Leaflet/src/dom/Draggable.js
2013-12-17 14:07:21 -05:00

135 lines
3.5 KiB
JavaScript

/*
* L.Draggable allows you to add dragging capabilities to any element. Supports mobile devices too.
*/
L.Draggable = L.Evented.extend({
statics: {
START: L.Browser.touch ? ['touchstart', 'mousedown'] : ['mousedown'],
END: {
mousedown: 'mouseup',
touchstart: 'touchend',
pointerdown: 'touchend',
MSPointerDown: 'touchend'
},
MOVE: {
mousedown: 'mousemove',
touchstart: 'touchmove',
pointerdown: 'touchmove',
MSPointerDown: 'touchmove'
}
},
initialize: function (element, dragStartTarget) {
this._element = element;
this._dragStartTarget = dragStartTarget || element;
},
enable: function () {
if (this._enabled) { return; }
for (var i = L.Draggable.START.length - 1; i >= 0; i--) {
L.DomEvent.on(this._dragStartTarget, L.Draggable.START[i], this._onDown, this);
}
this._enabled = true;
},
disable: function () {
if (!this._enabled) { return; }
for (var i = L.Draggable.START.length - 1; i >= 0; i--) {
L.DomEvent.off(this._dragStartTarget, L.Draggable.START[i], this._onDown, this);
}
this._enabled = false;
this._moved = false;
},
_onDown: function (e) {
this._moved = false;
if (e.shiftKey || ((e.which !== 1) && (e.button !== 1) && !e.touches)) { return; }
L.DomEvent.stopPropagation(e);
if (L.Draggable._disabled) { return; }
L.DomUtil.disableImageDrag();
L.DomUtil.disableTextSelection();
if (this._moving) { return; }
var first = e.touches ? e.touches[0] : e;
this._startPoint = new L.Point(first.clientX, first.clientY);
this._startPos = this._newPos = L.DomUtil.getPosition(this._element);
L.DomEvent
.on(document, L.Draggable.MOVE[e.type], this._onMove, this)
.on(document, L.Draggable.END[e.type], this._onUp, this);
},
_onMove: function (e) {
if (e.touches && e.touches.length > 1) {
this._moved = true;
return;
}
var first = (e.touches && e.touches.length === 1 ? e.touches[0] : e),
newPoint = new L.Point(first.clientX, first.clientY),
offset = newPoint.subtract(this._startPoint);
if (!offset.x && !offset.y) { return; }
L.DomEvent.preventDefault(e);
if (!this._moved) {
this.fire('dragstart');
this._moved = true;
this._startPos = L.DomUtil.getPosition(this._element).subtract(offset);
L.DomUtil.addClass(document.body, 'leaflet-dragging');
L.DomUtil.addClass((e.target || e.srcElement), 'leaflet-drag-target');
}
this._newPos = this._startPos.add(offset);
this._moving = true;
L.Util.cancelAnimFrame(this._animRequest);
this._animRequest = L.Util.requestAnimFrame(this._updatePosition, this, true, this._dragStartTarget);
},
_updatePosition: function () {
this.fire('predrag');
L.DomUtil.setPosition(this._element, this._newPos);
this.fire('drag');
},
_onUp: function (e) {
L.DomUtil.removeClass(document.body, 'leaflet-dragging');
L.DomUtil.removeClass((e.target || e.srcElement), 'leaflet-drag-target');
for (var i in L.Draggable.MOVE) {
L.DomEvent
.off(document, L.Draggable.MOVE[i], this._onMove)
.off(document, L.Draggable.END[i], this._onUp);
}
L.DomUtil.enableImageDrag();
L.DomUtil.enableTextSelection();
if (this._moved && this._moving) {
// ensure drag is not fired after dragend
L.Util.cancelAnimFrame(this._animRequest);
this.fire('dragend', {
distance: this._newPos.distanceTo(this._startPos)
});
}
this._moving = false;
}
});