added (and documented) trivial but useful IsSingleLine() and IsMultiLine() text control methods

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16242 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/textctrl.h

@@ -174,6 +174,10 @@ public:
     virtual bool IsModified() const = 0;
     virtual bool IsEditable() const = 0;
 
+    // more readable flag testing methods
+    bool IsSingleLine() const { return !(GetWindowStyle() & wxTE_MULTILINE); }
+    bool IsMultiLine() const { return !IsSingleLine(); }
+
     // If the return values from and to are the same, there is no selection.
     virtual void GetSelection(long* from, long* to) const = 0;