// branch_renderer.js - Rendering of branch DAGs on the client side

//

// Copyright 2010 Marcin Kuzminski <marcin AT python-works DOT com>

// Copyright 2008 Jesper Noehr <jesper AT noehr DOT org>

// Copyright 2008 Dirkjan Ochtman <dirkjan AT ochtman DOT nl>

// Copyright 2006 Alexander Schremmer <alex AT alexanderweb DOT de>

//

// derived from code written by Scott James Remnant <scott@ubuntu.com>

// Copyright 2005 Canonical Ltd.

//

// This software may be used and distributed according to the terms

// of the GNU General Public License, incorporated herein by reference.

var colors = [

	[ 1.0, 0.0, 0.0 ],

	[ 1.0, 1.0, 0.0 ],

	[ 0.0, 1.0, 0.0 ],

	[ 0.0, 1.0, 1.0 ],

	[ 0.0, 0.0, 1.0 ],

	[ 1.0, 0.0, 1.0 ],

	[ 1.0, 1.0, 0.0 ],

	[ 0.0, 0.0, 0.0 ]

];

function BranchRenderer(canvas_id, content_id) {

	this.canvas = document.getElementById(canvas_id);

	var t = document.getElementById(content_id);

	this.canvas.setAttribute('height',t.clientHeight);

	if (!document.createElement("canvas").getContext)

		this.canvas = window.G_vmlCanvasManager.initElement(this.canvas);

	this.ctx = this.canvas.getContext('2d');

	this.ctx.strokeStyle = 'rgb(0, 0, 0)';

	this.ctx.fillStyle = 'rgb(0, 0, 0)';

	this.cur = [0, 0];

	this.line_width = 2.0;

	this.dot_radius = 3.5;

		color %= colors.length;

		var red = (colors[color][0] * fg) || bg;

		var green = (colors[color][1] * fg) || bg;

		var blue = (colors[color][2] * fg) || bg;

		red = Math.round(red * 255);

		green = Math.round(green * 255);

		blue = Math.round(blue * 255);

		var s = 'rgb(' + red + ', ' + green + ', ' + blue + ')';

		this.ctx.strokeStyle = s;

		this.ctx.fillStyle = s;

	}

	this.render = function(data,canvasWidth) {

		var idx = 1;

		var rela = this.canvas;

		this.canvas.setAttribute('width',canvasWidth);

		var lineCount = 1;

		for (var i=0;i<data.length;i++) {

			var in_l = data[i][1];

			for (var j in in_l) {

				var m = in_l[j][0];

				if (m > lineCount)

					lineCount = m;

			}

		}

		var edge_pad = this.dot_radius + 2;

		var box_size = Math.min(18, Math.floor((canvasWidth - edge_pad*2)/(lineCount)));

		var base_x = canvasWidth - edge_pad;

		for (var i in data) {

			var row = document.getElementById("chg_"+idx);

			if (row == null)

				continue;

			var	next = document.getElementById("chg_"+(idx+1));

			var extra = 0;

			cur = data[i];

			node = cur[0];

			in_l = cur[1];

			var rowY = row.offsetTop + row.offsetHeight/2 - rela.offsetTop;

			var nextY = (next == null) ? rowY + row.offsetHeight/2 : next.offsetTop + next.offsetHeight/2 - rela.offsetTop;

			for (var j in in_l) {

				line = in_l[j];

				start = line[0];

				end = line[1];

				color = line[2];

				x = base_x - box_size * start;

				this.ctx.lineWidth=this.line_width;

				this.ctx.beginPath();

				this.ctx.moveTo(x, rowY);

				if (start == end)

				{

					this.ctx.lineTo(x,nextY+extra,3);

				}

				else

				{

					var x2 = base_x - box_size * end;

					var ymid = (rowY+nextY) / 2;

					this.ctx.bezierCurveTo (x,ymid,x2,ymid,x2,nextY);

				}

				this.ctx.stroke();

			}

			column = node[0];

			color = node[1];

			radius = this.dot_radius;

			x = base_x - box_size * column;

			this.ctx.beginPath();

			this.setColor(color, 0.25, 0.75);

			this.ctx.arc(x, rowY, radius, 0, Math.PI * 2, true);

			this.ctx.fill();

			idx++;

		}

	}

}