added wxTextBuffer::Clear() (patch 706188)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@19773 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/textfile.tex

@@ -35,6 +35,7 @@ changed with \helpref{GoToLine}{wxtextfilegotoline}.
 \item Add/remove lines to the file: \helpref{AddLine}{wxtextfileaddline} and 
 \helpref{InsertLine}{wxtextfileinsertline} add new lines while 
 \helpref{RemoveLine}{wxtextfileremoveline} deletes the existing ones.
+\helpref{Clear}{wxtextfileclear} resets the file to empty.
 \item Save your changes: notice that the changes you make to the file will {\bf
 not} be saved automatically; calling \helpref{Close}{wxtextfileclose} or doing
 nothing discards them! To save the changes you must explicitly call 
@@ -279,6 +280,12 @@ it is used to convert the file to wide character representation.
 
 Delete line number {\it n} from the file.
 
+\membersection{wxTextFile::Clear}\label{wxtextfileclear}
+
+\constfunc{void}{Clear}{\void}
+
+Delete all lines from the file, set current line number to 0.
+
 \membersection{wxTextFile::Write}\label{wxtextfilewrite}
 
 \constfunc{bool}{Write}{\param{wxTextFileType }{typeNew = wxTextFileType\_None}, \param{wxMBConv\&}{ conv = wxConvUTF8}}

include/wx/textbuf.h

@@ -145,6 +145,9 @@ public:
     // delete one line
     void RemoveLine(size_t n) { m_aLines.RemoveAt(n); m_aTypes.RemoveAt(n); }
 
+    // remove all lines
+    void Clear() { m_aLines.Clear(); m_nCurLine = 0; }
+    
     // change the buffer (default argument means "don't change type")
     // possibly in another format
     bool Write(wxTextFileType typeNew = wxTextFileType_None,