RMG-Input: implement support for mapping multiple inputs

Source/RMG-Input/UserInterface/Widget/AddMappingButton.cpp

@@ -0,0 +1,33 @@
+/*
+ * Rosalie's Mupen GUI - https://github.com/Rosalie241/RMG
+ *  Copyright (C) 2020 Rosalie Wanders <rosalie@mailbox.org>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 3.
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+#include "AddMappingButton.hpp"
+#include "ControllerWidget.hpp"
+#include "MappingButton.hpp"
+
+using namespace UserInterface::Widget;
+
+AddMappingButton::AddMappingButton(QWidget* parent) : QPushButton(parent)
+{
+}
+
+AddMappingButton::~AddMappingButton()
+{
+}
+
+void AddMappingButton::Initialize(ControllerWidget* widget, MappingButton* button)
+{
+    this->controllerWidget = widget;
+    this->mappingButton    = button;
+
+    connect(this, &QPushButton::released, [=]
+    {
+        emit this->controllerWidget->on_AddMappingButton_Released(this->mappingButton);
+    });
+}