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/projecttree.cpp

@@ -0,0 +1,80 @@
+// 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
+
+#include "projecttree.h"
+
+#include <set>
+
+namespace MesonProjectManager {
+namespace Internal {
+
+ProjectTree::ProjectTree() {}
+
+void buildTargetTree(std::unique_ptr<MesonProjectNode> &root, const Target &target)
+{
+    const auto path = Utils::FilePath::fromString(target.definedIn);
+    for (const auto &group : target.sources) {
+        for (const auto &file : group.sources) {
+            root->addNestedNode(
+                std::make_unique<ProjectExplorer::FileNode>(Utils::FilePath::fromString(file),
+                                                            ProjectExplorer::FileType::Source));
+        }
+    }
+    for (const auto &extraFile : target.extraFiles) {
+        root->addNestedNode(
+            std::make_unique<ProjectExplorer::FileNode>(Utils::FilePath::fromString(extraFile),
+                                                        ProjectExplorer::FileType::Unknown));
+    }
+}
+
+void addTargetNode(std::unique_ptr<MesonProjectNode> &root, const Target &target)
+{
+    root->findNode([&root, &target, path = Utils::FilePath::fromString(target.definedIn)](
+                       ProjectExplorer::Node *node) {
+        if (node->filePath() == path.absolutePath()) {
+            auto asFolder = dynamic_cast<ProjectExplorer::FolderNode *>(node);
+            if (asFolder) {
+                auto targetNode = std::make_unique<MesonTargetNode>(
+                    path.absolutePath().pathAppended(target.name),
+                    Target::fullName(root->path(), target));
+                targetNode->setDisplayName(target.name);
+                asFolder->addNode(std::move(targetNode));
+            }
+            return true;
+        }
+        return false;
+    });
+}
+
+void addOptionsFile(std::unique_ptr<MesonProjectNode> &project)
+{
+    auto meson_options = project->filePath().pathAppended("meson_options.txt");
+    if (meson_options.exists())
+        project->addNestedNode(
+            std::make_unique<ProjectExplorer::FileNode>(meson_options,
+                                                        ProjectExplorer::FileType::Project));
+}
+
+std::unique_ptr<MesonProjectNode> ProjectTree::buildTree(const Utils::FilePath &srcDir,
+                                                         const TargetsList &targets,
+                                                         const std::vector<Utils::FilePath> &bsFiles)
+{
+    using namespace ProjectExplorer;
+    std::set<Utils::FilePath> targetPaths;
+    auto root = std::make_unique<MesonProjectNode>(srcDir);
+    for (const Target &target : targets) {
+        buildTargetTree(root, target);
+        targetPaths.insert(Utils::FilePath::fromString(target.definedIn).absolutePath());
+        addTargetNode(root, target);
+    }
+    for (Utils::FilePath bsFile : bsFiles) {
+        if (!bsFile.toFileInfo().isAbsolute())
+            bsFile = srcDir.pathAppended(bsFile.toString());
+        root->addNestedNode(
+            std::make_unique<ProjectExplorer::FileNode>(bsFile, ProjectExplorer::FileType::Project));
+    }
+    return root;
+}
+
+} // namespace Internal
+} // namespace MesonProjectManager