BarChart: Added color scale support.

* Color scale's extents are not changed: the values are supposed to
  match the values used in the other plots
* Temporarily removed the bar outlines in order to properly display
  colors when the number of bars is equal to or greater than the
  number of available pixels to draw

3 files changed, 39 insertions, 8 deletions

diff --git a/barchart.cpp b/barchart.cpp
index 3c8e45d..ad20c63 100644
--- a/barchart.cpp
+++ b/barchart.cpp
@@ -11,6 +11,7 @@ static const float DEFAULT_OPACITY = 0.8f;
 BarChart::BarChart(QQuickItem *parent)
     : QQuickItem(parent)
     , m_shouldUpdateBars(false)
+    , m_colorScale(0)
     , m_scale(0, 1, 0, 1)
 {
     setClip(true);
@@ -38,9 +39,18 @@ void BarChart::setValues(const arma::vec &values)
         std::sort(m_originalIndices.begin(), m_originalIndices.end(),
             [this](int i, int j) { return m_values[i] > m_values[j]; });
     }
+    emit valuesChanged(values);
 
     m_shouldUpdateBars = true;
-    emit valuesChanged(values);
+}
+
+void BarChart::setColorScale(const ColorScale *scale)
+{
+    m_colorScale = scale;
+    emit colorScaleChanged(m_colorScale);
+
+    m_shouldUpdateBars = true;
+    update();
 }
 
 QSGNode *BarChart::newBarNode() const
@@ -73,21 +83,35 @@ QSGNode *BarChart::newBarNode() const
     QSGOpacityNode *opacityNode = new QSGOpacityNode;
     opacityNode->setOpacity(DEFAULT_OPACITY);
     opacityNode->appendChildNode(barGeomNode);
-    opacityNode->appendChildNode(outlineGeomNode);
+    //opacityNode->appendChildNode(outlineGeomNode);
 
     return opacityNode;
 }
 
 void BarChart::updateBarNodeGeom(QSGNode *barNode, float x, float barWidth, float barHeight)
 {
-    QSGGeometryNode *outlineGeomNode =
+    float y = height() - barHeight;
+
+    QSGGeometryNode *barGeomNode =
         static_cast<QSGGeometryNode *>(barNode->firstChild());
+    updateRectGeometry(barGeomNode->geometry(), x, y, barWidth, barHeight);
+    barGeomNode->markDirty(QSGNode::DirtyGeometry);
+
+    //QSGGeometryNode *outlineGeomNode =
+    //    static_cast<QSGGeometryNode *>(barGeomNode->nextSibling());
+    //updateRectGeometry(outlineGeomNode->geometry(), x, y, barWidth, barHeight);
+    //outlineGeomNode->markDirty(QSGNode::DirtyGeometry);
+}
+
+void BarChart::updateBarNodeColor(QSGNode *barNode, const QColor &color)
+{
     QSGGeometryNode *barGeomNode =
-        static_cast<QSGGeometryNode *>(barNode->firstChild()->nextSibling());
+        static_cast<QSGGeometryNode *>(barNode->firstChild());
 
-    float y = height() - barHeight;
-    updateRectGeometry(outlineGeomNode->geometry(), x, y, barWidth, barHeight);
-    updateRectGeometry(barGeomNode->geometry(), x, y, barWidth, barHeight);
+    QSGFlatColorMaterial *material =
+        static_cast<QSGFlatColorMaterial *>(barGeomNode->material());
+    material->setColor(color);
+    barGeomNode->markDirty(QSGNode::DirtyMaterial);
 }
 
 void BarChart::updateBars(QSGNode *root)
@@ -99,6 +123,7 @@ void BarChart::updateBars(QSGNode *root)
     m_scale.setRange(0, height());
     for (auto it = m_originalIndices.cbegin(); it != m_originalIndices.cend(); it++) {
         updateBarNodeGeom(node, x, barWidth, m_scale(m_values[*it]));
+        updateBarNodeColor(node, m_colorScale->color(m_values[*it]));
         x += barWidth;
         node = node->nextSibling();
     }
@@ -120,7 +145,7 @@ QSGNode *BarChart::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
             root->removeChildNode(root->firstChild());
         }
 
-        // Then, update the geometry of bars to reflect the values
+        // Then, update the bars to reflect the values
         updateBars(root);
         m_shouldUpdateBars = false;
     }
diff --git a/barchart.h b/barchart.h
index 933c004..2d37419 100644
--- a/barchart.h
+++ b/barchart.h
@@ -7,6 +7,7 @@
 
 #include <armadillo>
 
+#include "colorscale.h"
 #include "scale.h"
 
 class BarChart
@@ -19,9 +20,11 @@ public:
 
 signals:
     void valuesChanged(const arma::vec &values) const;
+    void colorScaleChanged(const ColorScale *scale) const;
 
 public slots:
     void setValues(const arma::vec &values);
+    void setColorScale(const ColorScale *scale);
 
 protected:
     QSGNode *updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *);
@@ -31,10 +34,12 @@ protected:
 private:
     QSGNode *newBarNode() const;
     void updateBarNodeGeom(QSGNode *barNode, float x, float width, float height);
+    void updateBarNodeColor(QSGNode *barNode, const QColor &color);
     void updateBars(QSGNode *root);
     bool m_shouldUpdateBars;
 
     arma::vec m_values;
+    const ColorScale *m_colorScale;
     std::vector<int> m_originalIndices;
     LinearScale<float> m_scale;
 };
diff --git a/main.cpp b/main.cpp
index 402ecef..d2eb5f6 100644
--- a/main.cpp
+++ b/main.cpp
@@ -179,6 +179,7 @@ int main(int argc, char **argv)
             cpPlot, SLOT(setScale(const LinearScale<float> &, const LinearScale<float> &)));
 
     BarChart *barChart = engine.rootObjects()[0]->findChild<BarChart *>("barChart");
+    barChart->setColorScale(&colorScale);
     barChart->setValues(labels);
 
     //history->addHistoryItem(Ys);