currentClip); //remove it from the display
currentClip = null;
}
//check if there's anything left to play
if(playQueue.length < 1) return;
var nextItem:* = playQueue.shift(); //shift retrieves and removes the first item in the array;
if(nextItem is Class){
//if it's a class, instantiate it
currentClip = new nextItem();
}else{
currentClip = MovieClip(nextItem);
}
//initialize the movie clip
addChildAt(currentClip, 0);
currentClip.gotoAndPlay(1);
//this is just what you were doing before:
currentClip.mask = myMask;
currentClip.x=412.4;
currentClip.y=244.5;
//add a command on the last frame of the movie clip to play the next item in the queue
currentClip.addFrameScript(currentClip.totalFrames-1, playNext);
//addFrameScript is 0 based, so 0 would refer to the first frame. This is why we subtract 1 to get the last frame
}
I should note, that addFrameScript is an undocumented function. It serves as a nice shortcut so you don't have to have an ENTER_FRAME listener checking currentFrame vs. totalFrames. Being undocumented however, one can not count on it's continued existence in future versions of the Flash/AIR runtimes (though it's been around for a long long time)
note
This answer is a work in progress. I'm waiting on a response from the OP.
// playClip(new a_door); don't call this yet, or they will just both play.
var clipData:CustomClass = new CustomClass(); // add an instance of a custom class to hold the value of the movie
//clip being played (so that you can use this value later in the event handler.)
// it will also hold a value of the next clip
clipData._currentClip = a_walk;
clipData._nextClip = a_door;
playClip(new a_walk);
function playClip (clip:MovieClip):void {
addChildAt(clip, 0);
clip.mask = myMask;
clip.x=412.4;
clip.y=244.5;
clip.addEventListener(Event.ENTER_FRAME, checkframes);
}
function checkframes(event:Event) {
if (clipData._currentClip.currentFrame == clipData._currentClip.totalFrames) {
//trace("wow! youre an idiot!");
if (clipData._currentClip.parent) {
playClip(clipData._nextClip);
clipData._currentClip.parent.removeChild(clipData._currentClip);
clipData._currentClip = clipData._nextClip; // moves the clips down
//clipData._nextClip = here we have
//a problem. Do these clips play in a set
//order, first to last? Or do the play out of
//order jumping back and forth? If so, how
//are you planning on controlling which clip
//plays next?
trace (100);
return;
}
}
}
I haven't checked this in Flash yet to see if it works, but I noticed that you are defining a function inside another function, which I don't think is good practice, so this might clean things up for you. Give it a try and let us know.
I'll try to fix my code above when I get a chance. In the meantime, you answered my question about playing the clips in order, so a simple solution would be to put all the clips in an array and then play them by playClip(clipArray[i]) and then when the clip ends and gets removed, do i++ and call the same function playClip(clipArray[i]) which will play the next clip in the array.

AS3 Loading multiple external SWFs and them closing them

I am trying to load multiple external SWFs in one main SWF.
I start with the main swf. Now I need to link 4 games to it.
I have created 4 different loaders and I make it load each game into a different frame for each game. Ie when I go to frame 1 for example it will load game1. The code I am using for each game frame is:
public function LoadGame1(evt:MouseEvent):void {
trace("load game1");
this.gotoAndPlay("Game1");
var url:URLRequest = new URLRequest("game1.swf");
game1Loader.load(url);
addChild(game1Loader);
}
game 2 is the same with the exception of game1 it will be game2 etc.
Now my issue is when I close each game and go to another it does not work. I can not load another game or reload it. When I go back to the menu I use:
public function backFunc(evt:MouseEvent):void {
trace("menu");
myLoader.unload();
game1Loader.unload();
game2Loader.unload();
game3Loader.unload();
game4Loader.unload();
this.gotoAndPlay("Menu");
}
I'm assuming it has something to do with the unloading - it unloads it all and closes the loader. Ive tried removeChild(game1Loader) etc but it doesn't work? The game will close and it will go back to the menu but then I will not be able to get back into the game or load another one?
Please help :(
Flash timelines are kind of like a static state machine; moving from frame-to-frame will run all of the document code at that frame (every time). It also resets the value of the content to the state it was in during design time (so, frame = design + code). Because of the headaches this model can cause, I highly recommend you do all of your design & code in a single frame.
The way you've written your sample code, it seems to imply that you're writing custom functions for each of your game loaders. You can unify that by driving all the btn events through the same function and depending on some differentiating property (like their names), load the appropriate game.
Finally, I suspect the reason your loaders stop working is because you've unloaded and removed them from the stage. That stuff gets garbage collected. Rather than making the loader a global object, feel free to create a new one each time you make your loadGame() call.
// We'll store our buttons in an array to make it easier to register for events.
var btns:Array = [
btn_Load1,
btn_Load2,
btn_Load3
]
// Now cycle over them in bind to our listener
for each (var btn:MovieClip in btns) {
btn.addEventListener("mouseUp", btnEvents);
}
function btnEvents(e:MouseEvent):void {
// With one event listener, we can sort out each condition
switch (e.currentTarget.name) {
case "btn_Load1":
loadGame("game1.swf")
break;
case "btn_Load2":
loadGame("game2.swf")
break;
case "btn_Load3":
loadGame("game3.swf")
break;
}
}
function loadGame(url:String):void {
// Now we only have to write our loader code once (for all buttons)
trace("Loading " + url);
// Because we're unloading our swfs (and unloaded assets get garbage collected),
// we'll want to make a new loader each time we call a load op
var loader:Loader = new Loader();
loader.name = "current_game";
loader.load(new URLRequest(url));
addChild(loader);
}
function backFunc(evt:MouseEvent):void {
// Dynamically find our current game, and unload it.
trace("menu");
getChildByName("current_game").unload();
}

Removing Children in AS3

My flash game exists of a timeline with multiple frames (I know I should avoid the timeline)
The point of the game is a point and click adventure. The object that you are able to pick up get spawned and destroyed accordingly as you enter and leave the room. now my problem is when entering frame 14 (accessibel from frame 12) it creates a piece of paper which you are able to pick up if you have another item. Now my problem is when you can't or don't pick up the paper and go back to frame 12 (only exit is to frame 12), you can't click on any other object and you are basicly stuck on frame 12. When leaving and entering other rooms it works properly but for some reason it doesn't for on the paper on frame 14.
My code to remove objects works as following
In my Main.as Documentclass I have a function that called as soon as the game starts which does the following
if (lastframe == 14)
{
trace (prop.numChildren);
while (prop.numChildren )
{
prop.removeChildAt(0);
}
}
The lastframe variable is established when moving from frames
this function is found on the frame itself (each exit function on it's own respective frame)
function exitKantine(event:MouseEvent):void
{
Main.lastframe = 14;
gotoAndStop(12);
}
The function to remove the prop actually removes it but then causes all other clickable objects to be unusable.
Thanks for looking at my question and thanks in advance for your suggestions
I would say instead of removing children, add it once in the beginning, add all the listeners in the beginning, and toggle the visibility instead of trying to addChild and removeChild every time you want to hide it. Use an array so you can have a few happening at the same time.
something like this:
private function init():void
{
assignVars();
addListeners();
stage.addChild // make sure this is in document class or you are passing stage to the class using it
}
for (var i = 0; i < _thingsAry.length; i++)
{
if (_thingsAry[i] == 14)
{
_thingsAry[i].visible = false;
trace("the visibility of _thingsAry[" + i + "] is " + _thingsAry[i].visible
}
}

Timeline instances not on first frame

It's been a while since I've had to write Actionscript that really needs to integrate with the timeline (in this case, controlling a series of frames that must happen in a certain sequence) and I am trying to figure out what to do.
In the first few frames, I have a button "next_1".
At frame 10, I need to have another button "next_2". I really really need this button to not be on frame one (I could possibly just make it invisible, but that's going to create a clickable area that I don't want).
The problem is, anything I don't put on "frame_1" renders as null in my Document class.
Is there any solution to this? I would rather not have to write my script on the timeline if possible (it seems easier in the long run to keep it in a document class)...
Items on the timeline are created on the fly, so if the playhead has not reached frame 10, next_2 is not created.
Easiest Document-class solution:
Create an array of frame labels like ["label1", "label2"]
Create sectionIndex var and set it to 0
Create a next button on its own layer so it is always showing.
When the next button is clicked, increment sectionIndex, then gotoAndPlay(myLabels[sectionIndex])
Okay, directly lifted from "Real World Flash Game Development":
/**************************************************
* FRAME LABELS *
**************************************************/
private function enumerateFrameLabels():void {
for each (var label:FrameLabel in currentLabels) {
addFrameScript(label.frame-1, dispatchFrameEvent);
}
}
private function dispatchFrameEvent():void {
dispatchEvent(new Event(currentLabel, true));
}
This dispatches an event at each frame label on the timeline.
Then you can just add event listeners for each frame:
addEventListener("name_of_my_framelabel", frameHandler);
addEventListener("another_framelabel", frameHandler);
And write a switch statement to add event listeners for the buttons when they actually show up on the timeline.
private function frameHandler(e:Event):void {
switch(e.type) {
case 'screen_2':
stop();
next_2.addEventListener(MouseEvent.CLICK, click2, false, 0, true)
break;
}
}