Add WindowSelectionWidget

Refreshes list of windows when widget becomes visible to support widget
caching

plugins/base/utils/window-selection.cpp

@@ -0,0 +1,25 @@
+#include "window-selection.hpp"
+#include "selection-helpers.hpp"
+
+namespace advss {
+
+WindowSelectionWidget::WindowSelectionWidget(QWidget *parent)
+	: FilterComboBox(parent)
+{
+	setEditable(true);
+	SetAllowUnmatchedSelection(true);
+	setMaxVisibleItems(20);
+	PopulateWindowSelection(this);
+}
+
+void WindowSelectionWidget::showEvent(QShowEvent *event)
+{
+	FilterComboBox::showEvent(event);
+	const QSignalBlocker b(this);
+	const auto text = currentText();
+	clear();
+	PopulateWindowSelection(this);
+	setCurrentText(text);
+}
+
+} // namespace advss