TopAxisLayout.js revision 5c25e6d712b880e314278e6395068dd208553b98
/**
* Contains algorithms for rendering a top axis.
*
* @module charts
* @class TopAxisLayout
* @constructor
*/
TopAxisLayout = function(){};
TopAxisLayout.prototype = {
/**
* Default margins for text fields.
*
* @private
* @method _getDefaultMargins
* @return Object
*/
_getDefaultMargins: function()
{
return {
top: 0,
left: 0,
right: 0,
bottom: 4
};
},
/**
* Sets the length of the tick on either side of the axis line.
*
* @method setTickOffsets
* @protected
*/
setTickOffsets: function()
{
var host = this,
majorTicks = host.get("styles").majorTicks,
tickLength = majorTicks.length,
halfTick = tickLength * 0.5,
display = majorTicks.display;
host.set("leftTickOffset", 0);
host.set("rightTickOffset", 0);
switch(display)
{
case "inside" :
host.set("bottomTickOffset", tickLength);
host.set("topTickOffset", 0);
break;
case "outside" :
host.set("bottomTickOffset", 0);
host.set("topTickOffset", tickLength);
break;
case "cross" :
host.set("topTickOffset", halfTick);
host.set("bottomTickOffset", halfTick);
break;
default:
host.set("topTickOffset", 0);
host.set("bottomTickOffset", 0);
break;
}
},
/**
* Calculates the coordinates for the first point on an axis.
*
* @method getLineStart
* @protected
*/
getLineStart: function()
{
var host = this,
style = host.get("styles"),
padding = style.padding,
majorTicks = style.majorTicks,
tickLength = majorTicks.length,
display = majorTicks.display,
pt = {x:0, y:padding.top};
if(display === "outside")
{
pt.y += tickLength;
}
else if(display === "cross")
{
pt.y += tickLength/2;
}
return pt;
},
/**
* Draws a tick
*
* @method drawTick
* @param {Path} path reference to the path `Path` element in which to draw the tick.
* @param {Object} pt hash containing x and y coordinates
* @param {Object} tickStyles hash of properties used to draw the tick
* @protected
*/
drawTick: function(path, pt, tickStyles)
{
var host = this,
style = host.get("styles"),
padding = style.padding,
tickLength = tickStyles.length,
start = {x:pt.x, y:padding.top},
end = {x:pt.x, y:tickLength + padding.top};
host.drawLine(path, start, end);
},
/**
* Calculates the point for a label.
*
* @method getLabelPoint
* @param {Object} pt hash containing x and y coordinates
* @return Object
* @protected
*/
getLabelPoint: function(pt)
{
return {x:pt.x, y:pt.y - this.get("topTickOffset")};
},
/**
* Updates the value for the `maxLabelSize` for use in calculating total size.
*
* @method updateMaxLabelSize
* @param {HTMLElement} label to measure
* @protected
*/
updateMaxLabelSize: function(labelWidth, labelHeight)
{
var host = this,
props = this._labelRotationProps,
rot = props.rot,
absRot = props.absRot,
sinRadians = props.sinRadians,
cosRadians = props.cosRadians,
max;
if(rot === 0)
{
max = labelHeight;
}
else if(absRot === 90)
{
max = labelWidth;
}
else
{
max = (sinRadians * labelWidth) + (cosRadians * labelHeight);
}
host._maxLabelSize = Math.max(host._maxLabelSize, max);
},
/**
* Determines the available label height when the axis width has been explicitly set.
*
* @method getExplicitlySized
* @return Boolean
* @protected
*/
getExplicitlySized: function(styles)
{
if(this._explicitHeight)
{
var host = this,
h = host._explicitHeight,
totalTitleSize = host._totalTitleSize,
topTickOffset = host.get("topTickOffset"),
margin = styles.label.margin.right;
host._maxLabelSize = h - (topTickOffset + margin + totalTitleSize);
return true;
}
return false;
},
/**
* Rotate and position title.
*
* @method positionTitle
* @param {HTMLElement} label to rotate position
* @protected
*/
positionTitle: function(label)
{
var host = this,
bounds = host._titleBounds,
margin = host.get("styles").title.margin,
props = host._titleRotationProps,
labelWidth = label.offsetWidth,
labelHeight = label.offsetHeight,
h = bounds.bottom - bounds.top,
x = (host.get("width") * 0.5) - (labelWidth * 0.5),
y = h/2 - labelHeight/2;
props.labelWidth = labelWidth;
props.labelHeight = labelHeight;
if(margin && margin.top)
{
y += margin.top;
}
props.x = x;
props.y = y;
props.transformOrigin = [0.5, 0.5];
host._rotate(label, props);
},
/**
* Rotate and position labels.
*
* @method positionLabel
* @param {HTMLElement} label to rotate position
* @param {Object} pt hash containing the x and y coordinates in which the label will be positioned
* against.
* @protected
*/
positionLabel: function(label, pt, styles, i)
{
var host = this,
totalTitleSize = this._totalTitleSize,
maxLabelSize = host._maxLabelSize,
leftOffset = pt.x,
topOffset = pt.y + totalTitleSize + maxLabelSize,
props = this._labelRotationProps,
rot = props.rot,
absRot = props.absRot,
labelWidth = this._labelWidths[i],
labelHeight = this._labelHeights[i];
if(rot === 0)
{
leftOffset -= labelWidth * 0.5;
topOffset -= labelHeight;
}
else
{
if(rot === 90)
{
leftOffset -= labelWidth;
topOffset -= (labelHeight * 0.5);
}
else if (rot === -90)
{
topOffset -= (labelHeight * 0.5);
}
else if(rot > 0)
{
leftOffset -= labelWidth;
topOffset -= labelHeight - (labelHeight * rot/180);
}
else
{
topOffset -= labelHeight - (labelHeight * absRot/180);
}
}
props.x = Math.round(leftOffset);
props.y = Math.round(topOffset);
props.labelWidth = labelWidth;
props.labelHeight = labelHeight;
this._rotate(label, props);
},
/**
* Adjusts the coordinates of an axis label based on the rotation.
*
* @method _setRotationCoords
* @param {Object} props Coordinates, dimension and rotation properties of the label.
* @protected
*/
_setRotationCoords: function(props)
{
var rot = props.rot,
absRot = props.absRot,
labelWidth = props.labelWidth,
labelHeight = props.labelHeight,
leftOffset,
topOffset;
if(rot === 0)
{
leftOffset = labelWidth * 0.5;
topOffset = labelHeight;
}
else
{
if(rot === 90)
{
leftOffset = labelWidth;
topOffset = (labelHeight * 0.5);
}
else if (rot === -90)
{
topOffset = (labelHeight * 0.5);
}
else if(rot > 0)
{
leftOffset = labelWidth;
topOffset = labelHeight - (labelHeight * rot/180);
}
else
{
topOffset = labelHeight - (labelHeight * absRot/180);
}
}
props.x -= leftOffset;
props.y -= topOffset;
},
/**
* Returns the transformOrigin to use for an axis label based on the position of the axis
* and the rotation of the label.
*
* @method _getTransformOrigin
* @param {Number} rot The rotation (in degrees) of the label.
* @return Array
* @protected
*/
_getTransformOrigin: function(rot)
{
var transformOrigin;
if(rot === 0)
{
transformOrigin = [0, 0];
}
else
{
if(rot === 90)
{
transformOrigin = [1, 0.5];
}
else if (rot === -90)
{
transformOrigin = [0, 0.5];
}
else if(rot > 0)
{
transformOrigin = [1, 0.5];
}
else
{
transformOrigin = [0, 0.5];
}
}
return transformOrigin;
},
/**
* Adjusts position for inner ticks.
*
* @method offsetNodeForTick
* @param {Node} cb contentBox of the axis
* @protected
*/
offsetNodeForTick: function(cb)
{
},
/**
* Assigns a height based on the size of the contents.
*
* @method setCalculatedSize
* @protected
*/
setCalculatedSize: function()
{
var host = this,
graphic = host.get("graphic"),
styles = host.get("styles"),
labelMargin = styles.label.margin,
totalLabelSize = labelMargin.bottom + host._maxLabelSize,
totalTitleSize = host._totalTitleSize,
topTickOffset = this.get("topTickOffset"),
ttl = Math.round(topTickOffset + totalLabelSize + totalTitleSize);
if(this._explicitHeight)
{
ttl = this._explicitWidth;
}
host.set("calculatedHeight", ttl);
graphic.set("y", ttl - topTickOffset);
}
};
Y.TopAxisLayout = TopAxisLayout;