[gnumeric] xlsx: handle interpolation.

[Morten Welinder <mortenw src gnome org>]

commit 55889d63a73881f01229e51ed7fc127cee1e897b
Author: Morten Welinder <terra gnome org>
Date:   Wed Jan 21 11:12:29 2015 -0500

    xlsx: handle interpolation.

 plugins/excel/ChangeLog            |    2 ++
 plugins/excel/xlsx-write-drawing.c |   21 +++++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)
---
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index e4f339b..228fc80 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -2,6 +2,8 @@
 
        * xlsx-write-drawing.c (xlsx_write_one_plot): varyColor defaults
        to TRUE, so be sure to output it for line plots etc.
+       (xlsx_write_one_plot): Set smooth for anything but linear
+       interpolation.
 
 2015-01-20  Morten Welinder  <terra gnome org>
 
diff --git a/plugins/excel/xlsx-write-drawing.c b/plugins/excel/xlsx-write-drawing.c
index 455ca8b..8a96997 100644
--- a/plugins/excel/xlsx-write-drawing.c
+++ b/plugins/excel/xlsx-write-drawing.c
@@ -400,7 +400,6 @@ xlsx_write_axis (XLSXWriteState *state, GsfXMLOut *xml, GogAxis *axis, GogAxisTy
 static void
 xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *chart, GogObject const *plot)
 {
-       gboolean use_xy = FALSE;
        double explosion = 0.;
        gboolean vary_by_element;
        GogAxisType axis_type[3] = {GOG_AXIS_X, GOG_AXIS_Y, GOG_AXIS_UNKNOWN};
@@ -409,6 +408,8 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
        const char *plot_type_name;
        GSList const *series;
        unsigned count;
+       gboolean use_xy = FALSE;
+       gboolean set_smooth = FALSE;
 
        g_object_get (G_OBJECT (plot),
                      "vary-style-by-element", &vary_by_element,
@@ -450,6 +451,7 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                gsf_xml_out_start_element (xml, "c:lineChart");
                xlsx_write_plot_1_5_type (xml, plot, FALSE);
                xlsx_write_chart_bool (xml, "c:varyColors", vary_by_element);
+               set_smooth = TRUE;
                break;
 
        case XLSX_PT_GOGPIEPLOT:
@@ -504,6 +506,7 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                                        (has_markers? "lineMarker": "line")):
                                (has_markers? "marker": "none");
                use_xy = TRUE;
+               set_smooth = TRUE;
                gsf_xml_out_start_element (xml, "c:scatterChart");
                xlsx_write_chart_cstr_unchecked (xml, "c:scatterStyle", style);
                xlsx_write_chart_bool (xml, "c:varyColors", vary_by_element);
@@ -522,6 +525,7 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
             series = series->next) {
                GogSeries *ser = series->data;
                GSList *l, *children;
+               GOStyle *style = go_styled_object_get_style (GO_STYLED_OBJECT (ser));
 
                gsf_xml_out_start_element (xml, "c:ser");
 
@@ -529,7 +533,7 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                xlsx_write_chart_int (xml, "c:order", -1, count);
                xlsx_write_series_dim (state, xml, ser, "c:tx", GOG_MS_DIM_LABELS);
                if (!vary_by_element) /* FIXME: we might loose some style elements */
-                       xlsx_write_go_style (xml, go_styled_object_get_style (GO_STYLED_OBJECT (ser)));
+                       xlsx_write_go_style (xml, style);
 
                children = gog_object_get_children (GOG_OBJECT (ser), NULL);
                for (l = children; l; l = l->next) {
@@ -586,6 +590,19 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                        xlsx_write_series_dim (state, xml, ser, "c:val", GOG_MS_DIM_VALUES);
                }
 
+               if (set_smooth) {
+                       gboolean smooth;
+                       GOLineInterpolation inter;
+                       char *s;
+
+                       g_object_get (ser, "interpolation", &s, NULL);
+                       inter = go_line_interpolation_from_str (s);
+                       g_free (s);
+
+                       smooth = inter != GO_LINE_INTERPOLATION_LINEAR;
+                       xlsx_write_chart_bool (xml, "c:smooth", smooth);
+               }
+
                gsf_xml_out_end_element (xml); /* </c:ser> */
        }