Meson: Flatten directory hierarchy

Keep tests/ and icons/ but put the rest into the toplevel.

The previous setup was so different from the rest of the bunch that
it regularly stuck out in maintenance tasks.

Change-Id: I69821be6268f69682353a388f6bb1fa343215303
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mesonprojectmanager/arrayoptionlineedit.h

@@ -0,0 +1,40 @@
+// Copyright (C) 2020 Alexis Jeandet.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0+ OR GPL-3.0 WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include <QColor>
+#include <QPlainTextEdit>
+#include <QRegularExpression>
+#include <QSyntaxHighlighter>
+
+namespace MesonProjectManager {
+namespace Internal {
+
+class RegexHighlighter : public QSyntaxHighlighter
+{
+    Q_OBJECT
+    const QRegularExpression m_regex{R"('([^']+)'+|([^', ]+)[, ]*)"};
+    QTextCharFormat m_format;
+
+public:
+    RegexHighlighter(QWidget *parent);
+    void highlightBlock(const QString &text) override;
+    QStringList options(const QString &text);
+};
+
+class ArrayOptionLineEdit : public QPlainTextEdit
+{
+    Q_OBJECT
+    RegexHighlighter *m_highLighter;
+
+public:
+    ArrayOptionLineEdit(QWidget *parent = nullptr);
+    QStringList options();
+
+protected:
+    void keyPressEvent(QKeyEvent *e) override;
+};
+
+} // namespace Internal
+} // namespace MesonProjectManager