qt: add Open URI dialog

src/qt/guiutil.cpp

@@ -278,6 +278,41 @@ QString getSaveFileName(QWidget *parent, const QString &caption, const QString &
     return result;
 }
 
+QString getOpenFileName(QWidget *parent, const QString &caption, const QString &dir,
+    const QString &filter,
+    QString *selectedSuffixOut)
+{
+    QString selectedFilter;
+    QString myDir;
+    if(dir.isEmpty()) // Default to user documents location
+    {
+#if QT_VERSION < 0x050000
+        myDir = QDesktopServices::storageLocation(QDesktopServices::DocumentsLocation);
+#else
+        myDir = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
+#endif
+    }
+    else
+    {
+        myDir = dir;
+    }
+    /* Directly convert path to native OS path separators */
+    QString result = QDir::toNativeSeparators(QFileDialog::getOpenFileName(parent, caption, myDir, filter, &selectedFilter));
+
+    if(selectedSuffixOut)
+    {
+        /* Extract first suffix from filter pattern "Description (*.foo)" or "Description (*.foo *.bar ...) */
+        QRegExp filter_re(".* \\(\\*\\.(.*)[ \\)]");
+        QString selectedSuffix;
+        if(filter_re.exactMatch(selectedFilter))
+        {
+            selectedSuffix = filter_re.cap(1);
+        }
+        *selectedSuffixOut = selectedSuffix;
+    }
+    return result;
+}
+
 Qt::ConnectionType blockingGUIThreadConnection()
 {
     if(QThread::currentThread() != qApp->thread())