Add Edit::ToggleLineNumbers() to the sample

Make it a bit simpler to show line numbers when showing the minimap.

samples/stc/edit.cpp

@@ -320,6 +320,10 @@ void Edit::OnIndentGuide (wxCommandEvent &WXUNUSED(event)) {
 }
 
 void Edit::OnLineNumber (wxCommandEvent &WXUNUSED(event)) {
+    ToggleLineNumbers();
+}
+
+void Edit::ToggleLineNumbers() {
     SetMarginWidth (m_LineNrID,
                     GetMarginWidth (m_LineNrID) == 0? m_LineNrMargin: 0);
 }

samples/stc/edit.h

@@ -131,6 +131,9 @@ public:
     wxString GetFilename () {return m_filename;}
     void SetFilename (const wxString &filename) {m_filename = filename;}
 
+    // Toggle showing line numbers in the margin.
+    void ToggleLineNumbers();
+
 private:
     // file
     wxString m_filename;

samples/stc/stctest.cpp

@@ -1616,8 +1616,8 @@ void App::ShowDocumentMap(wxWindow* parent)
     auto* const edit = new Edit(splitter);
     edit->LoadFile("stctest.cpp");
 
-    // Show line numbers and hide the other margins not used here.
-    edit->SetMarginWidth(0, edit->GetTextExtent("99999").x);
+    // Show line numbers in the margin, which are hidden by default.
+    edit->ToggleLineNumbers();
 
     edit->SetWrapMode(wxSTC_WRAP_WORD);
     edit->SetWrapVisualFlags(wxSTC_WRAPVISUALFLAG_END);