Restrict suggested file filters to registered supported mime types

When using File > Open File or Project, and with Save As.
It was containing all mime types registered in Qt Creator, including the
default one from freedesktop.org, most of them being not interesting.

Task-number: QTCREATORBUG-17913
Change-Id: Ic5e49b27b566eb41419240b78a6cd99b233aeb07
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/coreplugin/documentmanager.cpp

@@ -27,6 +27,7 @@
 
 #include "icore.h"
 #include "idocument.h"
+#include "idocumentfactory.h"
 #include "coreconstants.h"
 
 #include <coreplugin/diffservice.h>
@@ -710,6 +711,33 @@ bool DocumentManager::saveDocument(IDocument *document, const QString &fileName,
     return ret;
 }
 
+template<typename FactoryType>
+QSet<QString> filterStrings()
+{
+    QSet<QString> filters;
+    for (FactoryType *factory : ExtensionSystem::PluginManager::getObjects<FactoryType>()) {
+        for (const QString &mt : factory->mimeTypes()) {
+            const QString filter = mimeTypeForName(mt).filterString();
+            if (!filter.isEmpty())
+                filters.insert(filter);
+        }
+    }
+    return filters;
+}
+
+QString DocumentManager::allDocumentFactoryFiltersString(QString *allFilesFilter = 0)
+{
+    const QSet<QString> uniqueFilters = filterStrings<IDocumentFactory>()
+                                        + filterStrings<IEditorFactory>();
+    QStringList filters = uniqueFilters.toList();
+    filters.sort();
+    const QString allFiles = Utils::allFilesFilterString();
+    if (allFilesFilter)
+        *allFilesFilter = allFiles;
+    filters.prepend(allFiles);
+    return filters.join(QLatin1String(";;"));
+}
+
 QString DocumentManager::getSaveFileName(const QString &title, const QString &pathIn,
                                      const QString &filter, QString *selectedFilter)
 {
@@ -771,7 +799,7 @@ QString DocumentManager::getSaveFileNameWithExtension(const QString &title, cons
 QString DocumentManager::getSaveAsFileName(const IDocument *document)
 {
     QTC_ASSERT(document, return QString());
-    const QString filter = Utils::allFiltersString();
+    const QString filter = allDocumentFactoryFiltersString();
     const QString filePath = document->filePath().toString();
     QString selectedFilter;
     QString fileDialogPath = filePath;

src/plugins/coreplugin/documentmanager.h

@@ -84,6 +84,8 @@ public:
                              const QString &fileName = QString(),
                              bool *isReadOnly = nullptr);
 
+    static QString allDocumentFactoryFiltersString(QString *allFilesFilter);
+
     static QStringList getOpenFileNames(const QString &filters,
                                         const QString &path = QString(),
                                         QString *selectedFilter = nullptr);

src/plugins/coreplugin/editormanager/editormanager.cpp

@@ -2726,7 +2726,7 @@ void EditorManager::addCloseEditorListener(const std::function<bool (IEditor *)>
 QStringList EditorManager::getOpenFileNames()
 {
     QString selectedFilter;
-    const QString &fileFilters = Utils::allFiltersString(&selectedFilter);
+    const QString &fileFilters = DocumentManager::allDocumentFactoryFiltersString(&selectedFilter);
     return DocumentManager::getOpenFileNames(fileFilters, QString(), &selectedFilter);
 }