tdf#159043: combo chart render order isn't right

Change-Id: If20446c8bd5a67f73c24444126c26ed6bd160aed
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/161797
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

3 files changed, 51 insertions, 0 deletions

diff --git a/chart2/source/view/charttypes/VSeriesPlotter.cxx b/chart2/source/view/charttypes/VSeriesPlotter.cxx
index f9fa8fe0fea9..34a702d7b696 100644
--- a/chart2/source/view/charttypes/VSeriesPlotter.cxx
+++ b/chart2/source/view/charttypes/VSeriesPlotter.cxx
@@ -2307,6 +2307,48 @@ OUString VSeriesPlotter::getCategoryName( sal_Int32 nPointIndex ) const
     return OUString();
 }
 
+namespace {
+// The following it to support rendering order for combo charts. A chart type
+// with a lower rendering order is rendered before (i.e., behind) a chart with a
+// higher rendering order. The rendering orders are based on rough guesses about
+// how much one chart (type) will obscure another chart (type). The intent is to
+// minimize obscuring of data, by putting charts that generally cover more
+// pixels (e.g., area charts) behind ones that generally cover fewer (e.g., line
+// charts).
+struct ROrderPair
+{
+    ROrderPair(OUString n, sal_Int32 r) : chartName(n), renderOrder(r) {}
+
+    OUString chartName;
+    sal_Int32 renderOrder;
+};
+
+const ROrderPair pairList[] = {
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_AREA, 0),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_BAR, 6),   // bar & column are same
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_COLUMN, 6),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_LINE, 8),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_SCATTER, 5),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_PIE, 1),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_NET, 3),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_FILLED_NET, 2),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_CANDLESTICK, 7),
+    ROrderPair(CHART2_SERVICE_NAME_CHARTTYPE_BUBBLE, 4)
+};
+} // unnamed
+
+sal_Int32 VSeriesPlotter::getRenderOrder() const
+{
+    OUString aChartType = m_xChartTypeModel->getChartType();
+    for (size_t n = 0; n < sizeof(pairList); ++n) {
+        if (aChartType.equalsIgnoreAsciiCase(pairList[n].chartName)) {
+            return pairList[n].renderOrder;
+        }
+    }
+    SAL_WARN("chart2", "Unsupported chart type in getRenderOrder()");
+    return 0;
+}
+
 std::vector<VDataSeries const*> VSeriesPlotter::getAllSeries() const
 {
     std::vector<VDataSeries const*> aAllSeries;
diff --git a/chart2/source/view/inc/VSeriesPlotter.hxx b/chart2/source/view/inc/VSeriesPlotter.hxx
index eaf27495d0ed..45676830b538 100644
--- a/chart2/source/view/inc/VSeriesPlotter.hxx
+++ b/chart2/source/view/inc/VSeriesPlotter.hxx
@@ -275,6 +275,8 @@ public:
     OUString getLabelTextForValue(VDataSeries const & rDataSeries, sal_Int32 nPointIndex,
                                   double fValue, bool bAsPercentage);
 
+    sal_Int32 getRenderOrder() const;
+
 protected:
 
     VSeriesPlotter( rtl::Reference< ::chart::ChartType > xChartTypeModel
diff --git a/chart2/source/view/main/SeriesPlotterContainer.cxx b/chart2/source/view/main/SeriesPlotterContainer.cxx
index bcc5b0f482a3..67e4d75c0b9b 100644
--- a/chart2/source/view/main/SeriesPlotterContainer.cxx
+++ b/chart2/source/view/main/SeriesPlotterContainer.cxx
@@ -317,6 +317,13 @@ void SeriesPlotterContainer::initializeCooSysAndSeriesPlotter(ChartModel& rChart
         }
     }
 
+    auto order
+        = [](const std::unique_ptr<VSeriesPlotter>& a, const std::unique_ptr<VSeriesPlotter>& b) {
+              return a->getRenderOrder() < b->getRenderOrder();
+          };
+
+    std::stable_sort(m_aSeriesPlotterList.begin(), m_aSeriesPlotterList.end(), order);
+
     //transport seriesnames to the coordinatesystems if needed
     if (m_aSeriesPlotterList.empty())
         return;