Implement auto-completion support for wxTextEntry in wxOSX/Cocoa.

Both completing a set of fixed strings and dynamic completion using a custom
completer are supported, although completing the file names remains MSW-only
for now.

Note that, unlike under MSW, auto-completion under Mac is not automatic and
has to be triggered manually by calling complete: method. This is done by
pressing F5 key by default. In the future we should call it automatically on a
timer event to make it more obviously discoverable.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67526 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/textentry.h

@@ -32,12 +32,8 @@ class WXDLLIMPEXP_CORE wxTextEntry: public wxTextEntryBase
 {
 
 public:
-    wxTextEntry()
-        : m_editable(true),
-          m_maxLength(0)
-    { }
-
-    virtual ~wxTextEntry() {};
+    wxTextEntry();
+    virtual ~wxTextEntry();
 
     virtual bool IsEditable() const;
 
@@ -88,10 +84,18 @@ public:
     // --------------
 
     virtual wxTextWidgetImpl * GetTextPeer() const;
+    wxTextCompleter *OSXGetCompleter() const { return m_completer; }
+
 protected:
 
     virtual wxString DoGetValue() const;
 
+    virtual bool DoAutoCompleteStrings(const wxArrayString& choices);
+    virtual bool DoAutoCompleteCustom(wxTextCompleter *completer);
+
+    // The object providing auto-completions or NULL if none.
+    wxTextCompleter *m_completer;
+
     bool  m_editable;
 
   // need to make this public because of the current implementation via callbacks