web/wp-includes/js/imgareaselect/jquery.imgareaselect.dev.js
changeset 194 32102edaa81b
parent 136 bde1974c263b
--- a/web/wp-includes/js/imgareaselect/jquery.imgareaselect.dev.js	Thu Sep 16 15:45:36 2010 +0000
+++ b/web/wp-includes/js/imgareaselect/jquery.imgareaselect.dev.js	Mon Nov 19 18:26:13 2012 +0100
@@ -1,8 +1,8 @@
 /*
  * imgAreaSelect jQuery plugin
- * version 0.9.1
+ * version 0.9.9
  *
- * Copyright (c) 2008-2009 Michal Wojciechowski (odyniec.net)
+ * Copyright (c) 2008-2011 Michal Wojciechowski (odyniec.net)
  *
  * Dual licensed under the MIT (MIT-LICENSE.txt)
  * and GPL (GPL-LICENSE.txt) licenses.
@@ -13,86 +13,201 @@
 
 (function($) {
 
+/*
+ * Math functions will be used extensively, so it's convenient to make a few
+ * shortcuts
+ */
 var abs = Math.abs,
     max = Math.max,
     min = Math.min,
     round = Math.round;
 
+/**
+ * Create a new HTML div element
+ *
+ * @return A jQuery object representing the new element
+ */
 function div() {
     return $('<div/>');
 }
 
+/**
+ * imgAreaSelect initialization
+ *
+ * @param img
+ *            A HTML image element to attach the plugin to
+ * @param options
+ *            An options object
+ */
 $.imgAreaSelect = function (img, options) {
     var
-
+        /* jQuery object representing the image */
         $img = $(img),
 
+        /* Has the image finished loading? */
         imgLoaded,
 
+        /* Plugin elements */
+
+        /* Container box */
         $box = div(),
+        /* Selection area */
         $area = div(),
+        /* Border (four divs) */
         $border = div().add(div()).add(div()).add(div()),
+        /* Outer area (four divs) */
         $outer = div().add(div()).add(div()).add(div()),
+        /* Handles (empty by default, initialized in setOptions()) */
         $handles = $([]),
 
+        /*
+         * Additional element to work around a cursor problem in Opera
+         * (explained later)
+         */
         $areaOpera,
 
+        /* Image position (relative to viewport) */
         left, top,
 
-        imgOfs,
+        /* Image offset (as returned by .offset()) */
+        imgOfs = { left: 0, top: 0 },
 
+        /* Image dimensions (as returned by .width() and .height()) */
         imgWidth, imgHeight,
 
+        /*
+         * jQuery object representing the parent element that the plugin
+         * elements are appended to
+         */
         $parent,
 
-        parOfs,
+        /* Parent element offset (as returned by .offset()) */
+        parOfs = { left: 0, top: 0 },
 
+        /* Base z-index for plugin elements */
         zIndex = 0,
 
+        /* Plugin elements position */
         position = 'absolute',
 
+        /* X/Y coordinates of the starting point for move/resize operations */
         startX, startY,
 
+        /* Horizontal and vertical scaling factors */
         scaleX, scaleY,
 
-        resizeMargin = 10,
-
+        /* Current resize mode ("nw", "se", etc.) */
         resize,
 
+        /* Selection area constraints */
+        minWidth, minHeight, maxWidth, maxHeight,
+
+        /* Aspect ratio to maintain (floating point number) */
         aspectRatio,
 
+        /* Are the plugin elements currently displayed? */
         shown,
 
+        /* Current selection (relative to parent element) */
         x1, y1, x2, y2,
 
+        /* Current selection (relative to scaled image) */
         selection = { x1: 0, y1: 0, x2: 0, y2: 0, width: 0, height: 0 },
 
+        /* Document element */
+        docElem = document.documentElement,
+
+        /* Various helper variables used throughout the code */
         $p, d, i, o, w, h, adjusted;
 
+    /*
+     * Translate selection coordinates (relative to scaled image) to viewport
+     * coordinates (relative to parent element)
+     */
+
+    /**
+     * Translate selection X to viewport X
+     *
+     * @param x
+     *            Selection X
+     * @return Viewport X
+     */
     function viewX(x) {
         return x + imgOfs.left - parOfs.left;
     }
 
+    /**
+     * Translate selection Y to viewport Y
+     *
+     * @param y
+     *            Selection Y
+     * @return Viewport Y
+     */
     function viewY(y) {
         return y + imgOfs.top - parOfs.top;
     }
 
+    /*
+     * Translate viewport coordinates to selection coordinates
+     */
+
+    /**
+     * Translate viewport X to selection X
+     *
+     * @param x
+     *            Viewport X
+     * @return Selection X
+     */
     function selX(x) {
         return x - imgOfs.left + parOfs.left;
     }
 
+    /**
+     * Translate viewport Y to selection Y
+     *
+     * @param y
+     *            Viewport Y
+     * @return Selection Y
+     */
     function selY(y) {
         return y - imgOfs.top + parOfs.top;
     }
 
+    /*
+     * Translate event coordinates (relative to document) to viewport
+     * coordinates
+     */
+
+    /**
+     * Get event X and translate it to viewport X
+     *
+     * @param event
+     *            The event object
+     * @return Viewport X
+     */
     function evX(event) {
         return event.pageX - parOfs.left;
     }
 
+    /**
+     * Get event Y and translate it to viewport Y
+     *
+     * @param event
+     *            The event object
+     * @return Viewport Y
+     */
     function evY(event) {
         return event.pageY - parOfs.top;
     }
 
+    /**
+     * Get the current selection
+     *
+     * @param noScale
+     *            If set to <code>true</code>, scaling is not applied to the
+     *            returned selection
+     * @return Selection object
+     */
     function getSelection(noScale) {
         var sx = noScale || scaleX, sy = noScale || scaleY;
 
@@ -104,36 +219,79 @@
             height: round(selection.y2 * sy) - round(selection.y1 * sy) };
     }
 
+    /**
+     * Set the current selection
+     *
+     * @param x1
+     *            X coordinate of the upper left corner of the selection area
+     * @param y1
+     *            Y coordinate of the upper left corner of the selection area
+     * @param x2
+     *            X coordinate of the lower right corner of the selection area
+     * @param y2
+     *            Y coordinate of the lower right corner of the selection area
+     * @param noScale
+     *            If set to <code>true</code>, scaling is not applied to the
+     *            new selection
+     */
     function setSelection(x1, y1, x2, y2, noScale) {
         var sx = noScale || scaleX, sy = noScale || scaleY;
 
         selection = {
-            x1: round(x1 / sx),
-            y1: round(y1 / sy),
-            x2: round(x2 / sx),
-            y2: round(y2 / sy)
+            x1: round(x1 / sx || 0),
+            y1: round(y1 / sy || 0),
+            x2: round(x2 / sx || 0),
+            y2: round(y2 / sy || 0)
         };
 
-        selection.width = (x2 = viewX(selection.x2)) - (x1 = viewX(selection.x1));
-        selection.height = (y2 = viewX(selection.y2)) - (y1 = viewX(selection.y1));
+        selection.width = selection.x2 - selection.x1;
+        selection.height = selection.y2 - selection.y1;
     }
 
+    /**
+     * Recalculate image and parent offsets
+     */
     function adjust() {
+        /*
+         * Do not adjust if image width is not a positive number. This might
+         * happen when imgAreaSelect is put on a parent element which is then
+         * hidden.
+         */
         if (!$img.width())
             return;
 
+        /*
+         * Get image offset. The .offset() method returns float values, so they
+         * need to be rounded.
+         */
         imgOfs = { left: round($img.offset().left), top: round($img.offset().top) };
 
-        imgWidth = $img.width();
-        imgHeight = $img.height();
+        /* Get image dimensions */
+        imgWidth = $img.innerWidth();
+        imgHeight = $img.innerHeight();
+
+        imgOfs.top += ($img.outerHeight() - imgHeight) >> 1;
+        imgOfs.left += ($img.outerWidth() - imgWidth) >> 1;
 
-        if ($().jquery == '1.3.2' && $.browser.safari && position == 'fixed') {
-            imgOfs.top += max(document.documentElement.scrollTop, $('body').scrollTop());
+        /* Set minimum and maximum selection area dimensions */
+        minWidth = round(options.minWidth / scaleX) || 0;
+        minHeight = round(options.minHeight / scaleY) || 0;
+        maxWidth = round(min(options.maxWidth / scaleX || 1<<24, imgWidth));
+        maxHeight = round(min(options.maxHeight / scaleY || 1<<24, imgHeight));
 
-            imgOfs.left += max(document.documentElement.scrollLeft, $('body').scrollLeft());
+        /*
+         * Workaround for jQuery 1.3.2 incorrect offset calculation, originally
+         * observed in Safari 3. Firefox 2 is also affected.
+         */
+        if ($().jquery == '1.3.2' && position == 'fixed' &&
+            !docElem['getBoundingClientRect'])
+        {
+            imgOfs.top += max(document.body.scrollTop, docElem.scrollTop);
+            imgOfs.left += max(document.body.scrollLeft, docElem.scrollLeft);
         }
 
-        parOfs = $.inArray($parent.css('position'), ['absolute', 'relative']) + 1 ?
+        /* Determine parent element offset */
+        parOfs = /absolute|relative/.test($parent.css('position')) ?
             { left: round($parent.offset().left) - $parent.scrollLeft(),
                 top: round($parent.offset().top) - $parent.scrollTop() } :
             position == 'fixed' ?
@@ -142,20 +300,45 @@
 
         left = viewX(0);
         top = viewY(0);
+
+        /*
+         * Check if selection area is within image boundaries, adjust if
+         * necessary
+         */
+        if (selection.x2 > imgWidth || selection.y2 > imgHeight)
+            doResize();
     }
 
+    /**
+     * Update plugin elements
+     *
+     * @param resetKeyPress
+     *            If set to <code>false</code>, this instance's keypress
+     *            event handler is not activated
+     */
     function update(resetKeyPress) {
+        /* If plugin elements are hidden, do nothing */
         if (!shown) return;
 
+        /*
+         * Set the position and size of the container box and the selection area
+         * inside it
+         */
         $box.css({ left: viewX(selection.x1), top: viewY(selection.y1) })
             .add($area).width(w = selection.width).height(h = selection.height);
 
+        /*
+         * Reset the position of selection area, borders, and handles (IE6/IE7
+         * position them incorrectly if we don't do this)
+         */
         $area.add($border).add($handles).css({ left: 0, top: 0 });
 
+        /* Set border dimensions */
         $border
             .width(max(w - $border.outerWidth() + $border.innerWidth(), 0))
             .height(max(h - $border.outerHeight() + $border.innerHeight(), 0));
 
+        /* Arrange the outer area elements */
         $($outer[0]).css({ left: left, top: top,
             width: selection.x1, height: imgHeight });
         $($outer[1]).css({ left: left + selection.x1, top: top,
@@ -168,33 +351,62 @@
         w -= $handles.outerWidth();
         h -= $handles.outerHeight();
 
+        /* Arrange handles */
         switch ($handles.length) {
         case 8:
-            $($handles[4]).css({ left: w / 2 });
-            $($handles[5]).css({ left: w, top: h / 2 });
-            $($handles[6]).css({ left: w / 2, top: h });
-            $($handles[7]).css({ top: h / 2 });
+            $($handles[4]).css({ left: w >> 1 });
+            $($handles[5]).css({ left: w, top: h >> 1 });
+            $($handles[6]).css({ left: w >> 1, top: h });
+            $($handles[7]).css({ top: h >> 1 });
         case 4:
             $handles.slice(1,3).css({ left: w });
             $handles.slice(2,4).css({ top: h });
         }
 
         if (resetKeyPress !== false) {
+            /*
+             * Need to reset the document keypress event handler -- unbind the
+             * current handler
+             */
             if ($.imgAreaSelect.keyPress != docKeyPress)
                 $(document).unbind($.imgAreaSelect.keyPress,
                     $.imgAreaSelect.onKeyPress);
 
             if (options.keys)
+                /*
+                 * Set the document keypress event handler to this instance's
+                 * docKeyPress() function
+                 */
                 $(document)[$.imgAreaSelect.keyPress](
                     $.imgAreaSelect.onKeyPress = docKeyPress);
         }
 
+        /*
+         * Internet Explorer displays 1px-wide dashed borders incorrectly by
+         * filling the spaces between dashes with white. Toggling the margin
+         * property between 0 and "auto" fixes this in IE6 and IE7 (IE8 is still
+         * broken). This workaround is not perfect, as it requires setTimeout()
+         * and thus causes the border to flicker a bit, but I haven't found a
+         * better solution.
+         *
+         * Note: This only happens with CSS borders, set with the borderWidth,
+         * borderOpacity, borderColor1, and borderColor2 options (which are now
+         * deprecated). Borders created with GIF background images are fine.
+         */
         if ($.browser.msie && $border.outerWidth() - $border.innerWidth() == 2) {
             $border.css('margin', 0);
             setTimeout(function () { $border.css('margin', 'auto'); }, 0);
         }
     }
 
+    /**
+     * Do the complete update sequence: recalculate offsets, update the
+     * elements, and set the correct values of x1, y1, x2, and y2.
+     *
+     * @param resetKeyPress
+     *            If set to <code>false</code>, this instance's keypress
+     *            event handler is not activated
+     */
     function doUpdate(resetKeyPress) {
         adjust();
         update(resetKeyPress);
@@ -202,11 +414,24 @@
         x2 = viewX(selection.x2); y2 = viewY(selection.y2);
     }
 
+    /**
+     * Hide or fade out an element (or multiple elements)
+     *
+     * @param $elem
+     *            A jQuery object containing the element(s) to hide/fade out
+     * @param fn
+     *            Callback function to be called when fadeOut() completes
+     */
     function hide($elem, fn) {
         options.fadeSpeed ? $elem.fadeOut(options.fadeSpeed, fn) : $elem.hide();
-
     }
 
+    /**
+     * Selection area mousemove event handler
+     *
+     * @param event
+     *            The event object
+     */
     function areaMouseMove(event) {
         var x = selX(evX(event)) - selection.x1,
             y = selY(evY(event)) - selection.y1;
@@ -218,16 +443,21 @@
             $box.one('mouseout', function () { adjusted = false; });
         }
 
+        /* Clear the resize mode */
         resize = '';
 
         if (options.resizable) {
-            if (y <= resizeMargin)
+            /*
+             * Check if the mouse pointer is over the resize margin area and set
+             * the resize mode accordingly
+             */
+            if (y <= options.resizeMargin)
                 resize = 'n';
-            else if (y >= selection.height - resizeMargin)
+            else if (y >= selection.height - options.resizeMargin)
                 resize = 's';
-            if (x <= resizeMargin)
+            if (x <= options.resizeMargin)
                 resize += 'w';
-            else if (x >= selection.width - resizeMargin)
+            else if (x >= selection.width - options.resizeMargin)
                 resize += 'e';
         }
 
@@ -237,24 +467,42 @@
             $areaOpera.toggle();
     }
 
+    /**
+     * Document mouseup event handler
+     *
+     * @param event
+     *            The event object
+     */
     function docMouseUp(event) {
+        /* Set back the default cursor */
         $('body').css('cursor', '');
-
+        /*
+         * If autoHide is enabled, or if the selection has zero width/height,
+         * hide the selection and the outer area
+         */
         if (options.autoHide || selection.width * selection.height == 0)
             hide($box.add($outer), function () { $(this).hide(); });
 
-        options.onSelectEnd(img, getSelection());
-
         $(document).unbind('mousemove', selectingMouseMove);
         $box.mousemove(areaMouseMove);
+
+        options.onSelectEnd(img, getSelection());
     }
 
+    /**
+     * Selection area mousedown event handler
+     *
+     * @param event
+     *            The event object
+     * @return false
+     */
     function areaMouseDown(event) {
         if (event.which != 1) return false;
 
         adjust();
 
         if (resize) {
+            /* Resize mode is in effect */
             $('body').css('cursor', resize + '-resize');
 
             x1 = viewX(selection[/w/.test(resize) ? 'x2' : 'x1']);
@@ -284,59 +532,79 @@
         return false;
     }
 
-    function aspectRatioXY() {
-        x2 = max(left, min(left + imgWidth,
-            x1 + abs(y2 - y1) * aspectRatio * (x2 > x1 || -1)));
-
-        y2 = round(max(top, min(top + imgHeight,
-            y1 + abs(x2 - x1) / aspectRatio * (y2 > y1 || -1))));
-        x2 = round(x2);
-    }
-
-    function aspectRatioYX() {
-        y2 = max(top, min(top + imgHeight,
-            y1 + abs(x2 - x1) / aspectRatio * (y2 > y1 || -1)));
-        x2 = round(max(left, min(left + imgWidth,
-            x1 + abs(y2 - y1) * aspectRatio * (x2 > x1 || -1))));
-        y2 = round(y2);
+    /**
+     * Adjust the x2/y2 coordinates to maintain aspect ratio (if defined)
+     *
+     * @param xFirst
+     *            If set to <code>true</code>, calculate x2 first. Otherwise,
+     *            calculate y2 first.
+     */
+    function fixAspectRatio(xFirst) {
+        if (aspectRatio)
+            if (xFirst) {
+                x2 = max(left, min(left + imgWidth,
+                    x1 + abs(y2 - y1) * aspectRatio * (x2 > x1 || -1)));
+                y2 = round(max(top, min(top + imgHeight,
+                    y1 + abs(x2 - x1) / aspectRatio * (y2 > y1 || -1))));
+                x2 = round(x2);
+            }
+            else {
+                y2 = max(top, min(top + imgHeight,
+                    y1 + abs(x2 - x1) / aspectRatio * (y2 > y1 || -1)));
+                x2 = round(max(left, min(left + imgWidth,
+                    x1 + abs(y2 - y1) * aspectRatio * (x2 > x1 || -1))));
+                y2 = round(y2);
+            }
     }
 
+    /**
+     * Resize the selection area respecting the minimum/maximum dimensions and
+     * aspect ratio
+     */
     function doResize() {
-        if (abs(x2 - x1) < options.minWidth) {
-            x2 = x1 - options.minWidth * (x2 < x1 || -1);
+        /*
+         * Make sure the top left corner of the selection area stays within
+         * image boundaries (it might not if the image source was dynamically
+         * changed).
+         */
+        x1 = min(x1, left + imgWidth);
+        y1 = min(y1, top + imgHeight);
+
+        if (abs(x2 - x1) < minWidth) {
+            /* Selection width is smaller than minWidth */
+            x2 = x1 - minWidth * (x2 < x1 || -1);
 
             if (x2 < left)
-                x1 = left + options.minWidth;
+                x1 = left + minWidth;
             else if (x2 > left + imgWidth)
-                x1 = left + imgWidth - options.minWidth;
+                x1 = left + imgWidth - minWidth;
         }
 
-        if (abs(y2 - y1) < options.minHeight) {
-            y2 = y1 - options.minHeight * (y2 < y1 || -1);
+        if (abs(y2 - y1) < minHeight) {
+            /* Selection height is smaller than minHeight */
+            y2 = y1 - minHeight * (y2 < y1 || -1);
 
             if (y2 < top)
-                y1 = top + options.minHeight;
+                y1 = top + minHeight;
             else if (y2 > top + imgHeight)
-                y1 = top + imgHeight - options.minHeight;
+                y1 = top + imgHeight - minHeight;
         }
 
         x2 = max(left, min(x2, left + imgWidth));
         y2 = max(top, min(y2, top + imgHeight));
 
-        if (aspectRatio)
-            if (abs(x2 - x1) / aspectRatio > abs(y2 - y1))
-                aspectRatioYX();
-            else
-                aspectRatioXY();
+        fixAspectRatio(abs(x2 - x1) < abs(y2 - y1) * aspectRatio);
 
-        if (abs(x2 - x1) > options.maxWidth) {
-            x2 = x1 - options.maxWidth * (x2 < x1 || -1);
-            if (aspectRatio) aspectRatioYX();
+        if (abs(x2 - x1) > maxWidth) {
+            /* Selection width is greater than maxWidth */
+            x2 = x1 - maxWidth * (x2 < x1 || -1);
+            fixAspectRatio();
         }
 
-        if (abs(y2 - y1) > options.maxHeight) {
-            y2 = y1 - options.maxHeight * (y2 < y1 || -1);
-            if (aspectRatio) aspectRatioXY();
+        if (abs(y2 - y1) > maxHeight) {
+            /* Selection height is greater than maxHeight */
+            y2 = y1 - maxHeight * (y2 < y1 || -1);
+            fixAspectRatio(true);
         }
 
         selection = { x1: selX(min(x1, x2)), x2: selX(max(x1, x2)),
@@ -348,28 +616,49 @@
         options.onSelectChange(img, getSelection());
     }
 
+    /**
+     * Mousemove event handler triggered when the user is selecting an area
+     *
+     * @param event
+     *            The event object
+     * @return false
+     */
     function selectingMouseMove(event) {
-        x2 = resize == '' || /w|e/.test(resize) || aspectRatio ? evX(event) : viewX(selection.x2);
-        y2 = resize == '' || /n|s/.test(resize) || aspectRatio ? evY(event) : viewY(selection.y2);
+        x2 = /w|e|^$/.test(resize) || aspectRatio ? evX(event) : viewX(selection.x2);
+        y2 = /n|s|^$/.test(resize) || aspectRatio ? evY(event) : viewY(selection.y2);
 
         doResize();
 
         return false;
-
     }
 
+    /**
+     * Move the selection area
+     *
+     * @param newX1
+     *            New viewport X1
+     * @param newY1
+     *            New viewport Y1
+     */
     function doMove(newX1, newY1) {
         x2 = (x1 = newX1) + selection.width;
         y2 = (y1 = newY1) + selection.height;
 
-        selection = $.extend(selection, { x1: selX(x1), y1: selY(y1),
-            x2: selX(x2), y2: selY(y2) });
+        $.extend(selection, { x1: selX(x1), y1: selY(y1), x2: selX(x2),
+            y2: selY(y2) });
 
         update();
 
         options.onSelectChange(img, getSelection());
     }
 
+    /**
+     * Mousemove event handler triggered when the selection area is being moved
+     *
+     * @param event
+     *            The event object
+     * @return false
+     */
     function movingMouseMove(event) {
         x1 = max(left, min(startX + evX(event), left + imgWidth - selection.width));
         y1 = max(top, min(startY + evY(event), top + imgHeight - selection.height));
@@ -377,21 +666,24 @@
         doMove(x1, y1);
 
         event.preventDefault();
-
         return false;
     }
 
+    /**
+     * Start selection
+     */
     function startSelection() {
+        $(document).unbind('mousemove', startSelection);
         adjust();
 
         x2 = x1;
         y2 = y1;
-
         doResize();
 
         resize = '';
 
-        if ($outer.is(':not(:visible)'))
+        if (!$outer.is(':visible'))
+            /* Show the plugin elements */
             $box.add($outer).hide().fadeIn(options.fadeSpeed||0);
 
         shown = true;
@@ -403,42 +695,65 @@
         options.onSelectStart(img, getSelection());
     }
 
+    /**
+     * Cancel selection
+     */
     function cancelSelection() {
-        $(document).unbind('mousemove', startSelection);
+        $(document).unbind('mousemove', startSelection)
+            .unbind('mouseup', cancelSelection);
         hide($box.add($outer));
 
-        selection = { x1: selX(x1), y1: selY(y1), x2: selX(x1), y2: selY(y1),
-                width: 0, height: 0 };
+        setSelection(selX(x1), selY(y1), selX(x1), selY(y1));
 
-        options.onSelectChange(img, getSelection());
-        options.onSelectEnd(img, getSelection());
+        /* If this is an API call, callback functions should not be triggered */
+        if (!(this instanceof $.imgAreaSelect)) {
+            options.onSelectChange(img, getSelection());
+            options.onSelectEnd(img, getSelection());
+        }
     }
 
+    /**
+     * Image mousedown event handler
+     *
+     * @param event
+     *            The event object
+     * @return false
+     */
     function imgMouseDown(event) {
+        /* Ignore the event if animation is in progress */
         if (event.which != 1 || $outer.is(':animated')) return false;
 
         adjust();
         startX = x1 = evX(event);
         startY = y1 = evY(event);
 
-        $(document).one('mousemove', startSelection)
-            .one('mouseup', cancelSelection);
+        /* Selection will start when the mouse is moved */
+        $(document).mousemove(startSelection).mouseup(cancelSelection);
 
         return false;
     }
 
-    function parentScroll() {
+    /**
+     * Window resize event handler
+     */
+    function windowResize() {
         doUpdate(false);
     }
 
+    /**
+     * Image load event handler. This is the final part of the initialization
+     * process.
+     */
     function imgLoad() {
         imgLoaded = true;
 
+        /* Set options */
         setOptions(options = $.extend({
             classPrefix: 'imgareaselect',
             movable: true,
+            parent: 'body',
             resizable: true,
-            parent: 'body',
+            resizeMargin: 10,
             onInit: function () {},
             onSelectStart: function () {},
             onSelectChange: function () {},
@@ -454,11 +769,23 @@
             $box.add($outer).hide().fadeIn(options.fadeSpeed||0);
         }
 
+        /*
+         * Call the onInit callback. The setTimeout() call is used to ensure
+         * that the plugin has been fully initialized and the object instance is
+         * available (so that it can be obtained in the callback).
+         */
         setTimeout(function () { options.onInit(img, getSelection()); }, 0);
     }
 
+    /**
+     * Document keypress event handler
+     *
+     * @param event
+     *            The event object
+     * @return false
+     */
     var docKeyPress = function(event) {
-        var k = options.keys, d, t, key = event.keyCode || event.which;
+        var k = options.keys, d, t, key = event.keyCode;
 
         d = !isNaN(k.alt) && (event.altKey || event.originalEvent.altKey) ? k.alt :
             !isNaN(k.ctrl) && event.ctrlKey ? k.ctrl :
@@ -469,22 +796,28 @@
             (k.ctrl == 'resize' && event.ctrlKey) ||
             (k.alt == 'resize' && (event.altKey || event.originalEvent.altKey)))
         {
+            /* Resize selection */
+
             switch (key) {
             case 37:
+                /* Left */
                 d = -d;
             case 39:
+                /* Right */
                 t = max(x1, x2);
                 x1 = min(x1, x2);
                 x2 = max(t + d, x1);
-                if (aspectRatio) aspectRatioYX();
+                fixAspectRatio();
                 break;
             case 38:
+                /* Up */
                 d = -d;
             case 40:
+                /* Down */
                 t = max(y1, y2);
                 y1 = min(y1, y2);
                 y2 = max(t + d, y1);
-                if (aspectRatio) aspectRatioXY();
+                fixAspectRatio(true);
                 break;
             default:
                 return;
@@ -493,20 +826,26 @@
             doResize();
         }
         else {
+            /* Move selection */
+
             x1 = min(x1, x2);
             y1 = min(y1, y2);
 
             switch (key) {
             case 37:
+                /* Left */
                 doMove(max(x1 - d, left), y1);
                 break;
             case 38:
+                /* Up */
                 doMove(x1, max(y1 - d, top));
                 break;
             case 39:
+                /* Right */
                 doMove(x1 + min(d, imgWidth - selX(x2)), y1);
                 break;
             case 40:
+                /* Down */
                 doMove(x1, y1 + min(d, imgHeight - selY(y2)));
                 break;
             default:
@@ -517,21 +856,38 @@
         return false;
     };
 
+    /**
+     * Apply style options to plugin element (or multiple elements)
+     *
+     * @param $elem
+     *            A jQuery object representing the element(s) to style
+     * @param props
+     *            An object that maps option names to corresponding CSS
+     *            properties
+     */
     function styleOptions($elem, props) {
-        for (option in props)
+        for (var option in props)
             if (options[option] !== undefined)
                 $elem.css(props[option], options[option]);
     }
 
+    /**
+     * Set plugin options
+     *
+     * @param newOptions
+     *            The new options object
+     */
     function setOptions(newOptions) {
         if (newOptions.parent)
             ($parent = $(newOptions.parent)).append($box.add($outer));
 
-        options = $.extend(options, newOptions);
+        /* Merge the new options with the existing ones */
+        $.extend(options, newOptions);
 
         adjust();
 
         if (newOptions.handles != null) {
+            /* Recreate selection area handles */
             $handles.remove();
             $handles = $([]);
 
@@ -540,41 +896,60 @@
             while (i--)
                 $handles = $handles.add(div());
 
+            /* Add a class to handles and set the CSS properties */
             $handles.addClass(options.classPrefix + '-handle').css({
                 position: 'absolute',
+                /*
+                 * The font-size property needs to be set to zero, otherwise
+                 * Internet Explorer makes the handles too large
+                 */
                 fontSize: 0,
                 zIndex: zIndex + 1 || 1
             });
 
-            if (!parseInt($handles.css('width')))
+            /*
+             * If handle width/height has not been set with CSS rules, set the
+             * default 5px
+             */
+            if (!parseInt($handles.css('width')) >= 0)
                 $handles.width(5).height(5);
 
+            /*
+             * If the borderWidth option is in use, add a solid border to
+             * handles
+             */
             if (o = options.borderWidth)
                 $handles.css({ borderWidth: o, borderStyle: 'solid' });
 
+            /* Apply other style options */
             styleOptions($handles, { borderColor1: 'border-color',
                 borderColor2: 'background-color',
                 borderOpacity: 'opacity' });
         }
 
+        /* Calculate scale factors */
         scaleX = options.imageWidth / imgWidth || 1;
         scaleY = options.imageHeight / imgHeight || 1;
 
+        /* Set selection */
         if (newOptions.x1 != null) {
             setSelection(newOptions.x1, newOptions.y1, newOptions.x2,
-                    newOptions.y2);
+                newOptions.y2);
             newOptions.show = !newOptions.hide;
         }
 
         if (newOptions.keys)
+            /* Enable keyboard support */
             options.keys = $.extend({ shift: 1, ctrl: 'resize' },
                 newOptions.keys);
 
+        /* Add classes to plugin elements */
         $outer.addClass(options.classPrefix + '-outer');
         $area.addClass(options.classPrefix + '-selection');
         for (i = 0; i++ < 4;)
             $($border[i-1]).addClass(options.classPrefix + '-border' + i);
 
+        /* Apply style options */
         styleOptions($area, { selectionColor: 'background-color',
             selectionOpacity: 'opacity' });
         styleOptions($border, { borderOpacity: 'opacity',
@@ -586,12 +961,13 @@
         if (o = options.borderColor2)
             $($border[1]).css({ borderStyle: 'dashed', borderColor: o });
 
-        $box.append($area.add($border).add($handles).add($areaOpera));
+        /* Append all the selection area elements to the container box */
+        $box.append($area.add($border).add($areaOpera).add($handles));
 
         if ($.browser.msie) {
-            if (o = $outer.css('filter').match(/opacity=([0-9]+)/))
+            if (o = $outer.css('filter').match(/opacity=(\d+)/))
                 $outer.css('opacity', o[1]/100);
-            if (o = $border.css('filter').match(/opacity=([0-9]+)/))
+            if (o = $border.css('filter').match(/opacity=(\d+)/))
                 $border.css('opacity', o[1]/100);
         }
 
@@ -603,78 +979,205 @@
             doUpdate();
         }
 
+        /* Calculate the aspect ratio factor */
         aspectRatio = (d = (options.aspectRatio || '').split(/:/))[0] / d[1];
 
+        $img.add($outer).unbind('mousedown', imgMouseDown);
+
         if (options.disable || options.enable === false) {
+            /* Disable the plugin */
             $box.unbind('mousemove', areaMouseMove).unbind('mousedown', areaMouseDown);
-            $img.add($outer).unbind('mousedown', imgMouseDown);
-            $(window).unbind('resize', parentScroll);
-            $img.add($img.parents()).unbind('scroll', parentScroll);
+            $(window).unbind('resize', windowResize);
         }
-        else if (options.enable || options.disable === false) {
-            if (options.resizable || options.movable)
-                $box.mousemove(areaMouseMove).mousedown(areaMouseDown);
+        else {
+            if (options.enable || options.disable === false) {
+                /* Enable the plugin */
+                if (options.resizable || options.movable)
+                    $box.mousemove(areaMouseMove).mousedown(areaMouseDown);
+
+                $(window).resize(windowResize);
+            }
 
             if (!options.persistent)
                 $img.add($outer).mousedown(imgMouseDown);
-            $(window).resize(parentScroll);
-            $img.add($img.parents()).scroll(parentScroll);
         }
 
         options.enable = options.disable = undefined;
     }
 
+    /**
+     * Remove plugin completely
+     */
+    this.remove = function () {
+        /*
+         * Call setOptions with { disable: true } to unbind the event handlers
+         */
+        setOptions({ disable: true });
+        $box.add($outer).remove();
+    };
+
+    /*
+     * Public API
+     */
+
+    /**
+     * Get current options
+     *
+     * @return An object containing the set of options currently in use
+     */
     this.getOptions = function () { return options; };
 
+    /**
+     * Set plugin options
+     *
+     * @param newOptions
+     *            The new options object
+     */
     this.setOptions = setOptions;
 
+    /**
+     * Get the current selection
+     *
+     * @param noScale
+     *            If set to <code>true</code>, scaling is not applied to the
+     *            returned selection
+     * @return Selection object
+     */
     this.getSelection = getSelection;
 
+    /**
+     * Set the current selection
+     *
+     * @param x1
+     *            X coordinate of the upper left corner of the selection area
+     * @param y1
+     *            Y coordinate of the upper left corner of the selection area
+     * @param x2
+     *            X coordinate of the lower right corner of the selection area
+     * @param y2
+     *            Y coordinate of the lower right corner of the selection area
+     * @param noScale
+     *            If set to <code>true</code>, scaling is not applied to the
+     *            new selection
+     */
     this.setSelection = setSelection;
 
+    /**
+     * Cancel selection
+     */
+    this.cancelSelection = cancelSelection;
+
+    /**
+     * Update plugin elements
+     *
+     * @param resetKeyPress
+     *            If set to <code>false</code>, this instance's keypress
+     *            event handler is not activated
+     */
     this.update = doUpdate;
 
+    /*
+     * Traverse the image's parent elements (up to <body>) and find the
+     * highest z-index
+     */
     $p = $img;
 
-    while ($p.length && !$p.is('body')) {
-        if (!isNaN($p.css('z-index')) && $p.css('z-index') > zIndex)
-            zIndex = $p.css('z-index');
+    while ($p.length) {
+        zIndex = max(zIndex,
+            !isNaN($p.css('z-index')) ? $p.css('z-index') : zIndex);
+        /* Also check if any of the ancestor elements has fixed position */
         if ($p.css('position') == 'fixed')
             position = 'fixed';
 
-        $p = $p.parent();
+        $p = $p.parent(':not(body)');
     }
 
-    if (!isNaN(options.zIndex))
-        zIndex = options.zIndex;
+    /*
+     * If z-index is given as an option, it overrides the one found by the
+     * above loop
+     */
+    zIndex = options.zIndex || zIndex;
 
     if ($.browser.msie)
         $img.attr('unselectable', 'on');
 
+    /*
+     * In MSIE and WebKit, we need to use the keydown event instead of keypress
+     */
     $.imgAreaSelect.keyPress = $.browser.msie ||
         $.browser.safari ? 'keydown' : 'keypress';
 
+    /*
+     * There is a bug affecting the CSS cursor property in Opera (observed in
+     * versions up to 10.00) that prevents the cursor from being updated unless
+     * the mouse leaves and enters the element again. To trigger the mouseover
+     * event, we're adding an additional div to $box and we're going to toggle
+     * it when mouse moves inside the selection area.
+     */
     if ($.browser.opera)
         $areaOpera = div().css({ width: '100%', height: '100%',
             position: 'absolute', zIndex: zIndex + 2 || 2 });
 
+    /*
+     * We initially set visibility to "hidden" as a workaround for a weird
+     * behaviour observed in Google Chrome 1.0.154.53 (on Windows XP). Normally
+     * we would just set display to "none", but, for some reason, if we do so
+     * then Chrome refuses to later display the element with .show() or
+     * .fadeIn().
+     */
     $box.add($outer).css({ visibility: 'hidden', position: position,
         overflow: 'hidden', zIndex: zIndex || '0' });
     $box.css({ zIndex: zIndex + 2 || 2 });
-    $area.add($border).css({ position: 'absolute' });
+    $area.add($border).css({ position: 'absolute', fontSize: 0 });
 
+    /*
+     * If the image has been fully loaded, or if it is not really an image (eg.
+     * a div), call imgLoad() immediately; otherwise, bind it to be called once
+     * on image load event.
+     */
     img.complete || img.readyState == 'complete' || !$img.is('img') ?
         imgLoad() : $img.one('load', imgLoad);
 
+    /*
+     * MSIE 9.0 doesn't always fire the image load event -- resetting the src
+     * attribute seems to trigger it. The check is for version 7 and above to
+     * accommodate for MSIE 9 running in compatibility mode.
+     */
+   if (!imgLoaded && $.browser.msie && $.browser.version >= 7)
+        img.src = img.src;
 };
 
+/**
+ * Invoke imgAreaSelect on a jQuery object containing the image(s)
+ *
+ * @param options
+ *            Options object
+ * @return The jQuery object or a reference to imgAreaSelect instance (if the
+ *         <code>instance</code> option was specified)
+ */
 $.fn.imgAreaSelect = function (options) {
     options = options || {};
 
     this.each(function () {
-        if ($(this).data('imgAreaSelect'))
-            $(this).data('imgAreaSelect').setOptions(options);
-        else {
+        /* Is there already an imgAreaSelect instance bound to this element? */
+        if ($(this).data('imgAreaSelect')) {
+            /* Yes there is -- is it supposed to be removed? */
+            if (options.remove) {
+                /* Remove the plugin */
+                $(this).data('imgAreaSelect').remove();
+                $(this).removeData('imgAreaSelect');
+            }
+            else
+                /* Reset options */
+                $(this).data('imgAreaSelect').setOptions(options);
+        }
+        else if (!options.remove) {
+            /* No exising instance -- create a new one */
+
+            /*
+             * If neither the "enable" nor the "disable" option is present, add
+             * "enable" as the default
+             */
             if (options.enable === undefined && options.disable === undefined)
                 options.enable = true;
 
@@ -683,6 +1186,10 @@
     });
 
     if (options.instance)
+        /*
+         * Return the imgAreaSelect instance bound to the first element in the
+         * set
+         */
         return $(this).data('imgAreaSelect');
 
     return this;