1 files changed, 111 insertions, 0 deletions
diff --git a/src/charts/ChartScene.cpp b/src/charts/ChartScene.cpp
new file mode 100644
index 0000000..559ecc5
--- /dev/null
+++ b/src/charts/ChartScene.cpp
@@ -0,0 +1,111 @@
+#include "ChartScene.h"
+#include "ChartAxes.h"
+#include <cstdlib>
+#include <cmath>
+#include "ChartDataLine.h"
+
+const QSizeF ChartScene::Margin(30, 20);
+const QSizeF ChartScene::Padding(20, 20);
+const QSizeF ChartScene::DataSetPadding(10, 10);
+
+ChartScene::ChartScene(Chart* chart):
+    QGraphicsScene(chart), chart(chart), dataDirection(1)
+{
+    setSceneRect(0, 0, 600, 300);
+}
+
+void ChartScene::setDataSet(const QList<DataPoint>& dataSet, int xTickInterval)
+{
+    clear();
+    this->dataSet = dataSet;
+    initYScale();
+    ChartAxes(this, xTickInterval).paint();
+    ChartDataLine(this).paint();
+}
+
+void ChartScene::initYScale()
+{
+    yMin = computeMinY();
+    yMax = computeMaxY();
+    yTickSpacing = computeYTickSpacing();
+    extendYMinMax();
+    yScale = getDataSetSize().height() / getYDiff();
+}
+
+int ChartScene::computeMinY() const
+{
+    int min = 1000000;
+    foreach(DataPoint point, dataSet)
+        if(point.value < min)
+            min = point.value;
+    return min;
+}
+
+int ChartScene::computeMaxY() const
+{
+    int max = -1000000;
+    foreach(DataPoint point, dataSet)
+        if(point.value > max)
+            max = point.value;
+    return max;
+}
+
+int ChartScene::computeYTickSpacing() const
+{
+    const int higherZonesLimit = 4;
+    const int lowerZonesLimit = 3;
+
+    double order = floor(log10(getYDiff()));
+    double base = pow(10, order);
+    double zonesNum = ceil(getYDiff() / base);
+    if(zonesNum > higherZonesLimit)
+        base *= 2;
+    else if(zonesNum < lowerZonesLimit)
+        base /= 2;
+    int res = (int)base;
+    if(res == 0)
+        res = 10;
+    return res;
+}
+
+void ChartScene::extendYMinMax()
+{
+    yMin = int(floor(yMin / double(yTickSpacing))) * yTickSpacing;
+    yMax = int(ceil(yMax / double(yTickSpacing))) * yTickSpacing;
+    if (yMax == yMin)
+        yMax = yMin + yTickSpacing;
+}
+
+QSizeF ChartScene::getBorder()
+{
+    return Margin + Padding;
+}
+
+QRectF ChartScene::getChartRect() const
+{
+    QSizeF border = getBorder();
+    return sceneRect().adjusted(border.width(), border.height(),
+        -border.width(), -border.height());
+}
+
+QPointF ChartScene::getChartOrigin() const
+{
+    QRectF chartRect = getChartRect();
+    return QPointF(chartRect.left(), chartRect.bottom());
+}
+
+QSizeF ChartScene::getDataSetSize() const
+{
+    QSizeF dataSetBorder(2 * getBorder() + DataSetPadding);
+    return sceneRect().size() - dataSetBorder;
+}
+
+qreal ChartScene::getXTickSpacing() const
+{
+    return getDataSetSize().width() / (dataSet.size() - 1);
+}
+
+qreal ChartScene::getYPosFromValue(int value) const
+{
+    return yScale * value;
+}