500 lines
12 KiB
C
500 lines
12 KiB
C
/*
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* tkUnixEvent.c --
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*
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* This file implements an event source for X displays for the
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* UNIX version of Tk.
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*
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* Copyright (c) 1995-1997 Sun Microsystems, Inc.
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*
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* See the file "license.terms" for information on usage and redistribution
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* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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*
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* SCCS: @(#) tkUnixEvent.c 1.16 97/06/06 11:23:15
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*/
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#include "tkInt.h"
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#include "tkUnixInt.h"
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#include <signal.h>
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/*
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* The following static indicates whether this module has been initialized.
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*/
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static int initialized = 0;
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/*
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* Prototypes for procedures that are referenced only in this file:
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*/
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static void DisplayCheckProc _ANSI_ARGS_((ClientData clientData,
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int flags));
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static void DisplayExitHandler _ANSI_ARGS_((
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ClientData clientData));
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static void DisplayFileProc _ANSI_ARGS_((ClientData clientData,
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int flags));
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static void DisplaySetupProc _ANSI_ARGS_((ClientData clientData,
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int flags));
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/*
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*----------------------------------------------------------------------
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*
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* TkCreateXEventSource --
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*
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* This procedure is called during Tk initialization to create
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* the event source for X Window events.
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*
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* Results:
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* None.
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*
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* Side effects:
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* A new event source is created.
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*
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*----------------------------------------------------------------------
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*/
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void
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TkCreateXEventSource()
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{
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if (!initialized) {
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initialized = 1;
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Tcl_CreateEventSource(DisplaySetupProc, DisplayCheckProc, NULL);
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Tcl_CreateExitHandler(DisplayExitHandler, NULL);
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}
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}
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/*
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*----------------------------------------------------------------------
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*
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* DisplayExitHandler --
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*
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* This function is called during finalization to clean up the
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* display module.
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*
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* Results:
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* None.
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*
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* Side effects:
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* None.
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*
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*----------------------------------------------------------------------
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*/
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static void
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DisplayExitHandler(clientData)
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ClientData clientData; /* Not used. */
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{
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Tcl_DeleteEventSource(DisplaySetupProc, DisplayCheckProc, NULL);
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initialized = 0;
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}
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/*
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*----------------------------------------------------------------------
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*
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* TkpOpenDisplay --
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*
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* Allocates a new TkDisplay, opens the X display, and establishes
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* the file handler for the connection.
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*
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* Results:
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* A pointer to a Tk display structure.
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*
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* Side effects:
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* Opens a display.
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*
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*----------------------------------------------------------------------
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*/
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TkDisplay *
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TkpOpenDisplay(display_name)
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char *display_name;
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{
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TkDisplay *dispPtr;
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Display *display = XOpenDisplay(display_name);
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display = XOpenDisplay(display_name);
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if (display == NULL) {
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return NULL;
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}
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dispPtr = (TkDisplay *) ckalloc(sizeof(TkDisplay));
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dispPtr->display = display;
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Tcl_CreateFileHandler(ConnectionNumber(display), TCL_READABLE,
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DisplayFileProc, (ClientData) dispPtr);
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return dispPtr;
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}
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/*
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*----------------------------------------------------------------------
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*
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* TkpCloseDisplay --
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*
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* Cancels notifier callbacks and closes a display.
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*
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* Results:
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* None.
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*
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* Side effects:
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* Deallocates the displayPtr.
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*
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*----------------------------------------------------------------------
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*/
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void
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TkpCloseDisplay(displayPtr)
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TkDisplay *displayPtr;
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{
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TkDisplay *dispPtr = (TkDisplay *) displayPtr;
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if (dispPtr->display != 0) {
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Tcl_DeleteFileHandler(ConnectionNumber(dispPtr->display));
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(void) XCloseDisplay(dispPtr->display);
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}
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ckfree((char *) dispPtr);
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}
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/*
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*----------------------------------------------------------------------
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*
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* DisplaySetupProc --
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*
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* This procedure implements the setup part of the UNIX X display
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* event source. It is invoked by Tcl_DoOneEvent before entering
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* the notifier to check for events on all displays.
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*
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* Results:
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* None.
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*
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* Side effects:
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* If data is queued on a display inside Xlib, then the maximum
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* block time will be set to 0 to ensure that the notifier returns
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* control to Tcl even if there is no more data on the X connection.
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*
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*----------------------------------------------------------------------
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*/
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static void
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DisplaySetupProc(clientData, flags)
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ClientData clientData; /* Not used. */
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int flags;
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{
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TkDisplay *dispPtr;
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static Tcl_Time blockTime = { 0, 0 };
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if (!(flags & TCL_WINDOW_EVENTS)) {
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return;
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}
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for (dispPtr = tkDisplayList; dispPtr != NULL;
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dispPtr = dispPtr->nextPtr) {
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/*
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* Flush the display. If data is pending on the X queue, set
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* the block time to zero. This ensures that we won't block
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* in the notifier if there is data in the X queue, but not on
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* the server socket.
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*/
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XFlush(dispPtr->display);
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if (XQLength(dispPtr->display) > 0) {
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Tcl_SetMaxBlockTime(&blockTime);
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}
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}
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}
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/*
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*----------------------------------------------------------------------
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*
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* DisplayCheckProc --
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*
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* This procedure checks for events sitting in the X event
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* queue.
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*
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* Results:
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* None.
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*
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* Side effects:
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* Moves queued events onto the Tcl event queue.
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*
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*----------------------------------------------------------------------
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*/
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static void
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DisplayCheckProc(clientData, flags)
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ClientData clientData; /* Not used. */
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int flags;
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{
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TkDisplay *dispPtr;
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XEvent event;
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int numFound;
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if (!(flags & TCL_WINDOW_EVENTS)) {
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return;
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}
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for (dispPtr = tkDisplayList; dispPtr != NULL;
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dispPtr = dispPtr->nextPtr) {
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XFlush(dispPtr->display);
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numFound = XQLength(dispPtr->display);
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/*
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* Transfer events from the X event queue to the Tk event queue.
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*/
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while (numFound > 0) {
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XNextEvent(dispPtr->display, &event);
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Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
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numFound--;
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}
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}
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}
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/*
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*----------------------------------------------------------------------
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*
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* DisplayFileProc --
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*
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* This procedure implements the file handler for the X connection.
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*
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* Results:
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* None.
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*
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* Side effects:
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* Makes entries on the Tcl event queue for all the events available
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* from all the displays.
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*
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*----------------------------------------------------------------------
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*/
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static void
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DisplayFileProc(clientData, flags)
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ClientData clientData; /* The display pointer. */
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int flags; /* Should be TCL_READABLE. */
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{
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TkDisplay *dispPtr = (TkDisplay *) clientData;
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Display *display = dispPtr->display;
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XEvent event;
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int numFound;
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XFlush(display);
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numFound = XEventsQueued(display, QueuedAfterReading);
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if (numFound == 0) {
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/*
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* Things are very tricky if there aren't any events readable
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* at this point (after all, there was supposedly data
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* available on the connection). A couple of things could
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* have occurred:
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*
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* One possibility is that there were only error events in the
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* input from the server. If this happens, we should return
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* (we don't want to go to sleep in XNextEvent below, since
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* this would block out other sources of input to the
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* process).
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*
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* Another possibility is that our connection to the server
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* has been closed. This will not necessarily be detected in
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* XEventsQueued (!!), so if we just return then there will be
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* an infinite loop. To detect such an error, generate a NoOp
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* protocol request to exercise the connection to the server,
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* then return. However, must disable SIGPIPE while sending
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* the request, or else the process will die from the signal
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* and won't invoke the X error function to print a nice (?!)
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* message.
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*/
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void (*oldHandler)();
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oldHandler = (void (*)()) signal(SIGPIPE, SIG_IGN);
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XNoOp(display);
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XFlush(display);
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(void) signal(SIGPIPE, oldHandler);
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}
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/*
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* Transfer events from the X event queue to the Tk event queue.
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*/
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while (numFound > 0) {
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XNextEvent(display, &event);
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Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
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numFound--;
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}
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}
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/*
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*----------------------------------------------------------------------
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*
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* TkUnixDoOneXEvent --
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*
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* This routine waits for an X event to be processed or for
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* a timeout to occur. The timeout is specified as an absolute
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* time. This routine is called when Tk needs to wait for a
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* particular X event without letting arbitrary events be
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* processed. The caller will typically call Tk_RestrictEvents
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* to set up an event filter before calling this routine. This
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* routine will service at most one event per invocation.
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*
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* Results:
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* Returns 0 if the timeout has expired, otherwise returns 1.
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*
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* Side effects:
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* Can invoke arbitrary Tcl scripts.
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*
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*----------------------------------------------------------------------
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*/
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int
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TkUnixDoOneXEvent(timePtr)
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Tcl_Time *timePtr; /* Specifies the absolute time when the
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* call should time out. */
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{
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TkDisplay *dispPtr;
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static fd_mask readMask[MASK_SIZE];
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struct timeval blockTime, *timeoutPtr;
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Tcl_Time now;
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int fd, index, bit, numFound, numFdBits = 0;
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/*
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* Look for queued events first.
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*/
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if (Tcl_ServiceEvent(TCL_WINDOW_EVENTS)) {
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return 1;
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}
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/*
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* Compute the next block time and check to see if we have timed out.
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* Note that HP-UX defines tv_sec to be unsigned so we have to be
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* careful in our arithmetic.
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*/
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if (timePtr) {
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TclpGetTime(&now);
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blockTime.tv_sec = timePtr->sec;
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blockTime.tv_usec = timePtr->usec - now.usec;
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if (blockTime.tv_usec < 0) {
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now.sec += 1;
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blockTime.tv_usec += 1000000;
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}
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if (blockTime.tv_sec < now.sec) {
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blockTime.tv_sec = 0;
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blockTime.tv_usec = 0;
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} else {
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blockTime.tv_sec -= now.sec;
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}
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timeoutPtr = &blockTime;
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} else {
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timeoutPtr = NULL;
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}
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/*
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* Set up the select mask for all of the displays. If a display has
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* data pending, then we want to poll instead of blocking.
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*/
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memset((VOID *) readMask, 0, MASK_SIZE*sizeof(fd_mask));
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for (dispPtr = tkDisplayList; dispPtr != NULL;
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dispPtr = dispPtr->nextPtr) {
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XFlush(dispPtr->display);
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if (XQLength(dispPtr->display) > 0) {
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blockTime.tv_sec = 0;
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blockTime.tv_usec = 0;
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}
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fd = ConnectionNumber(dispPtr->display);
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index = fd/(NBBY*sizeof(fd_mask));
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bit = 1 << (fd%(NBBY*sizeof(fd_mask)));
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readMask[index] |= bit;
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if (numFdBits <= fd) {
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numFdBits = fd+1;
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}
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}
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numFound = select(numFdBits, (SELECT_MASK *) &readMask[0], NULL, NULL,
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timeoutPtr);
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if (numFound <= 0) {
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/*
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* Some systems don't clear the masks after an error, so
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* we have to do it here.
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*/
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memset((VOID *) readMask, 0, MASK_SIZE*sizeof(fd_mask));
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}
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/*
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* Process any new events on the display connections.
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*/
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for (dispPtr = tkDisplayList; dispPtr != NULL;
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dispPtr = dispPtr->nextPtr) {
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fd = ConnectionNumber(dispPtr->display);
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index = fd/(NBBY*sizeof(fd_mask));
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bit = 1 << (fd%(NBBY*sizeof(fd_mask)));
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if ((readMask[index] & bit) || (XQLength(dispPtr->display) > 0)) {
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DisplayFileProc((ClientData)dispPtr, TCL_READABLE);
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}
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}
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if (Tcl_ServiceEvent(TCL_WINDOW_EVENTS)) {
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return 1;
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}
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/*
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* Check to see if we timed out.
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*/
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if (timePtr) {
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TclpGetTime(&now);
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if ((now.sec > timePtr->sec) || ((now.sec == timePtr->sec)
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&& (now.usec > timePtr->usec))) {
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return 0;
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}
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}
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/*
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* We had an event but we did not generate a Tcl event from it. Behave
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* as though we dealt with it. (JYL&SS)
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*/
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return 1;
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}
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/*
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*----------------------------------------------------------------------
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*
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* TkpSync --
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*
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* This routine ensures that all pending X requests have been
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* seen by the server, and that any pending X events have been
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* moved onto the Tk event queue.
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*
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* Results:
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* None.
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*
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* Side effects:
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* Places new events on the Tk event queue.
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*
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*----------------------------------------------------------------------
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*/
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void
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TkpSync(display)
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Display *display; /* Display to sync. */
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{
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int numFound = 0;
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XEvent event;
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XSync(display, False);
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/*
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* Transfer events from the X event queue to the Tk event queue.
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*/
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numFound = XQLength(display);
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while (numFound > 0) {
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XNextEvent(display, &event);
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Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
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numFound--;
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}
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}
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