+static gboolean bv_chart_draw(GtkWidget *widget, cairo_t *cr) {
+ BVChart *chart = BV_CHART(widget);
+ BVChartPrivate *priv = bv_chart_get_instance_private(chart);
+
+ cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
+ cairo_paint(cr);
+
+ if (priv->points->len < 2)
+ return TRUE;
+
+ GtkAllocation allocation;
+ gtk_widget_get_allocation(widget, &allocation);
+
+ float xscale = allocation.width / (priv->maxx - priv->minx);
+ float yscale = allocation.height / (priv->miny - priv->maxy);
+ cairo_set_source_rgb(cr, 0.0, 0.0, 1.0);
+ struct BVChartPoint *start =
+ &g_array_index(priv->points, struct BVChartPoint, 0);
+ cairo_move_to(cr, xscale * (start->x - priv->minx),
+ yscale * (start->y - priv->maxy));
+ for (guint i = 1; i < priv->points->len; i++) {
+ struct BVChartPoint *p =
+ &g_array_index(priv->points, struct BVChartPoint, i);
+ cairo_line_to(cr, xscale * (p->x - priv->minx),
+ yscale * (p->y - priv->maxy));
+ }
+ cairo_stroke(cr);
+
+ return TRUE;
+}
+
+static void bv_chart_class_init(BVChartClass *klass) {
+ GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
+ widget_class->draw = bv_chart_draw;
+}