Titled.js

dojo.provide("dojox.charting.axis2d.Titled");

dojo.require("dojox.charting.axis2d.Default");
dojo.require("dojox.gfx");
dojo.require("dojox.gfx.matrix");

(function(){
	var dc = dojox.charting,
		g = dojox.gfx,
		m = dojox.gfx.matrix,
		labelGap = 4;	// in pixels

	dojo.declare("dojox.charting.axis2d.Titled", dojox.charting.axis2d.Default, {
		//	summary:
		//		Adds title support to the Default axis
		//
		//		Inspired by Brian Forbes, http://www.reigndropsfall.net/2010/08/12/dojox-charting-axis-titles/
			
		getOffsets: function(){
			//	summary:
			//		Get the physical offset values for this axis (used in drawing data series).
			//	returns: Object
			//		The calculated offsets in the form of { l, r, t, b } (left, right, top, bottom).
			var offsets = this.inherited(arguments),
				o = this.opt;
			if(o.title){
				var ta = this.chart.theme.axis,
					taFont = o.font || (ta.majorTick && ta.majorTick.font) || (ta.tick && ta.tick.font),
					size = taFont ? g.normalizedLength(g.splitFontString(taFont).size) : 0,
					leftBottom = o.leftBottom;
				if(this.vertical){
					offsets[leftBottom ? "l" : "r"] += size + labelGap;
				}else{
					offsets[leftBottom ? "b" : "t"] += size + labelGap;
				}
			}
			return offsets;	//	Object
		},
		render: function(dim, offsets){
			//	summary:
			//		Render/draw the axis.
			//	dim: Object
			//		An object of the form { width, height}.
			//	offsets: Object
			//		An object of the form { l, r, t, b }.
			//	returns: dojox.charting.axis2d.Titled
			//		The reference to the axis for functional chaining.
			if(!this.dirty){
				return this;	//	dojox.charting.axis2d.Titled
			}
			this.inherited(arguments);
			try {
				var o = this.opt,
					title = o.title,
					ta = this.chart.theme.axis,
					taFont = o.font || (ta.majorTick && ta.majorTick.font) || (ta.tick && ta.tick.font),
					taFontColor = o.fontColor || (ta.majorTick && ta.majorTick.fontColor) || (ta.tick && ta.tick.fontColor) || "black",
					size = taFont ? g.normalizedLength(g.splitFontString(taFont).size) : 0,
					cm = this.chart.margins,
					leftBottom = o.leftBottom;
				if(title){
					var x, y, rotate;
					// If the axis is vertical, rotate it
					if(this.vertical){
						rotate = leftBottom ? 270 : 90;
						x = leftBottom ? size + cm.l : dim.width - size - cm.r;
						y = (offsets.t + dim.height - offsets.b) / 2;
					}else{
						rotate = 0;
						x = (offsets.l + dim.width - offsets.r) / 2;
						y = leftBottom ? dim.height - cm.b : cm.t;
					}
					// Render the text at the origin, transform into place later
					var elem = this.group.createText({x: 0, y: 0, text: title, align: 'middle'});
					elem.setFont(taFont).setFill(taFontColor);
					// If the axis is vertical, rotate and move into position,
					// otherwise just move into position.
					if(rotate){
						elem.setTransform([
							m.translate(x, y),
							m.rotateg(rotate)
						]);
					}else{
						elem.setTransform(m.translate(x, y));
					}
				}
			}catch(e){
				// squelch
			}
			return this;	//	dojox.charting.axis2d.Titled
		}
	});
})();