First few additions to create scroll wheel support for multiline Fl_Input.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6888 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/Fl_Input_.H

@@ -120,7 +120,7 @@ class FL_EXPORT Fl_Input_ : public Fl_Widget {
       \p mark_, no text is selected */
   int mark_;
 
-  /** \internal Offset to text origin within wdget bounds */
+  /** \internal Offset to text origin within widget bounds */
   int xscroll_, yscroll_;
 
   /** \internal Minimal update pointer. Display requirs redraw from here to the end
@@ -206,6 +206,7 @@ protected:
 
   /** \internal Vertical offset of text to top edge of widget. */
   int yscroll() const {return yscroll_;}
+  void yscroll(int y) { yscroll_ = y; damage(FL_DAMAGE_EXPOSE);}
 
   /* Return the number of lines displayed on a single page.  */
   int linesPerPage();

src/Fl_Input.cxx

@@ -621,6 +621,18 @@ int Fl_Input::handle(int event) {
     take_focus();
     return 1;
 
+/* TODO: this will scroll the area, but stop if the cursor would become invisible.
+         That clipping happens in drawtext(). Do we change the clipping or should 
+         we move the cursor (ouch)?
+  case FL_MOUSEWHEEL:
+    if (Fl::e_dy > 0) {
+      yscroll( yscroll() - Fl::e_dy*15 );
+    } else if (Fl::e_dy < 0) {
+      yscroll( yscroll() - Fl::e_dy*15 );
+    }
+    return 1;
+*/
+
   }
   Fl_Boxtype b = box();
   return Fl_Input_::handletext(event,