JacksonDunstan.com

package
{
	import flash.geom.Point;
	import flash.system.LoaderContext;
	import flash.display.AVM1Movie;
	import flash.display.MovieClip;
	import flash.events.UncaughtErrorEvent;
	import flash.events.ProgressEvent;
	import flash.geom.Rectangle;
	import flash.utils.ByteArray;
	import flash.errors.IOError;
	import flash.events.SecurityErrorEvent;
	import flash.events.AsyncErrorEvent;
	import flash.display.LoaderInfo;
	import flash.net.URLRequest;
	import flash.display.Loader;
	import flash.errors.MemoryError;
	import flash.errors.IllegalOperationError;
	import flash.net.FileFilter;
	import flash.events.IOErrorEvent;
	import flash.events.Event;
	import flash.net.FileReference;
	import flash.display.DisplayObject;
	import flash.events.FocusEvent;
	import flash.text.TextFieldType;
	import flash.events.MouseEvent;
	import flash.text.TextFieldAutoSize;
	import flash.text.TextFormat;
	import flash.text.TextField;
	import flash.display.Sprite;
	import flash.display.StageAlign;
	import flash.display.StageScaleMode;
 
	/**
	 * A viewer for any file Flash's Loader class can load (PNG, JPEG, JPEG-XR, GIF, SWF)
	 * @author Jackson Dunstan, http://JacksonDunstan.com
	 */
	public class ImageViewer extends Sprite
	{
		private static const MAX_CLICK_DIST:Number = 5;
		private static const UI_SPACING:Number = 5;
 
		private static const URL_DEFAULT_TEXT:String = "Enter URL...";
		private var url:TextField;
		private var urlFocused:Boolean;
 
		private var scrollbar:Sprite;
		private var scrollbarText:TextField;
 
		private var browseFileRef:FileReference;
 
		private var image:Sprite;
 
		private var loader:Loader;
 
		private var mouseDownPos:Point;
		private var dragging:Boolean;
 
		public function ImageViewer()
		{
			stage.align = StageAlign.TOP_LEFT;
			stage.scaleMode = StageScaleMode.NO_SCALE;
 
			init();
		}
 
		private function init(): void
		{
			removeChildren();
 
			browseFileRef = new FileReference();
 
			this.loaderInfo.uncaughtErrorEvents.addEventListener(
				UncaughtErrorEvent.UNCAUGHT_ERROR,
				onUncaughtError
			);
 
			// Create UI elements
 
			var title:TextField = new TextField();
			title.selectable = false;
			title.defaultTextFormat = new TextFormat("_sans", 24);
			title.autoSize = TextFieldAutoSize.LEFT;
			title.text = "Image Viewer";
 
			var subTitle:TextField = new TextField();
			subTitle.selectable = false;
			subTitle.defaultTextFormat = new TextFormat("_sans", 12);
			subTitle.autoSize = TextFieldAutoSize.LEFT;
			subTitle.text = "(supports JPEG, JPEG-XR, PNG, GIF, SWF)";
 
			var linkText:TextField = new TextField();
			linkText.selectable = false;
			linkText.mouseEnabled = false;
			linkText.defaultTextFormat = new TextFormat("_sans", 12, 0x0000ff);
			linkText.autoSize = TextFieldAutoSize.LEFT;
			linkText.htmlText = "by <a href=\"http://jacksondunstan.com\">JacksonDunstan.com</a>";
 
			var link:Sprite = new Sprite();
			link.useHandCursor = true;
			link.buttonMode = true;
			link.addChild(linkText);
 
			url = new TextField();
			url.type = TextFieldType.INPUT;
			url.multiline = false;
			url.defaultTextFormat = new TextFormat("_sans", 12);
			url.border = true;
			url.borderColor = 0x000000;
			url.autoSize = TextFieldAutoSize.LEFT;
			url.text = URL_DEFAULT_TEXT;
			url.autoSize = TextFieldAutoSize.NONE;
			url.width = stage.stageWidth * 0.50;
			url.height = url.getLineMetrics(0).height * 1.5;
			url.addEventListener(FocusEvent.FOCUS_IN, onURLFocusedIn);
			url.addEventListener(FocusEvent.FOCUS_OUT, onURLFocusedOut);
 
			var loadURLButton:Sprite = makeButton("Load");
			loadURLButton.addEventListener(MouseEvent.CLICK, onLoadURLButton);
 
			var browsePrompt:TextField = new TextField();
			browsePrompt.selectable = false;
			browsePrompt.defaultTextFormat = new TextFormat("_sans", 12);
			browsePrompt.autoSize = TextFieldAutoSize.LEFT;
			browsePrompt.text = "or... ";
 
			var browseButton:Sprite = makeButton("Browse");
			browseButton.addEventListener(MouseEvent.CLICK, onBrowseButton);
 
			// Add and position elements
			var curY:Number = 0;
 
			addChild(title);
			curY += title.height + UI_SPACING;
 
			subTitle.y = curY;
			addChild(subTitle);
			curY += subTitle.height + UI_SPACING;
 
			link.y = curY;
			addChild(link);
			curY += link.height + UI_SPACING;
 
			url.y = curY;
			addChild(url);
			curY += url.height + UI_SPACING;
 
			loadURLButton.x = url.width;
			loadURLButton.y = url.y;
			addChild(loadURLButton);
 
			browsePrompt.y = curY;
			addChild(browsePrompt);
 
			browseButton.y = browsePrompt.y;
			addChild(browseButton);
			curY += browseButton.height + UI_SPACING;
 
			// Center some elements
			title.x = (this.width - title.width) / 2;
			link.x = (this.width - link.width) / 2;
			subTitle.x = (this.width - subTitle.width) / 2;
			browsePrompt.x = (this.width - browsePrompt.width) / 2;
			browseButton.x = browsePrompt.x + browsePrompt.width;
 
			centerAllChildren();
		}
 
		private function makeButton(label:String): Sprite
		{
			const PAD:Number = 3;
 
			var tf:TextField = new TextField();
			tf.mouseEnabled = false;
			tf.selectable = false;
			tf.defaultTextFormat = new TextFormat("_sans");
			tf.autoSize = TextFieldAutoSize.LEFT;
			tf.text = label;
			tf.name = "lbl";
 
			var button:Sprite = new Sprite();
			button.buttonMode = true;
			button.graphics.beginFill(0xF5F5F5);
			button.graphics.drawRect(0, 0, tf.width+PAD, tf.height+PAD);
			button.graphics.endFill();
			button.graphics.lineStyle(1);
			button.graphics.drawRect(0, 0, tf.width+PAD, tf.height+PAD);
			button.addChild(tf);
 
			return button;
		}
 
		private function onURLFocusedIn(ev:FocusEvent): void
		{
			if (!this.urlFocused)
			{
				this.url.text = "";
				this.urlFocused = true;
			}
		}
 
		private function onURLFocusedOut(ev:FocusEvent): void
		{
			if (this.url.text == "")
			{
				this.url.text = URL_DEFAULT_TEXT;
				this.urlFocused = false;
			}
		}
 
		private function onBrowseButton(ev:MouseEvent): void
		{
			browseFileRef.addEventListener(Event.SELECT, onBrowseSelect);
			browseFileRef.addEventListener(IOErrorEvent.IO_ERROR, onBrowseIOError);
			browseFileRef.browse(
				[
					new FileFilter("Images", "*.png;*.jpg;*.jpeg;*.jpg;*.jpe;*.jxr;*.gif;*.swf"),
					new FileFilter("All", "*.*")
				]
			);
		}
 
		private function onBrowseSelect(ev:Event): void
		{
			removeChildren();
			showScrollbar();
 
			browseFileRef.addEventListener(Event.OPEN, onBrowseOpen);
			browseFileRef.addEventListener(ProgressEvent.PROGRESS, onLoadProgress);
			browseFileRef.addEventListener(IOErrorEvent.IO_ERROR, onBrowseIOError);
			browseFileRef.addEventListener(Event.COMPLETE, onBrowseFileLoaded);
			try
			{
				browseFileRef.load();
			}
			catch (illegalOpErr:IllegalOperationError)
			{
				fatalError("Browsing not allowed");
			}
			catch (memoryErr:MemoryError)
			{
				fatalError("Out of memory");
			}
			catch (err:Error)
			{
				fatalError("Unknown error");
			}
		}
 
		private function onBrowseOpen(ev:Event): void
		{
			// Load started. Nothing to do.
		}
 
		private function onBrowseFileLoaded(ev:Event): void
		{
			loadSafely(browseFileRef.data, null);
		}
 
		private function onBrowseIOError(ev:IOErrorEvent): void
		{
			fatalError("Browsing error");
		}
 
		private function onLoadURLButton(ev:MouseEvent): void
		{
			loadSafely(null, this.url.text);
		}
 
		private function loadSafely(bytes:ByteArray, url:String): void
		{
			removeChildren();
			showScrollbar();
 
			try
			{
				// Allow loading SWF files with code in them on AIR
				var context:LoaderContext = new LoaderContext();
				context.allowCodeImport = true;
 
				loader = new Loader();
 
				var cli:LoaderInfo = loader.contentLoaderInfo;
				cli.addEventListener(AsyncErrorEvent.ASYNC_ERROR, onLoadAsyncError);
				cli.addEventListener(IOErrorEvent.IO_ERROR, onLoadIOError);
				cli.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onLoadSecurityError);
				cli.addEventListener(Event.COMPLETE, onImageLoaded);
				if (url)
				{
					cli.addEventListener(ProgressEvent.PROGRESS, onLoadProgress);
					loader.load(new URLRequest(url), context);
				}
				else
				{
					loader.loadBytes(bytes, context);
				}
			}
			catch (ioErr:IOError)
			{
				fatalError("Loading errror");
			}
			catch (securityErr:SecurityError)
			{
				fatalError("Security error");
			}
			catch (illegalOpErr:IllegalOperationError)
			{
				fatalError("Loading not supported");
			}
			catch (err:Error)
			{
				fatalError("Unknown error");
			}
		}
 
		private function showScrollbar(): void
		{
			var title:TextField = new TextField();
			title.selectable = false;
			title.defaultTextFormat = new TextFormat("_sans", 24);
			title.autoSize = TextFieldAutoSize.LEFT;
			title.text = "Loading...";
 
			scrollbar = new Sprite();
 
			scrollbarText = new TextField();
			scrollbarText.selectable = false;
			scrollbarText.defaultTextFormat = new TextFormat("_sans", 24, 0xffffff);
			scrollbarText.autoSize = TextFieldAutoSize.LEFT;
 
			setScrollbarPercent(0);
 
			var curY:Number = 0;
 
			addChild(title);
			curY += title.height + UI_SPACING;
 
			scrollbar.y = curY;
			addChild(scrollbar);
 
			addChild(scrollbarText);
 
			centerAllChildren();
		}
 
		private function setScrollbarPercent(percent:Number): void
		{
			var totalWidth:Number = stage.stageWidth * 0.5;
			var totalHeight:Number = this.url.height;
 
			// Draw border
			scrollbar.graphics.lineStyle(1, 0x000000);
			scrollbar.graphics.drawRect(0, 0, totalWidth, totalHeight);
 
			// Draw bar
			scrollbar.graphics.beginFill(0x000000);
			scrollbar.graphics.drawRect(0, 0, totalWidth*percent, totalHeight);
			scrollbar.graphics.endFill();
 
			// Center text on bar
			scrollbarText.text = int(percent) + "%";
			scrollbarText.x = scrollbar.width / 2;
			scrollbarText.y = (scrollbar.height - scrollbarText.height) / 2;
		}
 
		private function onLoadProgress(ev:ProgressEvent): void
		{
			setScrollbarPercent(ev.bytesLoaded / ev.bytesTotal);
		}
 
		private function onLoadAsyncError(ev:AsyncErrorEvent): void
		{
			fatalError("Async error");
		}
 
		private function onLoadIOError(ev:IOErrorEvent): void
		{
			fatalError("Loading error");
		}
 
		private function onLoadSecurityError(ev:SecurityErrorEvent): void
		{
			fatalError("Security error");
		}
 
		private function onImageLoaded(ev:Event): void
		{
			removeChildren();
 
			var loaderInfo:LoaderInfo = ev.target as LoaderInfo;
			image = new Sprite();
 
			// Match frame rate for AVM2 (AS3) SWFs
			if (image is MovieClip)
			{
				stage.frameRate = loaderInfo.frameRate;
				image.addChild(loaderInfo.content);
			}
			// Don't try to add AVM1 (AS1 & AS2) SWFs directly, since that throws an error. Use the
			// Loader instead.
			else if (image is AVM1Movie)
			{
				image.addChild(loader);
			}
			else
			{
				image.addChild(loaderInfo.content);
			}
 
			addChild(image);
 
			// Too big. Put at 0,0 and zoom with click.
			if (image.width > stage.stageWidth || image.height > stage.stageHeight)
			{
				image.scaleX = image.scaleY = getImageScale();
				stage.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
				stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
			}
			// Fits. Center image.
			else
			{
				var bounds:Rectangle = image.getBounds(image);
				image.x = -bounds.x + (stage.stageWidth - bounds.width) / 2;
				image.y = -bounds.y + (stage.stageHeight - bounds.height) / 2;
			}
		}
 
		private function onMouseDown(ev:MouseEvent): void
		{
			mouseDownPos = new Point(ev.stageX, ev.stageY);
			dragging = false;
			stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
		}
 
		private function onMouseUp(ev:MouseEvent): void
		{
			if (dragging)
			{
				dragging = false;
				image.stopDrag();
			}
			else if (getClickDistance(ev) < MAX_CLICK_DIST)
			{
				if (image.scaleX < 1 || image.scaleY < 1)
				{
					image.x = image.y = 0;
					image.scaleX = image.scaleY = 1;
				}
				else
				{
					image.x = image.y = 0;
					image.scaleX = image.scaleY = getImageScale();
				}
			}
		}
 
		private function onMouseMove(ev:MouseEvent): void
		{
			if (
				!dragging
				&& image.scaleX == 1
				&& image.scaleY == 1
				&& getClickDistance(ev) > MAX_CLICK_DIST
			)
			{
				dragging = true;
				image.startDrag();
				stage.removeEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
			}
		}
 
		private function getImageScale(): Number
		{
			return Math.min(
				stage.stageWidth / image.width,
				stage.stageHeight / image.height
			);
		}
 
		private function getClickDistance(ev:MouseEvent): Number
		{
			return Point.distance(new Point(ev.stageX, ev.stageY), mouseDownPos);
		}
 
		private function fatalError(msg:String): void
		{
			removeChildren();
 
			var title:TextField = new TextField();
			title.selectable = false;
			title.defaultTextFormat = new TextFormat("_sans", 24);
			title.autoSize = TextFieldAutoSize.LEFT;
			title.text = msg + ". Please restart and try again.";
			addChild(title);
 
			var restartButton:Sprite = makeButton("Restart");
			restartButton.addEventListener(MouseEvent.CLICK, onRestartButton);
			restartButton.x = (title.width - restartButton.width) / 2;
			restartButton.y = title.height;
			addChild(restartButton);
 
			centerAllChildren();
		}
 
		private function onRestartButton(ev:MouseEvent): void
		{
			init();
		}
 
		private function centerAllChildren(): void
		{
			var padX:Number = (stage.stageWidth - this.width) / 2;
			var padY:Number = (stage.stageHeight - this.height) / 2;
			for (var i:int; i < this.numChildren; ++i)
			{
				var child:DisplayObject = getChildAt(i);
				child.x += padX;
				child.y += padY;
			}
		}
 
		private function onUncaughtError(ev:UncaughtErrorEvent): void
		{
			fatalError("An error occurred: " + ev.error);
		}
	}
}