Meson build plugin initial support

Most basic project management is implemented:
- Project config/build
- Build options accessible to user
- Lists most build targets
- Meson and Ninja added to kit setup
- Basic project file tree with files known by Meson
- Some basic meson and ninja process output parsing
- Some project templates

Missing features, that will come later:
- Configurable project tree layout
- Locators for Meson
- Build importer
- Access to Machine files for better user fine tuning
- ...

Fixes: QTCREATORBUG-18117
Change-Id: I2811e71562c113fb0fc6b6177bcf0698fa71ef63
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mesonprojectmanager/settings/tools/toolsmodel.cpp

@@ -0,0 +1,117 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Alexis Jeandet.
+** 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 "toolsmodel.h"
+#include "tooltreeitem.h"
+#include "utils/qtcassert.h"
+#include "utils/stringutils.h"
+#include <exewrappers/mesontools.h>
+
+namespace MesonProjectManager {
+namespace Internal {
+
+ToolsModel::ToolsModel()
+{
+    setHeader({tr("Name"), tr("Location")});
+    rootItem()->appendChild(new Utils::StaticTreeItem(tr("Auto-detected")));
+    rootItem()->appendChild(new Utils::StaticTreeItem(tr("Manual")));
+    for (const auto &tool : MesonTools::tools()) {
+        addMesonTool(tool);
+    }
+}
+
+ToolTreeItem *ToolsModel::mesoneToolTreeItem(const QModelIndex &index) const
+{
+    return itemForIndexAtLevel<2>(index);
+}
+
+void ToolsModel::updateItem(const Core::Id &itemId, const QString &name, const Utils::FilePath &exe)
+{
+    auto treeItem = findItemAtLevel<2>([itemId](ToolTreeItem *n) { return n->id() == itemId; });
+    QTC_ASSERT(treeItem, return );
+    treeItem->update(name, exe);
+}
+
+void ToolsModel::addMesonTool()
+{
+    manualGroup()->appendChild(new ToolTreeItem{uniqueName(tr("New Meson or Ninja tool"))});
+}
+
+void ToolsModel::removeMesonTool(ToolTreeItem *item)
+{
+    QTC_ASSERT(item, return );
+    destroyItem(item);
+    m_itemsToRemove.enqueue(item->id());
+}
+
+ToolTreeItem *ToolsModel::cloneMesonTool(ToolTreeItem *item)
+{
+    QTC_ASSERT(item, return nullptr);
+    auto newItem = new ToolTreeItem(*item);
+    manualGroup()->appendChild(newItem);
+    return item;
+}
+
+void ToolsModel::apply()
+{
+    forItemsAtLevel<2>([this](ToolTreeItem *item) {
+        if (item->hasUnsavedChanges()) {
+            MesonTools::updateTool(item->id(), item->name(), item->executable());
+            item->setSaved();
+            emit this->dataChanged(item->index(),item->index());
+        }
+    });
+    while (!m_itemsToRemove.isEmpty()) {
+        MesonTools::removeTool(m_itemsToRemove.dequeue());
+    }
+
+}
+
+void ToolsModel::addMesonTool(const MesonTools::Tool_t &tool)
+{
+    if (tool->autoDetected())
+        autoDetectedGroup()->appendChild(new ToolTreeItem(tool));
+    else
+        manualGroup()->appendChild(new ToolTreeItem(tool));
+}
+
+QString ToolsModel::uniqueName(const QString &baseName)
+{
+    QStringList names;
+    forItemsAtLevel<2>([&names](auto *item) { names << item->name(); });
+    return Utils::makeUniquelyNumbered(baseName, names);
+}
+
+Utils::TreeItem *ToolsModel::autoDetectedGroup() const
+{
+    return rootItem()->childAt(0);
+}
+
+Utils::TreeItem *ToolsModel::manualGroup() const
+{
+    return rootItem()->childAt(1);
+}
+} // namespace Internal
+} // namespace MesonProjectManager