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194 | /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* Copyright © 2002 Red Hat, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of Red Hat not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. Red Hat makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
* RED HAT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL RED HAT
* BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: Owen Taylor, Red Hat, Inc.
*/
#include <config.h>
#include <ctk/ctk.h>
#include <cdk/cdkx.h>
#include "drw-selection.h"
struct _DrwSelection
{
CdkWindow *owner_window;
CtkWidget *invisible;
};
#define SELECTION_NAME "_CODEFACTORY_DRWRIGHT"
static CdkFilterReturn drw_selection_filter (CdkXEvent *xevent,
CdkEvent *event,
gpointer data);
static void drw_selection_negotiate (DrwSelection *drw_selection);
static void
drw_selection_reset (DrwSelection *drw_selection)
{
if (drw_selection->owner_window) {
cdk_window_remove_filter (drw_selection->owner_window,
drw_selection_filter, drw_selection);
g_object_unref (drw_selection->owner_window);
drw_selection->owner_window = NULL;
}
if (drw_selection->invisible) {
ctk_widget_destroy (drw_selection->invisible);
drw_selection->invisible = NULL;
}
}
static void
drw_selection_clear (CtkWidget *widget,
CdkEventSelection *event,
gpointer user_data)
{
DrwSelection *drw_selection = user_data;
drw_selection_reset (drw_selection);
drw_selection_negotiate (drw_selection);
}
static gboolean
drw_selection_find_existing (DrwSelection *drw_selection)
{
CdkDisplay *display;
Window old;
Display *xdisplay;
display = cdk_display_get_default ();
xdisplay = CDK_DISPLAY_XDISPLAY(display);
cdk_x11_display_error_trap_push (display);
old = XGetSelectionOwner (xdisplay,
cdk_x11_get_xatom_by_name (SELECTION_NAME));
if (old) {
XSelectInput (xdisplay, old, StructureNotifyMask);
drw_selection->owner_window = cdk_x11_window_foreign_new_for_display (cdk_display_get_default (), old);
}
XSync (xdisplay, False);
if (cdk_x11_display_error_trap_pop (display) == 0 && drw_selection->owner_window) {
cdk_window_add_filter (drw_selection->owner_window,
drw_selection_filter, drw_selection);
XUngrabServer (xdisplay);
return TRUE;
} else {
if (drw_selection->owner_window) {
g_object_unref (drw_selection->owner_window);
drw_selection->owner_window = NULL;
}
return FALSE;
}
}
static gboolean
drw_selection_claim (DrwSelection *drw_selection)
{
drw_selection->invisible = ctk_invisible_new ();
g_signal_connect (drw_selection->invisible, "selection-clear-event",
G_CALLBACK (drw_selection_clear), drw_selection);
if (ctk_selection_owner_set (drw_selection->invisible,
cdk_atom_intern (SELECTION_NAME, FALSE),
CDK_CURRENT_TIME)) {
return TRUE;
} else {
drw_selection_reset (drw_selection);
return FALSE;
}
}
static void
drw_selection_negotiate (DrwSelection *drw_selection)
{
Display *xdisplay = CDK_DISPLAY_XDISPLAY(cdk_display_get_default());
gboolean found = FALSE;
/* We don't need both the XGrabServer() and the loop here;
* the XGrabServer() should make sure that we only go through
* the loop once. It also works if you remove the XGrabServer()
* and just have the loop, but then the selection ownership
* can get transfered a bunch of times before things
* settle down.
*/
while (!found)
{
XGrabServer (xdisplay);
if (drw_selection_find_existing (drw_selection))
found = TRUE;
else if (drw_selection_claim (drw_selection))
found = TRUE;
XUngrabServer (xdisplay);
}
}
static CdkFilterReturn
drw_selection_filter (CdkXEvent *xevent,
CdkEvent *event,
gpointer data)
{
DrwSelection *drw_selection = data;<--- The scope of the variable 'drw_selection' can be reduced. [+]The scope of the variable 'drw_selection' can be reduced. Warning: Be careful when fixing this message, especially when there are inner loops. Here is an example where cppcheck will write that the scope for 'i' can be reduced:
void f(int x)
{
int i = 0;
if (x) {
// it's safe to move 'int i = 0;' here
for (int n = 0; n < 10; ++n) {
// it is possible but not safe to move 'int i = 0;' here
do_something(&i);
}
}
}
When you see this message it is always safe to reduce the variable scope 1 level.
XEvent *xev = (XEvent *)xevent;
if (xev->xany.type == DestroyNotify &&
xev->xdestroywindow.window == xev->xdestroywindow.event)
{
drw_selection_reset (drw_selection);
drw_selection_negotiate (drw_selection);
return CDK_FILTER_REMOVE;
}
return CDK_FILTER_CONTINUE;
}
DrwSelection *
drw_selection_start (void)
{
DrwSelection *drw_selection = g_new (DrwSelection, 1);
drw_selection->owner_window = NULL;
drw_selection->invisible = NULL;
drw_selection_negotiate (drw_selection);
return drw_selection;
}
void
drw_selection_stop (DrwSelection *drw_selection)
{
drw_selection_reset (drw_selection);
g_free (drw_selection);
}
gboolean
drw_selection_is_master (DrwSelection *drw_selection)<--- Parameter 'drw_selection' can be declared as pointer to const
{
return drw_selection->invisible != NULL;
}
|