1
|
/*
|
2
|
License: LGPL as per: http://www.gnu.org/copyleft/lesser.html
|
3
|
$Id: Listener.js 3835 2008-02-13 02:20:23Z ahocevar $
|
4
|
*/
|
5
|
|
6
|
/**
|
7
|
* Base Listener class that is instanciated by all objects which provide
|
8
|
* event listeners.
|
9
|
* @constructor
|
10
|
* @author Cameron Shorter
|
11
|
*/
|
12
|
function Listener() {
|
13
|
/** An array [params] of (listener, target). */
|
14
|
this.listeners=new Array();
|
15
|
|
16
|
/**
|
17
|
* An array [params] of values. These values might not be used if the set/get
|
18
|
* functions are overwritten.
|
19
|
*/
|
20
|
this.values=new Array();
|
21
|
|
22
|
/**
|
23
|
* Add a listener function which will be called when param is updated; The
|
24
|
* listener function should usually be: paint(target).
|
25
|
* @param listener The function to call when the parameter changes.
|
26
|
* @param target The object which owns the listener function.
|
27
|
* @param param Parameter name; if this parameter changes then an event is
|
28
|
* sent to all interested listeners.
|
29
|
*/
|
30
|
this.addListener=function(param, listener, target) {
|
31
|
if (window.logger) logger.logEvent("addListener: "+param,this.id,target.id);
|
32
|
if(!this.listeners[param]){
|
33
|
this.listeners[param]=new Array();
|
34
|
}
|
35
|
this.removeListener(param,listener,target);
|
36
|
//for(var i=0;i<this.listeners[param].length;i++){
|
37
|
// if(this.listeners[param][i][0]==listener && this.listeners[param][i][1]==target){
|
38
|
// return;
|
39
|
// alert("Listener.addListener again: target="+target.id);
|
40
|
// }
|
41
|
//}
|
42
|
this.listeners[param].push(new Array(listener,target));
|
43
|
if( !listener ) {
|
44
|
alert(mbGetMessage("undefinedListener", target.id));
|
45
|
}
|
46
|
}
|
47
|
|
48
|
/**
|
49
|
* Add a listener function at the start of the list.
|
50
|
* @param listener The function to call when the parameter changes.
|
51
|
* @param target The object which owns the listener function.
|
52
|
* @param param Parameter name; if this parameter changes then an event is
|
53
|
* sent to all interested listeners.
|
54
|
*/
|
55
|
this.addFirstListener=function(param, listener, target) {
|
56
|
if (window.logger) logger.logEvent("addFirstListener: "+param,this.id,target.id);
|
57
|
if(!this.listeners[param]){
|
58
|
this.listeners[param]=new Array();
|
59
|
}
|
60
|
this.removeListener(param,listener,target);
|
61
|
this.listeners[param].unshift(new Array(listener,target));
|
62
|
if( !listener ) {
|
63
|
alert(mbGetMessage("undefinedListener", target));
|
64
|
}
|
65
|
}
|
66
|
|
67
|
/**
|
68
|
* Remove a listener so that it is not called anymore when a param changes.
|
69
|
* @param listener The function to call when the parameter changes.
|
70
|
* @param target The object which owns the listener function.
|
71
|
* @param param Parameter name; if this parameter changes then an event is
|
72
|
* sent to all interested listeners.
|
73
|
*/
|
74
|
this.removeListener=function(param,listener,target){
|
75
|
if(this.listeners[param]){
|
76
|
for(var i=0;i<this.listeners[param].length;i++){
|
77
|
if(this.listeners[param][i][0]==listener && this.listeners[param][i][1]==target){
|
78
|
for(var j=i;j<this.listeners[param].length-1;j++){
|
79
|
this.listeners[param][j]=this.listeners[param][j+1];
|
80
|
}
|
81
|
this.listeners[param].pop();
|
82
|
return;
|
83
|
}
|
84
|
}
|
85
|
}
|
86
|
}
|
87
|
|
88
|
/**
|
89
|
* Call all the listeners that have registered interest in this parameter
|
90
|
* using addListener.
|
91
|
* @param param The parameter that has changed.
|
92
|
* @param value The new parameter value.
|
93
|
*/
|
94
|
this.callListeners=function(param,value) {
|
95
|
if (this.listeners[param]){
|
96
|
var count = this.listeners[param].length;
|
97
|
for(var i=0;i<count;i++){
|
98
|
if (window.logger) logger.logEvent(param,this.id,this.listeners[param][i][1].id,value);
|
99
|
//this is listenerFunction(target,value)
|
100
|
if (this.listeners[param][i][0]) {
|
101
|
this.listeners[param][i][0](this.listeners[param][i][1],value);
|
102
|
} else {
|
103
|
alert(mbGetMessage("listenerError", param, this.listeners[param][i][1].id, this.listeners[param][i][0]));
|
104
|
}
|
105
|
}
|
106
|
}
|
107
|
}
|
108
|
|
109
|
/**
|
110
|
* Update parameter and call all interested listeners. This function may
|
111
|
* be overloaded to store the parameter in a elsewhere (eg in an XML
|
112
|
* document).
|
113
|
* @param param The parameter to change.
|
114
|
* @parma value The new value of the param.
|
115
|
*/
|
116
|
this.setParam=function(param,value) {
|
117
|
this.values[param] = value;
|
118
|
|
119
|
// Call all the interested listeners
|
120
|
this.callListeners(param,value);
|
121
|
}
|
122
|
|
123
|
/**
|
124
|
* Return the param value, or return null if it does not exist. This
|
125
|
* function may be overloaded to store the param elsewhere (eg in
|
126
|
* an XML document).
|
127
|
* @param param The parameter to get.
|
128
|
* @return The value of the param.
|
129
|
*/
|
130
|
this.getParam=function(param) {
|
131
|
return this.values[param];
|
132
|
}
|
133
|
}
|