diff options
Diffstat (limited to 'unix/tkUnixFocus.c')
| -rw-r--r-- | unix/tkUnixFocus.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/unix/tkUnixFocus.c b/unix/tkUnixFocus.c new file mode 100644 index 0000000..5c1a4f6 --- /dev/null +++ b/unix/tkUnixFocus.c @@ -0,0 +1,149 @@ +/* + * tkUnixFocus.c -- + * + * This file contains platform specific procedures that manage + * focus for Tk. + * + * Copyright (c) 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: @(#) tkUnixFocus.c 1.9 97/10/31 09:54:04 + */ + +#include "tkInt.h" +#include "tkPort.h" +#include "tkUnixInt.h" + +extern int tclFocusDebug; + +/* + *---------------------------------------------------------------------- + * + * TkpChangeFocus -- + * + * This procedure is invoked to move the official X focus from + * one window to another. + * + * Results: + * The return value is the serial number of the command that + * changed the focus. It may be needed by the caller to filter + * out focus change events that were queued before the command. + * If the procedure doesn't actually change the focus then + * it returns 0. + * + * Side effects: + * The official X focus window changes; the application's focus + * window isn't changed by this procedure. + * + *---------------------------------------------------------------------- + */ + +int +TkpChangeFocus(winPtr, force) + TkWindow *winPtr; /* Window that is to receive the X focus. */ + int force; /* Non-zero means claim the focus even + * if it didn't originally belong to + * topLevelPtr's application. */ +{ + TkDisplay *dispPtr = winPtr->dispPtr; + Tk_ErrorHandler errHandler; + Window window, root, parent, *children; + unsigned int numChildren, serial; + TkWindow *winPtr2; + int dummy; + + /* + * Don't set the X focus to a window that's marked + * override-redirect. This is a hack to avoid problems with menus + * under olvwm: if we move the focus then the focus can get lost + * during keyboard traversal. Fortunately, we don't really need to + * move the focus for menus: events will still find their way to the + * focus window, and menus aren't decorated anyway so the window + * manager doesn't need to hear about the focus change in order to + * redecorate the menu. + */ + + serial = 0; + if (winPtr->atts.override_redirect) { + return serial; + } + + /* + * Check to make sure that the focus is still in one of the windows + * of this application or one of their descendants. Furthermore, + * grab the server to make sure that the focus doesn't change in the + * middle of this operation. + */ + + XGrabServer(dispPtr->display); + if (!force) { + /* + * Find the focus window, then see if it or one of its ancestors + * is a window in our application (it's possible that the focus + * window is in an embedded application, which may or may not be + * in the same process. + */ + + XGetInputFocus(dispPtr->display, &window, &dummy); + while (1) { + winPtr2 = (TkWindow *) Tk_IdToWindow(dispPtr->display, window); + if ((winPtr2 != NULL) && (winPtr2->mainPtr == winPtr->mainPtr)) { + break; + } + if ((window == PointerRoot) || (window == None)) { + goto done; + } + XQueryTree(dispPtr->display, window, &root, &parent, &children, + &numChildren); + if (children != NULL) { + XFree((void *) children); + } + if (parent == root) { + goto done; + } + window = parent; + } + } + + /* + * Tell X to change the focus. Ignore errors that occur when changing + * the focus: it is still possible that the window we're focussing + * to could have gotten unmapped, which will generate an error. + */ + + errHandler = Tk_CreateErrorHandler(dispPtr->display, -1, -1, -1, + (Tk_ErrorProc *) NULL, (ClientData) NULL); + if (winPtr->window == None) { + panic("ChangeXFocus got null X window"); + } + XSetInputFocus(dispPtr->display, winPtr->window, RevertToParent, + CurrentTime); + Tk_DeleteErrorHandler(errHandler); + + /* + * Remember the current serial number for the X server and issue + * a dummy server request. This marks the position at which we + * changed the focus, so we can distinguish FocusIn and FocusOut + * events on either side of the mark. + */ + + serial = NextRequest(winPtr->display); + XNoOp(winPtr->display); + + done: + XUngrabServer(dispPtr->display); + + /* + * After ungrabbing the server, it's important to flush the output + * immediately so that the server sees the ungrab command. Otherwise + * we might do something else that needs to communicate with the + * server (such as invoking a subprocess that needs to do I/O to + * the screen); if the ungrab command is still sitting in our + * output buffer, we could deadlock. + */ + + XFlush(dispPtr->display); + return serial; +} |