User Guide

The Floating panel API 229
/* check to see if the node is a script marker */
if (theNode.nodeType == Node.ELEMENT_NODE && ¬
theNode.tagName == "SCRIPT"){
document.layers['blanklayer'].visibility = 'hidden';
document.layers['scriptlayer'].visibility = 'visible';}
else{
document.layers['scriptlayer'].visibility = 'hidden';
document.layers['blanklayer'].visibility = 'visible';
}
}
About performance
Declaring the
selectionChanged() or documentEdited() function in your custom floating
panels can impact Dreamweaver performance adversely. Consider that the
documentEdited()
and
selectionChanged() functions are called after every keystroke and mouse click when
Dreamweaver is idle for more than one-tenth of a second. It’s important to use different scenarios
to test your floating panel, using large documents (100K or more of HTML) whenever possible,
to test performance impact.
To help avoid performance penalties, the
setTimeout() function was implemented as a global
method in Dreamweaver 3. As in the browsers, the
setTimeout() function takes two arguments:
the JavaScript to be called and the amount of time in milliseconds to wait before calling it.
The
setTimeout() method lets you build pauses into your processing. These pauses let the user
continue interacting with the application. You must build in these pauses explicitly because the
screen freezes while scripts process, which prevents the user from performing further edits. The
pauses also prevent you from updating the interface or the floating panel.
The following example is from a floating panel that displays information about every layer in the
document. It uses the
setTimeout() method to pause for a half second after processing
each layer.
/* create a flag that specifies whether an edit is being processed, and set it
to false. */
document.running = false;
/* this function called when document is edited */
function documentEdited(){
/* create a list of all the layers to be processed */
var dom = dw.getDocumentDOM();
document.layers = dom.getElementsByTagName("layer");
document.numLayers = document.layers.length;
document.numProcessed = 0;
/* set a timer to call processLayer(); if we didn't get
* to finish processing the previous edit, then the timer
* is already set. */
if (document.running = false){
setTimeout("processLayer()", 500);
}
/* set the processing flag to true */
document.running = true;
}
/* process one layer */
function processLayer(){