FLUID: Adds undo for all grid operations.

9 files changed, 160 insertions, 62 deletions

diff --git a/fluid/Fl_Grid_Type.cxx b/fluid/Fl_Grid_Type.cxx
index 493565b6a..1565f19da 100644
--- a/fluid/Fl_Grid_Type.cxx
+++ b/fluid/Fl_Grid_Type.cxx
@@ -93,30 +93,25 @@ void Fl_Grid_Proxy::draw_overlay() {
 /**
  Move a cell into the grid or within the grid.
 
- \param[in] in_child must already be a child of grid
- \param[in] to_row, to_col move the child into this cell
- \param[in] how 0: replace occupant, 1: don't replace, 2 = make transient
-    if occupied
+ If the target cell is already taken, \p how will determine what to do:
 
- \todo If the target cell is already taken, this function will remove the old
- child from the cell and leave it in limbo (a child of grid, but with no
- assigned cell). As this function is used to move children around with arrow
- keys, it must be possible to move a widget past a cell that is already taken
- without disturbing the existing system.
+ If \p how is 0, the existing cell at \p to_row, \p to_col will be deleted,
+ unlinking the occupant from the grid. \p in_child will the be inserted at the
+ given location.
 
- One solution would be to make the widget "hover", meaning, it will be registered
- in Fl_Grid_Proxy as using the same cell as another widget. I am not sure at all
- how to implement that yet. We could return the original cell, but that may have
- different minsize, etc. . It would be better to have a temporary cell to store
- all the information.
+ If \p how is 1, the old cell will remain intact, however \p in_child will be
+ unlinked from the grid.
 
- We must make sure that a hovering cell (or multiple cells) are a very temporary
- solution, because all this information will be skewed if Grid::layout is
- called, and all information is lost when we save the file for compilation.
+ If \p how is 2, the old cell will remain intact, and \p in_child will be
+ removed from the grid, but it will be stored in the transient list and
+ resized to the target cell position and size. If \p in_child is later
+ moved to an unoccupied cell, it will be removed from the transient list and
+ relinked to the grid. Rowspan and colspan are ignored here.
 
- We must show a conflict grid under or around the hovering cell!
-
- Also mind the rowspan and colspan!
+ \param[in] in_child must already be a child of grid
+ \param[in] to_row, to_col move the child into this cell
+ \param[in] how 0: replace occupant, 1: don't replace, 2: make transient
+    if occupied
  */
 void Fl_Grid_Proxy::move_cell(Fl_Widget *in_child, int to_row, int to_col, int how) {
   // the child must already be a true child of grid
@@ -127,6 +122,7 @@ void Fl_Grid_Proxy::move_cell(Fl_Widget *in_child, int to_row, int to_col, int h
   int w = 20, h = 20;
   const Fl_Grid::Cell *old_cell = cell(in_child);
   if (old_cell) {
+    if (old_cell->row() == to_row && old_cell->col() == to_col) return;
     rowspan = old_cell->rowspan();
     colspan = old_cell->colspan();
     align = old_cell->align();
@@ -162,8 +158,10 @@ void Fl_Grid_Proxy::move_cell(Fl_Widget *in_child, int to_row, int to_col, int h
 
 /**
  Generate or replace a transient widget entry.
+
  If the widget is in the cell list, it will be removed there.
  If the widget is already transient, the cell will be replaced.
+
  \param[in] wi a child of this Fl_Grid_Proxy, that may be linked to a cell or transient cell
  \param[in] row, col, row_span, col_span, align cell parameters
  */
@@ -239,6 +237,15 @@ void Fl_Grid_Proxy::transient_remove_(Fl_Widget *w) {
 Fl_Grid_Proxy::Cell *Fl_Grid_Proxy::any_cell(Fl_Widget *widget) const {
   Cell *c = cell(widget);
   if (c) return c;
+  return transient_cell(widget);
+}
+
+/**
+ Find a cell in the transient cell list.
+ \param[in] widget must be a child of the grid.
+ \return the transient cell, or NULL if it was not found.
+ */
+Fl_Grid_Proxy::Cell *Fl_Grid_Proxy::transient_cell(Fl_Widget *widget) const {
   for (int i=0; i<num_transient_; i++) {
     if (transient_[i].widget == widget)
       return transient_[i].cell;
@@ -634,6 +641,11 @@ Fl_Grid *Fl_Grid_Type::selected() {
   return NULL;
 }
 
+/**
+ Insert a child widget into the cell at the x, y position inside the window.
+ /param[in] child
+ /param[in] x, y pixels from the top left of the window
+ */
 void Fl_Grid_Type::insert_child_at(Fl_Widget *child, int x, int y) {
   Fl_Grid_Proxy *grid = (Fl_Grid_Proxy*)o;
   int row = -1, col = -1, ml, mt, grg, gcg;
@@ -656,10 +668,11 @@ void Fl_Grid_Type::insert_child_at(Fl_Widget *child, int x, int y) {
     x0 += gap;
   }
 
-  grid->move_cell(child, row, col);
+  grid->move_cell(child, row, col, 2);
 }
 
-/** Insert a child widget into the first new cell we can find .
+/** 
+ Insert a child widget into the first new cell we can find .
 
  There are many other possible strategies. How about inserting to the right
  of the last added child. Also, what happens if the grid is full? Should
@@ -667,17 +680,28 @@ void Fl_Grid_Type::insert_child_at(Fl_Widget *child, int x, int y) {
 
  /param[in] child
  */
-void Fl_Grid_Type::insert_child(Fl_Widget *child) {
+void Fl_Grid_Type::insert_child_at_next_free_cell(Fl_Widget *child) {
   Fl_Grid_Proxy *grid = (Fl_Grid_Proxy*)o;
   if (grid->cell(child)) return;
-  for (int r=0; r<grid->rows(); r++) {
-    for (int c=0; c<grid->cols(); c++) {
+// The code below would insert the new widget after the last selected one, but
+// unfortunately the current_widget is already invalid.
+//  if (current_widget && (current_widget->parent == this)) {
+//    Fl_Grid::Cell *current_cell = grid->any_cell(current_widget->o);
+//    if (current_cell) {
+//      r = current_cell->row();
+//      c = current_cell->col();
+//    }
+//  }
+  for (int r = 0; r < grid->rows(); r++) {
+    for (int c = 0; c < grid->cols(); c++) {
       if (!grid->cell(r, c)) {
         grid->move_cell(child, r, c);
         return;
       }
     }
   }
+  grid->layout(grid->rows() + 1, grid->cols());
+  grid->move_cell(child, grid->rows() - 1, 0);
 }
 
 /** Move cells around using the keyboard.
@@ -712,29 +736,17 @@ void Fl_Grid_Type::layout_widget() {
 
 // ---- Widget Panel Callbacks  ---------------------------------------- MARK: -
 
-// FIXME: when changing the cell location, and another cell would be overridden,
-//        don't actually move the cell (hard to implement!) and activate
-//        a red button "replace". If clicked, user gets the option to delete
-//        the old widget, or just remove the cell, or cancel.
-// TODO: move cells by using the arrow keys?
-// TODO: move cells via drag'n'drop -> int Fl_Window_Type::handle(int event)
-// TODO: handling of children that are themselves Groups. As it is, the children
-//        are not moved correctly if a parent group repositions or resizes groups.
-//        The same is true for Fl_Flex.
 // TODO: better grid overlay?
 // TODO: grid_child_cb should move all selected cells, not just the current_selected.
 // TODO: buttons to add and delete rows and columns in the widget dialog
 // TODO: ways to resize rows and columns, add and delete them in the project window, pulldown menu?
 // TODO: alignment can be FL_GRID_LEFT|FL_GRID_VERTICAL?
-// TODO: we must set undo checkpoints in all callbacks!
 
 extern Fluid_Coord_Input *widget_grid_row_input, *widget_grid_col_input,
 *widget_grid_rowspan_input, *widget_grid_colspan_input;
 extern Fl_Group *widget_tab_grid_child;
 
-
 void grid_child_cb(Fluid_Coord_Input* i, void* v, int what) {
-  static Fl_Widget *prev_widget = NULL;
   if (   !current_widget
       || !current_widget->parent
       || !current_widget->parent->is_a(ID_Grid))
@@ -743,8 +755,7 @@ void grid_child_cb(Fluid_Coord_Input* i, void* v, int what) {
   }
   Fl_Widget *child = ((Fl_Widget_Type*)current_widget)->o;
   Fl_Grid_Proxy *g = ((Fl_Grid_Proxy*)((Fl_Widget_Type*)current_widget->parent)->o);
-  Fl_Grid::Cell *cell = g->cell(child);
-  bool freeze_row_col = (!cell && prev_widget==child && ((what&0x00ff)==8 || (what&0x00ff)==9));
+  Fl_Grid::Cell *cell = g->any_cell(child);
   if (v == LOAD) {
     int v = -1;
     if (cell) {
@@ -757,12 +768,10 @@ void grid_child_cb(Fluid_Coord_Input* i, void* v, int what) {
         case 13: cell->minimum_size(NULL, &v); break;
       }
     }
-    if (!cell && prev_widget!=child && what==11)
-      prev_widget = child;
-    if (!freeze_row_col)
-      i->value(v);
+    i->value(v);
   } else {
-    int v2 = -1, old_v = -1, v = i->value();
+    undo_checkpoint();
+    int v2 = -2, old_v = -2, v = i->value();
     if (i==widget_grid_row_input) v2 = widget_grid_col_input->value();
     if (i==widget_grid_col_input) v2 = widget_grid_row_input->value();
     Fl_Grid::Cell *new_cell = NULL;
@@ -782,19 +791,21 @@ void grid_child_cb(Fluid_Coord_Input* i, void* v, int what) {
     }
     if (old_v != v) {
       switch (what & 0x00ff) {
-        case 8: if (v>=0 && v2>=0) g->move_cell(current_widget->o, v, v2);
-          if (freeze_row_col) i->value(v);
+        case 8:
+          if (v2 == -1 && v >= 0) v2 = 0;
+          g->move_cell(current_widget->o, v, v2, 2); i->value(v);
           break;
-        case 9: if (v>=0 && v2>=0) g->move_cell(current_widget->o, v2, v);
-          if (freeze_row_col) i->value(v);
+        case 9: 
+          if (v2 == -1 && v >= 0) v2 = 0;
+          g->move_cell(current_widget->o, v2, v, 2); i->value(v);
           break;
-        case 10: if (cell && cell->row()+v<=g->rows()) cell->rowspan(v); 
+        case 10: if (cell && cell->row()+v<=g->rows() && v>0) cell->rowspan(v);
           break;
-        case 11: if (cell && cell->col()+v<=g->cols()) cell->colspan(v);
+        case 11: if (cell && cell->col()+v<=g->cols() && v>0) cell->colspan(v);
           break;
-        case 12: if (cell) cell->minimum_size(v, v2); 
+        case 12: if (cell && v>=0) cell->minimum_size(v, v2);
           break;
-        case 13: if (cell) cell->minimum_size(v2, v); 
+        case 13: if (cell && v>=0) cell->minimum_size(v2, v);
           break;
       }
       if (!cell && new_cell)
@@ -893,6 +904,7 @@ void grid_align_horizontal_cb(Fl_Choice* i, void* v) {
     const Fl_Menu_Item *mi = i->find_item_with_argument(a);
     if (mi) i->value(mi);
   } else {
+    undo_checkpoint();
     int v = FL_GRID_FILL & mask, old_v = FL_GRID_FILL & mask;
     const Fl_Menu_Item *mi = i->mvalue();
     if (mi) v = (int)mi->argument();
@@ -927,6 +939,7 @@ void grid_align_vertical_cb(Fl_Choice* i, void* v) {
     const Fl_Menu_Item *mi = i->find_item_with_argument(a);
     if (mi) i->value(mi);
   } else {
+    undo_checkpoint();
     int v = FL_GRID_FILL & mask, old_v = FL_GRID_FILL & mask;
     const Fl_Menu_Item *mi = i->mvalue();
     if (mi) v = (int)mi->argument();
diff --git a/fluid/Fl_Grid_Type.h b/fluid/Fl_Grid_Type.h
index 9780ace76..4c922f97d 100644
--- a/fluid/Fl_Grid_Type.h
+++ b/fluid/Fl_Grid_Type.h
@@ -40,6 +40,7 @@ public:
   void draw_overlay();
   void move_cell(Fl_Widget *child, int to_row, int to_col, int how = 0);
   Cell* any_cell(Fl_Widget *widget) const;
+  Cell* transient_cell(Fl_Widget *widget) const;
   Cell* transient_widget(Fl_Widget *wi, int row, int col, int row_span, int col_span, Fl_Grid_Align align = FL_GRID_FILL);
   Cell* widget(Fl_Widget *wi, int row, int col, Fl_Grid_Align align = FL_GRID_FILL);
   Cell* widget(Fl_Widget *wi, int row, int col, int rowspan, int colspan, Fl_Grid_Align align = FL_GRID_FILL);
@@ -69,7 +70,7 @@ public:
   void layout_widget() FL_OVERRIDE;
   void child_resized(Fl_Widget_Type *child);
   void insert_child_at(Fl_Widget *child, int x, int y);
-  void insert_child(Fl_Widget *child);
+  void insert_child_at_next_free_cell(Fl_Widget *child);
   void keyboard_move_child(Fl_Widget_Type*, int key);
 
   static class Fl_Grid *selected();
diff --git a/fluid/Fl_Window_Type.cxx b/fluid/Fl_Window_Type.cxx
index 793744ee7..8a5d4962e 100644
--- a/fluid/Fl_Window_Type.cxx
+++ b/fluid/Fl_Window_Type.cxx
@@ -47,6 +47,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 
+extern Fl_Window *the_panel;
 extern void draw_width(int x, int y, int r, Fl_Align a);
 extern void draw_height(int x, int y, int b, Fl_Align a);
 
@@ -857,6 +858,7 @@ extern Fl_Menu_Item New_Menu[];
  */
 void Fl_Window_Type::moveallchildren(int key)
 {
+  bool update_widget_panel = false;
   undo_checkpoint();
   Fl_Type *i;
   for (i=next; i && i->level>level;) {
@@ -915,6 +917,7 @@ void Fl_Window_Type::moveallchildren(int key)
         allow_layout++;
         g->layout();
         allow_layout--;
+        update_widget_panel = true;
       } else if (myo->parent && myo->parent->is_a(ID_Group)) {
         Fl_Group_Type* gt = (Fl_Group_Type*)myo->parent;
         ((Fl_Group*)gt->o)->init_sizes();
@@ -942,6 +945,9 @@ void Fl_Window_Type::moveallchildren(int key)
   dx = dy = 0;
 
   update_xywh();
+  if (update_widget_panel && the_panel && the_panel->visible()) {
+    propagate_load(the_panel, LOAD);
+  }
 }
 
 int Fl_Window_Type::popupx = 0x7FFFFFFF; // mark as invalid (MAXINT)
diff --git a/fluid/factory.cxx b/fluid/factory.cxx
index cd25e96df..bb832af45 100644
--- a/fluid/factory.cxx
+++ b/fluid/factory.cxx
@@ -1232,7 +1232,7 @@ Fl_Type *add_new_widget_from_user(Fl_Type *inPrototype, Strategy strategy) {
         if (Fl_Window_Type::popupx != 0x7FFFFFFF) {
           ((Fl_Grid_Type*)t->parent)->insert_child_at(((Fl_Widget_Type*)t)->o, Fl_Window_Type::popupx, Fl_Window_Type::popupy);
         } else {
-          ((Fl_Grid_Type*)t->parent)->insert_child(((Fl_Widget_Type*)t)->o);
+          ((Fl_Grid_Type*)t->parent)->insert_child_at_next_free_cell(((Fl_Widget_Type*)t)->o);
         }
       }
     }
diff --git a/fluid/file.cxx b/fluid/file.cxx
index 3f0fafd47..317fc0469 100644
--- a/fluid/file.cxx
+++ b/fluid/file.cxx
@@ -399,7 +399,7 @@ Fl_Type *Fd_Project_Reader::read_children(Fl_Type *p, int merge, Strategy strate
         if (Fl_Window_Type::popupx != 0x7FFFFFFF) {
           ((Fl_Grid_Type*)t->parent)->insert_child_at(((Fl_Widget_Type*)t)->o, Fl_Window_Type::popupx, Fl_Window_Type::popupy);
         } else {
-          ((Fl_Grid_Type*)t->parent)->insert_child(((Fl_Widget_Type*)t)->o);
+          ((Fl_Grid_Type*)t->parent)->insert_child_at_next_free_cell(((Fl_Widget_Type*)t)->o);
         }
       }
 
diff --git a/fluid/widget_browser.cxx b/fluid/widget_browser.cxx
index 56716cf0a..993b564fb 100644
--- a/fluid/widget_browser.cxx
+++ b/fluid/widget_browser.cxx
@@ -423,7 +423,7 @@ int Widget_Browser::item_width(void *v) const {
 }
 
 /**
- Callback to tell the FLuid UI when the list of selected items changed.
+ Callback to tell the Fluid UI when the list of selected items changed.
  */
 void Widget_Browser::callback() {
   selection_changed((Fl_Type*)selection());
diff --git a/fluid/widget_panel.cxx b/fluid/widget_panel.cxx
index efd19f5af..da8021a28 100644
--- a/fluid/widget_panel.cxx
+++ b/fluid/widget_panel.cxx
@@ -123,6 +123,26 @@ Fluid_Coord_Input *widget_grid_row_input=(Fluid_Coord_Input *)0;
 
 Fluid_Coord_Input *widget_grid_col_input=(Fluid_Coord_Input *)0;
 
+Fl_Box *widget_grid_transient=(Fl_Box *)0;
+
+static void cb_widget_grid_transient(Fl_Box* o, void* v) {
+  if (v==LOAD) {
+    Fl_Widget *child = ((Fl_Widget_Type*)current_widget)->o;
+    Fl_Grid_Proxy *g = ((Fl_Grid_Proxy*)((Fl_Widget_Type*)current_widget->parent)->o);
+    Fl_Grid::Cell *cell = g->cell(child);
+    Fl_Grid::Cell *tcell = g->transient_cell(child);
+    widget_grid_transient->hide();
+    widget_grid_unlinked->hide();
+    if (g->transient_cell(child)) {
+      widget_grid_transient->show();
+    } else if (!g->cell(child)) {
+      widget_grid_unlinked->show();
+    }
+  }
+}
+
+Fl_Box *widget_grid_unlinked=(Fl_Box *)0;
+
 Fl_Menu_Item menu_Horizontal[] = {
  {"GRID_LEFT", 0,  0, (void*)(FL_GRID_LEFT), 0, (uchar)FL_NORMAL_LABEL, 0, 11, 0},
  {"GRID_CENTER", 0,  0, (void*)(FL_GRID_CENTER), 0, (uchar)FL_NORMAL_LABEL, 0, 11, 0},
@@ -240,6 +260,7 @@ static void cb_Left(Fl_Value_Input* o, void* v) {
     int m = (int)o->value(), old_m;
     grid->margin(&old_m, NULL, NULL, NULL); 
     if (m != old_m) {
+      undo_checkpoint();
       grid->margin(m, -1, -1, -1); 
       grid->need_layout(true);
       set_modflag(1);
@@ -258,6 +279,7 @@ static void cb_Top(Fl_Value_Input* o, void* v) {
     int m = (int)o->value(), old_m;
     grid->margin(NULL, &old_m, NULL, NULL); 
     if (m != old_m) {
+      undo_checkpoint();
       grid->margin(-1, m, -1, -1); 
       grid->need_layout(true);
       set_modflag(1);
@@ -276,6 +298,7 @@ static void cb_Right(Fl_Value_Input* o, void* v) {
     int m = (int)o->value(), old_m;
     grid->margin(NULL, NULL, &old_m, NULL); 
     if (m != old_m) {
+      undo_checkpoint();
       grid->margin(-1, -1, m, -1); 
       grid->need_layout(true);
       set_modflag(1);
@@ -294,6 +317,7 @@ static void cb_Bottom(Fl_Value_Input* o, void* v) {
     int m = (int)o->value(), old_m;
     grid->margin(NULL, NULL, NULL, &old_m);
     if (m != old_m) {
+      undo_checkpoint();
       grid->margin(-1, -1, -1, m);
       grid->need_layout(true);
       set_modflag(1);
@@ -312,6 +336,7 @@ static void cb_Row(Fl_Value_Input* o, void* v) {
     int m = (int)o->value(), old_m, m2;
     grid->gap(&old_m, &m2);
     if (m != old_m) {
+      undo_checkpoint();
       grid->gap(m, m2);
       grid->need_layout(true);
       set_modflag(1);
@@ -330,6 +355,7 @@ static void cb_Col(Fl_Value_Input* o, void* v) {
     int m = (int)o->value(), old_m, m2;
     grid->gap(&m2, &old_m);
     if (m != old_m) {
+      undo_checkpoint();
       grid->gap(m2, m);
       grid->need_layout(true);
       set_modflag(1);
@@ -390,6 +416,7 @@ static void cb_Height(Fluid_Coord_Input* o, void* v) {
     int h = o->value(), old_h = grid->row_height(r);
     if (h < 0) h = 0;
     if (h != old_h) {
+      undo_checkpoint();
       grid->row_height(r, h);
       grid->need_layout(true);
       set_modflag(1);
@@ -407,6 +434,7 @@ static void cb_Weight(Fluid_Coord_Input* o, void* v) {
     int h = o->value(), old_h = grid->row_weight(r);
     if (h < 0) h = 0;
     if (h != old_h) {
+      undo_checkpoint();
       grid->row_weight(r, h);
       grid->need_layout(true);
       set_modflag(1); 
@@ -424,6 +452,7 @@ static void cb_Gap(Fluid_Coord_Input* o, void* v) {
     int h = o->value(), old_h = grid->row_gap(r);
     if (h < -1) h = -1;
     if (h != old_h) {
+      undo_checkpoint();
       grid->row_gap(r, h);
       grid->need_layout(true);
       set_modflag(1);
@@ -473,6 +502,7 @@ static void cb_Width(Fluid_Coord_Input* o, void* v) {
     int h = o->value(), old_h = grid->col_width(c);
     if (h < 0) h = 0;
     if (h != old_h) {
+      undo_checkpoint();
       grid->col_width(c, h);
       grid->need_layout(true);
       set_modflag(1);
@@ -490,6 +520,7 @@ static void cb_Weight1(Fluid_Coord_Input* o, void* v) {
     int h = o->value(), old_h = grid->col_weight(c);
     if (h < 0) h = 0;
     if (h != old_h) {
+      undo_checkpoint();
       grid->col_weight(c, h);
       grid->need_layout(true);
       set_modflag(1);
@@ -507,6 +538,7 @@ static void cb_Gap1(Fluid_Coord_Input* o, void* v) {
     int h = o->value(), old_h = grid->col_gap(c);
     if (h < -1) h = -1;
     if (h != old_h) {
+      undo_checkpoint();
       grid->col_gap(c, h);
       grid->need_layout(true);
       set_modflag(1);
@@ -1415,7 +1447,9 @@ access the Widget pointer and \'v\' to access the user value.");
       { widget_tab_grid_child = new Fl_Group(10, 30, 400, 330, "Grid Child");
         widget_tab_grid_child->labelsize(11);
         widget_tab_grid_child->callback((Fl_Callback*)propagate_load);
+        widget_tab_grid_child->hide();
         { Fl_Group* o = new Fl_Group(95, 60, 315, 20, "Location:");
+          o->box(FL_FLAT_BOX);
           o->labelfont(1);
           o->labelsize(11);
           o->callback((Fl_Callback*)propagate_load);
@@ -1480,6 +1514,16 @@ access the Widget pointer and \'v\' to access the user value.");
             o->hide();
             Fl_Group::current()->resizable(o);
           } // Fl_Box* o
+          { widget_grid_transient = new Fl_Box(250, 60, 80, 20, "TRANSIENT");
+            widget_grid_transient->labelsize(11);
+            widget_grid_transient->labelcolor((Fl_Color)1);
+            widget_grid_transient->callback((Fl_Callback*)cb_widget_grid_transient);
+          } // Fl_Box* widget_grid_transient
+          { widget_grid_unlinked = new Fl_Box(250, 60, 80, 20, "UNLINKED");
+            widget_grid_unlinked->labelsize(11);
+            widget_grid_unlinked->labelcolor((Fl_Color)1);
+            widget_grid_unlinked->hide();
+          } // Fl_Box* widget_grid_unlinked
           o->end();
         } // Fl_Group* o
         { Fl_Group* o = new Fl_Group(95, 90, 315, 30, "Align:");
@@ -1623,7 +1667,6 @@ access the Widget pointer and \'v\' to access the user value.");
       { widget_tab_grid = new Fl_Group(10, 30, 400, 330, "Grid");
         widget_tab_grid->labelsize(11);
         widget_tab_grid->callback((Fl_Callback*)propagate_load);
-        widget_tab_grid->hide();
         { Fl_Group* o = new Fl_Group(95, 60, 315, 20, "Grid Layout:");
           o->labelfont(1);
           o->labelsize(11);
diff --git a/fluid/widget_panel.fl b/fluid/widget_panel.fl
index 26ec7f277..cc42315a2 100644
--- a/fluid/widget_panel.fl
+++ b/fluid/widget_panel.fl
@@ -44,7 +44,7 @@ decl {extern void set_modflag(int mf, int mfc=-1);} {private local
 }
 
 Function {make_widget_panel()} {
-  comment {Create a panel that can be used with all known widgets} open
+  comment {Create a panel that can be used with all known widgets} open selected
 } {
   Fl_Window {} {
     comment {Use a Double Window to avoid flickering.} open
@@ -835,12 +835,12 @@ wCallback->do_callback(wCallback, v);} open
       Fl_Group widget_tab_grid_child {
         label {Grid Child}
         callback propagate_load open
-        xywh {10 30 400 330} labelsize 11
+        xywh {10 30 400 330} labelsize 11 hide
       } {
         Fl_Group {} {
           label {Location:}
           callback propagate_load open
-          xywh {95 60 315 20} labelfont 1 labelsize 11 align 4
+          xywh {95 60 315 20} box FLAT_BOX labelfont 1 labelsize 11 align 4
         } {
           Fl_Input widget_grid_row_input {
             label {Row:}
@@ -889,6 +889,27 @@ wCallback->do_callback(wCallback, v);} open
           Fl_Box {} {
             xywh {395 60 1 20} hide resizable
           }
+          Fl_Box widget_grid_transient {
+            label TRANSIENT
+            callback {if (v==LOAD) {
+  Fl_Widget *child = ((Fl_Widget_Type*)current_widget)->o;
+  Fl_Grid_Proxy *g = ((Fl_Grid_Proxy*)((Fl_Widget_Type*)current_widget->parent)->o);
+  Fl_Grid::Cell *cell = g->cell(child);
+  Fl_Grid::Cell *tcell = g->transient_cell(child);
+  widget_grid_transient->hide();
+  widget_grid_unlinked->hide();
+  if (g->transient_cell(child)) {
+    widget_grid_transient->show();
+  } else if (!g->cell(child)) {
+    widget_grid_unlinked->show();
+  }
+}}
+            xywh {250 60 80 20} labelsize 11 labelcolor 1
+          }
+          Fl_Box widget_grid_unlinked {
+            label UNLINKED
+            xywh {250 60 80 20} labelsize 11 labelcolor 1 hide
+          }
         }
         Fl_Group {} {
           label {Align:}
@@ -943,7 +964,7 @@ wCallback->do_callback(wCallback, v);} open
             }
             MenuItem {} {
               label GRID_FILL
-              user_data FL_GRID_VERTICAL user_data_type long selected
+              user_data FL_GRID_VERTICAL user_data_type long
               xywh {10 10 31 20} labelsize 11
             }
           }
@@ -1032,7 +1053,7 @@ wCallback->do_callback(wCallback, v);} open
       Fl_Group widget_tab_grid {
         label Grid
         callback propagate_load open
-        xywh {10 30 400 330} labelsize 11 hide
+        xywh {10 30 400 330} labelsize 11
       } {
         Fl_Group {} {
           label {Grid Layout:}
@@ -1160,6 +1181,7 @@ if (v == LOAD) {
   int m = (int)o->value(), old_m;
   grid->margin(&old_m, NULL, NULL, NULL); 
   if (m != old_m) {
+    undo_checkpoint();
     grid->margin(m, -1, -1, -1); 
     grid->need_layout(true);
     set_modflag(1);
@@ -1179,6 +1201,7 @@ if (v == LOAD) {
   int m = (int)o->value(), old_m;
   grid->margin(NULL, &old_m, NULL, NULL); 
   if (m != old_m) {
+    undo_checkpoint();
     grid->margin(-1, m, -1, -1); 
     grid->need_layout(true);
     set_modflag(1);
@@ -1198,6 +1221,7 @@ if (v == LOAD) {
   int m = (int)o->value(), old_m;
   grid->margin(NULL, NULL, &old_m, NULL); 
   if (m != old_m) {
+    undo_checkpoint();
     grid->margin(-1, -1, m, -1); 
     grid->need_layout(true);
     set_modflag(1);
@@ -1217,6 +1241,7 @@ if (v == LOAD) {
   int m = (int)o->value(), old_m;
   grid->margin(NULL, NULL, NULL, &old_m);
   if (m != old_m) {
+    undo_checkpoint();
     grid->margin(-1, -1, -1, m);
     grid->need_layout(true);
     set_modflag(1);
@@ -1245,6 +1270,7 @@ if (v == LOAD) {
   int m = (int)o->value(), old_m, m2;
   grid->gap(&old_m, &m2);
   if (m != old_m) {
+    undo_checkpoint();
     grid->gap(m, m2);
     grid->need_layout(true);
     set_modflag(1);
@@ -1264,6 +1290,7 @@ if (v == LOAD) {
   int m = (int)o->value(), old_m, m2;
   grid->gap(&m2, &old_m);
   if (m != old_m) {
+    undo_checkpoint();
     grid->gap(m2, m);
     grid->need_layout(true);
     set_modflag(1);
@@ -1345,6 +1372,7 @@ if (v == LOAD) {
   int h = o->value(), old_h = grid->row_height(r);
   if (h < 0) h = 0;
   if (h != old_h) {
+    undo_checkpoint();
     grid->row_height(r, h);
     grid->need_layout(true);
     set_modflag(1);
@@ -1364,6 +1392,7 @@ if (v == LOAD) {
   int h = o->value(), old_h = grid->row_weight(r);
   if (h < 0) h = 0;
   if (h != old_h) {
+    undo_checkpoint();
     grid->row_weight(r, h);
     grid->need_layout(true);
     set_modflag(1); 
@@ -1383,6 +1412,7 @@ if (v == LOAD) {
   int h = o->value(), old_h = grid->row_gap(r);
   if (h < -1) h = -1;
   if (h != old_h) {
+    undo_checkpoint();
     grid->row_gap(r, h);
     grid->need_layout(true);
     set_modflag(1);
@@ -1458,6 +1488,7 @@ if (v == LOAD) {
   int h = o->value(), old_h = grid->col_width(c);
   if (h < 0) h = 0;
   if (h != old_h) {
+    undo_checkpoint();
     grid->col_width(c, h);
     grid->need_layout(true);
     set_modflag(1);
@@ -1477,6 +1508,7 @@ if (v == LOAD) {
   int h = o->value(), old_h = grid->col_weight(c);
   if (h < 0) h = 0;
   if (h != old_h) {
+    undo_checkpoint();
     grid->col_weight(c, h);
     grid->need_layout(true);
     set_modflag(1);
@@ -1496,6 +1528,7 @@ if (v == LOAD) {
   int h = o->value(), old_h = grid->col_gap(c);
   if (h < -1) h = -1;
   if (h != old_h) {
+    undo_checkpoint();
     grid->col_gap(c, h);
     grid->need_layout(true);
     set_modflag(1);
diff --git a/fluid/widget_panel.h b/fluid/widget_panel.h
index 437029df4..83e1f9766 100644
--- a/fluid/widget_panel.h
+++ b/fluid/widget_panel.h
@@ -143,6 +143,8 @@ extern void grid_set_col_cb(Fluid_Coord_Input*, void*);
 extern Fluid_Coord_Input *widget_grid_col_input;
 extern void grid_dec_col_cb(Fl_Button*, void*);
 extern void grid_inc_col_cb(Fl_Button*, void*);
+extern Fl_Box *widget_grid_transient;
+extern Fl_Box *widget_grid_unlinked;
 extern void grid_align_horizontal_cb(Fl_Choice*, void*);
 extern void grid_align_vertical_cb(Fl_Choice*, void*);
 extern void grid_set_min_wdt_cb(Fluid_Coord_Input*, void*);