Initial revision

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
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+/* 
+ * 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;
+}