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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
|
<HTML
><HEAD
><TITLE
>Signal and Slot Support</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
REL="HOME"
TITLE="Python Bindings for KDE (PyKDE-3.16.0)"
HREF="index.html"><LINK
REL="PREVIOUS"
TITLE="General Limitations"
HREF="limits.html"><LINK
REL="NEXT"
TITLE="Static Member Functions"
HREF="static.html"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>Python Bindings for KDE (PyKDE-3.16.0)</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="limits.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="static.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="AEN81"
></A
>Signal and Slot Support</H1
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN83"
></A
>General Signals and Slots</H2
><P
>A signal may be either a TQt signal (specified using
<TT
CLASS="LITERAL"
>SIGNAL()</TT
>) or a Python signal (specified using
<TT
CLASS="LITERAL"
>PYSIGNAL()</TT
>).</P
><P
>A slot can be either a Python callable object, a TQt signal (specified using
<TT
CLASS="LITERAL"
>SIGNAL()</TT
>), a Python signal (specified using
<TT
CLASS="LITERAL"
>PYSIGNAL()</TT
>), or a TQt slot (specified using
<TT
CLASS="LITERAL"
>SLOT()</TT
>).</P
><P
>You connect signals to slots (and other signals) as you would from C++. For
example:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>TQObject.connect(a,SIGNAL("TQtSig()"),pyFunction)
TQObject.connect(a,SIGNAL("TQtSig()"),pyClass.pyMethod)
TQObject.connect(a,SIGNAL("TQtSig()"),PYSIGNAL("PySig"))
TQObject.connect(a,SIGNAL("TQtSig()"),SLOT("TQtSlot()"))
TQObject.connect(a,PYSIGNAL("PySig"),pyFunction)
TQObject.connect(a,PYSIGNAL("PySig"),pyClass.pyMethod)
TQObject.connect(a,PYSIGNAL("PySig"),SIGNAL("TQtSig()"))
TQObject.connect(a,PYSIGNAL("PySig"),SLOT("TQtSlot()"))</PRE
></TD
></TR
></TABLE
><P
>When a slot is a Python method that corresponds to a TQt slot then a signal can
be connected to either the Python method or the TQt slot. The following
connections achieve the same effect.</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>sbar = TQScrollBar()
lcd = TQLCDNumber()
TQObject.connect(sbar,SIGNAL("valueChanged(int)"),lcd.display)
TQObject.connect(sbar,SIGNAL("valueChanged(int)"),lcd,SLOT("display(int)"))</PRE
></TD
></TR
></TABLE
><P
>The difference is that the second connection is made at the C++ level and is
more efficient.</P
><P
>Disconnecting signals works in exactly the same way.</P
><P
>Any instance of a class that is derived from the <TT
CLASS="LITERAL"
>TQObject</TT
>
class can emit a signal using the <TT
CLASS="LITERAL"
>emit</TT
> method. This takes
two arguments. The first is the Python or TQt signal, the second is a Python
tuple which are the arguments to the signal. For example:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>a.emit(SIGNAL("clicked()"),())
a.emit(PYSIGNAL("pySig"),("Hello","World"))</PRE
></TD
></TR
></TABLE
><P
>TQt allows a signal to be connected to a slot that requires fewer arguments than
the signal passes. The extra arguments are tquietly discarded. Python slots
can be used in the same way.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN103"
></A
>Slots in Menus, Toolbars and Actions</H2
><P
>The C++ declarations for menu items or KActions are similar to these examples:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int TQMenuData::insertItem (const TQString & text,
const TQObject * receiver, const char * member,
int accel = 0, int id = -1, int index = -1 )
KAction ( const TQString& text, int accel,
const TQObject* receiver, const char* slot,
TQObject* parent, const char* name = 0 )</PRE
></TD
></TR
></TABLE
><P
>Notice the "const TQObject* receiver, const char* slot" parameters for each declaration.</P
><P
>In PyKDE, these two parameters are replaced with a SINGLE parameter that specifies the
slot to be connected to the menu item, toolbar button or KAction:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>p = insertItem ("Open", self.slotOpen, 0, -1, -1)
action = KAction ("Open", 0, self.slotOpen, None, 0)</PRE
></TD
></TR
></TABLE
><P
>This substitution applies to appropriate methods in KStdAction, KAction and related
subclasses, KAccelMenu and KToolBar</P
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="limits.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="static.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>General Limitations</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
> </TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Static Member Functions</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
|
