QmlDesigner: Parse .metainfo files from the share folder

We have some plugins that essentially only contain a .metainfo file.
the possibility to drop .metainfo files into that folder simplifies things.
In QDS 3.2 this will be used for the particle library.

Change-Id: I0c4bb7f66bb8eaa3f806ec9d34c6991d08ef5a5f
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/designercore/metainfo/metainfo.cpp

@@ -30,10 +30,16 @@
 #include "iwidgetplugin.h"
 
 #include <coreplugin/messagebox.h>
+#include <coreplugin/icore.h>
+
+#include <utils/filepath.h>
+
 #include "pluginmanager/widgetpluginmanager.h"
 
 #include <QDebug>
 #include <QMessageBox>
+#include <QDir>
+#include <QDirIterator>
 #include <QMutex>
 
 enum {
@@ -43,6 +49,30 @@ enum {
 namespace QmlDesigner {
 namespace Internal {
 
+
+static QString globalMetaInfoPath()
+{
+#ifdef SHARE_QML_PATH
+    if (qEnvironmentVariableIsSet("LOAD_QML_FROM_SOURCE"))
+        return QLatin1String(SHARE_QML_PATH) + "/globalMetaInfo";
+#endif
+    return Core::ICore::resourcePath("qmldesigner/globalMetaInfo").toString();
+}
+
+Utils::FilePaths allGlobalMetaInfoFiles()
+{
+    static Utils::FilePaths paths;
+
+    if (!paths.isEmpty())
+        return paths;
+
+    QDirIterator it(globalMetaInfoPath(), { "*.metainfo" }, QDir::Files, QDirIterator::Subdirectories);
+    while (it.hasNext())
+        paths.append(Utils::FilePath::fromString(it.next()));
+
+    return paths;
+}
+
 class MetaInfoPrivate
 {
     Q_DISABLE_COPY(MetaInfoPrivate)
@@ -99,6 +129,19 @@ void MetaInfoPrivate::parseItemLibraryDescriptions()
                                   errorMessage);
         }
     }
+
+    const Utils::FilePaths allMetaInfoFiles = allGlobalMetaInfoFiles();
+    for (const Utils::FilePath &path : allMetaInfoFiles) {
+        Internal::MetaInfoReader reader(*m_q);
+        try {
+            reader.readMetaInfoFile(path.toString());
+        } catch (const InvalidMetaInfoException &e) {
+            qWarning() << e.description();
+            const QString errorMessage = path.toString() + QLatin1Char('\n') + QLatin1Char('\n') + reader.errors().join(QLatin1Char('\n'));
+            Core::AsynchronousMessageBox::warning(QCoreApplication::translate("QmlDesigner::Internal::MetaInfoPrivate", "Invalid meta info"),
+                                  errorMessage);
+        }
+    }
 #endif
 }