stk/Tcl/tclWinNotify.c

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1999-02-02 06:13:40 -05:00
/*
* tclWinNotify.c --
*
* This file contains Windows-specific procedures for the notifier,
* which is the lowest-level part of the Tcl event loop. This file
* works together with ../generic/tclNotify.c.
*
* Copyright (c) 1995-1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tclWinNotify.c 1.17 97/05/23 10:48:44
*/
#include "tclInt.h"
#include "tclPort.h"
#include <winsock.h>
/*
* The follwing static indicates whether this module has been initialized.
*/
static int initialized = 0;
#define INTERVAL_TIMER 1 /* Handle of interval timer. */
/*
* The following static structure contains the state information for the
* Windows implementation of the Tcl notifier.
*/
static struct {
HWND hwnd; /* Messaging window. */
int timeout; /* Current timeout value. */
int timerActive; /* 1 if interval timer is running. */
} notifier;
/*
* Static routines defined in this file.
*/
static void InitNotifier(void);
static void NotifierExitHandler(ClientData clientData);
static LRESULT CALLBACK NotifierProc(HWND hwnd, UINT message,
WPARAM wParam, LPARAM lParam);
static void UpdateTimer(int timeout);
/*
*----------------------------------------------------------------------
*
* InitNotifier --
*
* Initializes the notifier window.
*
* Results:
* None.
*
* Side effects:
* Creates a new notifier window and window class.
*
*----------------------------------------------------------------------
*/
static void
InitNotifier(void)
{
WNDCLASS class;
initialized = 1;
notifier.timerActive = 0;
class.style = 0;
class.cbClsExtra = 0;
class.cbWndExtra = 0;
class.hInstance = TclWinGetTclInstance();
class.hbrBackground = NULL;
class.lpszMenuName = NULL;
class.lpszClassName = "TclNotifier";
class.lpfnWndProc = NotifierProc;
class.hIcon = NULL;
class.hCursor = NULL;
if (!RegisterClass(&class)) {
panic("Unable to register TclNotifier window class");
}
notifier.hwnd = CreateWindow("TclNotifier", "TclNotifier", WS_TILED,
0, 0, 0, 0, NULL, NULL, TclWinGetTclInstance(), NULL);
Tcl_CreateExitHandler(NotifierExitHandler, NULL);
}
/*
*----------------------------------------------------------------------
*
* NotifierExitHandler --
*
* This function is called to cleanup the notifier state before
* Tcl is unloaded.
*
* Results:
* None.
*
* Side effects:
* Destroys the notifier window.
*
*----------------------------------------------------------------------
*/
static void
NotifierExitHandler(
ClientData clientData) /* Old window proc */
{
initialized = 0;
if (notifier.hwnd) {
KillTimer(notifier.hwnd, INTERVAL_TIMER);
DestroyWindow(notifier.hwnd);
UnregisterClass("TclNotifier", TclWinGetTclInstance());
notifier.hwnd = NULL;
}
}
/*
*----------------------------------------------------------------------
*
* UpdateTimer --
*
* This function starts or stops the notifier interval timer.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
UpdateTimer(
int timeout) /* ms timeout, 0 means cancel timer */
{
notifier.timeout = timeout;
if (timeout != 0) {
notifier.timerActive = 1;
SetTimer(notifier.hwnd, INTERVAL_TIMER,
(unsigned long) notifier.timeout, NULL);
} else {
notifier.timerActive = 0;
KillTimer(notifier.hwnd, INTERVAL_TIMER);
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetTimer --
*
* This procedure sets the current notifier timer value. The
* notifier will ensure that Tcl_ServiceAll() is called after
* the specified interval, even if no events have occurred.
*
* Results:
* None.
*
* Side effects:
* Replaces any previous timer.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetTimer(
Tcl_Time *timePtr) /* Maximum block time, or NULL. */
{
UINT timeout;
if (!initialized) {
InitNotifier();
}
if (!timePtr) {
timeout = 0;
} else {
/*
* Make sure we pass a non-zero value into the timeout argument.
* Windows seems to get confused by zero length timers.
*/
timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
if (timeout == 0) {
timeout = 1;
}
}
UpdateTimer(timeout);
}
/*
*----------------------------------------------------------------------
*
* NotifierProc --
*
* This procedure is invoked by Windows to process the timer
* message whenever we are using an external dispatch loop.
*
* Results:
* A standard windows result.
*
* Side effects:
* Services any pending events.
*
*----------------------------------------------------------------------
*/
static LRESULT CALLBACK
NotifierProc(
HWND hwnd,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
if (message != WM_TIMER) {
return DefWindowProc(hwnd, message, wParam, lParam);
}
/*
* Process all of the runnable events.
*/
Tcl_ServiceAll();
return 0;
}
/*
*----------------------------------------------------------------------
*
* Tcl_WaitForEvent --
*
* This function is called by Tcl_DoOneEvent to wait for new
* events on the message queue. If the block time is 0, then
* Tcl_WaitForEvent just polls the event queue without blocking.
*
* Results:
* Returns -1 if a WM_QUIT message is detected, returns 1 if
* a message was dispatched, otherwise returns 0.
*
* Side effects:
* Dispatches a message to a window procedure, which could do
* anything.
*
*----------------------------------------------------------------------
*/
int
Tcl_WaitForEvent(
Tcl_Time *timePtr) /* Maximum block time, or NULL. */
{
MSG msg;
int timeout;
if (!initialized) {
InitNotifier();
}
/*
* Only use the interval timer for non-zero timeouts. This avoids
* generating useless messages when we really just want to poll.
*/
if (timePtr) {
timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
} else {
timeout = 0;
}
UpdateTimer(timeout);
if (!timePtr || (timeout != 0)
|| PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
if (!GetMessage(&msg, NULL, 0, 0)) {
/*
* The application is exiting, so repost the quit message
* and start unwinding.
*/
PostQuitMessage(msg.wParam);
return -1;
}
/*
* Handle timer expiration as a special case so we don't
* claim to be doing work when we aren't.
*/
if (msg.message == WM_TIMER && msg.hwnd == notifier.hwnd) {
return 0;
}
TranslateMessage(&msg);
DispatchMessage(&msg);
return 1;
}
return 0;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Sleep --
*
* Delay execution for the specified number of milliseconds.
*
* Results:
* None.
*
* Side effects:
* Time passes.
*
*----------------------------------------------------------------------
*/
void
Tcl_Sleep(ms)
int ms; /* Number of milliseconds to sleep. */
{
Sleep(ms);
}