Add offline mode support

launcher/ui/dialogs/OfflineLoginDialog.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <QtWidgets/QDialog>
+#include <QtCore/QEventLoop>
+
+#include "minecraft/auth/MinecraftAccount.h"
+#include "tasks/Task.h"
+
+namespace Ui
+{
+class OfflineLoginDialog;
+}
+
+class OfflineLoginDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    ~OfflineLoginDialog();
+
+    static MinecraftAccountPtr newAccount(QWidget *parent, QString message);
+
+private:
+    explicit OfflineLoginDialog(QWidget *parent = 0);
+
+    void setUserInputsEnabled(bool enable);
+
+protected
+slots:
+    void accept();
+
+    void onTaskFailed(const QString &reason);
+    void onTaskSucceeded();
+    void onTaskStatus(const QString &status);
+    void onTaskProgress(qint64 current, qint64 total);
+
+    void on_userTextBox_textEdited(const QString &newText);
+
+private:
+    Ui::OfflineLoginDialog *ui;
+    MinecraftAccountPtr m_account;
+    Task::Ptr m_loginTask;
+};