View difference between Paste ID: 42m8FAZH and LNaWDQZk

 /*
 New Perspectives on JavaScript, 2nd Edition
 Tutorial 6
 Case Problem 2
 Author: Kenneth Hitchcock
 Date: 6/16/2011
-Filename: slideshow.js
+Filename: flibrary.js
-Global Variables:
+
-scrollButton
+getStyle(object, styleName)
-References the scrolling button in the slide show
+Returns the computed style value for a specified styleName applied to
-diffX
+an object.
-Stores the horizontal distance in pixels between the
+addEvent(object, evName, fnName, cap)
-mouse pointer when the scrolling button is clicked
+Assigns an event handers to object where evName is the name of the event,
-and the left edge of the scrolling button.
+fnName is the name of the function, and cap is the capture phase.
 This function works for both the IE and W3C event models.
-setup()
+removeEvent(object, evName, fnName, cap)
-Initializes the contents of the Web page. Creates
+Removes an event handers from object where evName is the name of the event,
-event handlers for the mouse and keyboard events
+fnName is the name of the function, and cap is the capture phase.
-grabIt(e)
+This function works for both the IE and W3C event models.
-"Grabs" the scrolling button to set up the
+
-horizontal scrolling of the slide show
+function getStyle(object, styleName) {
-moveIt(e)
+if (window.getComputedStyle) {
-Moves the scrolling button horizontally through
+return document.defaultView.getComputedStyle(object, null).getPropertyValue(styleName);
-the scrollbar
+} else if (object.currentStyle) {
-showSlide(x)
+return object.currentStyle[styleName]
-Shows the image corresponding the to the x coordinate
+
-on the scrollbar
+
-dropIt(e)
+
-Drops the scrolling button after the user releases the
+Assigns an event handers to object where evName is the name of the event,
-mouse button
+fnName is the name of the function, and cap is the capture phase.
-keyShow(e)
+This function works for both the IE and W3C event models.
-Uses the left and right arrow keys to move the scrolling
+
-button through the scrollbar
+function addEvent(object, evName, fnName, cap)
 {
-window.onload = setup;
+if (object.attachEvent)
-var scrollButton;
+
-var diffX = null;
+object.attachEvent("on" + evName, fnName);
 }
-Initializes the contents of the Web page. Creates
+else if (object.addEventListener)
-event handlers for the mouse and keyboard events.
+
 object.addEventListener(evName, fnName, cap);
-function setup()
+
 }
-scrollButton = document.getElementById("button");
+
-scrollButton.style.top = getStyle(scrollButton, "top");
+Removes an event handers from object where evName is the name of the event,
-scrollButton.style.left = getStyle(scrollButton, "left");
+fnName is the name of the function, and cap is the capture phase.
-scrollButton.style.cursor = getStyle(scrollButton, "pointer");
+This function works for both the IE and W3C event models.
-addEvent(scrollButton, "mousedown", grabIt, false); //310
+
-addEvent(document, "keydown", keyShow, false);
+function removeEvent(object, evName, fnName, cap)
 {
 if (object.detachEvent)
-"Grabs" the scrolling button to set up the
+
-horizontal scrolling of the slide show.
+object.detachEvent("on" + evName, fnName);
 }
-function grabIt(e)
+else if (object.removeEventListener)
 {
-var evt = e || window.event; //314
+object.removeEventListener(evName, fnName, cap);
-var mouseX = evt.clientX; //x-coordinate of pointer. 318
+
-diffX = parseInt(scrollButton.style.left) - mouseX //319
+