* licenses updated

[helm.git] / helm / DEVEL / mathml_editor / src / TPushLexer.cc

diff --git a/helm/DEVEL/mathml_editor/src/TPushLexer.cc b/helm/DEVEL/mathml_editor/src/TPushLexer.cc
index 1d25abbe98edff1fa8299e0eb82fc7585b6397d7..2411a0e219dc65d0dbb8667530f10c7f3356e6f0 100644 (file)
--- a/helm/DEVEL/mathml_editor/src/TPushLexer.cc
+++ b/helm/DEVEL/mathml_editor/src/TPushLexer.cc
@@ -1,3 +1,27 @@
+/* This file is part of EdiTeX, an editor of mathematical
+ * expressions based on TeX syntax.
+ * 
+ * Copyright (C) 2002-2003 Luca Padovani <lpadovan@cs.unibo.it>,
+ *                    2003 Paolo Marinelli <pmarinel@cs.unibo.it>.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * For more information, please visit the project's home page
+ * http://helm.cs.unibo.it/editex/
+ * or send an email to <lpadovan@cs.unibo.it>
+ */
 
 #include "TToken.hh"
 #include "TPushLexer.hh"
@@ -55,7 +79,6 @@ TPushLexer::push(char ch)
     case ACCEPT:
       if (ch == '\\') state = ESCAPE;
       else if (ch == '#') state = PARAMETER;
-      else if (ch == '\b') parser.push(TToken(TToken::GDELETE));
       else if (ch == -1) ;
       else transaction(ch, ACCEPT);
       break;
@@ -65,10 +88,6 @@ TPushLexer::push(char ch)
          buffer.push_back(ch);
          state = MACRO;
        }
-      else if (ch == '\b')
-        {
-         state = ACCEPT;
-       }
       else if (ch == -1) error();
       else
        {
@@ -89,11 +108,6 @@ TPushLexer::push(char ch)
          buffer.erase();
          state = PARAMETER;
        }
-      else if (ch == '\b')
-       {
-         buffer.erase(buffer.length() - 1, 1);
-         if (buffer.length() == 0) state = ESCAPE;
-       }
       else if (isalpha(ch))
        buffer.push_back(ch);
       else if (ch == -1)
@@ -114,7 +128,6 @@ TPushLexer::push(char ch)
       if (ch == '\\') state = ESCAPE;
       else if (ch == '#') state = PARAMETER;
       else if (isspace(ch)) ;
-      else if (ch == '\b') parser.push(TToken(TToken::GDELETE));
       else if (ch == -1) state = ACCEPT;
       else transaction(ch, ACCEPT);
       break;
@@ -140,6 +153,45 @@ TPushLexer::push(char ch)
     }
 }
 
+void
+TPushLexer::drop(bool alt)
+{
+  std::string restore = "";
+
+  switch (state)
+    {
+    case ACCEPT:
+    case IGNORE_SPACE:
+      restore = parser.drop(alt);
+      if (restore.length() > 0 && restore[0] == '\\')
+       {
+         buffer = std::string(restore, 1, restore.length() - 1);
+         state = (buffer.length() > 0) ? MACRO : ESCAPE;
+       }
+      break;
+    case ESCAPE:
+      state = ACCEPT;
+      break;
+    case MACRO:
+      if (alt) buffer.erase();
+      else buffer.erase(buffer.length() - 1, 1);
+      if (buffer.length() == 0) state = ESCAPE;
+      break;
+    case PARAMETER:
+    default:
+      assert(0);
+      break;
+    }
+
+  switch (state)
+    {
+    case ESCAPE: parser.setCursorHint("\\"); break;
+    case MACRO: parser.setCursorHint("\\" + buffer); break;
+    case PARAMETER: parser.setCursorHint("#"); break;
+    default: parser.setCursorHint(""); break;
+    }
+}
+
 bool
 TPushLexer::error() const
 {