This function is the applications main message pump. While this function is running all events that go through the nano-X event queue will be dispatched to the specified event callback function.
![]() | This function never returns. |
Type | Name | Description |
---|---|---|
GR_FNCALLBACKEVENT | fncb | A pointer to the event callback function. This callback function will be called each time an event enters the nano-X event queue. |
Example 2-1. Using GrMainLoop()
#include <stdio.h> #define MWINCLUDECOLORS #include "microwin/nano-X.h" GR_WINDOW_ID wid; GR_GC_ID gc; void event_handler (GR_EVENT *event); int main (void) { if (GrOpen() < 0) { fprintf (stderr, "GrOpen failed"); exit (1); } gc = GrNewGC(); GrSetGCUseBackground (gc, GR_FALSE); GrSetGCForeground (gc, RED); wid = GrNewWindowEx (GR_WM_PROPS_APPFRAME | GR_WM_PROPS_CAPTION | GR_WM_PROPS_CLOSEBOX, "Hello Window", GR_ROOT_WINDOW_ID, 50, 50, 200, 100, WHITE); GrSelectEvents (wid, GR_EVENT_MASK_EXPOSURE | GR_EVENT_MASK_CLOSE_REQ); GrMapWindow (wid); GrMainLoop (event_handler); } void event_handler (GR_EVENT *event) { switch (event->type) { case GR_EVENT_TYPE_EXPOSURE: GrText (wid, gc, 50, 50, "Hello World", -1, GR_TFASCII); break; case GR_EVENT_TYPE_CLOSE_REQ: GrClose(); exit (0); } } |