[goffice] Fix evaluation of regression curves for area plots. [#777334]

[Jean Bréfort <jbrefort src gnome org>]

commit e569c64232fca934f57ebcb0248e288cbe020a0c
Author: Jean Brefort <jean brefort normalesup org>
Date:   Mon Jan 23 22:07:59 2017 +0100

    Fix evaluation of regression curves for area plots. [#777334]

 ChangeLog                      |    5 ++
 NEWS                           |    1 +
 plugins/plot_barcol/gog-line.c |   94 +++++++++++++++++-----------------------
 3 files changed, 46 insertions(+), 54 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index c55bda0..f5e11bc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-01-23  Jean Brefort  <jean brefort normalesup org>
+
+       * plugins/plot_barcol/gog-line.c : fix evaluation of regression curves
+       for area plots. [#777334]
+
 2017-01-22  Jean Brefort  <jean brefort normalesup org>
 
        * goffice/graph/gog-object.c (gog_object_clear_parent): fix add child menu
diff --git a/NEWS b/NEWS
index fdfd0c4..2bd0c03 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,7 @@ Jean:
        Rousseau). [#774439]
        * Reimplement major grids for discrete axes. [#775624].
        * Fix add child menu in graph guru. [#777336]
+       * Fix evaluation of regression curves for area plots. [#777334]
 
 Morten:
        * Introspection fixes.
diff --git a/plugins/plot_barcol/gog-line.c b/plugins/plot_barcol/gog-line.c
index 60fcc1e..a5e8aee 100644
--- a/plugins/plot_barcol/gog-line.c
+++ b/plugins/plot_barcol/gog-line.c
@@ -129,6 +129,7 @@ typedef struct {
        GogSeries1_5d base;
        double  clamped_derivs[2]; /* start and slopes for clamped cubic splines */
        GogDataset        *interpolation_props;
+       double *x;
 } GogAreaSeries;
 
 /****************************************************************************/
@@ -219,7 +220,7 @@ enum {
        SERIES_PROP_CLAMP1
 };
 
-typedef GogSeries1_5dClass     GogAreaSeriesClass;
+typedef GogSeries1_5dClass GogAreaSeriesClass;
 
 static GogStyledObjectClass *area_series_parent_klass;
 
@@ -237,6 +238,37 @@ gog_area_series_get_interpolation_params (GogSeries const *series)
 }
 
 static void
+gog_area_series_update (GogObject *obj)
+{
+       GogAreaSeries *series = GOG_AREA_SERIES (obj);
+       GogSeries *base_series = GOG_SERIES (obj);
+       unsigned i, nb = base_series->num_elements;
+       GSList *ptr;
+       (GOG_OBJECT_CLASS (area_series_parent_klass))->update (obj);
+       if (nb != base_series->num_elements) {
+               nb = base_series->num_elements;
+               g_free (series->x);
+               series->x = g_new (double, nb);
+               for (i = 0; i < nb; i++)
+                       series->x[i] = i + 1;
+       }
+       /* update children */
+       for (ptr = obj->children; ptr != NULL; ptr = ptr->next)
+               if (!GOG_IS_SERIES_LINES (ptr->data))
+                       gog_object_request_update (GOG_OBJECT (ptr->data));
+}
+
+static unsigned
+gog_area_series_get_xy_data (GogSeries const *series,
+                                       double const **x, double const **y)
+{
+       GogAreaSeries *area_ser = GOG_AREA_SERIES (series);
+       *x = area_ser->x;
+       *y = go_data_get_values (series->values[1].data);
+       return series->num_elements;
+}
+
+static void
 gog_area_series_set_property (GObject *obj, guint param_id,
                            GValue const *value, GParamSpec *pspec)
 {
@@ -284,6 +316,9 @@ gog_area_series_finalize (GObject *obj)
                series->interpolation_props = NULL;
        }
 
+       g_free (series->x);
+       series->x = NULL;
+
        G_OBJECT_CLASS (area_series_parent_klass)->finalize (obj);
 }
 
@@ -300,6 +335,8 @@ gog_area_series_class_init (GogStyledObjectClass *gso_klass)
        gog_klass->view_type = gog_line_series_view_get_type ();
        series_klass->has_interpolation = TRUE;
        series_klass->get_interpolation_params = gog_area_series_get_interpolation_params;
+       gog_klass->update = gog_area_series_update;
+       series_klass->get_xy_data = gog_area_series_get_xy_data;
        g_object_class_install_property (obj_klass, SERIES_PROP_CLAMP0,
                g_param_spec_double ("clamp0",
                        _("Clamp at start"),
@@ -330,10 +367,7 @@ GSF_DYNAMIC_CLASS (GogAreaSeries, gog_area_series,
 
 /*****************************************************************************/
 
-typedef struct {
-       GogAreaSeries base;
-       double *x;
-} GogLineSeries;
+typedef  GogAreaSeries GogLineSeries;
 
 typedef GogSeries1_5dClass     GogLineSeriesClass;
 
@@ -367,58 +401,10 @@ gog_line_series_init_style (GogStyledObject *gso, GOStyle *style)
 }
 
 static void
-gog_line_series_update (GogObject *obj)
-{
-       GogLineSeries *series = GOG_LINE_SERIES (obj);
-       GogSeries *base_series = GOG_SERIES (obj);
-       unsigned i, nb = base_series->num_elements;
-       GSList *ptr;
-       (GOG_OBJECT_CLASS (line_series_parent_klass))->update (obj);
-       if (nb != base_series->num_elements) {
-               nb = base_series->num_elements;
-               g_free (series->x);
-               series->x = g_new (double, nb);
-               for (i = 0; i < nb; i++)
-                       series->x[i] = i + 1;
-       }
-       /* update children */
-       for (ptr = obj->children; ptr != NULL; ptr = ptr->next)
-               if (!GOG_IS_SERIES_LINES (ptr->data))
-                       gog_object_request_update (GOG_OBJECT (ptr->data));
-}
-
-static unsigned
-gog_line_series_get_xy_data (GogSeries const *series,
-                                       double const **x, double const **y)
-{
-       GogLineSeries *line_ser = GOG_LINE_SERIES (series);
-       *x = line_ser->x;
-       *y = go_data_get_values (series->values[1].data);
-       return series->num_elements;
-}
-
-static void
-gog_line_series_finalize (GObject *obj)
-{
-       GogLineSeries *series = GOG_LINE_SERIES (obj);
-
-       g_free (series->x);
-       series->x = NULL;
-
-       G_OBJECT_CLASS (line_series_parent_klass)->finalize (obj);
-}
-
-static void
 gog_line_series_class_init (GogStyledObjectClass *gso_klass)
 {
-       GObjectClass *obj_klass = (GObjectClass *)gso_klass;
-       GogObjectClass *gog_klass = (GogObjectClass *)gso_klass;
-       GogSeriesClass *series_klass = (GogSeriesClass*) gso_klass;
        line_series_parent_klass = g_type_class_peek_parent (gso_klass);
-       obj_klass->finalize = gog_line_series_finalize;
        gso_klass->init_style = gog_line_series_init_style;
-       gog_klass->update = gog_line_series_update;
-       series_klass->get_xy_data = gog_line_series_get_xy_data;
 }
 
 GSF_DYNAMIC_CLASS (GogLineSeries, gog_line_series,
@@ -1263,7 +1249,7 @@ gog_line_view_render (GogView *view, GogViewAllocation const *bbox)
                        if (lengths[i] == 0)
                                continue;
 
-                               gog_renderer_push_style (view->renderer, styles[i]);
+                       gog_renderer_push_style (view->renderer, styles[i]);
 
                        for (j = 0; j < lengths[i]; j++) {
                                x = points[i][j].x;