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.cpp

@@ -0,0 +1,160 @@
+/****************************************************************************
+**
+** 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.
+**
+****************************************************************************/
+
+#include "layoutbuilder.h"
+
+#include <utils/algorithm.h>
+#include <utils/aspects.h>
+#include <utils/qtcassert.h>
+
+#include <QFormLayout>
+#include <QGridLayout>
+#include <QWidget>
+
+namespace Utils {
+
+LayoutBuilder::LayoutBuilder(QWidget *parent, LayoutType layoutType)
+{
+    if (layoutType == FormLayout) {
+        m_formLayout = new QFormLayout(parent);
+        m_formLayout->setContentsMargins(0, 0, 0, 0);
+        m_formLayout->setFieldGrowthPolicy(QFormLayout::ExpandingFieldsGrow);
+    } else {
+        m_gridLayout = new QGridLayout(parent);
+        m_gridLayout->setContentsMargins(0, 0, 0, 0);
+    }
+}
+
+LayoutBuilder::LayoutBuilder(QLayout *layout)
+{
+    if (auto fl = qobject_cast<QFormLayout *>(layout)) {
+        m_formLayout = fl;
+    } else if (auto grid = qobject_cast<QGridLayout *>(layout)) {
+        m_gridLayout = grid;
+        m_currentGridRow = grid->rowCount();
+        m_currentGridColumn = 0;
+    }
+}
+
+LayoutBuilder::~LayoutBuilder()
+{
+    flushPendingFormItems();
+}
+
+LayoutBuilder &LayoutBuilder::startNewRow()
+{
+    if (m_formLayout)
+        flushPendingFormItems();
+    if (m_gridLayout) {
+        if (m_currentGridColumn != 0) {
+            ++m_currentGridRow;
+            m_currentGridColumn = 0;
+        }
+    }
+    return *this;
+}
+
+LayoutBuilder &LayoutBuilder::addRow(const LayoutItem &item)
+{
+    startNewRow();
+    addItem(item);
+    return *this;
+}
+
+void LayoutBuilder::flushPendingFormItems()
+{
+    QTC_ASSERT(m_formLayout, return);
+
+    if (m_pendingFormItems.isEmpty())
+        return;
+
+    // If there are more than two items, we cram the last ones in one hbox.
+    if (m_pendingFormItems.size() > 2) {
+        auto hbox = new QHBoxLayout;
+        hbox->setContentsMargins(0, 0, 0, 0);
+        for (int i = 1; i < m_pendingFormItems.size(); ++i) {
+            if (QWidget *w = m_pendingFormItems.at(i).widget)
+                hbox->addWidget(w);
+            else if (QLayout *l = m_pendingFormItems.at(i).layout)
+                hbox->addItem(l);
+            else
+                QTC_CHECK(false);
+        }
+        while (m_pendingFormItems.size() >= 2)
+            m_pendingFormItems.takeLast();
+        m_pendingFormItems.append(LayoutItem(hbox));
+    }
+
+    if (m_pendingFormItems.size() == 1) { // One one item given, so this spans both columns.
+        if (auto layout = m_pendingFormItems.at(0).layout)
+            m_formLayout->addRow(layout);
+        else if (auto widget = m_pendingFormItems.at(0).widget)
+            m_formLayout->addRow(widget);
+    } else if (m_pendingFormItems.size() == 2) { // Normal case, both columns used.
+        if (auto label = m_pendingFormItems.at(0).widget) {
+            if (auto layout = m_pendingFormItems.at(1).layout)
+                m_formLayout->addRow(label, layout);
+            else if (auto widget = m_pendingFormItems.at(1).widget)
+                m_formLayout->addRow(label, widget);
+        } else  {
+            if (auto layout = m_pendingFormItems.at(1).layout)
+                m_formLayout->addRow(m_pendingFormItems.at(0).text, layout);
+            else if (auto widget = m_pendingFormItems.at(1).widget)
+                m_formLayout->addRow(m_pendingFormItems.at(0).text, widget);
+        }
+    } else {
+        QTC_CHECK(false);
+    }
+
+    m_pendingFormItems.clear();
+}
+
+QLayout *LayoutBuilder::layout() const
+{
+    if (m_formLayout)
+        return m_formLayout;
+    return m_gridLayout;
+}
+
+LayoutBuilder &LayoutBuilder::addItem(LayoutItem item)
+{
+    if (item.widget && !item.widget->parent())
+        item.widget->setParent(layout()->parentWidget());
+
+    if (item.aspect) {
+        item.aspect->addToLayout(*this);
+    } else {
+        if (m_gridLayout) {
+            if (auto widget = item.widget)
+                m_gridLayout->addWidget(widget, m_currentGridRow, m_currentGridColumn, 1, item.span, item.align);
+            m_currentGridColumn += item.span;
+        } else {
+            m_pendingFormItems.append(item);
+        }
+    }
+    return *this;
+}
+
+} // Utils