The base Drag Class. Can be used to drag and resize Elements using mouse events.
var Drag = new Class({
Implements: [Events, Options],
options: {/*
onBeforeStart: function(thisElement){},
onStart: function(thisElement, event){},
onSnap: function(thisElement){},
onDrag: function(thisElement, event){},
onCancel: function(thisElement){},
onComplete: function(thisElement, event){},*/
snap: 6,
unit: 'px',
grid: false,
style: true,
limit: false,
handle: false,
invert: false,
preventDefault: false,
stopPropagation: false,
modifiers: {x: 'left', y: 'top'}
},
initialize: function(){
var params = Array.link(arguments, {
'options': Type.isObject,
'element': function(obj){
return obj != null;
}
});
this.element = document.id(params.element);
this.document = this.element.getDocument();
this.setOptions(params.options || {});
var htype = typeOf(this.options.handle);
this.handles = ((htype == 'array' || htype == 'collection') ? $$(this.options.handle) : document.id(this.options.handle)) || this.element;
this.mouse = {'now': {}, 'pos': {}};
this.value = {'start': {}, 'now': {}};
this.selection = (Browser.ie) ? 'selectstart' : 'mousedown';
this.bound = {
start: this.start.bind(this),
check: this.check.bind(this),
drag: this.drag.bind(this),
stop: this.stop.bind(this),
cancel: this.cancel.bind(this),
eventStop: Function.from(false)
};
this.attach();
},
attach: function(){
this.handles.addEvent('mousedown', this.bound.start);
return this;
},
detach: function(){
this.handles.removeEvent('mousedown', this.bound.start);
return this;
},
start: function(event){
var options = this.options;
if (event.rightClick) return;
if (options.preventDefault) event.preventDefault();
if (options.stopPropagation) event.stopPropagation();
this.mouse.start = event.page;
this.fireEvent('beforeStart', this.element);
var limit = options.limit;
this.limit = {x: [], y: []};
for (var z in options.modifiers){
if (!options.modifiers[z]) continue;
if (options.style) this.value.now[z] = this.element.getStyle(options.modifiers[z]).toInt();
else this.value.now[z] = this.element[options.modifiers[z]];
if (options.invert) this.value.now[z] *= -1;
this.mouse.pos[z] = event.page[z] - this.value.now[z];
if (limit && limit[z]){
var i = 2;
while (i--){
var limitZI = limit[z][i];
if (limitZI || limitZI === 0) this.limit[z][i] = (typeof limitZI == 'function') ? limitZI() : limitZI;
}
}
}
if (typeOf(this.options.grid) == 'number') this.options.grid = {
x: this.options.grid,
y: this.options.grid
};
var events = {
mousemove: this.bound.check,
mouseup: this.bound.cancel
};
events[this.selection] = this.bound.eventStop;
this.document.addEvents(events);
},
check: function(event){
if (this.options.preventDefault) event.preventDefault();
var distance = Math.round(Math.sqrt(Math.pow(event.page.x - this.mouse.start.x, 2) + Math.pow(event.page.y - this.mouse.start.y, 2)));
if (distance > this.options.snap){
this.cancel();
this.document.addEvents({
mousemove: this.bound.drag,
mouseup: this.bound.stop
});
this.fireEvent('start', [this.element, event]).fireEvent('snap', this.element);
}
},
drag: function(event){
var options = this.options;
if (options.preventDefault) event.preventDefault();
this.mouse.now = event.page;
for (var z in options.modifiers){
if (!options.modifiers[z]) continue;
this.value.now[z] = this.mouse.now[z] - this.mouse.pos[z];
if (options.invert) this.value.now[z] *= -1;
if (options.limit && this.limit[z]){
if ((this.limit[z][1] || this.limit[z][1] === 0) && (this.value.now[z] > this.limit[z][1])){
this.value.now[z] = this.limit[z][1];
} else if ((this.limit[z][0] || this.limit[z][0] === 0) && (this.value.now[z] < this.limit[z][0])){
this.value.now[z] = this.limit[z][0];
}
}
if (options.grid[z]) this.value.now[z] -= ((this.value.now[z] - (this.limit[z][0]||0)) % options.grid[z]);
if (options.style) {
this.element.setStyle(options.modifiers[z], this.value.now[z] + options.unit);
} else {
this.element[options.modifiers[z]] = this.value.now[z];
}
}
this.fireEvent('drag', [this.element, event]);
},
cancel: function(event){
this.document.removeEvents({
mousemove: this.bound.check,
mouseup: this.bound.cancel
});
if (event){
this.document.removeEvent(this.selection, this.bound.eventStop);
this.fireEvent('cancel', this.element);
}
},
stop: function(event){
var events = {
mousemove: this.bound.drag,
mouseup: this.bound.stop
};
events[this.selection] = this.bound.eventStop;
this.document.removeEvents(events);
if (event) this.fireEvent('complete', [this.element, event]);
}
});
Element.implement({
makeResizable: function(options){
var drag = new Drag(this, Object.merge({
modifiers: {
x: 'width',
y: 'height'
}
}, options));
this.store('resizer', drag);
return drag.addEvent('drag', function(){
this.fireEvent('resize', drag);
}.bind(this));
}
});