+// helper of AdjustForGrowables() which is called for rows/columns separately
+//
+// parameters:
+// delta: the extra space, we do nothing unless it's positive
+// growable: indices or growable rows/cols in sizes array
+// sizes: the height/widths of rows/cols to adjust
+// proportions: proportions of the growable rows/cols or NULL if they all
+// should be assumed to have proportion of 1
+static void
+DoAdjustForGrowables(int delta,
+ const wxArrayInt& growable,
+ wxArrayInt& sizes,
+ const wxArrayInt *proportions)
+{
+ if ( delta <= 0 )
+ return;
+
+ // total sum of proportions of all non-hidden rows
+ int sum_proportions = 0;
+
+ // number of currently shown growable rows
+ int num = 0;
+
+ const int max_idx = sizes.size();
+
+ const size_t count = growable.size();
+ size_t idx;
+ for ( idx = 0; idx < count; idx++ )
+ {
+ // Since the number of rows/columns can change as items are
+ // inserted/deleted, we need to verify at runtime that the
+ // requested growable rows/columns are still valid.
+ if ( growable[idx] >= max_idx )
+ continue;
+
+ // If all items in a row/column are hidden, that row/column will
+ // have a dimension of -1. This causes the row/column to be
+ // hidden completely.
+ if ( sizes[growable[idx]] == -1 )
+ continue;
+
+ if ( proportions )
+ sum_proportions += (*proportions)[idx];
+
+ num++;
+ }
+
+ if ( !num )
+ return;
+
+ // the remaining extra free space, adjusted during each iteration
+ for ( idx = 0; idx < count; idx++ )
+ {
+ if ( growable[idx] >= max_idx )
+ continue;
+
+ if ( sizes[ growable[idx] ] == -1 )
+ continue;
+
+ int cur_delta;
+ if ( sum_proportions == 0 )
+ {
+ // no growable rows -- divide extra space evenly among all
+ cur_delta = delta/num;
+ num--;
+ }
+ else // allocate extra space proportionally
+ {
+ const int cur_prop = (*proportions)[idx];
+ cur_delta = (delta*cur_prop)/sum_proportions;
+ sum_proportions -= cur_prop;
+ }
+
+ sizes[growable[idx]] += cur_delta;
+ delta -= cur_delta;
+ }
+}