Utils/ProjectExplorer: Move re-usabled bits of aspects to Utils

Classes involved are BaseAspect and some derived classes,
LayoutBuilder and VariableChooser.

This is mostly mechanical, with various include/using changes
to make it compile.

Change-Id: I624a457f3555f102e541c4c71e33a9423af32250
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/layoutbuilder.h

@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** 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.
+**
+****************************************************************************/
+
+#pragma once
+
+#include "utils_global.h"
+
+#include <QList>
+#include <QString>
+
+QT_BEGIN_NAMESPACE
+class QFormLayout;
+class QGridLayout;
+class QLayout;
+class QWidget;
+QT_END_NAMESPACE
+
+namespace Utils {
+
+class BaseAspect;
+
+class QTCREATOR_UTILS_EXPORT LayoutBuilder
+{
+public:
+    enum LayoutType { GridLayout, FormLayout };
+    explicit LayoutBuilder(QWidget *parent, LayoutType layoutType = FormLayout);
+    explicit LayoutBuilder(QLayout *layout); // Adds to existing layout.
+
+    ~LayoutBuilder();
+
+    class LayoutItem
+    {
+    public:
+        LayoutItem(QLayout *layout, int span = 1) : layout(layout), span(span) {}
+        LayoutItem(QWidget *widget, int span = 1, Qt::Alignment align = {})
+            : widget(widget), span(span), align(align) {}
+        LayoutItem(BaseAspect *aspect) : aspect(aspect) {}
+        LayoutItem(const QString &text) : text(text) {}
+
+        QLayout *layout = nullptr;
+        QWidget *widget = nullptr;
+        BaseAspect *aspect = nullptr;
+        QString text;
+        int span = 1;
+        Qt::Alignment align;
+    };
+
+    template<typename ...Items>
+    LayoutBuilder &addItems(LayoutItem first, Items... rest) {
+        return addItem(first).addItems(rest...);
+    }
+    LayoutBuilder &addItems() { return *this; }
+    LayoutBuilder &addItem(LayoutItem item);
+
+    LayoutBuilder &startNewRow();
+    LayoutBuilder &addRow(const LayoutItem &item);
+
+    QLayout *layout() const;
+
+private:
+    void flushPendingFormItems();
+
+    QFormLayout *m_formLayout = nullptr;
+    QGridLayout *m_gridLayout = nullptr;
+    QList<LayoutItem> m_pendingFormItems;
+    int m_currentGridRow = 0;
+    int m_currentGridColumn = 0;
+};
+
+} // namespace Utils