Merge pull request #2 from matterhorn103/read-utf16

Adopt simpler approach to file reading on Qt6

avogadro/backgroundfileformat.cpp

@@ -42,57 +42,70 @@ void BackgroundFileFormat::read()
     m_error = tr("No file name set in BackgroundFileFormat!");
 
   if (m_error.isEmpty()) {
-    // sometimes we hit UTF-16 files, so we need to convert them to UTF-8
-    // first check whether the file is UTF-16
-    QFile file(m_fileName);
-    QTextStream in(&file);
-    QString text;
-    bool isUTF16 = false;
-    if (file.open(QIODevice::ReadOnly)) {
-      QByteArray data = file.read(2);
-      // look for a byte-order mark
-      if ((data.size() == 2 && data[0] == '\xff' && data[1] == '\xfe') ||
-          (data.size() == 2 && data[0] == '\xfe' && data[1] == '\xff')) {
-        // UTF-16, read the file and let QString handle decoding
-        isUTF16 = true;
-        file.close();
-        file.open(QIODevice::ReadOnly | QIODevice::Text);
-        in.setCodec("UTF-16");
+    #if QT_VERSION >= 0x060000
+      QFile file(m_fileName);
+      if (file.open(QFile::ReadOnly | QIODevice::Text)) {
+        QTextStream in(&file);
+        QString text;
         text = in.readAll();
         file.close();
-      }
-    }
-
-    if (!isUTF16)
-      m_success =
-        m_format->readFile(m_fileName.toLocal8Bit().data(), *m_molecule);
-    else {
-      // write it to a temporary file and we'll read it back in
-      // some formats (like the generic output) need a file
-      // not just a string bugger
-
-      // first, we need the *name* of the file, not the full path
-      // because we're going to save a copy in a temp directory
-      QTemporaryDir tempDir;
-      QString tempFileName = tempDir.filePath(QFileInfo(m_fileName).fileName());
-      QFile tempFile(tempFileName);
-      if (tempFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
-        QTextStream out(&tempFile);
-        // set it to UTF-8
-        out.setCodec("UTF-8");
-        out << text;
-        out.flush();
-        tempFile.close();
-        m_success =
-          m_format->readFile(tempFileName.toLocal8Bit().data(), *m_molecule);
-        tempFile.remove();
-      } else // try just reading the string
         m_success =
           m_format->readString(text.toLocal8Bit().data(), *m_molecule);
-    }
+      }
 
-    if (!m_success)
-      m_error = QString::fromStdString(m_format->error());
+    #else
+      // sometimes we hit UTF-16 files, so we need to convert them to UTF-8
+      // first check whether the file is UTF-16
+      QFile file(m_fileName);
+      QTextStream in(&file);
+      QString text;
+      bool isUTF16 = false;
+      if (file.open(QIODevice::ReadOnly)) {
+        QByteArray data = file.read(2);
+        // look for a byte-order mark
+        if ((data.size() == 2 && data[0] == '\xff' && data[1] == '\xfe') ||
+            (data.size() == 2 && data[0] == '\xfe' && data[1] == '\xff')) {
+          // UTF-16, read the file and let QString handle decoding
+          isUTF16 = true;
+          file.close();
+          file.open(QIODevice::ReadOnly | QIODevice::Text);
+          in.setCodec("UTF-16");
+          text = in.readAll();
+          file.close();
+        }
+      }
+
+      if (!isUTF16)
+        m_success =
+          m_format->readFile(m_fileName.toLocal8Bit().data(), *m_molecule);
+      else {
+        // write it to a temporary file and we'll read it back in
+        // some formats (like the generic output) need a file
+        // not just a string bugger
+
+        // first, we need the *name* of the file, not the full path
+        // because we're going to save a copy in a temp directory
+        QTemporaryDir tempDir;
+        QString tempFileName = tempDir.filePath(QFileInfo(m_fileName).fileName());
+        QFile tempFile(tempFileName);
+        if (tempFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
+          QTextStream out(&tempFile);
+          // set it to UTF-8
+          out.setCodec("UTF-8");
+          out << text;
+          out.flush();
+          tempFile.close();
+          m_success =
+            m_format->readFile(tempFileName.toLocal8Bit().data(), *m_molecule);
+          tempFile.remove();
+        } else // try just reading the string
+          m_success =
+            m_format->readString(text.toLocal8Bit().data(), *m_molecule);
+      }
+
+      if (!m_success)
+        m_error = QString::fromStdString(m_format->error());
+    #endif
   }
 
   emit finished();