From 17624d030c393a78f440e7e442d7c5e0ebb3bba4 2017-08-18 14:18:58
From: Alexandre Leroux <aleroux@itlink.fr>
Date: 2017-08-18 14:18:58
Subject: [PATCH] Sets differents colors for components of a vector

---

diff --git a/gui/include/Common/ColorUtils.h b/gui/include/Common/ColorUtils.h
new file mode 100644
index 0000000..2ef4f9e
--- /dev/null
+++ b/gui/include/Common/ColorUtils.h
@@ -0,0 +1,19 @@
+#ifndef SCIQLOP_COLORUTILS_H
+#define SCIQLOP_COLORUTILS_H
+
+#include <vector>
+
+class QColor;
+
+/**
+ * Utility class with methods for colors
+ */
+struct ColorUtils {
+    /// Generates a color scale from min / max values and a number of colors.
+    /// The algorithm uses the HSV color model to generate color variations (see
+    /// http://doc.qt.io/qt-4.8/qcolor.html#the-hsv-color-model)
+    static std::vector<QColor> colors(const QColor &minColor, const QColor &maxColor,
+                                      int nbColors) noexcept;
+};
+
+#endif // SCIQLOP_COLORUTILS_H
diff --git a/gui/src/Common/ColorUtils.cpp b/gui/src/Common/ColorUtils.cpp
new file mode 100644
index 0000000..c4f6324
--- /dev/null
+++ b/gui/src/Common/ColorUtils.cpp
@@ -0,0 +1,29 @@
+#include "Common/ColorUtils.h"
+
+#include <QtGui/QColor>
+
+std::vector<QColor> ColorUtils::colors(const QColor &minColor, const QColor &maxColor,
+                                       int nbColors) noexcept
+{
+    auto result = std::vector<QColor>{};
+
+    if (nbColors == 1) {
+        result.push_back(minColor);
+    }
+    else if (nbColors > 0) {
+        const auto nbSteps = static_cast<double>(nbColors - 1);
+
+        const auto colorHStep = (maxColor.hue() - minColor.hue()) / nbSteps;
+        const auto colorSStep = (maxColor.saturation() - minColor.saturation()) / nbSteps;
+        const auto colorVStep = (maxColor.value() - minColor.value()) / nbSteps;
+        const auto colorAStep = (maxColor.alpha() - minColor.alpha()) / nbSteps;
+
+        for (auto i = 0; i < nbColors; ++i) {
+            result.push_back(QColor::fromHsv(
+                minColor.hue() + i * colorHStep, minColor.saturation() + i * colorSStep,
+                minColor.value() + i * colorVStep, minColor.alpha() + i * colorAStep));
+        }
+    }
+
+    return result;
+}
diff --git a/gui/src/Visualization/VisualizationGraphHelper.cpp b/gui/src/Visualization/VisualizationGraphHelper.cpp
index bcff078..022a6a1 100644
--- a/gui/src/Visualization/VisualizationGraphHelper.cpp
+++ b/gui/src/Visualization/VisualizationGraphHelper.cpp
@@ -1,6 +1,8 @@
 #include "Visualization/VisualizationGraphHelper.h"
 #include "Visualization/qcustomplot.h"
 
+#include <Common/ColorUtils.h>
+
 #include <Data/ScalarSeries.h>
 #include <Data/VectorSeries.h>
 
@@ -84,9 +86,12 @@ struct PlottablesCreator<T,
         // Gets the number of components of the data series
         auto componentCount = dataSeries.valuesData()->componentCount();
 
+        auto colors = ColorUtils::colors(Qt::blue, Qt::red, componentCount);
+
         // For each component of the data series, creates a QCPGraph to add to the plot
         for (auto i = 0; i < componentCount; ++i) {
             auto graph = plot.addGraph();
+            graph->setPen(QPen{colors.at(i)});
 
             result.insert({i, graph});
         }