STR 1183: swapping two items in an Fl_Browser_ widget would corrupt redrawing if either item was "top". This fix swaps the top_ variable correctly, and also swaps the selection flag as the user would expect.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@4879 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

3 files changed, 11 insertions, 2 deletions

diff --git a/FL/Fl_Browser_.H b/FL/Fl_Browser_.H
index 062759679..663eca55e 100644
--- a/FL/Fl_Browser_.H
+++ b/FL/Fl_Browser_.H
@@ -88,6 +88,7 @@ protected:
   void new_list(); // completely clobber all data, as though list replaced
   void deleting(void *a); // get rid of any pointers to a
   void replacing(void *a,void *b); // change a pointers to b
+  void swapping(void *a,void *b); // exchange pointers a and b
   void inserting(void *a,void *b); // insert b near a
   int displayed(void *) const ; // true if this line is visible
   void redraw_line(void *); // minimal update, no change in size
diff --git a/src/Fl_Browser.cxx b/src/Fl_Browser.cxx
index 96f2dfe05..03c43d82b 100644
--- a/src/Fl_Browser.cxx
+++ b/src/Fl_Browser.cxx
@@ -503,6 +503,7 @@ int Fl_Browser::value() const {
 void Fl_Browser::swap(FL_BLINE *a, FL_BLINE *b) {
 
   if ( a == b || !a || !b) return;          // nothing to do
+  swapping(a, b);
   FL_BLINE *aprev  = a->prev;
   FL_BLINE *anext  = a->next;
   FL_BLINE *bprev  = b->prev;
@@ -535,8 +536,6 @@ void Fl_Browser::swap(FL_BLINE *a, FL_BLINE *b) {
   }
   // Disable cache -- we played around with positions
   cacheline = 0;
-  // Redraw modified lines
-  redraw_lines();
 }
 
 void Fl_Browser::swap(int ai, int bi) {
diff --git a/src/Fl_Browser_.cxx b/src/Fl_Browser_.cxx
index 8f51318fe..8637e9cba 100644
--- a/src/Fl_Browser_.cxx
+++ b/src/Fl_Browser_.cxx
@@ -470,6 +470,15 @@ void Fl_Browser_::replacing(void* a, void* b) {
   if (a == max_width_item) {max_width_item = 0; max_width = 0;}
 }
 
+void Fl_Browser_::swapping(void* a, void* b) {
+  redraw_line(a);
+  redraw_line(b);
+  if (a == selection_) selection_ = b;
+  else if (b == selection_) selection_ = a;
+  if (a == top_) top_ = b;
+  else if (b == top_) top_ = a;
+}
+
 void Fl_Browser_::inserting(void* a, void* b) {
   if (displayed(a)) redraw_lines();
   if (a == top_) top_ = b;