jquery-ui/ui/jquery.ui.draggable.js
2012-01-27 22:06:37 -05:00

370 lines
10 KiB
JavaScript

/*
* jQuery UI Draggable @VERSION
*
* Copyright 2011, AUTHORS.txt (http://jqueryui.com/about)
* Dual licensed under the MIT or GPL Version 2 licenses.
* http://jquery.org/license
*
* http://docs.jquery.com/UI/Draggable
*
* Depends:
* jquery.ui.core.js
* jquery.ui.interaction.js
* jquery.ui.widget.js
*/
(function( $, undefined ) {
// create a shallow copy of an object
function copy( obj ) {
var prop,
ret = {};
for ( prop in obj ) {
ret[ prop ] = obj[ prop ];
}
return ret;
}
$.widget( "ui.draggable", $.ui.interaction, {
version: "@VERSION",
widgetEventPrefix: "drag",
options: {
appendTo: null,
handle: null,
helper: null
},
// dragEl: element being dragged (original or helper)
// position: final CSS position of dragEl
// offset: offset of dragEl
// originalPosition: CSS position before drag start
// originalOffset: offset before drag start
// startPointer: pageX/Y of the mousedown (offset of pointer)
// startPosition: CSS position at drag start (after beforeStart)
// startOffset: offset at drag start (after beforeStart)
// tempPosition: overridable CSS position of dragEl
// overflowOffset: offset of scroll parent
// overflow: object containing width and height keys of scroll parent
// domPosition: object containing original parent and index when using
// appendTo option without a helper
_create: function() {
this._super();
// Static position elements can't be moved with top/left
if ( this.element.css( "position" ) === "static" ) {
this.element.css( "position", "relative" );
}
},
/** interaction interface **/
_isValidTarget: function( element ) {
return this.options.handle ? element.is( this.options.handle ) : true;
},
_start: function( event, pointerPosition ) {
var offset;
// The actual dragging element, should always be a jQuery object
this.dragEl = this.options.helper ?
this._createHelper( pointerPosition ) :
this.element;
// _createHelper() ensures that helpers are in the correct position
// in the DOM, but we need to handle appendTo when there is no helper
if ( this.options.appendTo && this.dragEl === this.element ) {
this.domPosition = {
parent: this.element.parent(),
index: this.element.index()
};
offset = this.dragEl.offset();
this.dragEl
.appendTo( this.options.appendTo )
.offset( offset );
}
this.cssPosition = this.dragEl.css( "position" );
this.scrollParent = this.element.scrollParent();
// Cache starting positions
this.startPointer = pointerPosition;
this.originalPosition = this.startPosition = this._getPosition();
this.originalOffset = this.startOffset = this.dragEl.offset();
// Cache current position and offset
this.position = copy( this.startPosition );
this.offset = copy( this.startOffset );
// Cache the offset of scrollParent, if required for _handleScrolling
if ( this.scrollParent[0] !== this.document[0] && this.scrollParent[0].tagName !== "HTML" ) {
this.overflowOffset = this.scrollParent.offset();
}
this.overflow = {
height: this.scrollParent[0] === this.document[0] ?
this.window.height() : this.scrollParent.height(),
width: this.scrollParent[0] === this.document[0] ?
this.window.width() : this.scrollParent.width()
};
this._preparePosition( pointerPosition );
// If user cancels beforeStart, don't allow dragging
if ( this._trigger( "beforeStart", event, {
position: this.position,
offset: copy( this.offset ),
pointer: copy( pointerPosition )
}) === false ) {
return false;
}
this._setCss();
this.startPosition = this._getPosition();
this.startOffset = this.dragEl.offset();
this._trigger( "start", event, this._uiHash( pointerPosition ) );
this._blockFrames();
},
_move: function( event, pointerPosition ) {
this._preparePosition( pointerPosition );
// If user cancels drag, don't move the element
if ( this._trigger( "drag", event, this._uiHash( pointerPosition ) ) === false ) {
return;
}
this._setCss();
// Scroll the scrollParent, if needed
this._handleScrolling( pointerPosition );
},
_stop: function( event, pointerPosition ) {
var parent, next;
this._preparePosition( pointerPosition );
// If user cancels stop, leave helper there
if ( this._trigger( "stop", event, this._uiHash( pointerPosition ) ) !== false ) {
if ( this.options.helper ) {
this.dragEl.remove();
}
if ( this.domPosition ) {
parent = this.domPosition.parent;
next = parent.children().eq( this.domPosition.index );
if ( next.length ) {
next.before( this.element );
} else {
parent.append( this.element );
}
this.element.offset( this.offset );
this.domPosition = null;
}
}
this._unblockFrames();
},
/** internal **/
_createHelper: function( pointerPosition ) {
var helper,
offset = this.element.offset(),
xPos = (pointerPosition.x - offset.left) / this.element.outerWidth(),
yPos = (pointerPosition.y - offset.top) / this.element.outerHeight();
// clone
if ( this.options.helper === true ) {
helper = this.element.clone()
.removeAttr( "id" )
.find( "[id]" )
.removeAttr( "id" )
.end();
} else {
// TODO: figure out the signature for this; see #4957
helper = $( this.options.helper() );
}
// Ensure the helper is in the DOM; obey the appendTo option if it exists
if ( this.options.appendTo || !helper.closest( "body" ).length ) {
helper.appendTo( this.options.appendTo || this.document[0].body );
}
return helper
// Helper must be absolute to function properly
.css( "position", "absolute" )
.offset({
left: pointerPosition.x - helper.outerWidth() * xPos,
top: pointerPosition.y - helper.outerHeight() * yPos
});
},
_getPosition: function() {
var left, top, position,
scrollTop = this.scrollParent.scrollTop(),
scrollLeft = this.scrollParent.scrollLeft();
// If fixed or absolute
if ( this.cssPosition !== "relative" ) {
position = this.dragEl.position();
// Take into account scrollbar
position.top -= scrollTop;
position.left -= scrollLeft;
return position;
}
// When using relative, css values are checked
// Otherwise the position wouldn't account for padding on ancestors
left = this.dragEl.css( "left" );
top = this.dragEl.css( "top" );
// Webkit will give back auto if there is no explicit value
left = ( left === "auto" ) ? 0: parseInt( left, 10 );
top = ( top === "auto" ) ? 0: parseInt( top, 10 );
return {
left: left - scrollLeft,
top: top - scrollTop
};
},
_handleScrolling: function( pointerPosition ) {
var scrollTop = this.scrollParent.scrollTop(),
scrollLeft = this.scrollParent.scrollLeft(),
scrollSensitivity = 20,
baseSpeed = 5,
speed = function( distance ) {
return baseSpeed + Math.round( distance / 2 );
},
// overflowOffset is only set when scrollParent is not doc/html
overflowLeft = this.overflowOffset ?
this.overflowOffset.left :
scrollLeft,
overflowTop = this.overflowOffset ?
this.overflowOffset.top :
scrollTop,
xRight = this.overflow.width + overflowLeft - pointerPosition.x,
xLeft = pointerPosition.x- overflowLeft,
yBottom = this.overflow.height + overflowTop - pointerPosition.y,
yTop = pointerPosition.y - overflowTop;
// Handle vertical scrolling
if ( yBottom < scrollSensitivity ) {
this.scrollParent.scrollTop( scrollTop +
speed( scrollSensitivity - yBottom ) );
} else if ( yTop < scrollSensitivity ) {
this.scrollParent.scrollTop( scrollTop -
speed( scrollSensitivity - yTop ) );
}
// Handle horizontal scrolling
if ( xRight < scrollSensitivity ) {
this.scrollParent.scrollLeft( scrollLeft +
speed( scrollSensitivity - xRight ) );
} else if ( xLeft < scrollSensitivity ) {
this.scrollParent.scrollLeft( scrollLeft -
speed( scrollSensitivity - xLeft ) );
}
},
// Uses event to determine new position of draggable, before any override from callbacks
// TODO: handle absolute element inside relative parent like a relative element
_preparePosition: function( pointerPosition ) {
var leftDiff = pointerPosition.x - this.startPointer.x,
topDiff = pointerPosition.y - this.startPointer.y,
newLeft = leftDiff + this.startPosition.left,
newTop = topDiff + this.startPosition.top;
// Save off new values for .css() in various callbacks using this function
this.position = {
left: newLeft,
top: newTop
};
// Save off values to compare user override against automatic coordinates
this.tempPosition = {
left: newLeft,
top: newTop
};
// Refresh offset cache with new positions
this.offset.left = this.startOffset.left + leftDiff;
this.offset.top = this.startOffset.top + topDiff;
},
// Places draggable where event, or user via event/callback, indicates
_setCss: function() {
var newLeft = this.position.left,
newTop = this.position.top;
// User overriding left/top so shortcut math is no longer valid
if ( this.tempPosition.left !== this.position.left ||
this.tempPosition.top !== this.position.top ) {
// Reset offset based on difference of expected and overridden values
this.offset.left += newLeft - this.tempPosition.left;
this.offset.top += newTop - this.tempPosition.top;
}
// TODO: does this work with nested scrollable parents?
if ( this.cssPosition !== "fixed" ) {
newLeft += this.scrollParent.scrollLeft();
newTop += this.scrollParent.scrollTop();
}
this.dragEl.css({
left: newLeft,
top: newTop
});
},
_uiHash: function( pointerPosition ) {
var ret = {
originalPosition: copy( this.originalPosition ),
originalOffset: copy( this.originalOffset ),
startPosition: copy( this.startPosition ),
startOffset: copy( this.startOffset ),
startPointer: copy( this.startPointer ),
position: this.position,
offset: copy( this.offset ),
pointer: copy( pointerPosition )
};
if ( this.options.helper ) {
ret.helper = this.dragEl;
}
return ret;
},
_blockFrames: function() {
var body = this.document[0].body;
this.iframeBlocks = this.document.find( "iframe" ).map(function() {
var iframe = $( this ),
iframeOffset = iframe.offset();
return $( "<div>" )
.css({
position: "absolute",
width: iframe.outerWidth(),
height: iframe.outerHeight(),
top: iframeOffset.top,
left: iframeOffset.left
})
.appendTo( body )[0];
});
},
_unblockFrames: function() {
if ( this.iframeBlocks ) {
this.iframeBlocks.remove();
delete this.iframeBlocks;
}
}
});
})( jQuery );