Plugins: new serial terminal plugin

Plugin adding serial terminals in the output pane.

Change-Id: I75d0f69f8d90268ff774e4eae30e36eda022d3aa
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/serialterminal/consolelineedit.cpp

@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Benjamin Balga
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "consolelineedit.h"
+#include "serialterminalconstants.h"
+
+#include <QKeyEvent>
+
+namespace SerialTerminal {
+namespace Internal {
+
+ConsoleLineEdit::ConsoleLineEdit(QWidget *parent) :
+    QLineEdit(parent),
+    m_maxEntries(Constants::DEFAULT_MAX_ENTRIES)
+{
+    connect(this, &QLineEdit::returnPressed, this, &ConsoleLineEdit::addHistoryEntry);
+}
+
+// Add current text to history entries, if not empty and different from last entry.
+// Called when return key is pressed.
+void ConsoleLineEdit::addHistoryEntry()
+{
+    m_currentEntryIndex = 0;
+    const QString currentText = text();
+
+    if (currentText.isEmpty())
+        return;
+
+    if (!m_history.isEmpty() && m_history.first() == currentText)
+        return;
+
+    m_history.prepend(currentText);
+    if (m_history.size() > m_maxEntries)
+        m_history.removeLast();
+}
+
+// Load a specific history entry: 0 = current, n = n-most last entry
+void ConsoleLineEdit::loadHistoryEntry(int entryIndex)
+{
+    if (entryIndex < 0 || entryIndex > m_history.size())
+        return;
+
+    if (m_currentEntryIndex == 0)
+        m_editingEntry = text();
+
+    if (entryIndex <= 0 && m_currentEntryIndex > 0) {
+        m_currentEntryIndex = 0;
+        setText(m_editingEntry);
+    } else if (entryIndex > 0) {
+        m_currentEntryIndex = entryIndex;
+        setText(m_history.at(entryIndex-1));
+    }
+}
+
+void ConsoleLineEdit::keyPressEvent(QKeyEvent *event)
+{
+    // Navigate history with up/down keys
+    if (event->key() == Qt::Key_Up) {
+        loadHistoryEntry(m_currentEntryIndex+1);
+        event->accept();
+    } else if (event->key() == Qt::Key_Down) {
+        loadHistoryEntry(m_currentEntryIndex-1);
+        event->accept();
+    } else {
+        QLineEdit::keyPressEvent(event);
+    }
+}
+
+} // namespace Internal
+} // namespace SerialTerminal