position.js

/*!
 * jQuery UI Position @VERSION
 * http://jqueryui.com
 *
 * Copyright jQuery Foundation and other contributors
 * Released under the MIT license.
 * http://jquery.org/license
 *
 * http://api.jqueryui.com/position/
 */

//>>label: Position
//>>group: UI Core
//>>description: Positions elements relative to other elements.
//>>docs: http://api.jqueryui.com/position/
//>>demos: http://jqueryui.com/position/

( function( factory ) {
	if ( typeof define === "function" && define.amd ) {

		// AMD. Register as an anonymous module.
		define( [ "jquery" ], factory );
	} else {

		// Browser globals
		factory( jQuery );
	}
}( function( $ ) {
( function() {

$.ui = $.ui || {};

var cachedScrollbarWidth, supportsOffsetFractions,
	max = Math.max,
	abs = Math.abs,
	round = Math.round,
	rhorizontal = /left|center|right/,
	rvertical = /top|center|bottom/,
	roffset = /[\+\-]\d+(\.[\d]+)?%?/,
	rposition = /^\w+/,
	rpercent = /%$/,
	_position = $.fn.position;

// Support: IE <=9 only
supportsOffsetFractions = function() {
	var element = $( "<div>" )
			.css( "position", "absolute" )
			.appendTo( "body" )
			.offset( {
				top: 1.5,
				left: 1.5
			} ),
		support = element.offset().top === 1.5;

	element.remove();

	supportsOffsetFractions = function() {
		return support;
	};

	return support;
};

function getOffsets( offsets, width, height ) {
	return [
		parseFloat( offsets[ 0 ] ) * ( rpercent.test( offsets[ 0 ] ) ? width / 100 : 1 ),
		parseFloat( offsets[ 1 ] ) * ( rpercent.test( offsets[ 1 ] ) ? height / 100 : 1 )
	];
}

function parseCss( element, property ) {
	return parseInt( $.css( element, property ), 10 ) || 0;
}

function getDimensions( elem ) {
	var raw = elem[ 0 ];
	if ( raw.nodeType === 9 ) {
		return {
			width: elem.width(),
			height: elem.height(),
			offset: { top: 0, left: 0 }
		};
	}
	if ( $.isWindow( raw ) ) {
		return {
			width: elem.width(),
			height: elem.height(),
			offset: { top: elem.scrollTop(), left: elem.scrollLeft() }
		};
	}
	if ( raw.preventDefault ) {
		return {
			width: 0,
			height: 0,
			offset: { top: raw.pageY, left: raw.pageX }
		};
	}
	return {
		width: elem.outerWidth(),
		height: elem.outerHeight(),
		offset: elem.offset()
	};
}

$.position = {
	scrollbarWidth: function() {
		if ( cachedScrollbarWidth !== undefined ) {
			return cachedScrollbarWidth;
		}
		var w1, w2,
			div = $( "<div style='display:block;position:absolute;width:50px;height:50px;overflow:hidden;'><div style='height:100px;width:auto;'></div></div>" ),
			innerDiv = div.children()[ 0 ];

		$( "body" ).append( div );
		w1 = innerDiv.offsetWidth;
		div.css( "overflow", "scroll" );

		w2 = innerDiv.offsetWidth;

		if ( w1 === w2 ) {
			w2 = div[ 0 ].clientWidth;
		}

		div.remove();

		return ( cachedScrollbarWidth = w1 - w2 );
	},
	getScrollInfo: function( within ) {
		var overflowX = within.isWindow || within.isDocument ? "" :
				within.element.css( "overflow-x" ),
			overflowY = within.isWindow || within.isDocument ? "" :
				within.element.css( "overflow-y" ),
			hasOverflowX = overflowX === "scroll" ||
				( overflowX === "auto" && within.width < within.element[ 0 ].scrollWidth ),
			hasOverflowY = overflowY === "scroll" ||
				( overflowY === "auto" && within.height < within.element[ 0 ].scrollHeight );
		return {
			width: hasOverflowY ? $.position.scrollbarWidth() : 0,
			height: hasOverflowX ? $.position.scrollbarWidth() : 0
		};
	},
	getWithinInfo: function( element ) {
		var withinElement = $( element || window ),
			isWindow = $.isWindow( withinElement[ 0 ] ),
			isDocument = !!withinElement[ 0 ] && withinElement[ 0 ].nodeType === 9,
			hasOffset = !isWindow && !isDocument;
		return {
			element: withinElement,
			isWindow: isWindow,
			isDocument: isDocument,
			offset: hasOffset ? $( element ).offset() : { left: 0, top: 0 },
			scrollLeft: withinElement.scrollLeft(),
			scrollTop: withinElement.scrollTop(),
			width: withinElement.outerWidth(),
			height: withinElement.outerHeight()
		};
	}
};

$.fn.position = function( options ) {
	if ( !options || !options.of ) {
		return _position.apply( this, arguments );
	}

	// make a copy, we don't want to modify arguments
	options = $.extend( {}, options );

	var atOffset, targetWidth, targetHeight, targetOffset, basePosition, dimensions,
		target = $( options.of ),
		within = $.position.getWithinInfo( options.within ),
		scrollInfo = $.position.getScrollInfo( within ),
		collision = ( options.collision || "flip" ).split( " " ),
		offsets = {};

	dimensions = getDimensions( target );
	if ( target[ 0 ].preventDefault ) {
		// force left top to allow flipping
		options.at = "left top";
	}
	targetWidth = dimensions.width;
	targetHeight = dimensions.height;
	targetOffset = dimensions.offset;
	// clone to reuse original targetOffset later
	basePosition = $.extend( {}, targetOffset );

	// force my and at to have valid horizontal and vertical positions
	// if a value is missing or invalid, it will be converted to center
	$.each( [ "my", "at" ], function() {
		var pos = ( options[ this ] || "" ).split( " " ),
			horizontalOffset,
			verticalOffset;

		if ( pos.length === 1 ) {
			pos = rhorizontal.test( pos[ 0 ] ) ?
				pos.concat( [ "center" ] ) :
				rvertical.test( pos[ 0 ] ) ?
					[ "center" ].concat( pos ) :
					[ "center", "center" ];
		}
		pos[ 0 ] = rhorizontal.test( pos[ 0 ] ) ? pos[ 0 ] : "center";
		pos[ 1 ] = rvertical.test( pos[ 1 ] ) ? pos[ 1 ] : "center";

		// calculate offsets
		horizontalOffset = roffset.exec( pos[ 0 ] );
		verticalOffset = roffset.exec( pos[ 1 ] );
		offsets[ this ] = [
			horizontalOffset ? horizontalOffset[ 0 ] : 0,
			verticalOffset ? verticalOffset[ 0 ] : 0
		];

		// reduce to just the positions without the offsets
		options[ this ] = [
			rposition.exec( pos[ 0 ] )[ 0 ],
			rposition.exec( pos[ 1 ] )[ 0 ]
		];
	} );

	// normalize collision option
	if ( collision.length === 1 ) {
		collision[ 1 ] = collision[ 0 ];
	}

	if ( options.at[ 0 ] === "right" ) {
		basePosition.left += targetWidth;
	} else if ( options.at[ 0 ] === "center" ) {
		basePosition.left += targetWidth / 2;
	}

	if ( options.at[ 1 ] === "bottom" ) {
		basePosition.top += targetHeight;
	} else if ( options.at[ 1 ] === "center" ) {
		basePosition.top += targetHeight / 2;
	}

	atOffset = getOffsets( offsets.at, targetWidth, targetHeight );
	basePosition.left += atOffset[ 0 ];
	basePosition.top += atOffset[ 1 ];

	return this.each( function() {
		var collisionPosition, using,
			elem = $( this ),
			elemWidth = elem.outerWidth(),
			elemHeight = elem.outerHeight(),
			marginLeft = parseCss( this, "marginLeft" ),
			marginTop = parseCss( this, "marginTop" ),
			collisionWidth = elemWidth + marginLeft + parseCss( this, "marginRight" ) + scrollInfo.width,
			collisionHeight = elemHeight + marginTop + parseCss( this, "marginBottom" ) + scrollInfo.height,
			position = $.extend( {}, basePosition ),
			myOffset = getOffsets( offsets.my, elem.outerWidth(), elem.outerHeight() );

		if ( options.my[ 0 ] === "right" ) {
			position.left -= elemWidth;
		} else if ( options.my[ 0 ] === "center" ) {
			position.left -= elemWidth / 2;
		}

		if ( options.my[ 1 ] === "bottom" ) {
			position.top -= elemHeight;
		} else if ( options.my[ 1 ] === "center" ) {
			position.top -= elemHeight / 2;
		}

		position.left += myOffset[ 0 ];
		position.top += myOffset[ 1 ];

		// if the browser doesn't support fractions, then round for consistent results
		if ( !supportsOffsetFractions() ) {
			position.left = round( position.left );
			position.top = round( position.top );
		}

		collisionPosition = {
			marginLeft: marginLeft,
			marginTop: marginTop
		};

		$.each( [ "left", "top" ], function( i, dir ) {
			if ( $.ui.position[ collision[ i ] ] ) {
				$.ui.position[ collision[ i ] ][ dir ]( position, {
					targetWidth: targetWidth,
					targetHeight: targetHeight,
					elemWidth: elemWidth,
					elemHeight: elemHeight,
					collisionPosition: collisionPosition,
					collisionWidth: collisionWidth,
					collisionHeight: collisionHeight,
					offset: [ atOffset[ 0 ] + myOffset[ 0 ], atOffset [ 1 ] + myOffset[ 1 ] ],
					my: options.my,
					at: options.at,
					within: within,
					elem: elem
				} );
			}
		} );

		if ( options.using ) {
			// adds feedback as second argument to using callback, if present
			using = function( props ) {
				var left = targetOffset.left - position.left,
					right = left + targetWidth - elemWidth,
					top = targetOffset.top - position.top,
					bottom = top + targetHeight - elemHeight,
					feedback = {
						target: {
							element: target,
							left: targetOffset.left,
							top: targetOffset.top,
							width: targetWidth,
							height: targetHeight
						},
						element: {
							element: elem,
							left: position.left,
							top: position.top,
							width: elemWidth,
							height: elemHeight
						},
						horizontal: right < 0 ? "left" : left > 0 ? "right" : "center",
						vertical: bottom < 0 ? "top" : top > 0 ? "bottom" : "middle"
					};
				if ( targetWidth < elemWidth && abs( left + right ) < targetWidth ) {
					feedback.horizontal = "center";
				}
				if ( targetHeight < elemHeight && abs( top + bottom ) < targetHeight ) {
					feedback.vertical = "middle";
				}
				if ( max( abs( left ), abs( right ) ) > max( abs( top ), abs( bottom ) ) ) {
					feedback.important = "horizontal";
				} else {
					feedback.important = "vertical";
				}
				options.using.call( this, props, feedback );
			};
		}

		elem.offset( $.extend( position, { using: using } ) );
	} );
};

$.ui.position = {
	fit: {
		left: function( position, data ) {
			var within = data.within,
				withinOffset = within.isWindow ? within.scrollLeft : within.offset.left,
				outerWidth = within.width,
				collisionPosLeft = position.left - data.collisionPosition.marginLeft,
				overLeft = withinOffset - collisionPosLeft,
				overRight = collisionPosLeft + data.collisionWidth - outerWidth - withinOffset,
				newOverRight;

			// element is wider than within
			if ( data.collisionWidth > outerWidth ) {
				// element is initially over the left side of within
				if ( overLeft > 0 && overRight <= 0 ) {
					newOverRight = position.left + overLeft + data.collisionWidth - outerWidth - withinOffset;
					position.left += overLeft - newOverRight;
				// element is initially over right side of within
				} else if ( overRight > 0 && overLeft <= 0 ) {
					position.left = withinOffset;
				// element is initially over both left and right sides of within
				} else {
					if ( overLeft > overRight ) {
						position.left = withinOffset + outerWidth - data.collisionWidth;
					} else {
						position.left = withinOffset;
					}
				}
			// too far left -> align with left edge
			} else if ( overLeft > 0 ) {
				position.left += overLeft;
			// too far right -> align with right edge
			} else if ( overRight > 0 ) {
				position.left -= overRight;
			// adjust based on position and margin
			} else {
				position.left = max( position.left - collisionPosLeft, position.left );
			}
		},
		top: function( position, data ) {
			var within = data.within,
				withinOffset = within.isWindow ? within.scrollTop : within.offset.top,
				outerHeight = data.within.height,
				collisionPosTop = position.top - data.collisionPosition.marginTop,
				overTop = withinOffset - collisionPosTop,
				overBottom = collisionPosTop + data.collisionHeight - outerHeight - withinOffset,
				newOverBottom;

			// element is taller than within
			if ( data.collisionHeight > outerHeight ) {
				// element is initially over the top of within
				if ( overTop > 0 && overBottom <= 0 ) {
					newOverBottom = position.top + overTop + data.collisionHeight - outerHeight - withinOffset;
					position.top += overTop - newOverBottom;
				// element is initially over bottom of within
				} else if ( overBottom > 0 && overTop <= 0 ) {
					position.top = withinOffset;
				// element is initially over both top and bottom of within
				} else {
					if ( overTop > overBottom ) {
						position.top = withinOffset + outerHeight - data.collisionHeight;
					} else {
						position.top = withinOffset;
					}
				}
			// too far up -> align with top
			} else if ( overTop > 0 ) {
				position.top += overTop;
			// too far down -> align with bottom edge
			} else if ( overBottom > 0 ) {
				position.top -= overBottom;
			// adjust based on position and margin
			} else {
				position.top = max( position.top - collisionPosTop, position.top );
			}
		}
	},
	flip: {
		left: function( position, data ) {
			var within = data.within,
				withinOffset = within.offset.left + within.scrollLeft,
				outerWidth = within.width,
				offsetLeft = within.isWindow ? within.scrollLeft : within.offset.left,
				collisionPosLeft = position.left - data.collisionPosition.marginLeft,
				overLeft = collisionPosLeft - offsetLeft,
				overRight = collisionPosLeft + data.collisionWidth - outerWidth - offsetLeft,
				myOffset = data.my[ 0 ] === "left" ?
					-data.elemWidth :
					data.my[ 0 ] === "right" ?
						data.elemWidth :
						0,
				atOffset = data.at[ 0 ] === "left" ?
					data.targetWidth :
					data.at[ 0 ] === "right" ?
						-data.targetWidth :
						0,
				offset = -2 * data.offset[ 0 ],
				newOverRight,
				newOverLeft;

			if ( overLeft < 0 ) {
				newOverRight = position.left + myOffset + atOffset + offset + data.collisionWidth - outerWidth - withinOffset;
				if ( newOverRight < 0 || newOverRight < abs( overLeft ) ) {
					position.left += myOffset + atOffset + offset;
				}
			} else if ( overRight > 0 ) {
				newOverLeft = position.left - data.collisionPosition.marginLeft + myOffset + atOffset + offset - offsetLeft;
				if ( newOverLeft > 0 || abs( newOverLeft ) < overRight ) {
					position.left += myOffset + atOffset + offset;
				}
			}
		},
		top: function( position, data ) {
			var within = data.within,
				withinOffset = within.offset.top + within.scrollTop,
				outerHeight = within.height,
				offsetTop = within.isWindow ? within.scrollTop : within.offset.top,
				collisionPosTop = position.top - data.collisionPosition.marginTop,
				overTop = collisionPosTop - offsetTop,
				overBottom = collisionPosTop + data.collisionHeight - outerHeight - offsetTop,
				top = data.my[ 1 ] === "top",
				myOffset = top ?
					-data.elemHeight :
					data.my[ 1 ] === "bottom" ?
						data.elemHeight :
						0,
				atOffset = data.at[ 1 ] === "top" ?
					data.targetHeight :
					data.at[ 1 ] === "bottom" ?
						-data.targetHeight :
						0,
				offset = -2 * data.offset[ 1 ],
				newOverTop,
				newOverBottom;
			if ( overTop < 0 ) {
				newOverBottom = position.top + myOffset + atOffset + offset + data.collisionHeight - outerHeight - withinOffset;
				if ( newOverBottom < 0 || newOverBottom < abs( overTop ) ) {
					position.top += myOffset + atOffset + offset;
				}
			} else if ( overBottom > 0 ) {
				newOverTop = position.top - data.collisionPosition.marginTop + myOffset + atOffset + offset - offsetTop;
				if ( newOverTop > 0 || abs( newOverTop ) < overBottom ) {
					position.top += myOffset + atOffset + offset;
				}
			}
		}
	},
	flipfit: {
		left: function() {
			$.ui.position.flip.left.apply( this, arguments );
			$.ui.position.fit.left.apply( this, arguments );
		},
		top: function() {
			$.ui.position.flip.top.apply( this, arguments );
			$.ui.position.fit.top.apply( this, arguments );
		}
	}
};

} )();

return $.ui.position;

} ) );