/*
* jquery.draggable
* https://github.com/ducksboard/gridster.js
*
* Copyright (c) 2012 ducksboard
* Licensed under the MIT, GPL licenses.
*/
;(function($, window, document, undefined){
var defaults = {
items: '.gs_w',
distance: 1,
limit: true,
offset_left: 0,
autoscroll: true
// ,drag: function(e){},
// start : function(e, ui){},
// stop : function(e){}
};
var $body = $(document.body);
var $window = $(window);
/**
* Basic drag implementation for DOM elements inside a container.
* Provide start/stop/drag callbacks.
*
* @class Draggable
* @param {HTMLElement} el The HTMLelement that contains all the widgets
* to be dragged.
* @param {Object} [options] An Object with all options you want to
* overwrite:
* @param {HTMLElement|String} [options.items] Define who will
* be the draggable items. Can be a CSS Selector String or a
* collection of HTMLElements.
* @param {Number} [options.distance] Distance in pixels after mousedown
* the mouse must move before dragging should start.
* @param {Boolean} [options.limit] Constrains dragging to the width of
* the container
* @param {offset_left} [options.offset_left] Offset added to the item
* that is being dragged.
* @param {Number} [options.drag] Executes a callback when the mouse is
* moved during the dragging.
* @param {Number} [options.start] Executes a callback when the drag
* starts.
* @param {Number} [options.stop] Executes a callback when the drag stops.
* @return {Object} Returns `el`.
* @constructor
*/
function Draggable(el, options) {
this.options = $.extend({}, defaults, options);
this.$container = $(el);
this.$dragitems = $(this.options.items, this.$container);
this.is_dragging = false;
this.player_min_left = 0 + this.options.offset_left;
this.init();
}
var fn = Draggable.prototype;
fn.init = function() {
this.calculate_positions();
this.$container.css('position', 'relative');
this.enable();
$(window).bind('resize',
throttle($.proxy(this.calculate_positions, this), 200));
};
fn.get_actual_pos = function($el) {
var pos = $el.position();
return pos;
};
fn.get_mouse_pos = function(e) {
return {
left: e.clientX,
top: e.clientY
};
};
fn.get_offset = function(e) {
e.preventDefault();
var mouse_actual_pos = this.get_mouse_pos(e);
var diff_x = Math.round(
mouse_actual_pos.left - this.mouse_init_pos.left);
var diff_y = Math.round(mouse_actual_pos.top - this.mouse_init_pos.top);
var left = Math.round(this.el_init_offset.left + diff_x - this.baseX);
var top = Math.round(
this.el_init_offset.top + diff_y - this.baseY + this.scrollOffset);
if (this.options.limit) {
if (left > this.player_max_left) {
left = this.player_max_left;
}else if(left < this.player_min_left) {
left = this.player_min_left;
}
}
return {
left: left,
top: top,
mouse_left: mouse_actual_pos.left,
mouse_top: mouse_actual_pos.top
};
};
fn.manage_scroll = function(offset) {
/* scroll document */
var nextScrollTop;
var scrollTop = $window.scrollTop();
var min_window_y = scrollTop;
var max_window_y = min_window_y + this.window_height;
var mouse_down_zone = max_window_y - 30;
var mouse_up_zone = min_window_y + 20;
var abs_mouse_left = offset.mouse_left;
var abs_mouse_top = min_window_y + offset.mouse_top;
var max_player_y = (this.doc_height - this.window_height +
this.player_height);
if (abs_mouse_top >= mouse_down_zone) {
nextScrollTop = scrollTop + 10;
if (nextScrollTop < max_player_y) {
$window.scrollTop(nextScrollTop);
this.scrollOffset = this.scrollOffset + 10;
}
};
if (abs_mouse_top <= mouse_up_zone) {
nextScrollTop = scrollTop - 10;
if (nextScrollTop > 0) {
$window.scrollTop(nextScrollTop);
this.scrollOffset = this.scrollOffset - 10;
}
};
}
fn.calculate_positions = function(e) {
this.window_height = $window.height();
}
fn.drag_handler = function(e) {
if (e.which !== 1) {
return false;
}
var self = this;
var first = true;
this.$player = $(e.currentTarget);
this.el_init_pos = this.get_actual_pos(this.$player);
this.mouse_init_pos = this.get_mouse_pos(e);
this.offsetY = this.mouse_init_pos.top - this.el_init_pos.top;
$body.on('mousemove.draggable', function(mme){
var mouse_actual_pos = self.get_mouse_pos(mme);
var diff_x = Math.abs(
mouse_actual_pos.left - self.mouse_init_pos.left);
var diff_y = Math.abs(
mouse_actual_pos.top - self.mouse_init_pos.top);
if (!(diff_x > self.options.distance ||
diff_y > self.options.distance)
) {
return false;
}
if (first) {
first = false;
self.on_dragstart.call(self, mme);
return false;
}
if (self.is_dragging == true) {
self.on_dragmove.call(self, mme);
}
return false;
});
return false;
};
fn.on_dragstart = function(e) {
e.preventDefault();
this.drag_start = true;
this.is_dragging = true;
var offset = this.$container.offset();
this.baseX = Math.round(offset.left);
this.baseY = Math.round(offset.top);
this.doc_height = $(document).height();
if (this.options.helper === 'clone') {
this.$helper = this.$player.clone()
.appendTo(this.$container).addClass('helper');
this.helper = true;
}else{
this.helper = false;
}
this.scrollOffset = 0;
this.el_init_offset = this.$player.offset();
this.player_width = this.$player.width();
this.player_height = this.$player.height();
this.player_max_left = (this.$container.width() - this.player_width +
this.options.offset_left);
if (this.options.start) {
this.options.start.call(this.$player, e, {
helper: this.helper ? this.$helper : this.$player
});
}
return false;
};
fn.on_dragmove = function(e) {
var offset = this.get_offset(e);
this.options.autoscroll && this.manage_scroll(offset);
(this.helper ? this.$helper : this.$player).css({
'position': 'absolute',
'left' : offset.left,
'top' : offset.top
});
var ui = {
'position': {
'left': offset.left,
'top': offset.top
}
};
if (this.options.drag) {
this.options.drag.call(this.$player, e, ui);
}
return false;
};
fn.on_dragstop = function(e) {
var offset = this.get_offset(e);
this.drag_start = false;
var ui = {
'position': {
'left': offset.left,
'top': offset.top
}
};
if (this.options.stop) {
this.options.stop.call(this.$player, e, ui);
}
if (this.helper) {
this.$helper.remove();
}
return false;
};
fn.enable = function(){
this.$container.on('mousedown.draggable', this.options.items, $.proxy(
this.drag_handler, this));
$body.on('mouseup.draggable', $.proxy(function(e) {
this.is_dragging = false;
$body.off('mousemove.draggable');
if (this.drag_start) {
this.on_dragstop(e);
}
}, this));
};
fn.disable = function(){
this.$container.off('mousedown.draggable');
$body.off('mouseup.draggable');
};
fn.destroy = function(){
this.disable();
$.removeData(this.$container, 'draggable');
};
//jQuery adapter
$.fn.draggable = function ( options ) {
return this.each(function () {
if (!$.data(this, 'draggable')) {
$.data(this, 'draggable', new Draggable( this, options ));
}
});
};
}(jQuery, window, document));
