Add Keyboard.

src/keyboard/SwitchInputModeButton.h

@@ -0,0 +1,29 @@
+#ifndef SWITCHINPUTMODEBUTTON_H
+#define SWITCHINPUTMODEBUTTON_H
+
+#include <QPushButton>
+#include <QTimer>
+
+class SwitchInputModeButton : public QPushButton
+{
+    Q_OBJECT
+
+public:
+    explicit SwitchInputModeButton(QWidget *aParent = nullptr);
+    ~SwitchInputModeButton();
+
+signals:
+    void repeatPress();
+    void singlePress();
+
+private slots:
+    void handleButtonPressed();
+    void handleButtonReleased();
+    void prepareRepeatPress();
+
+private:
+    bool mIsRepeat;
+    QTimer* mTimer;
+};
+
+#endif // SWITCHINPUTMODEBUTTON_H