// ==UserScript==
// @name          Collapsing Paragraphs
// @namespace     http://chrislord.net/
// @description	  Collapses paragraphs to a GtkExpander-like structure
// @include       *
// ==/UserScript==

function getText (element, size)
{
	for (var child = element.firstChild; child; child = child.nextSibling) {
		if ((child.nodeType == child.TEXT_NODE) &&
		    (child.nodeValue.length >= size)) {
			return child.nodeValue;
		} else {
			if ((element.tagName != "A") &&
	    		    (element.nodeType != child.COMMENT_NODE) &&
	    		    (element.tagName != "SCRIPT")) {
				var text = getText (child, size);
				if (text) return text;
			}
		}
	}
	return null;
}

function flatten (element)
{
	if ((element.tagName == "TABLE") ||
	    (element.tagName == "TBODY") ||
	    (element.tagName == "THEAD") ||
	    (element.tagName == "TFOOT") ||
	    (element.tagName == "TR") ||
	    (element.tagName == "TD") ||
	    (element.tagName == "TH") ||
	    (element.tagName == "COL") ||
	    (element.tagName == "COLGROUP")) {
		element.setAttribute ("style", "display: block ! important;");
	}
	for (var child = element.firstChild; child; child = child.nextSibling)
		flatten (child);
}

function flatten_table (element)
{
	if ((!element) || (element.nodeType != element.ELEMENT_NODE))
		return;

	if (element.tagName == "TABLE") {
		flatten (element);
	}
	flatten_table (element.parentNode);
}

function collapse (element, min_size, summary_size, ellipses_size)
{
	var text, para, event;
	if (element.nodeType == element.TEXT_NODE)
		text = element.nodeValue;
	else {
		text = getText (element, min_size);
		if (!text) return;
		text = getText (element, summary_size);
	}
	if (text.length > ellipses_size)
		text = text.substr(0, ellipses_size - 3) + "...";
		
	para = document.createElement ("p");
	para.appendChild (document.createTextNode (text));
	para.style.textDecoration = "underline";
	para.style.cursor = "pointer";
	element.parentNode.insertBefore (para, element);
	/* Note, some firefox bugs (or at least, things that go against docs):
	 * - DOM elements have no 'click' function
	 *   http://www.mozilla.org/docs/dom/domref/dom_el_ref34.html#1028373
	 * - Can't set 'onclick' by doing element.onclick = ...;
	 *   http://www.mozilla.org/docs/dom/domref/dom_event_ref.html#998197
	 *   - Works in Firefox < 1.5
	 * - dispatchEvent example is wrong
	 *   http://www.mozilla.org/docs/dom/domref/dom_el_ref36.html#1028419
	 */
	para.addEventListener ("click", function (e) {
		var node = this.nextSibling;
		var j, new_display, old_display;
		
		if (node.hasAttribute ("old-display"))
			old_display = node.getAttribute ("old-display");
		else
			old_display = "none";
			
		node.setAttribute ("old-display", node.style.display);
		node.style.display = old_display;
	}, true);
/*	event = document.createEvent ("MouseEvents");
	event.initEvent ("click", true, true);
	para.dispatchEvent (event);*/
}

function collapse_image (image)
{
	var para, event;
	para = document.createElement ("p");
	para.appendChild (document.createTextNode ("Hide image"));
	para.style.textDecoration = "underline";
	para.style.cursor = "pointer";
	para.style.border = "1px dashed #CCCCCC";
	image.parentNode.insertBefore (para, image);
	para.addEventListener ("click", function (e) {
		var node = this.nextSibling;
		var j, new_display, old_display;
		
		if (node.hasAttribute ("old-display"))
			old_display = node.getAttribute ("old-display");
		else
			old_display = "none";
		
		node.setAttribute ("old-display", node.style.display);
		node.style.display = old_display;
		if (node.style.display == "none") {
			this.firstChild.nodeValue = "View image";
		} else {
			this.firstChild.nodeValue = "Hide image";
		}
	}, true);
/*	event = document.createEvent ("MouseEvents");
	event.initEvent ("click", true, true);
	para.dispatchEvent (event);*/
}

function is_parent (parent, element)
{
	if (!element) {
		return false;
	} if (element == parent) {
		return true;
	} else
		return is_parent (parent, element.parentNode);
}

function getTextParents (array, element, size)
{
	/* Stop at certain tags */
	if ((element.nodeType != element.ELEMENT_NODE) ||
	    (element.tagName == "A") ||
	    (element.tagName == "SCRIPT"))
		return array;
		
	for (var child = element.firstChild; child; child = child.nextSibling) {
		if (child.nodeType == child.TEXT_NODE) {
			if ((child.nodeValue.length >= size) &&
			    (element.tagName != "BODY")) {
				array.push (element);
				break;
			}
		} else
			getTextParents (array, child, size);
	}
	
	return array;
}


/* Flatten tables with images in them */
img_array = document.getElementsByTagName ("img");
for (i = 0; i < img_array.length; i++) {
/*	flatten_table (img_array[i]);*/
	if ((img_array[i].width > 32) || (img_array[i].height > 32)) {
		if (img_array[i].parentNode.tagName == "A")
			collapse_image (img_array[i].parentNode);
		else
			collapse_image (img_array[i]);
	}
}

collapse_array = getTextParents (new Array (), document.body, 80);

for (i = 0; i < collapse_array.length; i++) {
	/* Flatten tables with long paragraphs in them */
/*	flatten_table (collapse_array[i]);*/
	collapse (collapse_array[i], 80, 10, 40);
}