Saving history of line edit for command line ("dot commands")

src/blackgui/lineedithistory.cpp

@@ -0,0 +1,58 @@
+/* Copyright (C) 2017
+ * swift project Community / Contributors
+ *
+ * This file is part of swift Project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "lineedithistory.h"
+#include <QKeyEvent>
+
+namespace BlackGui
+{
+    QString CLineEditHistory::getLastEnteredLine() const
+    {
+        if (m_history.isEmpty()) return {};
+        return m_history.first();
+    }
+
+    QString CLineEditHistory::getLastEnteredLineFormatted() const
+    {
+        return getLastEnteredLine().trimmed().simplified();
+    }
+
+    void CLineEditHistory::keyPressEvent(QKeyEvent *event)
+    {
+        if (event->key() == Qt::Key_Up)
+        {
+            // move back in history
+            if (m_history.size() > m_position)
+            {
+                setText(m_history.at(m_position++));
+            }
+        }
+        else if (event->key() == Qt::Key_Down)
+        {
+            // move forward in history
+            if (m_position <= 0) { clear(); return; }
+            if (m_position == m_history.size()) { --m_position; } // avoid need of 2xKeyDown at end
+            if (m_position > 0 && m_history.size() > --m_position)
+            {
+                setText(m_history.at(m_position));
+            }
+        }
+        else if (event->key() == Qt::Key_Return)
+        {
+            if (!text().isEmpty())
+            {
+                m_history.push_front(text());
+                m_position = 0;
+                clear();
+            }
+        }
+        // default handler for event
+        QLineEdit::keyPressEvent(event);
+    }
+} // ns