6 files changed, 99 insertions, 3 deletions

diff --git a/src/gui/kernel/qplatformdialoghelper.cpp b/src/gui/kernel/qplatformdialoghelper.cpp
index c36186b815..16f31db50d 100644
--- a/src/gui/kernel/qplatformdialoghelper.cpp
+++ b/src/gui/kernel/qplatformdialoghelper.cpp
@@ -451,6 +451,7 @@ public:
     QString defaultSuffix;
     QStringList history;
     QUrl initialDirectory;
+    QString initiallySelectedMimeTypeFilter;
     QString initiallySelectedNameFilter;
     QList<QUrl> initiallySelectedFiles;
     QStringList supportedSchemes;
@@ -668,6 +669,16 @@ void QFileDialogOptions::setInitialDirectory(const QUrl &directory)
     d->initialDirectory = directory;
 }
 
+QString QFileDialogOptions::initiallySelectedMimeTypeFilter() const
+{
+    return d->initiallySelectedMimeTypeFilter;
+}
+
+void QFileDialogOptions::setInitiallySelectedMimeTypeFilter(const QString &filter)
+{
+    d->initiallySelectedMimeTypeFilter = filter;
+}
+
 QString QFileDialogOptions::initiallySelectedNameFilter() const
 {
     return d->initiallySelectedNameFilter;
@@ -699,6 +710,16 @@ QStringList QFileDialogOptions::supportedSchemes() const
     return d->supportedSchemes;
 }
 
+void QPlatformFileDialogHelper::selectMimeTypeFilter(const QString &filter)
+{
+    Q_UNUSED(filter)
+}
+
+QString QPlatformFileDialogHelper::selectedMimeTypeFilter() const
+{
+    return QString();
+}
+
 // Return true if the URL is supported by the filedialog implementation *and* by the application.
 bool QPlatformFileDialogHelper::isSupportedUrl(const QUrl &url) const
 {
diff --git a/src/gui/kernel/qplatformdialoghelper.h b/src/gui/kernel/qplatformdialoghelper.h
index 6caef070e2..ed88c19c84 100644
--- a/src/gui/kernel/qplatformdialoghelper.h
+++ b/src/gui/kernel/qplatformdialoghelper.h
@@ -372,6 +372,9 @@ public:
     QUrl initialDirectory() const;
     void setInitialDirectory(const QUrl &);
 
+    QString initiallySelectedMimeTypeFilter() const;
+    void setInitiallySelectedMimeTypeFilter(const QString &);
+
     QString initiallySelectedNameFilter() const;
     void setInitiallySelectedNameFilter(const QString &);
 
@@ -397,7 +400,9 @@ public:
     virtual void selectFile(const QUrl &filename) = 0;
     virtual QList<QUrl> selectedFiles() const = 0;
     virtual void setFilter() = 0;
+    virtual void selectMimeTypeFilter(const QString &filter);
     virtual void selectNameFilter(const QString &filter) = 0;
+    virtual QString selectedMimeTypeFilter() const;
     virtual QString selectedNameFilter() const = 0;
 
     virtual bool isSupportedUrl(const QUrl &url) const;
diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index 8058dee567..5bfb7553a5 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -1461,6 +1461,19 @@ void QFileDialog::selectNameFilter(const QString &filter)
 }
 
 /*!
+ * \since 5.9
+ * \return The mimetype of the file that the user selected in the file dialog.
+ */
+QString QFileDialog::selectedMimeTypeFilter() const
+{
+    Q_D(const QFileDialog);
+    if (!d->usingWidgets())
+        return d->selectedMimeTypeFilter_sys();
+
+    return d->options->initiallySelectedMimeTypeFilter();
+}
+
+/*!
     \since 4.4
 
     Returns the filter that the user selected in the file dialog.
@@ -1579,9 +1592,19 @@ QStringList QFileDialog::mimeTypeFilters() const
 */
 void QFileDialog::selectMimeTypeFilter(const QString &filter)
 {
-    const QString text = nameFilterForMime(filter);
-    if (!text.isEmpty())
-        selectNameFilter(text);
+    Q_D(QFileDialog);
+    d->options->setInitiallySelectedMimeTypeFilter(filter);
+
+    const QString filterForMime = nameFilterForMime(filter);
+
+    if (!d->usingWidgets()) {
+        d->selectMimeTypeFilter_sys(filter);
+        if (d->selectedMimeTypeFilter_sys().isEmpty() && !filterForMime.isEmpty()) {
+            selectNameFilter(filterForMime);
+        }
+    } else if (!filterForMime.isEmpty()) {
+        selectNameFilter(filterForMime);
+    }
 }
 
 #endif // QT_NO_MIMETYPE
diff --git a/src/widgets/dialogs/qfiledialog.h b/src/widgets/dialogs/qfiledialog.h
index c2ab0b3918..7959eebd7b 100644
--- a/src/widgets/dialogs/qfiledialog.h
+++ b/src/widgets/dialogs/qfiledialog.h
@@ -125,6 +125,7 @@ public:
     void setNameFilters(const QStringList &filters);
     QStringList nameFilters() const;
     void selectNameFilter(const QString &filter);
+    QString selectedMimeTypeFilter() const;
     QString selectedNameFilter() const;
 
 #ifndef QT_NO_MIMETYPE
diff --git a/src/widgets/dialogs/qfiledialog_p.h b/src/widgets/dialogs/qfiledialog_p.h
index afebad4457..b665b54a9b 100644
--- a/src/widgets/dialogs/qfiledialog_p.h
+++ b/src/widgets/dialogs/qfiledialog_p.h
@@ -258,6 +258,8 @@ public:
     void selectFile_sys(const QUrl &filename);
     QList<QUrl> selectedFiles_sys() const;
     void setFilter_sys();
+    void selectMimeTypeFilter_sys(const QString &filter);
+    QString selectedMimeTypeFilter_sys() const;
     void selectNameFilter_sys(const QString &filter);
     QString selectedNameFilter_sys() const;
     //////////////////////////////////////////////
@@ -400,6 +402,20 @@ inline void QFileDialogPrivate::setFilter_sys()
         helper->setFilter();
 }
 
+inline void QFileDialogPrivate::selectMimeTypeFilter_sys(const QString &filter)
+{
+    if (QPlatformFileDialogHelper *helper = platformFileDialogHelper())
+        helper->selectMimeTypeFilter(filter);
+}
+
+QString QFileDialogPrivate::selectedMimeTypeFilter_sys() const
+{
+    if (QPlatformFileDialogHelper *helper = platformFileDialogHelper())
+        return helper->selectedMimeTypeFilter();
+
+    return QString();
+}
+
 inline void QFileDialogPrivate::selectNameFilter_sys(const QString &filter)
 {
     if (QPlatformFileDialogHelper *helper = platformFileDialogHelper())
diff --git a/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp b/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
index c9aef497af..44cb5a5bf8 100644
--- a/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
+++ b/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
@@ -119,6 +119,8 @@ private slots:
     void selectFilter();
     void viewMode();
     void proxymodel();
+    void setMimeTypeFilters_data();
+    void setMimeTypeFilters();
     void setNameFilter_data();
     void setNameFilter();
     void setEmptyNameFilter();
@@ -1039,6 +1041,34 @@ void tst_QFiledialog::proxymodel()
     QCOMPARE(fd.proxyModel(), nullptr);
 }
 
+void tst_QFiledialog::setMimeTypeFilters_data()
+{
+    QTest::addColumn<QStringList>("mimeTypeFilters");
+    QTest::addColumn<QString>("targetMimeTypeFilter");
+    QTest::addColumn<QString>("expectedSelectedMimeTypeFilter");
+
+    const auto headerMime = QStringLiteral("text/x-chdr");
+    const auto jsonMime = QStringLiteral("application/json");
+    const auto zipMime = QStringLiteral("application/zip");
+
+    QTest::newRow("single mime filter (C header file)") << QStringList {headerMime} << headerMime << headerMime;
+    QTest::newRow("single mime filter (JSON file)") << QStringList {jsonMime} << jsonMime << jsonMime;
+    QTest::newRow("multiple mime filters") << QStringList {jsonMime, zipMime} << jsonMime << jsonMime;
+}
+
+void tst_QFiledialog::setMimeTypeFilters()
+{
+    QFETCH(QStringList, mimeTypeFilters);
+    QFETCH(QString, targetMimeTypeFilter);
+    QFETCH(QString, expectedSelectedMimeTypeFilter);
+
+    QFileDialog fd;
+    fd.setMimeTypeFilters(mimeTypeFilters);
+    fd.selectMimeTypeFilter(targetMimeTypeFilter);
+
+    QCOMPARE(fd.selectedMimeTypeFilter(), expectedSelectedMimeTypeFilter);
+}
+
 void tst_QFiledialog::setEmptyNameFilter()
 {
     QFileDialog fd;