Leaflet/src/dom/Draggable.js
2012-02-22 09:00:54 +02:00

152 lines
3.8 KiB
JavaScript

/*
* L.Draggable allows you to add dragging capabilities to any element. Supports mobile devices too.
*/
L.Draggable = L.Class.extend({
includes: L.Mixin.Events,
statics: {
START: L.Browser.touch ? 'touchstart' : 'mousedown',
END: L.Browser.touch ? 'touchend' : 'mouseup',
MOVE: L.Browser.touch ? 'touchmove' : 'mousemove',
TAP_TOLERANCE: 15
},
initialize: function (element, dragStartTarget) {
this._element = element;
this._dragStartTarget = dragStartTarget || element;
},
enable: function () {
if (this._enabled) {
return;
}
L.DomEvent.addListener(this._dragStartTarget, L.Draggable.START, this._onDown, this);
this._enabled = true;
},
disable: function () {
if (!this._enabled) {
return;
}
L.DomEvent.removeListener(this._dragStartTarget, L.Draggable.START, this._onDown);
this._enabled = false;
this._moved = false;
},
_onDown: function (e) {
if ((!L.Browser.touch && e.shiftKey) || ((e.which !== 1) && (e.button !== 1) && !e.touches)) {
return;
}
this._simulateClick = true;
if (e.touches && e.touches.length > 1) {
this._simulateClick = false;
return;
}
var first = (e.touches && e.touches.length === 1 ? e.touches[0] : e),
el = first.target;
L.DomEvent.preventDefault(e);
if (L.Browser.touch && el.tagName.toLowerCase() === 'a') {
el.className += ' leaflet-active';
}
this._moved = false;
if (this._moving) {
return;
}
if (!L.Browser.touch) {
L.DomUtil.disableTextSelection();
this._setMovingCursor();
}
this._startPos = this._newPos = L.DomUtil.getPosition(this._element);
this._startPoint = new L.Point(first.clientX, first.clientY);
L.DomEvent.addListener(document, L.Draggable.MOVE, this._onMove, this);
L.DomEvent.addListener(document, L.Draggable.END, this._onUp, this);
},
_onMove: function (e) {
if (e.touches && e.touches.length > 1) {
return;
}
L.DomEvent.preventDefault(e);
var first = (e.touches && e.touches.length === 1 ? e.touches[0] : e);
if (!this._moved) {
this.fire('dragstart');
this._moved = true;
}
this._moving = true;
var newPoint = new L.Point(first.clientX, first.clientY);
this._newPos = this._startPos.add(newPoint).subtract(this._startPoint);
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) {
if (this._simulateClick && e.changedTouches) {
var first = e.changedTouches[0],
el = first.target,
dist = (this._newPos && this._newPos.distanceTo(this._startPos)) || 0;
if (el.tagName.toLowerCase() === 'a') {
el.className = el.className.replace(' leaflet-active', '');
}
if (dist < L.Draggable.TAP_TOLERANCE) {
this._simulateEvent('click', first);
}
}
if (!L.Browser.touch) {
L.DomUtil.enableTextSelection();
this._restoreCursor();
}
L.DomEvent.removeListener(document, L.Draggable.MOVE, this._onMove);
L.DomEvent.removeListener(document, L.Draggable.END, this._onUp);
if (this._moved) {
this.fire('dragend');
}
this._moving = false;
},
_setMovingCursor: function () {
document.body.className += ' leaflet-dragging';
},
_restoreCursor: function () {
document.body.className = document.body.className.replace(/ leaflet-dragging/g, '');
},
_simulateEvent: function (type, e) {
var simulatedEvent = document.createEvent('MouseEvents');
simulatedEvent.initMouseEvent(
type, true, true, window, 1,
e.screenX, e.screenY,
e.clientX, e.clientY,
false, false, false, false, 0, null);
e.target.dispatchEvent(simulatedEvent);
}
});