Sort out decoded text font and font changes

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5159 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

displaytext.cpp

@@ -2,6 +2,9 @@
 #include <QDebug>
 #include <QMouseEvent>
 #include <QDateTime>
+#include <QTextCharFormat>
+#include <QFont>
+#include <QTextCursor>
 
 #include "qt_helpers.hpp"
 
@@ -14,6 +17,20 @@ DisplayText::DisplayText(QWidget *parent) :
     viewport ()->setCursor (Qt::ArrowCursor);
 }
 
+void DisplayText::setContentFont(QFont const& font)
+{
+  document ()->setDefaultFont (font);
+  QTextCharFormat format;
+  format.setFont (font);
+  selectAll ();
+  auto cursor = textCursor ();
+  cursor.mergeCharFormat (format);
+  cursor.clearSelection ();
+  cursor.movePosition (QTextCursor::End);
+  setTextCursor (cursor);
+  ensureCursorVisible ();
+}
+
 void DisplayText::mouseDoubleClickEvent(QMouseEvent *e)
 {
   bool ctrl = (e->modifiers() & Qt::ControlModifier);
@@ -36,6 +53,7 @@ void DisplayText::_insertText(const QString text, const QString bg)
     moveCursor (QTextCursor::End);
     append (s);
     moveCursor (QTextCursor::End);
+    ensureCursorVisible ();
 }