summaryrefslogtreecommitdiffstats
path: root/doc/html/tqcustomevent.html
blob: f8626d291543482168a352a4ed34d5a1d9f36856 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>TQCustomEvent Class</title>
<style type="text/css"><!--
fn { margin-left: 1cm; text-indent: -1cm; }
a:link { color: #004faf; text-decoration: none }
a:visited { color: #672967; text-decoration: none }
body { background: #ffffff; color: black; }
--></style>
</head>
<body>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr bgcolor="#E5E5E5">
<td valign=center>
 <a href="index.html">
<font color="#004faf">Home</font></a>
 | <a href="classes.html">
<font color="#004faf">All&nbsp;Classes</font></a>
 | <a href="mainclasses.html">
<font color="#004faf">Main&nbsp;Classes</font></a>
 | <a href="annotated.html">
<font color="#004faf">Annotated</font></a>
 | <a href="groups.html">
<font color="#004faf">Grouped&nbsp;Classes</font></a>
 | <a href="functions.html">
<font color="#004faf">Functions</font></a>
</td>
<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQCustomEvent Class Reference</h1>

<p>The TQCustomEvent class provides support for custom events.
<a href="#details">More...</a>
<p><tt>#include &lt;<a href="tqevent-h.html">tqevent.h</a>&gt;</tt>
<p>Inherits <a href="tqevent.html">TQEvent</a>.
<p><a href="tqcustomevent-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li class=fn><a href="#TQCustomEvent"><b>TQCustomEvent</b></a> ( int&nbsp;type )</li>
<li class=fn><a href="#TQCustomEvent-2"><b>TQCustomEvent</b></a> ( Type&nbsp;type, void&nbsp;*&nbsp;data )</li>
<li class=fn>void * <a href="#data"><b>data</b></a> () const</li>
<li class=fn>void <a href="#setData"><b>setData</b></a> ( void&nbsp;*&nbsp;data )</li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>


The TQCustomEvent class provides support for custom events.
<p> 
<p> TQCustomEvent is a generic event class for user-defined events.
User defined events can be sent to widgets or other <a href="tqobject.html">TQObject</a>
instances using <a href="tqapplication.html#postEvent">TQApplication::postEvent</a>() or
<a href="tqapplication.html#sendEvent">TQApplication::sendEvent</a>(). Subclasses of TQObject can easily
receive custom events by implementing the <a href="tqobject.html#customEvent">TQObject::customEvent</a>()
event handler function.
<p> TQCustomEvent objects should be created with a type ID that
uniquely identifies the event type. To avoid clashes with the
TQt-defined events types, the value should be at least as large as
the value of the "User" entry in the TQEvent::Type enum.
<p> TQCustomEvent contains a generic void* data member that may be used
for transferring event-specific data to the receiver. Note that
since events are normally delivered asynchronously, the data
pointer, if used, must remain valid until the event has been
received and processed.
<p> TQCustomEvent can be used as-is for simple user-defined event
types, but normally you will want to make a subclass of it for
your event types. In a subclass, you can add data members that are
suitable for your event type.
<p> Example:
<pre>
    class ColorChangeEvent : public TQCustomEvent
    {
    public:
        ColorChangeEvent( <a href="tqcolor.html">TQColor</a> color )
            : TQCustomEvent( 65432 ), c( color ) {}
        <a href="tqcolor.html">TQColor</a> color() const { return c; }
    private:
        <a href="tqcolor.html">TQColor</a> c;
    };

    // To send an event of this custom event type:

    ColorChangeEvent* ce = new ColorChangeEvent( blue );
    TQApplication::<a href="tqapplication.html#postEvent">postEvent</a>( receiver, ce );  // TQt will delete it when done

    // To receive an event of this custom event type:

    void MyWidget::customEvent( TQCustomEvent * e )
    {
        if ( e-&gt;<a href="tqevent.html#type">type</a>() == 65432 ) {  // It must be a ColorChangeEvent
            ColorChangeEvent* ce = (ColorChangeEvent*)e;
            newColor = ce-&gt;color();
        }
    }
    </pre>
 
<p> <p>See also <a href="tqobject.html#customEvent">TQWidget::customEvent</a>(), <a href="tqapplication.html#notify">TQApplication::notify</a>(), and <a href="events.html">Event Classes</a>.

<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="TQCustomEvent"></a>TQCustomEvent::TQCustomEvent ( int&nbsp;type )
</h3>
Constructs a custom event object with event type <em>type</em>. The
value of <em>type</em> must be at least as large as TQEvent::User. The
data pointer is set to 0.

<h3 class=fn><a name="TQCustomEvent-2"></a>TQCustomEvent::TQCustomEvent ( <a href="tqevent.html#Type-enum">Type</a>&nbsp;type, void&nbsp;*&nbsp;data )
</h3>

<p> Constructs a custom event object with the event type <em>type</em> and a
pointer to <em>data</em>. (Note that any int value may safely be cast to
TQEvent::Type).

<h3 class=fn>void * <a name="data"></a>TQCustomEvent::data () const
</h3>

<p> Returns a pointer to the generic event data.
<p> <p>See also <a href="#setData">setData</a>().

<h3 class=fn>void <a name="setData"></a>TQCustomEvent::setData ( void&nbsp;*&nbsp;data )
</h3>

<p> Sets the generic data pointer to <em>data</em>.
<p> <p>See also <a href="#data">data</a>().

<!-- eof -->
<hr><p>
This file is part of the <a href="index.html">TQt toolkit</a>.
Copyright &copy; 1995-2007
<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
<table width=100% cellspacing=0 border=0><tr>
<td>Copyright &copy; 2007
<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
<td align=right><div align=right>TQt 3.3.8</div>
</table></div></address></body>
</html>