1 files changed, 154 insertions, 0 deletions
diff --git a/src/ui/dialog/desktop-tracker.cpp b/src/ui/dialog/desktop-tracker.cpp
new file mode 100644
index 0000000..67f2cef
--- /dev/null
+++ b/src/ui/dialog/desktop-tracker.cpp
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Authors:
+ *   Jon A. Cruz
+ *
+ * Copyright (C) 2010 Jon A. Cruz
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "widgets/desktop-widget.h"
+
+#include "desktop-tracker.h"
+
+#include "inkscape.h"
+#include "desktop.h"
+
+namespace Inkscape {
+namespace UI {
+namespace Dialog {
+
+DesktopTracker::DesktopTracker() :
+    base(nullptr),
+    desktop(nullptr),
+    widget(nullptr),
+    hierID(0),
+    trackActive(false),
+    desktopChangedSig()
+{
+}
+
+DesktopTracker::~DesktopTracker()
+{
+    disconnect();
+}
+
+void DesktopTracker::connect(GtkWidget *widget)
+{
+    disconnect();
+
+    this->widget = widget;
+
+    // Use C/gobject callbacks to avoid gtkmm rewrap-during-destruct issues:
+    hierID = g_signal_connect( G_OBJECT(widget), "hierarchy-changed", G_CALLBACK(hierarchyChangeCB), this );
+    inkID = INKSCAPE.signal_activate_desktop.connect(
+              sigc::bind(
+              sigc::ptr_fun(&DesktopTracker::activateDesktopCB), this)
+    );
+
+    GtkWidget *wdgt = gtk_widget_get_ancestor(widget, SP_TYPE_DESKTOP_WIDGET);
+    if (wdgt && !base) {
+        SPDesktopWidget *dtw = SP_DESKTOP_WIDGET(wdgt);
+        if (dtw && dtw->desktop) {
+            setBase(dtw->desktop); // may also set desktop
+        }
+    }
+}
+
+void DesktopTracker::disconnect()
+{
+    if (hierID) {
+        if (widget) {
+            g_signal_handler_disconnect(G_OBJECT(widget), hierID);
+        }
+        hierID = 0;
+    }
+    if (inkID.connected()) {
+        inkID.disconnect();
+    }
+}
+
+void DesktopTracker::setBase(SPDesktop *desktop)
+{
+    if (this->base != desktop) {
+        base = desktop;
+        // Do not override an existing target desktop
+        if (!this->desktop) {
+            setDesktop(desktop);
+        }
+    }
+}
+
+SPDesktop *DesktopTracker::getBase() const
+{
+    return base;
+}
+
+SPDesktop *DesktopTracker::getDesktop() const
+{
+    return desktop;
+}
+
+sigc::connection DesktopTracker::connectDesktopChanged( const sigc::slot<void, SPDesktop*> & slot )
+{
+    return desktopChangedSig.connect(slot);
+}
+
+void DesktopTracker::activateDesktopCB(SPDesktop *desktop, DesktopTracker *self )
+{
+    if (self && self->trackActive) {
+        self->setDesktop(desktop);
+    }
+    //return FALSE;
+}
+
+bool DesktopTracker::hierarchyChangeCB(GtkWidget * /*widget*/, GtkWidget* /*prev*/, DesktopTracker *self)
+{
+    if (self) {
+        self->handleHierarchyChange();
+    }
+    return false;
+}
+
+void DesktopTracker::handleHierarchyChange()
+{
+    GtkWidget *wdgt = gtk_widget_get_ancestor(widget, SP_TYPE_DESKTOP_WIDGET);
+    bool newFlag = (wdgt == nullptr); // true means not in an SPDesktopWidget, thus floating.
+    if (wdgt && !base) {
+        SPDesktopWidget *dtw = SP_DESKTOP_WIDGET(wdgt);
+        if (dtw && dtw->desktop) {
+            setBase(dtw->desktop); // may also set desktop
+        }
+    }
+    if (newFlag != trackActive) {
+        trackActive = newFlag;
+        if (trackActive) {
+            setDesktop(SP_ACTIVE_DESKTOP);
+        } else if (desktop != base) {
+            setDesktop(getBase());
+        }
+    }
+}
+
+void DesktopTracker::setDesktop(SPDesktop *desktop)
+{
+    if (desktop != this->desktop) {
+        this->desktop = desktop;
+        desktopChangedSig.emit(desktop);
+    }
+}
+
+
+} // namespace Dialog
+} // namespace UI
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :