|
0
|
1 <HTML
|
|
|
2 ><HEAD
|
|
|
3 ><TITLE
|
|
|
4 >Events</TITLE
|
|
|
5 ><META
|
|
|
6 NAME="GENERATOR"
|
|
|
7 CONTENT="Modular DocBook HTML Stylesheet Version 1.61
|
|
|
8 "><LINK
|
|
|
9 REL="HOME"
|
|
|
10 TITLE="SDL Library Documentation"
|
|
|
11 HREF="index.html"><LINK
|
|
|
12 REL="UP"
|
|
|
13 TITLE="SDL Reference"
|
|
|
14 HREF="reference.html"><LINK
|
|
|
15 REL="PREVIOUS"
|
|
|
16 TITLE="SDL_WM_GrabInput"
|
|
|
17 HREF="sdlwmgrabinput.html"><LINK
|
|
|
18 REL="NEXT"
|
|
|
19 TITLE="SDL Event Structures."
|
|
|
20 HREF="eventstructures.html"><META
|
|
|
21 NAME="KEYWORD"
|
|
|
22 CONTENT="events"><META
|
|
|
23 NAME="KEYWORD"
|
|
|
24 CONTENT="function"></HEAD
|
|
|
25 ><BODY
|
|
|
26 CLASS="CHAPTER"
|
|
|
27 BGCOLOR="#FFF8DC"
|
|
|
28 TEXT="#000000"
|
|
|
29 LINK="#0000ee"
|
|
|
30 VLINK="#551a8b"
|
|
|
31 ALINK="#ff0000"
|
|
|
32 ><DIV
|
|
|
33 CLASS="NAVHEADER"
|
|
|
34 ><TABLE
|
|
|
35 WIDTH="100%"
|
|
|
36 BORDER="0"
|
|
|
37 CELLPADDING="0"
|
|
|
38 CELLSPACING="0"
|
|
|
39 ><TR
|
|
|
40 ><TH
|
|
|
41 COLSPAN="3"
|
|
|
42 ALIGN="center"
|
|
|
43 >SDL Library Documentation</TH
|
|
|
44 ></TR
|
|
|
45 ><TR
|
|
|
46 ><TD
|
|
|
47 WIDTH="10%"
|
|
|
48 ALIGN="left"
|
|
|
49 VALIGN="bottom"
|
|
|
50 ><A
|
|
|
51 HREF="sdlwmgrabinput.html"
|
|
|
52 >Prev</A
|
|
|
53 ></TD
|
|
|
54 ><TD
|
|
|
55 WIDTH="80%"
|
|
|
56 ALIGN="center"
|
|
|
57 VALIGN="bottom"
|
|
|
58 ></TD
|
|
|
59 ><TD
|
|
|
60 WIDTH="10%"
|
|
|
61 ALIGN="right"
|
|
|
62 VALIGN="bottom"
|
|
|
63 ><A
|
|
|
64 HREF="eventstructures.html"
|
|
|
65 >Next</A
|
|
|
66 ></TD
|
|
|
67 ></TR
|
|
|
68 ></TABLE
|
|
|
69 ><HR
|
|
|
70 ALIGN="LEFT"
|
|
|
71 WIDTH="100%"></DIV
|
|
|
72 ><DIV
|
|
|
73 CLASS="CHAPTER"
|
|
|
74 ><H1
|
|
|
75 ><A
|
|
|
76 NAME="EVENT"
|
|
|
77 >Chapter 8. Events</A
|
|
|
78 ></H1
|
|
|
79 ><DIV
|
|
|
80 CLASS="TOC"
|
|
|
81 ><DL
|
|
|
82 ><DT
|
|
|
83 ><B
|
|
|
84 >Table of Contents</B
|
|
|
85 ></DT
|
|
|
86 ><DT
|
|
|
87 ><A
|
|
|
88 HREF="event.html#AEN3194"
|
|
|
89 >Introduction</A
|
|
|
90 ></DT
|
|
|
91 ><DT
|
|
|
92 ><A
|
|
|
93 HREF="eventstructures.html"
|
|
|
94 >SDL Event Structures.</A
|
|
|
95 ></DT
|
|
|
96 ><DT
|
|
|
97 ><A
|
|
|
98 HREF="eventfunctions.html"
|
|
|
99 >Event Functions.</A
|
|
|
100 ></DT
|
|
|
101 ></DL
|
|
|
102 ></DIV
|
|
|
103 ><DIV
|
|
|
104 CLASS="SECT1"
|
|
|
105 ><H1
|
|
|
106 CLASS="SECT1"
|
|
|
107 ><A
|
|
|
108 NAME="AEN3194"
|
|
|
109 >Introduction</A
|
|
|
110 ></H1
|
|
|
111 ><P
|
|
|
112 >Event handling allows your application to receive input from the user. Event handling is initalised (along with video) with a call to:
|
|
|
113 <PRE
|
|
|
114 CLASS="PROGRAMLISTING"
|
|
|
115 >SDL_Init(SDL_INIT_VIDEO);</PRE
|
|
|
116 >
|
|
|
117 Interally, SDL stores all the events waiting to be handled in an event queue. Using functions like <A
|
|
|
118 HREF="sdlpollevent.html"
|
|
|
119 ><TT
|
|
|
120 CLASS="FUNCTION"
|
|
|
121 >SDL_PollEvent</TT
|
|
|
122 ></A
|
|
|
123 > and <A
|
|
|
124 HREF="sdlpeepevents.html"
|
|
|
125 ><TT
|
|
|
126 CLASS="FUNCTION"
|
|
|
127 >SDL_PeepEvents</TT
|
|
|
128 ></A
|
|
|
129 > you can observe and handle waiting input events.</P
|
|
|
130 ><P
|
|
|
131 >The key to event handling in SDL is the <A
|
|
|
132 HREF="sdlevent.html"
|
|
|
133 ><SPAN
|
|
|
134 CLASS="STRUCTNAME"
|
|
|
135 >SDL_Event</SPAN
|
|
|
136 ></A
|
|
|
137 > union. The event queue itself is composed of a series of <SPAN
|
|
|
138 CLASS="STRUCTNAME"
|
|
|
139 >SDL_Event</SPAN
|
|
|
140 > unions, one for each waiting event. <SPAN
|
|
|
141 CLASS="STRUCTNAME"
|
|
|
142 >SDL_Event</SPAN
|
|
|
143 > unions are read from the queue with the <TT
|
|
|
144 CLASS="FUNCTION"
|
|
|
145 >SDL_PollEvent</TT
|
|
|
146 > function and it is then up to the application to process the information stored with them.</P
|
|
|
147 ></DIV
|
|
|
148 ></DIV
|
|
|
149 ><DIV
|
|
|
150 CLASS="NAVFOOTER"
|
|
|
151 ><HR
|
|
|
152 ALIGN="LEFT"
|
|
|
153 WIDTH="100%"><TABLE
|
|
|
154 WIDTH="100%"
|
|
|
155 BORDER="0"
|
|
|
156 CELLPADDING="0"
|
|
|
157 CELLSPACING="0"
|
|
|
158 ><TR
|
|
|
159 ><TD
|
|
|
160 WIDTH="33%"
|
|
|
161 ALIGN="left"
|
|
|
162 VALIGN="top"
|
|
|
163 ><A
|
|
|
164 HREF="sdlwmgrabinput.html"
|
|
|
165 >Prev</A
|
|
|
166 ></TD
|
|
|
167 ><TD
|
|
|
168 WIDTH="34%"
|
|
|
169 ALIGN="center"
|
|
|
170 VALIGN="top"
|
|
|
171 ><A
|
|
|
172 HREF="index.html"
|
|
|
173 >Home</A
|
|
|
174 ></TD
|
|
|
175 ><TD
|
|
|
176 WIDTH="33%"
|
|
|
177 ALIGN="right"
|
|
|
178 VALIGN="top"
|
|
|
179 ><A
|
|
|
180 HREF="eventstructures.html"
|
|
|
181 >Next</A
|
|
|
182 ></TD
|
|
|
183 ></TR
|
|
|
184 ><TR
|
|
|
185 ><TD
|
|
|
186 WIDTH="33%"
|
|
|
187 ALIGN="left"
|
|
|
188 VALIGN="top"
|
|
|
189 >SDL_WM_GrabInput</TD
|
|
|
190 ><TD
|
|
|
191 WIDTH="34%"
|
|
|
192 ALIGN="center"
|
|
|
193 VALIGN="top"
|
|
|
194 ><A
|
|
|
195 HREF="reference.html"
|
|
|
196 >Up</A
|
|
|
197 ></TD
|
|
|
198 ><TD
|
|
|
199 WIDTH="33%"
|
|
|
200 ALIGN="right"
|
|
|
201 VALIGN="top"
|
|
|
202 >SDL Event Structures.</TD
|
|
|
203 ></TR
|
|
|
204 ></TABLE
|
|
|
205 ></DIV
|
|
|
206 ></BODY
|
|
|
207 ></HTML
|
|
|
208 > |
