/*
 *  SPL - The SPL Programming Language
 *  Copyright (C) 2004, 2005  Clifford Wolf <clifford@clifford.at>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  mod_wsf_graph.spl: A WSF Component for viewing and editing graphs
 */

/**
 * A module which implemnts a WSF Component for displaying and editing
 * graphs.
 */

load "wsf";

/**
 * A WSF Component for displaying and editing graphs.
 *
 * In order for this component to work properly, the browser must have support
 * for iframes and must allow javascripts to modify the DOM tree. This is the
 * case with most of todays graphical web browsers.
 *
 * For various technical reasons, the graph editor itself is displayed in an
 * iframe. This object creates an extra SPL task for this iframe.
 *
 * The constructor is passed a function which returns a list of node objects
 * which must implement the [[WsfGraphNode]] interface. If there is any
 * outside change of what that function would return, the 'dirty' attribute
 * of the WsfGraph instance must be set to '1'.
 *
 * This object is derived from [[wsf:WsfComponent]].
 */
object WsfGraph WsfComponent
{
	/**
	 * The function which returns the node list. This is set by the
	 * constructor to its first argument.
	 */
	var get_list;

	/**
	 * The (relative or absolute) URL to the directory in which the images
	 * used by this component can be found.
	 *
	 * This are the files 'images/wsf_graph_*' in the SPL sources.
	 */
	var ibase;

	/**
	 * Per default, nodes can be moved to any position. It is possible to
	 * use a raster to align the nodes. If you want that, set this variable
	 * to the size of the raster (e.g. 10 is a good value).
	 */
	var raster;

	/**
	 * Additional HTML text to be inserted in the HTML header of the iframe.
	 */
	var iframe_header;

	/**
	 * Additional HTML text to be inserted at the end of the HTML text in the
	 * iframe.
	 */
	var iframe_footer;

	/**
	 * Additional attributes to be added in the <iframe> tag. Usually this
	 * is something like 'style="width:100%; height:100%"'.
	 */
	var iframe_attributes;

	/**
	 * Some changes require a reload of the iframe.
	 * The current scroll position is then preserved using this attributes.
	 * It is also possible to adjust this values when setting the 'dirty'
	 * variable to '1'.
	 */
	var scroll_x, scroll_y;

	/**
	 * The main method for the iframe.
	 *
	 * This is called whenever the iframe content is reloaded and prints
	 * the new content of the iframe.
	 */
	method iframe_main()
	{
		write(iframe_header);

		write(
<>
<script><!--

var MouseX = 0, MouseX_Old = 0;
var MouseY = 0, MouseY_Old = 0;

var MouseMoveManager = 0;
var MouseUpManager = 0;

function getMouseXY(e) {
  if (IE) { // grab the x-y pos.s if browser is IE
    MouseX = event.clientX + document.body.scrollLeft;
    MouseY = event.clientY + document.body.scrollTop;
  } else {  // grab the x-y pos.s if browser is NS
    MouseX = e.pageX;
    MouseY = e.pageY;
  }
  if (MouseX < 0) MouseX = 0;
  if (MouseY < 0) MouseY = 0;
  if (MouseMoveManager) MouseMoveManager();
  MouseX_Old = MouseX;
  MouseY_Old = MouseY;
}

function MouseUp() {
  if (MouseUpManager) MouseUpManager();
}

var IE = document.all?true:false;
if (!IE) {
	document.captureEvents(Event.MOUSEMOVE);
	document.captureEvents(Event.MOUSEUP);
}

document.onmousemove = getMouseXY;
document.onmouseup = MouseUp;

//--></script>

<div id="dbg">
</div>

<script><!--

var gnodes = new Object();
var gnodes_id = new Array();

var gnode_move = 0;
var gconn_sel = 0;

var gnodes_xpos;
var gnodes_ypos;

var max_x = 0;
var max_y = 0;

function handle_down(id)
{
	gnode_move = id;
}

function handle_conn_enter(id)
{
	gconn_sel = id;
	draw();
}

function handle_conn_click(id, trg)
{
	var href = '${cgi.url}?sid=$sid&n=' + id + '&t=' + trg;
	
	if (!IE)
		href = href + "&sx=" + pageXOffset + "&sy=" + pageYOffset;

   <spl:if code="WsfDocument.domupdate ~== 'iframe'">
	parent.wsftarget.location.href = href;
   </spl:if>

   <spl:if code="WsfDocument.domupdate ~!= 'iframe'">
	parent.location.href = href;
   </spl:if>
}

function handle_conn_leave(id)
{
	if (gconn_sel == id) {
		gconn_sel = 0;
		draw();
	}
}

function handle_move()
{
	if (!gnode_move) return;

	gnodes[gnode_move]["top"]  += MouseY - MouseY_Old;
	gnodes[gnode_move]["left"] += MouseX - MouseX_Old;

	draw();
}

function handle_up()
{
	if (!gnode_move) return;
	var id = gnode_move;
	gnode_move = 0;

   <spl:if code="defined raster">
	gnodes[id]["top"]  = Math.round(gnodes[id]["top"]  / $raster) * $raster;
	gnodes[id]["left"] = Math.round(gnodes[id]["left"] / $raster) * $raster;
   </spl:if>

	var href =
		'${cgi.url}?sid=$sid&n=' + id + '&x=' +
		gnodes[id]["left"] + '&y=' + gnodes[id]["top"];

	if (!IE)
		href = href + "&sx=" + pageXOffset + "&sy=" + pageYOffset;

   <spl:if code="WsfDocument.domupdate ~== 'iframe'">
	parent.wsftarget.location.href = href;
   <spl:if code="defined raster">
	draw();
   </spl:if>
   </spl:if>

   <spl:if code="WsfDocument.domupdate ~!= 'iframe'">
	parent.location.href = href;
   </spl:if>
}

function setpos(id, top, left, height, width)
{
	document.getElementById(id).style.position   = "absolute";
	document.getElementById(id).style.overflow   = "visible";
	document.getElementById(id).style.top        = top  + "px";
	document.getElementById(id).style.left       = left + "px";
	document.getElementById(id).style.height     = height + "px";
	document.getElementById(id).style.width      = width  + "px";
	document.getElementById(id).style.visibility = "visible";

	if (id != "max_scroll") {
		if ( top + height > max_y ) max_y = top + height;
		if ( left + width > max_x ) max_x = left + width;
	}
}

function setpic(id, pic)
{
	if ( (gconn_sel + "_a") == id ) pic = pic + 'X';
	if ( (gconn_sel + "_b") == id ) pic = pic + 'X';
	if ( (gconn_sel + "_c") == id ) pic = pic + 'X';
	document.getElementById(id).setAttribute("src", "${ibase}" + pic + ".gif");
}

function register(id, top, left, height, width)
{
	gnodes[id] = new Object();
	gnodes[id]["links"]  = new Array();

	gnodes[id]["top"]    = top;
	gnodes[id]["left"]   = left;
	gnodes[id]["height"] = height;
	gnodes[id]["width"]  = width;

	gnodes_id.push(id);
}

function setlink_helper(id1, id2, id3, a, b)
{
	var y1, x1, y2, x2;
	var rel_y = 0;
	var rel_x = 0;

	var changedit = 1;
	var changecount = 0;

	while (changedit && changecount < 5) {
		changedit = 0;
		changecount++;

		if ( !rel_y ) {
			x1 = a.left + a.width/2;
			x2 = b.left;
		}

		if ( !rel_x ) {
			y1 = a.top + a.height;
			y2 = b.top + b.height/2;
		}

		var old_rel_y = rel_y;
		var old_rel_x = rel_x;

		rel_y = y1-2 < y2 ? 1 : y1-2 > y2+a.height ? -1 : 0;
		rel_x = x1+2 < x2 ? 1 : x1+2 > x2+b.width  ? -1 : 0;

		if ( old_rel_y != rel_y ) changedit = 1;
		if ( old_rel_x != rel_x ) changedit = 1;

		if ( rel_y ) {
			var offset = 5, dir = 1;
			while ( gnodes_xpos[x1] && gnodes_xpos[x1] != id1 ) {
				x1 += offset * dir;
				changedit = 1;
				offset += 5;
				dir *= -1;
			}
			gnodes_xpos[x1] = id1;
		}

		if ( rel_x ) {
			var offset = 5, dir = 1;
			while ( gnodes_ypos[y2] && gnodes_ypos[y2] != id2 ) {
				y2 += offset * dir;
				changedit = 1;
				offset += 5;
				dir *= -1;
			}
			gnodes_ypos[y2] = id2;
		}
	}

	if ( rel_y == 1 ) {
		if (!rel_x) y2 -= b.height/2;
		setpos(id1, y1, x1, (y2 - y1), 4);
		if (!rel_x) {
			setpos(id3, y2-7, x1-3, 10, 10);
			setpic(id3, "down");
		}
	} else
	if ( rel_y == -1 ) {
		y1 -= a.height;
		if (!rel_x) y2 += b.height/2;
		setpos(id1, y2, x1, (y1 - y2), 4);
		if (!rel_x) {
			setpos(id3, y2-3, x1-3, 10, 10);
			setpic(id3, "up");
		}
	} else {
		x1 += a.width/2;
		document.getElementById(id1).style.visibility = "hidden";
	}

	if ( rel_x == 1 ) {
		setpos(id2, y2, x1, 4, (x2 - x1));
		setpos(id3, y2-3, x2-7, 10, 10);
		setpic(id3, "right");
	} else
	if ( rel_x == -1 ) {
		x2 += b.width;
		x1 += !rel_y ? -a.width : 4;
		setpos(id2, y2, x2, 4, (x1 - x2));
		setpos(id3, y2-3, x2-3, 10, 10);
		setpic(id3, "left");
	} else {
		document.getElementById(id2).style.visibility = "hidden";
	}
}

function setlink(id1, id2)
{
	setpic(id1 + "_" + id2 + "_a", "line");
	setpic(id1 + "_" + id2 + "_b", "line");
	setlink_helper(id1 + "_" + id2 + "_a", id1 + "_" + id2 + "_b",
	               id1 + "_" + id2 + "_c", gnodes[id1], gnodes[id2]);
}

function draw()
{
	var i, j;

	gnodes_xpos = new Object();
	gnodes_ypos = new Object();

	for (i=0; i<gnodes_id.length; i++) {
		var id = gnodes_id[i];
		setpos(id, gnodes[id].top, gnodes[id].left,
		           gnodes[id].height, gnodes[id].width);
		for (j=0; j<gnodes[id].links.length; j++)
			setlink(id, gnodes[id].links[j]);
	}

	setpos("max_scroll", max_y, max_x, 20, 20);
}

function connect(id1, id2)
{
	gnodes[id1]["links"].push(id2);
}

MouseMoveManager = handle_move;
MouseUpManager = handle_up;

//--></script>

<img id="max_scroll" src="${ibase}trans.gif">

</>
			);

		var list = get_list();
		foreach i (list) {
			write(
<>
<table id="$i" cellspacing="0" cellpadding="0" onMouseDown="handle_down('$i')">
<tr><td <spl:if code="declared list[i].get_color">bgcolor="${list[i].get_color()}"</spl:if> align="center" valign="middle">
<spl:if code="declared list[i].get_html">${list[i].get_html()}</spl:if>
</td></tr></table>
</>
				);
		}

		foreach i (list) {
			if (declared list[i].get_links) {
				var links = list[i].get_links();
				foreach j (links) {
					write(
<>
<img id="${i}_${links[j]}_a" src="${ibase}line.gif" onClick="handle_conn_click('${i}', '${links[j]}')"
	onMouseOver="handle_conn_enter('${i}_${links[j]}')" onMouseOut="handle_conn_leave('${i}_${links[j]}')">
<img id="${i}_${links[j]}_b" src="${ibase}line.gif" onClick="handle_conn_click('${i}', '${links[j]}')"
	onMouseOver="handle_conn_enter('${i}_${links[j]}')" onMouseOut="handle_conn_leave('${i}_${links[j]}')">
<img id="${i}_${links[j]}_c" src="${ibase}line.gif" onClick="handle_conn_click('${i}', '${links[j]}')"
	onMouseOver="handle_conn_enter('${i}_${links[j]}')" onMouseOut="handle_conn_leave('${i}_${links[j]}')">
</>
						);
				}
			}
		}

		write('<script><!--\n');

		foreach i (list) {
			var pos = [ x: 10, y:10, w:10, h:10 ];
			if (declared list[i].get_xywh) pos = list[i].get_xywh();
			write('register("$i", $pos.y, $pos.x, $pos.h, $pos.w);\n');
		}

		foreach i (list) {
			if (declared list[i].get_links) {
				var links = list[i].get_links();
				foreach j (links) {
					write('connect("$i", "${links[j]}");\n');
				}
			}
		}

		write('draw();\n');
		if (defined scroll_x and defined scroll_y)
			write('scrollTo($scroll_x, $scroll_y);\n');
		write('//--></script>\n');
		write(iframe_footer);
	}

	/**
	 * Overloaded [[wsf:WsfComponent.get_html()]].
	 */
	method get_html()
	{
		return '<iframe $iframe_attributes id="$id" src="${cgi.url}?sid=${cgi.sid_vm}:${id}_iframe"></iframe>\n';
	}

	/**
	 * Overloaded [[wsf:WsfComponent.main()]].
	 */
	method main()
	{
		task_co_return();

		if (declared cgi.param.n)
		{
			var i = cgi.param.n;
			var list = get_list();

			if (declared cgi.param.sx) scroll_x = cgi.param.sx;
			if (declared cgi.param.sy) scroll_y = cgi.param.sy;

			if (declared cgi.param.x and declared cgi.param.y and declared list[i].set_xy)
				list[i].set_xy(cgi.param.x, cgi.param.y);

			if (declared cgi.param.t and declared list[i].set_link)
				list[i].set_link(cgi.param.t);
		}
	}

	/**
	 * Overloaded [[wsf:WsfComponent.destroy()]].
	 */
	method destroy()
	{
		task_kill("${id}_iframe");
		return *WsfComponent.destroy();
	}

	/**
	 * The Constructor.
	 *
	 * The parameters are copied to the [[.get_list]] and [[.ibase]]
	 * variables.
	 *
	 * The first parameter must be a function pointer. This function, when
	 * called, must return an array of objects implementing the
	 * [[WsfGraphNode]] interface. This objects describe the entire graph
	 * and also provide callbacks to react on user events.
	 */
	method init(_get_list, _ibase)
	{
		*WsfComponent.init();

		get_list = _get_list;
		ibase = _ibase;

		task_create("${id}_iframe", "while (1) { iframe_main(); task_pause(); }", this);
		task_public("${id}_iframe");

		return this;
	}
}

/**
 * The node objects used by [[WsfGraph]] must implement this interface.
 * Some of the methods in this interface are optional.
 */
// interface WsfGraphNode
// {
	/**
	 * This method returns the position and size of the node in pixel.
	 * The return value must be a hash with the keys 'x' and 'y' for
	 * the x- and y-coordinate of the left upper corner (0,0 is the
	 * left upper corner of the drawing area) and 'w' and 'h' for the
	 * width and height.
	 */
	// method get_xywh()

	/**
	 * When a node is moved or clicked, this callback is called. The new
	 * x- and y-coordinates are passed as parameters.
	 */
	// method set_xy(x, y)

	/**
	 * This method returns an array with the IDs of the nodes this node
	 * has connections to. The IDs must correspond with the keys in the
	 * array returned by [[WsfGraph.get_list]].
	 */
	// method get_links()

	/**
	 * This callback is called when one of the connections of the node
	 * are clicked. The ID (see [[.get_links]]) of the target node of the
	 * connection is passed as parameter.
	 *
	 * This method is optional. [[WsfGraph]] will not try to call it when
	 * is is not declared.
	 */
	// method set_link(trg)

	/**
	 * This method must return the background color for this node. The
	 * return value is a string in the usual HTML color '#RRGGBB' format.
	 *
	 * This method is optional. [[WsfGraph]] will not try to call it when
	 * it is not declared.
	 */
	// method get_color()

	/**
	 * This method must return the HTML content for this node. Usually
	 * this is just a label text, but it can any HTML code.
	 *
	 * This method is optional. [[WsfGraph]] will not try to call it when
	 * it is not declared.
	 */
	// method get_html()
// }