+++ /dev/null
-.TH "SDL_Event" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference"
-.SH "NAME"
-SDL_Event \- General event structure
-.SH "STRUCTURE DEFINITION"
-.PP
-.nf
-\f(CWtypedef union{
- Uint8 type;
- SDL_ActiveEvent active;
- SDL_KeyboardEvent key;
- SDL_MouseMotionEvent motion;
- SDL_MouseButtonEvent button;
- SDL_JoyAxisEvent jaxis;
- SDL_JoyBallEvent jball;
- SDL_JoyHatEvent jhat;
- SDL_JoyButtonEvent jbutton;
- SDL_ResizeEvent resize;
- SDL_ExposeEvent expose;
- SDL_QuitEvent quit;
- SDL_UserEvent user;
- SDL_SysWMEvent syswm;
-} SDL_Event;\fR
-.fi
-.PP
-.SH "STRUCTURE DATA"
-.TP 20
-\fBtype\fR
-The type of event
-.TP 20
-\fBactive\fR
-\fIActivation event\fR
-.TP 20
-\fBkey\fR
-\fIKeyboard event\fR
-.TP 20
-\fBmotion\fR
-\fIMouse motion event\fR
-.TP 20
-\fBbutton\fR
-\fIMouse button event\fR
-.TP 20
-\fBjaxis\fR
-\fIJoystick axis motion event\fR
-.TP 20
-\fBjball\fR
-\fIJoystick trackball motion event\fR
-.TP 20
-\fBjhat\fR
-\fIJoystick hat motion event\fR
-.TP 20
-\fBjbutton\fR
-\fIJoystick button event\fR
-.TP 20
-\fBresize\fR
-\fIApplication window resize event\fR
-.TP 20
-\fBexpose\fR
-\fIApplication window expose event\fR
-.TP 20
-\fBquit\fR
-\fIApplication quit request event\fR
-.TP 20
-\fBuser\fR
-\fIUser defined event\fR
-.TP 20
-\fBsyswm\fR
-\fIUndefined window manager event\fR
-.SH "DESCRIPTION"
-.PP
-The \fBSDL_Event\fR union is the core to all event handling is SDL, its probably the most important structure after \fBSDL_Surface\fR\&. \fBSDL_Event\fR is a union of all event structures used in SDL, using it is a simple matter of knowing which union member relates to which event \fBtype\fR\&.
-.PP
-.TP 20
-\fBEvent \fBtype\fR\fR
-\fBEvent Structure\fR
-.TP 20
-\fBSDL_ACTIVEEVENT\fP
-\fI\fBSDL_ActiveEvent\fR\fR
-.TP 20
-\fBSDL_KEYDOWN/UP\fP
-\fI\fBSDL_KeyboardEvent\fR\fR
-.TP 20
-\fBSDL_MOUSEMOTION\fP
-\fI\fBSDL_MouseMotionEvent\fR\fR
-.TP 20
-\fBSDL_MOUSEBUTTONDOWN/UP\fP
-\fI\fBSDL_MouseButtonEvent\fR\fR
-.TP 20
-\fBSDL_JOYAXISMOTION\fP
-\fI\fBSDL_JoyAxisEvent\fR\fR
-.TP 20
-\fBSDL_JOYBALLMOTION\fP
-\fI\fBSDL_JoyBallEvent\fR\fR
-.TP 20
-\fBSDL_JOYHATMOTION\fP
-\fI\fBSDL_JoyHatEvent\fR\fR
-.TP 20
-\fBSDL_JOYBUTTONDOWN/UP\fP
-\fI\fBSDL_JoyButtonEvent\fR\fR
-.TP 20
-\fBSDL_QUIT\fP
-\fI\fBSDL_QuitEvent\fR\fR
-.TP 20
-\fBSDL_SYSWMEVENT\fP
-\fI\fBSDL_SysWMEvent\fR\fR
-.TP 20
-\fBSDL_VIDEORESIZE\fP
-\fI\fBSDL_ResizeEvent\fR\fR
-.TP 20
-\fBSDL_VIDEOEXPOSE\fP
-\fI\fBSDL_ExposeEvent\fR\fR
-.TP 20
-\fBSDL_USEREVENT\fP
-\fI\fBSDL_UserEvent\fR\fR
-.SH "USE"
-.PP
-The \fBSDL_Event\fR structure has two uses
-.IP " \(bu" 6
-Reading events on the event queue
-.IP " \(bu" 6
-Placing events on the event queue
-.PP
-Reading events from the event queue is done with either \fI\fBSDL_PollEvent\fP\fR or \fI\fBSDL_PeepEvents\fP\fR\&. We\&'ll use \fBSDL_PollEvent\fP and step through an example\&.
-.PP
-First off, we create an empty \fBSDL_Event\fR structure\&.
-.PP
-.nf
-\f(CWSDL_Event test_event;\fR
-.fi
-.PP
- \fBSDL_PollEvent\fP removes the next event from the event queue, if there are no events on the queue it returns \fB0\fR otherwise it returns \fB1\fR\&. We use a \fBwhile\fP loop to process each event in turn\&.
-.PP
-.nf
-\f(CWwhile(SDL_PollEvent(&test_event)) {\fR
-.fi
-.PP
- The \fBSDL_PollEvent\fP function take a pointer to an \fBSDL_Event\fR structure that is to be filled with event information\&. We know that if \fBSDL_PollEvent\fP removes an event from the queue then the event information will be placed in our \fBtest_event\fR structure, but we also know that the \fItype\fP of event will be placed in the \fBtype\fR member of \fBtest_event\fR\&. So to handle each event \fBtype\fR seperately we use a \fBswitch\fP statement\&.
-.PP
-.nf
-\f(CW switch(test_event\&.type) {\fR
-.fi
-.PP
- We need to know what kind of events we\&'re looking for \fIand\fP the event \fBtype\fR\&'s of those events\&. So lets assume we want to detect where the user is moving the mouse pointer within our application\&. We look through our event types and notice that \fBSDL_MOUSEMOTION\fP is, more than likely, the event we\&'re looking for\&. A little \fImore\fR research tells use that \fBSDL_MOUSEMOTION\fP events are handled within the \fI\fBSDL_MouseMotionEvent\fR\fR structure which is the \fBmotion\fR member of \fBSDL_Event\fR\&. We can check for the \fBSDL_MOUSEMOTION\fP event \fBtype\fR within our \fBswitch\fP statement like so:
-.PP
-.nf
-\f(CW case SDL_MOUSEMOTION:\fR
-.fi
-.PP
- All we need do now is read the information out of the \fBmotion\fR member of \fBtest_event\fR\&.
-.PP
-.nf
-\f(CW printf("We got a motion event\&.
-");
- printf("Current mouse position is: (%d, %d)
-", test_event\&.motion\&.x, test_event\&.motion\&.y);
- break;
- default:
- printf("Unhandled Event!
-");
- break;
- }
-}
-printf("Event queue empty\&.
-");\fR
-.fi
-.PP
-.PP
-It is also possible to push events onto the event queue and so use it as a two-way communication path\&. Both \fI\fBSDL_PushEvent\fP\fR and \fI\fBSDL_PeepEvents\fP\fR allow you to place events onto the event queue\&. This is usually used to place a \fBSDL_USEREVENT\fP on the event queue, however you could use it to post fake input events if you wished\&. Creating your own events is a simple matter of choosing the event type you want, setting the \fBtype\fR member and filling the appropriate member structure with information\&.
-.PP
-.nf
-\f(CWSDL_Event user_event;
-
-user_event\&.type=SDL_USEREVENT;
-user_event\&.user\&.code=2;
-user_event\&.user\&.data1=NULL;
-user_event\&.user\&.data2=NULL;
-SDL_PushEvent(&user_event);\fR
-.fi
-.PP
-.SH "SEE ALSO"
-.PP
-\fI\fBSDL_PollEvent\fP\fR, \fI\fBSDL_PushEvent\fP\fR, \fI\fBSDL_PeepEvents\fP\fR
-.\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59
projects / xonotic / xonotic.git / blobdiff