Read UTF-16 files through Qt decoding to a temporary file

avogadro/backgroundfileformat.cpp

@@ -7,11 +7,18 @@
 
 #include <avogadro/io/fileformat.h>
 
+#include <QtCore/QFile>
+#include <QtCore/QTemporaryDir>
+#include <QtCore/QTextStream>
+
 namespace Avogadro {
 
 BackgroundFileFormat::BackgroundFileFormat(Io::FileFormat* format,
                                            QObject* aparent)
-  : QObject(aparent), m_format(format), m_molecule(nullptr), m_success(false)
+  : QObject(aparent)
+  , m_format(format)
+  , m_molecule(nullptr)
+  , m_success(false)
 {
 }
 
@@ -35,11 +42,70 @@
     m_error = tr("No file name set in BackgroundFileFormat!");
 
   if (m_error.isEmpty()) {
-    m_success = m_format->readFile(m_fileName.toLocal8Bit().data(),
-                                   *m_molecule);
-
-    if (!m_success)
-      m_error = QString::fromStdString(m_format->error());
+    #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();
+        m_success =
+          m_format->readString(text.toLocal8Bit().data(), *m_molecule);
+      }
+
+    #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();
@@ -60,8 +126,8 @@
     m_error = tr("No file name set in BackgroundFileFormat!");
 
   if (m_error.isEmpty()) {
-    m_success = m_format->writeFile(m_fileName.toLocal8Bit().data(),
-                                    *m_molecule);
+    m_success =
+      m_format->writeFile(m_fileName.toLocal8Bit().data(), *m_molecule);
 
     if (!m_success)
       m_error = QString::fromStdString(m_format->error());