SemanticScuttle/includes/js/dojo/dnd/Mover.js

84 lines
2.7 KiB
JavaScript

if(!dojo._hasResource["dojo.dnd.Mover"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo.dnd.Mover"] = true;
dojo.provide("dojo.dnd.Mover");
dojo.require("dojo.dnd.common");
dojo.require("dojo.dnd.autoscroll");
dojo.declare("dojo.dnd.Mover", null, {
constructor: function(node, e, host){
// summary: an object, which makes a node follow the mouse,
// used as a default mover, and as a base class for custom movers
// node: Node: a node (or node's id) to be moved
// e: Event: a mouse event, which started the move;
// only pageX and pageY properties are used
// host: Object?: object which implements the functionality of the move,
// and defines proper events (onMoveStart and onMoveStop)
this.node = dojo.byId(node);
this.marginBox = {l: e.pageX, t: e.pageY};
this.mouseButton = e.button;
var h = this.host = host, d = node.ownerDocument,
firstEvent = dojo.connect(d, "onmousemove", this, "onFirstMove");
this.events = [
dojo.connect(d, "onmousemove", this, "onMouseMove"),
dojo.connect(d, "onmouseup", this, "onMouseUp"),
// cancel text selection and text dragging
dojo.connect(d, "ondragstart", dojo, "stopEvent"),
dojo.connect(d, "onselectstart", dojo, "stopEvent"),
firstEvent
];
// notify that the move has started
if(h && h.onMoveStart){
h.onMoveStart(this);
}
},
// mouse event processors
onMouseMove: function(e){
// summary: event processor for onmousemove
// e: Event: mouse event
dojo.dnd.autoScroll(e);
var m = this.marginBox;
this.host.onMove(this, {l: m.l + e.pageX, t: m.t + e.pageY});
},
onMouseUp: function(e){
if(this.mouseButton == e.button){
this.destroy();
}
},
// utilities
onFirstMove: function(){
// summary: makes the node absolute; it is meant to be called only once
var s = this.node.style, l, t;
switch(s.position){
case "relative":
case "absolute":
// assume that left and top values are in pixels already
l = Math.round(parseFloat(s.left));
t = Math.round(parseFloat(s.top));
break;
default:
s.position = "absolute"; // enforcing the absolute mode
var m = dojo.marginBox(this.node);
l = m.l;
t = m.t;
break;
}
this.marginBox.l = l - this.marginBox.l;
this.marginBox.t = t - this.marginBox.t;
this.host.onFirstMove(this);
dojo.disconnect(this.events.pop());
},
destroy: function(){
// summary: stops the move, deletes all references, so the object can be garbage-collected
dojo.forEach(this.events, dojo.disconnect);
// undo global settings
var h = this.host;
if(h && h.onMoveStop){
h.onMoveStop(this);
}
// destroy objects
this.events = this.node = null;
}
});
}