add QAD::VirtualKeyboard library, vkbd for widgets with JSON-based description

libs/virtual_keyboard/virtual_keyboard_layout.h

@@ -0,0 +1,39 @@
+#ifndef virtual_keyboard_layout_h
+#define virtual_keyboard_layout_h
+
+#include <QWidget>
+#include "virtual_keyboard_layout_page.h"
+
+
+class VirtualKeyboardLayout: public QObject {
+	Q_OBJECT
+
+public:
+	VirtualKeyboardLayout(QJsonObject root);
+	~VirtualKeyboardLayout();
+
+	QVector<VirtualKeyboardLayoutPage * > getPages() const {return pages;}
+	VirtualKeyboardLayoutPage * getPageByName(QString name) const;
+
+	void setDefaultPage();
+	void setCurrentPage(VirtualKeyboardLayoutPage * p);
+	void applyHints(Qt::InputMethodHints hints);
+
+protected:
+	void setGotoEnabled(bool yes);
+	void setCapitalEnabled(bool yes);
+	void setCapital(bool yes);
+
+	QVector<VirtualKeyboardLayoutPage * > pages;
+	VirtualKeyboardLayoutPage * current_page = nullptr;
+	QString default_page;
+
+private slots:
+
+signals:
+	void gotoPageRequest(QString);
+	void hideRequest();
+
+};
+
+#endif