UI: Add item widget helper functions

These functions are designed to manually delete item widgets within
other widgets to prevent ->deleteLater from being called on them.  This
prevents the item widgets from being stuck in the event queue, and
prevents references to things like sources from being stuck in the event
queue along with them if they're used in the item widget's class or
functions.

obs/CMakeLists.txt

@@ -114,6 +114,7 @@ set(obs_SOURCES
 	double-slider.cpp
 	volume-control.cpp
 	adv-audio-control.cpp
+	item-widget-helpers.cpp
 	visibility-checkbox.cpp
 	vertical-scroll-area.cpp
 	visibility-item-widget.cpp
@@ -152,6 +153,7 @@ set(obs_HEADERS
 	mute-checkbox.hpp
 	volume-control.hpp
 	adv-audio-control.hpp
+	item-widget-helpers.hpp
 	visibility-checkbox.hpp
 	vertical-scroll-area.hpp
 	visibility-item-widget.hpp

obs/item-widget-helpers.cpp

+/******************************************************************************
+    Copyright (C) 2015 by Hugh Bailey <obs.jim@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+******************************************************************************/
+
+#include <QListWidget>
+
+QListWidgetItem *TakeListItem(QListWidget *widget, int row)
+{
+	QListWidgetItem *item = widget->item(row);
+
+	if (item)
+		delete widget->itemWidget(item);
+
+	return widget->takeItem(row);
+}
+
+void DeleteListItem(QListWidget *widget, QListWidgetItem *item)
+{
+	if (item) {
+		delete widget->itemWidget(item);
+		delete item;
+	}
+}
+
+void ClearListItems(QListWidget *widget)
+{
+	for (int i = 0; i < widget->count(); i++)
+		delete widget->itemWidget(widget->item(i));
+
+	QListWidgetItem *item = nullptr;
+	while ((item = widget->takeItem(0)))
+		delete item;
+}

obs/item-widget-helpers.hpp

+/******************************************************************************
+    Copyright (C) 2015 by Hugh Bailey <obs.jim@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+******************************************************************************/
+
+#pragma once
+
+/* This file exists to prevent ->deleteLater from being called on custom-made
+ * item widgets in widgets such as list widgets.  We do this to prevent things
+ * such as references to sources/etc from getting stuck in the Qt event queue
+ * with no way of controlling when they'll be released. */
+
+class QListWidget;
+class QListWidgetItem;
+
+QListWidgetItem *TakeListItem(QListWidget *widget, int row);
+void DeleteListItem(QListWidget *widget, QListWidgetItem *item);
+void ClearListItems(QListWidget *widget);