The following example uses a custom class to load and hold external images from a given list (this will be supplied by a configuration file in future examples). Note that Flash 9.0 includes the Loader class which will load any display assets, this is not available in earlier versions which have to use either the MovieClip or MovieClipLoader classes. The Loader and MovieClipLoader classes are able to give more information about download progress and (importantly) errors than our simple example.

1. Make a new movie and create 2 extra layers, naming them scripts, labels, and display.


2. Select frame 10 in all of your layers and then choose Blank Keyframe from the Insert menu.


3. Do the same for frame 20.


4. Select Frame 1 of the labels layer and then, using the Frame palette, give it the label init.


5. Select Frame 10 of the labels layer and give that the label main.


6. Lock the scripts and labels layers. Your timeline should look something like this: -




7. Save your movie as slideshow_auto.fla in a new project folder.


8. Choose New from the file menu and then select ActionScript File. This opens a new .as external script file – the only place you are allowed to create classes.


9. Carefully type the following: -
class AssetManager{ // assets' references are held in an array // *** properties *** var assets:Array; var owner:MovieClip; // *** methods *** // the constructor function public function AssetManager(mClip:MovieClip){ // set up the array this.assets = new Array(); this.owner = mClip; } // loads an asset from a given location public function addAsset(fileName:String):MovieClip{ // make an empty movieclip in a free level var mcName:String = "asset"+this.getAssetCount()+"_mc"; var myClip:MovieClip = owner.createEmptyMovieClip(mcName,this.getAssetCount()+1); myClip.loadMovie(fileName); // hide the clip myClip._alpha = 0; // store the reference in the array this.assets.push(myClip); // and send it back in case it's wanted return myClip; } // tests if all assets have loaded yet public function loaded():Boolean{ var loadDone:Boolean = true; // go through each in turn using a loop for(var i:Number = 0; i‹getAssetCount();i++){ if(assets[i].getBytesLoaded()!=assets[i].getBytesTotal()){ loadDone = false; } } return loadDone; } // gets an asset based on its number public function getAsset(id:Number):MovieClip{ // send back the asset in that position in the array return this.assets[id]; } // gets an asset based on the number public function getAssetCount():Number{ // send back the number of assets return this.assets.length; } }


10. Save the file as AssetManager.as in the same folder that the flash movie is in. Make sure the file name is exactly the same as the Class name.


11. Copy the Timer.as file from the previous tutorial and put it in the same folder.


12. In the folder make a new folder called images and put 3 jpg files in it.


13. Select Frame 1 of the scripts layer. In the Actions panel type the following (you will need to change the image file names for those you are using); -
// script for init // make a new asset manager var pics:AssetManager = new AssetManager(this); // load 3 images // change the file names to those of your images pics.addAsset("images/impact.jpg"); pics.addAsset("images/iss.jpg"); pics.addAsset("images/titan.jpg");


14. Select Frame 3 of the scripts layer and insert a blank Keyframe.


15. In the actions panel, type the following:-
// see if all the assets have loaded yet if (pics.loaded()) { // all loaded, go on this.gotoAndPlay("main"); } else { // not yet, wait for loading to finish this.gotoAndPlay(2); }


16. Select the frame actions for Frame 10 of the scripts layer. Type the following: -
// make a new Timer with an interval of 3 seconds var timer:Timer = new Timer(3000, this); // set the first image number var curImage:Number = 0; // set up the first image setUpClip(pics.getAsset(curImage)); // start the timer timer.startTimer(); // hold the movie here stop(); // the update function which is called by the timer function update():Void { //hide the last picture pics.getAsset(curImage)._alpha = 0; // get the next image's number curImage++; if (curImage>=pics.getAssetCount()) { curImage = 0; } // set up this image setUpClip(pics.getAsset(curImage)); } // resizes a clip to the same dimensions as the stage function setUpClip(myClip:MovieClip):Void { myClip._height = Stage.height; myClip._width = Stage.width; myClip._alpha = 100; }


17. Check your code syntax and close the Actions pane. Your movie is finished.


18. Test it by pressing the CONTROL and ENTER keys together.