Added ChangeValueDisplay for string

src/changevaluedisplay_string.h

@@ -0,0 +1,44 @@
+#pragma once
+
+// local includes
+#include "changevaluedisplay.h"
+#include "displaywithtitle.h"
+#include "confirminterface.h"
+#include "backinterface.h"
+#include "errorhandlerinterface.h"
+#include "widgets/label.h"
+
+namespace espgui {
+
+template<>
+class ChangeValueDisplay<std::string> :
+    public DisplayWithTitle,
+    public virtual AccessorInterface<std::string>,
+    public virtual ConfirmInterface,
+    public virtual BackInterface,
+    public virtual ErrorHandlerInterface
+{
+    using Base = DisplayWithTitle;
+
+public:
+    ChangeValueDisplay<std::string> *asChangeValueDisplayString() override { return this; }
+    const ChangeValueDisplay<std::string> *asChangeValueDisplayString() const override { return this; }
+
+    void start() override;
+    void initScreen() override;
+    void update() override;
+    void redraw() override;
+
+    void buttonPressed(Button button) override;
+
+    const std::string &shownValue() const { return m_value; }
+    void setShownValue(std::string &&value) { m_value = std::move(value); }
+
+private:
+    std::string m_value;
+    bool m_pressed{};
+
+    Label m_valueLabel{26, 81}; // 188, 53
+};
+
+} // namespace espgui