geomorillo/code-1.htm

## code-1.htm
<!DOCTYPE HTML>
<html>
<head>
	<title>Image Zoom With jQuery</title>
	<style type="text/css">

		#view {
			border: 1px solid #333333 ;
			overflow: hidden ;
			position: relative ;
			width: 400px ;
			}

		#image {
			display: block ;
			left: 0px ;
			top: 0px ;
			}

		#zoom {
			background-image: url( "./white_fade.png" ) ;
			border: 1px solid #000000 ;
			cursor: pointer ;
			display: none ;
			height: 200px ;
			position: absolute ;
			width: 200px ;
			z-index: 100 ;
			}

	</style>
	<script type="text/javascript" src="../jquery-1.4.js"></script>
	<script type="text/javascript">

		// When the WINDOW is ready, initialize. We are going with
		// the window load rather than the document so that we
		// know our image will be ready as well (complete with
		// gettable dimentions).
		$( window ).load(function(){

			// First, let's get refernces to the elements we will
			// be using.
			var view = $( "#view" );
			var image = $( "#image" );

			// Create the ZOOM element - this will be added with
			// Javascript since it's more of an "effect".
			var zoom = $( "<a id='zoom'><span><br /></span></a>" );

			// Before we start messing with the scripts, let's
			// update the display to allow for the absolute
			// positioning of the image and zoomer.

			// Set an explicit height / width on the view based
			// on the initial size of the image.
			view.width( image.width() );
			view.height( image.height() );

			// Now that the view has an explicit width and height,
			// we can change the displays for positioning.
			image.css( "position", "absolute" );

			// Set an exlicit height on the image (to make sure
			// that some of the later calcualtions don't get
			// messed up - I saw some irradic caculated-height
			// behavior).
			image.height( image.height() );

			// Before we add the zoom square, we need it to match
			// the aspect ratio of the image.
			zoom.width( Math.floor( image.width() / 2 ) );
			zoom.height( Math.floor( image.height() / 2 ) );

			// Now, add the zoom square to the view.
			view.append( zoom );


			// ---------------------------------------------- //
			// ---------------------------------------------- //


			// Now that we have our UI set up physically, we need
			// to bind the event handlers.

			// We want to show and hide the zoom only when the
			// user hovers over the view.
			view.hover(
				function( event ){
					// Show the soom.
					zoom.show();
				},
				function( event ){
					// Hide the zoom.
					zoom.hide();
				}
			);


			// As the user mouses over the view, we can get the
			// mouse coordinates in terms of the page; we need
			// to be able to translate those into VIEW-based
			// X and Y cooridates. As such, let's get the offset
			// of the view as our base 0x0 coordinate.
			//
			// NOTE: We are doing this here so that we do it once,
			// rather than every time the mouse moves.
			viewOffset = view.offset();

			// Get the jQuery-ed version of the window as we will
			// need to access it's scroll offsets every time the
			// mouse moves over the div.
			//
			// NOTE: This will change the change the refernce to
			// "window" for all of the code in this closure.
			var window = $( window );


			// As the user moves across the view, we want to move
			// the zoom square with them.
			view.mousemove(
				function( event ){
					// Get the window scroll top; the mouse
					// position is relative to the window, NOT
					// the document.
					var windowScrollTop = window.scrollTop();
					var windowScrollLeft = window.scrollLeft();

					// Translate the mouse X / Y into view-local
					// coordinates that can be used to position
					// the zoom box.
					setZoomPosition(
						Math.floor(
							event.clientX - viewOffset.left + windowScrollLeft
						),
						Math.floor(
							event.clientY - viewOffset.top + windowScrollTop
						)
					);
				}
			);


			// I position the zoom box within the view based on
			// the given view-local mouse coordinates.
			var setZoomPosition = function( mouseLeft, mouseTop ){
				// Ideally, we want to keep the zoom box centered
				// on the mouse. As such, we want the given mouse
				// left and mouse top coordiantes to be in the
				// middle of the zoom box.
				var zoomLeft = (mouseLeft - (zoom.width() / 2));
				var zoomTop = (mouseTop - (zoom.height() / 2))

				// As we move the zoom box around, however, we
				// never want it to go out of bounds of the view.

				// Protect the top-left bounds.
				zoomLeft = Math.max( zoomLeft, 0 );
				zoomTop = Math.max( zoomTop, 0 );

				// Protect the bottom-right bounds. Because the
				// bottom and right need to take the dimensions
				// of the zoom box into account, be sure to use
				// the outer width to include the border.
				zoomLeft = Math.min(
					zoomLeft,
					(view.width() - zoom.outerWidth())
					);
				zoomTop = Math.min(
					zoomTop,
					(view.height() - zoom.outerHeight())
					);

				// Position the zoom box in the bounds of the
				// image view box.
				zoom.css({
					left: (zoomLeft + "px"),
					top: (zoomTop + "px")
				});
			};


			// Now that we have the mouse movements being tracked
			// properly, we need to track the click on the zoom to
			// zoom in the image on demand. To do that, however,
			// we need to start storing some information with the
			// image so we can manipulate it as needed.
			image.data({
				zoomFactor: (view.width() / zoom.width()),
				zoom: 1,
				top: 0,
				left: 0,
				width: image.width(),
				height: image.height(),
				originalWidth: image.width(),
				originalHeight: image.height()
			});


			// Now, let's attach the click event handler to the
			// zoom box.
			zoom.click(
				function( event ){
					// First, prevent the default since this is
					// not a navigational link.
					event.preventDefault();

					// Let's pass the position of the zoom box
					// off to the function that is responsible
					// for zooming the image.
					zoomImage(
						zoom.position().left,
						zoom.position().top
					);
				}
			);


			// I take the zoom box coordinates and translate them
			// into an actual image zoom based on the existing
			// zoom and offset of the image.
			//
			// NOTE: We don't care about the dimensions of the
			// zoom box itself as those should have already been
			// properly translated into the zoom *factor*.
			var zoomImage = function( zoomLeft, zoomTop ){
				// Get a reference to the image data object so we
				// don't need to keep retreiving it.
				var imageData = image.data();

				// Check to see if we have reached the max zoom
				// or if the image is currently animating.
				// If so, just return out.
				if (
					(imageData.zoom == 5) ||
					(image.is( ":animated" ))
					){

					// Zooming in beyond this is pointless (and
					// can cause the browser to mis-render the
					// image).
					return;

				}

				// Scale the image up based on the zoom factor.
				imageData.width =
					(image.width() * imageData.zoomFactor);

				imageData.height =
					(image.height() * imageData.zoomFactor);

				// Change the offset set data to re-position the
				// 0,0 coordinate back up in the top left.
				imageData.left =
					((imageData.left - zoomLeft) * imageData.zoomFactor);

				imageData.top =
					((imageData.top - zoomTop) * imageData.zoomFactor);

				// Increase the zoom.
				imageData.zoom++;

				// Animate the zoom.
				image.animate(
					{
						width: imageData.width,
						height: imageData.height,
						left: imageData.left,
						top: imageData.top
					},
					500
				);
			};


			// I reset the image zoom.
			var resetZoom = function(){
				// Get a reference to the image data object so we
				// don't need to keep retreiving it.
				var imageData = image.data();

				// Reset the image data.
				imageData.zoom = 1;
				imageData.top = 0;
				imageData.left = 0;
				imageData.width = imageData.originalWidth;
				imageData.height = imageData.originalHeight;

				// Animate the zoom.
				image.animate(
					{
						width: imageData.width,
						height: imageData.height,
						left: imageData.left,
						top: imageData.top
					},
					300
				);
			};


			// As a final step, to make sure that the image can
			// be zoomed out, bind the mousedown to the document.
			$( document ).mousedown(
				function( event ){
					// Check to see if the view is in the event
					// bubble chain for the mouse down. If it is,
					// then this click was in the view or its
					// child elements.
					var closestView = $( event.target ).closest( "#view" );

					// Check to see if this mouse down was in the
					// image view.
					if (!closestView.size()){

						// The view was not found in the chain.
						// This was clicked outside of the view.
						// Reset the image zoom.
						resetZoom();

					}
				}
			);

		});

	</script>
</head>
<body>

	<h1>
		Image Zoom And Clip With jQuery
	</h1>

	<div id="view">
		<img id="image" src="./girl.jpg" width="400" />
	</div>

</body>
</html>
	<!DOCTYPE HTML>
	<html>
	<head>
	<title>Image Zoom With jQuery</title>
	<style type="text/css">

	#view {
	border: 1px solid #333333 ;
	overflow: hidden ;
	position: relative ;
	width: 400px ;
	}

	#image {
	display: block ;
	left: 0px ;
	top: 0px ;
	}

	#zoom {
	background-image: url( "./white_fade.png" ) ;
	border: 1px solid #000000 ;
	cursor: pointer ;
	display: none ;
	height: 200px ;
	position: absolute ;
	width: 200px ;
	z-index: 100 ;
	}

	</style>
	<script type="text/javascript" src="../jquery-1.4.js"></script>
	<script type="text/javascript">

	// When the WINDOW is ready, initialize. We are going with
	// the window load rather than the document so that we
	// know our image will be ready as well (complete with
	// gettable dimentions).
	$( window ).load(function(){

	// First, let's get refernces to the elements we will
	// be using.
	var view = $( "#view" );
	var image = $( "#image" );

	// Create the ZOOM element - this will be added with
	// Javascript since it's more of an "effect".
	var zoom = $( "<a id='zoom'><span><br /></span></a>" );

	// Before we start messing with the scripts, let's
	// update the display to allow for the absolute
	// positioning of the image and zoomer.

	// Set an explicit height / width on the view based
	// on the initial size of the image.
	view.width( image.width() );
	view.height( image.height() );

	// Now that the view has an explicit width and height,
	// we can change the displays for positioning.
	image.css( "position", "absolute" );

	// Set an exlicit height on the image (to make sure
	// that some of the later calcualtions don't get
	// messed up - I saw some irradic caculated-height
	// behavior).
	image.height( image.height() );

	// Before we add the zoom square, we need it to match
	// the aspect ratio of the image.
	zoom.width( Math.floor( image.width() / 2 ) );
	zoom.height( Math.floor( image.height() / 2 ) );

	// Now, add the zoom square to the view.
	view.append( zoom );


	// ---------------------------------------------- //
	// ---------------------------------------------- //


	// Now that we have our UI set up physically, we need
	// to bind the event handlers.

	// We want to show and hide the zoom only when the
	// user hovers over the view.
	view.hover(
	function( event ){
	// Show the soom.
	zoom.show();
	},
	function( event ){
	// Hide the zoom.
	zoom.hide();
	}
	);


	// As the user mouses over the view, we can get the
	// mouse coordinates in terms of the page; we need
	// to be able to translate those into VIEW-based
	// X and Y cooridates. As such, let's get the offset
	// of the view as our base 0x0 coordinate.
	//
	// NOTE: We are doing this here so that we do it once,
	// rather than every time the mouse moves.
	viewOffset = view.offset();

	// Get the jQuery-ed version of the window as we will
	// need to access it's scroll offsets every time the
	// mouse moves over the div.
	//
	// NOTE: This will change the change the refernce to
	// "window" for all of the code in this closure.
	var window = $( window );


	// As the user moves across the view, we want to move
	// the zoom square with them.
	view.mousemove(
	function( event ){
	// Get the window scroll top; the mouse
	// position is relative to the window, NOT
	// the document.
	var windowScrollTop = window.scrollTop();
	var windowScrollLeft = window.scrollLeft();

	// Translate the mouse X / Y into view-local
	// coordinates that can be used to position
	// the zoom box.
	setZoomPosition(
	Math.floor(
	event.clientX - viewOffset.left + windowScrollLeft
	),
	Math.floor(
	event.clientY - viewOffset.top + windowScrollTop
	)
	);
	}
	);


	// I position the zoom box within the view based on
	// the given view-local mouse coordinates.
	var setZoomPosition = function( mouseLeft, mouseTop ){
	// Ideally, we want to keep the zoom box centered
	// on the mouse. As such, we want the given mouse
	// left and mouse top coordiantes to be in the
	// middle of the zoom box.
	var zoomLeft = (mouseLeft - (zoom.width() / 2));
	var zoomTop = (mouseTop - (zoom.height() / 2))

	// As we move the zoom box around, however, we
	// never want it to go out of bounds of the view.

	// Protect the top-left bounds.
	zoomLeft = Math.max( zoomLeft, 0 );
	zoomTop = Math.max( zoomTop, 0 );

	// Protect the bottom-right bounds. Because the
	// bottom and right need to take the dimensions
	// of the zoom box into account, be sure to use
	// the outer width to include the border.
	zoomLeft = Math.min(
	zoomLeft,
	(view.width() - zoom.outerWidth())
	);
	zoomTop = Math.min(
	zoomTop,
	(view.height() - zoom.outerHeight())
	);

	// Position the zoom box in the bounds of the
	// image view box.
	zoom.css({
	left: (zoomLeft + "px"),
	top: (zoomTop + "px")
	});
	};


	// Now that we have the mouse movements being tracked
	// properly, we need to track the click on the zoom to
	// zoom in the image on demand. To do that, however,
	// we need to start storing some information with the
	// image so we can manipulate it as needed.
	image.data({
	zoomFactor: (view.width() / zoom.width()),
	zoom: 1,
	top: 0,
	left: 0,
	width: image.width(),
	height: image.height(),
	originalWidth: image.width(),
	originalHeight: image.height()
	});


	// Now, let's attach the click event handler to the
	// zoom box.
	zoom.click(
	function( event ){
	// First, prevent the default since this is
	// not a navigational link.
	event.preventDefault();

	// Let's pass the position of the zoom box
	// off to the function that is responsible
	// for zooming the image.
	zoomImage(
	zoom.position().left,
	zoom.position().top
	);
	}
	);


	// I take the zoom box coordinates and translate them
	// into an actual image zoom based on the existing
	// zoom and offset of the image.
	//
	// NOTE: We don't care about the dimensions of the
	// zoom box itself as those should have already been
	// properly translated into the zoom factor.
	var zoomImage = function( zoomLeft, zoomTop ){
	// Get a reference to the image data object so we
	// don't need to keep retreiving it.
	var imageData = image.data();

	// Check to see if we have reached the max zoom
	// or if the image is currently animating.
	// If so, just return out.
	if (
	(imageData.zoom == 5) \|\|
	(image.is( ":animated" ))
	){

	// Zooming in beyond this is pointless (and
	// can cause the browser to mis-render the
	// image).
	return;

	}

	// Scale the image up based on the zoom factor.
	imageData.width =
	(image.width() * imageData.zoomFactor);

	imageData.height =
	(image.height() * imageData.zoomFactor);

	// Change the offset set data to re-position the
	// 0,0 coordinate back up in the top left.
	imageData.left =
	((imageData.left - zoomLeft) * imageData.zoomFactor);

	imageData.top =
	((imageData.top - zoomTop) * imageData.zoomFactor);

	// Increase the zoom.
	imageData.zoom++;

	// Animate the zoom.
	image.animate(
	{
	width: imageData.width,
	height: imageData.height,
	left: imageData.left,
	top: imageData.top
	},
	500
	);
	};


	// I reset the image zoom.
	var resetZoom = function(){
	// Get a reference to the image data object so we
	// don't need to keep retreiving it.
	var imageData = image.data();

	// Reset the image data.
	imageData.zoom = 1;
	imageData.top = 0;
	imageData.left = 0;
	imageData.width = imageData.originalWidth;
	imageData.height = imageData.originalHeight;

	// Animate the zoom.
	image.animate(
	{
	width: imageData.width,
	height: imageData.height,
	left: imageData.left,
	top: imageData.top
	},
	300
	);
	};


	// As a final step, to make sure that the image can
	// be zoomed out, bind the mousedown to the document.
	$( document ).mousedown(
	function( event ){
	// Check to see if the view is in the event
	// bubble chain for the mouse down. If it is,
	// then this click was in the view or its
	// child elements.
	var closestView = $( event.target ).closest( "#view" );

	// Check to see if this mouse down was in the
	// image view.
	if (!closestView.size()){

	// The view was not found in the chain.
	// This was clicked outside of the view.
	// Reset the image zoom.
	resetZoom();

	}
	}
	);

	});

	</script>
	</head>
	<body>

	<h1>
	Image Zoom And Clip With jQuery
	</h1>

	<div id="view">
	<img id="image" src="./girl.jpg" width="400" />
	</div>

	</body>
	</html>