[gnumeric] Styles: fix optimizer to not ignore apparently-empty cells.

[Morten Welinder <mortenw src gnome org>]

commit 5f9d29d8a512cda273cb63be63a3388a00fdace5
Author: Morten Welinder <terra gnome org>
Date:   Tue May 17 13:55:03 2011 -0400

    Styles: fix optimizer to not ignore apparently-empty cells.
    
    We should look at *all* cells, including those with expressions and
    those that happen to have empty values.

 ChangeLog   |    3 +++
 src/sheet.c |   38 ++++++++++++++++++++++++++++++++++++--
 src/sheet.h |    1 +
 3 files changed, 40 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index e000668..d585654 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2011-05-17  Morten Welinder  <terra gnome org>
 
+	* src/sheet.c (sheet_colrow_optimize): Use sheet_get_cells_extent.
+	(sheet_get_cells_extent): New function.
+
 	* src/xml-sax-write.c (xml_write_named_expressions): Do nothing if
 	there are no names.
 
diff --git a/src/sheet.c b/src/sheet.c
index 83f68d4..76bacac 100644
--- a/src/sheet.c
+++ b/src/sheet.c
@@ -2014,6 +2014,7 @@ sheet_colrow_gutter (Sheet *sheet, gboolean is_cols, int max_outline)
 struct sheet_extent_data {
 	GnmRange range;
 	gboolean spans_and_merges_extend;
+	gboolean ignore_empties;
 };
 
 static void
@@ -2022,7 +2023,7 @@ cb_sheet_get_extent (gpointer ignored, gpointer value, gpointer data)
 	GnmCell const *cell = (GnmCell const *) value;
 	struct sheet_extent_data *res = data;
 
-	if (gnm_cell_is_empty (cell))
+	if (res->ignore_empties && gnm_cell_is_empty (cell))
 		return;
 
 	/* Remember the first cell is the min & max */
@@ -2067,6 +2068,9 @@ cb_sheet_get_extent (gpointer ignored, gpointer value, gpointer data)
  * NOTE: When spans_and_merges_extend is TRUE, this function will calculate
  * all spans.  That might be expensive.
  *
+ * NOTE: This refers to *visible* contents.  Cells with empty values, including
+ * formulas with such values, are *ignored.
+ *
  * Return value: the range.
  **/
 GnmRange
@@ -2084,6 +2088,7 @@ sheet_get_extent (Sheet const *sheet, gboolean spans_and_merges_extend)
 	closure.range.end.col   = 0;
 	closure.range.end.row   = 0;
 	closure.spans_and_merges_extend = spans_and_merges_extend;
+	closure.ignore_empties = TRUE;
 
 	sheet_cell_foreach (sheet, &cb_sheet_get_extent, &closure);
 
@@ -2112,6 +2117,35 @@ sheet_get_extent (Sheet const *sheet, gboolean spans_and_merges_extend)
 	return closure.range;
 }
 
+/**
+ * sheet_get_cells_extent:
+ * @sheet: the sheet
+ *
+ * calculates the area occupied by cells, including empty cells.
+ *
+ * Return value: the range.
+ **/
+GnmRange
+sheet_get_cells_extent (Sheet const *sheet)
+{
+	static GnmRange const dummy = { { 0,0 }, { 0,0 } };
+	struct sheet_extent_data closure;
+
+	g_return_val_if_fail (IS_SHEET (sheet), dummy);
+
+	closure.range.start.col = gnm_sheet_get_last_col (sheet);
+	closure.range.start.row = gnm_sheet_get_last_row (sheet);
+	closure.range.end.col   = 0;
+	closure.range.end.row   = 0;
+	closure.spans_and_merges_extend = FALSE;
+	closure.ignore_empties = FALSE;
+
+	sheet_cell_foreach (sheet, &cb_sheet_get_extent, &closure);
+
+	return closure.range;
+}
+
+
 GnmRange *
 sheet_get_nominal_printarea (Sheet const *sheet)
 {
@@ -3456,7 +3490,7 @@ sheet_colrow_optimize (Sheet *sheet)
 
 	g_return_if_fail (IS_SHEET (sheet));
 
-	extent = sheet_get_extent (sheet, TRUE);
+	extent = sheet_get_cells_extent (sheet);
 
 	sheet_colrow_optimize1 (gnm_sheet_get_max_cols (sheet),
 				extent.end.col,
diff --git a/src/sheet.h b/src/sheet.h
index d0307bf..008693d 100644
--- a/src/sheet.h
+++ b/src/sheet.h
@@ -306,6 +306,7 @@ void	 sheet_scrollbar_config		(Sheet const *s);
 void     sheet_mark_dirty	(Sheet *sheet);
 GnmRange    sheet_get_extent	(Sheet const *sheet,
 				 gboolean spans_and_merges_extend);
+GnmRange    sheet_get_cells_extent (Sheet const *sheet);
 GnmRange    sheet_get_printarea	(Sheet const *sheet,
 				 gboolean include_styles,
 				 gboolean ignore_printarea);