Fix logarithmic axis point calculation

For logarithmic axis the geometry point is set even if the point value
is zero or negative. For zero and negative values the x-point is set to
zero and the y-point is set to chart height. This way the bar chart
items can ignore the return value from calculateGeometryPoint() method
and not draw the bar for a value that does not have logarithm defined.

Task-number: QTRD-2065
Change-Id: I7ba4efed6a0678eb487377e3e88bdee9c849a9a3
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@digia.com>

9 files changed, 41 insertions, 40 deletions

diff --git a/src/barchart/horizontal/bar/horizontalbarchartitem.cpp b/src/barchart/horizontal/bar/horizontalbarchartitem.cpp
index 97d8ecb7..941a1645 100644
--- a/src/barchart/horizontal/bar/horizontalbarchartitem.cpp
+++ b/src/barchart/horizontal/bar/horizontalbarchartitem.cpp
@@ -81,9 +81,6 @@ QVector<QRectF> HorizontalBarChartItem::calculateLayout()
 
             QPointF bottomRight = domain()->calculateGeometryPoint(QPointF(value, category - barWidth / 2 + (set + 1)/setCount * barWidth), m_validData);
 
-            if (!m_validData)
-                return QVector<QRectF>();
-
             rect.setTopLeft(topLeft);
             rect.setBottomRight(bottomRight);
             layout.append(rect.normalized());
diff --git a/src/barchart/horizontal/percent/horizontalpercentbarchartitem.cpp b/src/barchart/horizontal/percent/horizontalpercentbarchartitem.cpp
index 9d530e93..0a169ec5 100644
--- a/src/barchart/horizontal/percent/horizontalpercentbarchartitem.cpp
+++ b/src/barchart/horizontal/percent/horizontalpercentbarchartitem.cpp
@@ -82,8 +82,6 @@ QVector<QRectF> HorizontalPercentBarChartItem::calculateLayout()
                 topLeft = domain()->calculateGeometryPoint(QPointF(set ? 100 * sum/categorySum : 0, category - barWidth/2), m_validData);
             QPointF bottomRight = domain()->calculateGeometryPoint(QPointF(100 * (value + sum)/categorySum, category + barWidth/2), m_validData);
 
-            if (!m_validData)
-                 return QVector<QRectF>();
             rect.setTopLeft(topLeft);
             rect.setBottomRight(bottomRight);
             layout.append(rect.normalized());
diff --git a/src/barchart/horizontal/stacked/horizontalstackedbarchartitem.cpp b/src/barchart/horizontal/stacked/horizontalstackedbarchartitem.cpp
index 0bfe8e6d..a4fad23c 100644
--- a/src/barchart/horizontal/stacked/horizontalstackedbarchartitem.cpp
+++ b/src/barchart/horizontal/stacked/horizontalstackedbarchartitem.cpp
@@ -92,8 +92,7 @@ QVector<QRectF> HorizontalStackedBarChartItem::calculateLayout()
                     topLeft = domain()->calculateGeometryPoint(QPointF(set ? positiveSum : 0, category + barWidth / 2), m_validData);
                 positiveSum += value;
             }
-            if (!m_validData)
-                 return QVector<QRectF>();
+
             rect.setTopLeft(topLeft);
             rect.setBottomRight(bottomRight);
             layout.append(rect.normalized());
diff --git a/src/barchart/vertical/bar/barchartitem.cpp b/src/barchart/vertical/bar/barchartitem.cpp
index f5ea55ce..4b948afd 100644
--- a/src/barchart/vertical/bar/barchartitem.cpp
+++ b/src/barchart/vertical/bar/barchartitem.cpp
@@ -81,9 +81,6 @@ QVector<QRectF> BarChartItem::calculateLayout()
             else
                 bottomRight = domain()->calculateGeometryPoint(QPointF(category - barWidth / 2 + (set + 1)/(setCount) * barWidth, 0), m_validData);
 
-            if (!m_validData)
-                 return QVector<QRectF>();
-
             rect.setTopLeft(topLeft);
             rect.setBottomRight(bottomRight);
             layout.append(rect.normalized());
diff --git a/src/barchart/vertical/percent/percentbarchartitem.cpp b/src/barchart/vertical/percent/percentbarchartitem.cpp
index 893b88da..e0e4a4a5 100644
--- a/src/barchart/vertical/percent/percentbarchartitem.cpp
+++ b/src/barchart/vertical/percent/percentbarchartitem.cpp
@@ -84,8 +84,6 @@ QVector<QRectF> PercentBarChartItem::calculateLayout()
             else
                 bottomRight = domain()->calculateGeometryPoint(QPointF(category + barWidth/2, set ? 100 * sum/categorySum : 0), m_validData);
 
-            if (!m_validData)
-                 return QVector<QRectF>();
             rect.setTopLeft(topLeft);
             rect.setBottomRight(bottomRight);
             layout.append(rect.normalized());
diff --git a/src/barchart/vertical/stacked/stackedbarchartitem.cpp b/src/barchart/vertical/stacked/stackedbarchartitem.cpp
index 42c2aad3..909d7d50 100644
--- a/src/barchart/vertical/stacked/stackedbarchartitem.cpp
+++ b/src/barchart/vertical/stacked/stackedbarchartitem.cpp
@@ -93,8 +93,7 @@ QVector<QRectF> StackedBarChartItem::calculateLayout()
                     bottomRight = domain()->calculateGeometryPoint(QPointF(category + barWidth / 2, set ? positiveSum : 0), m_validData);
                 positiveSum += value;
             }
-            if (!m_validData)
-                 return QVector<QRectF>();
+
             rect.setTopLeft(topLeft);
             rect.setBottomRight(bottomRight);
             layout.append(rect.normalized());
diff --git a/src/domain/logxlogydomain.cpp b/src/domain/logxlogydomain.cpp
index 9aa75fbe..85b9a019 100644
--- a/src/domain/logxlogydomain.cpp
+++ b/src/domain/logxlogydomain.cpp
@@ -138,18 +138,29 @@ void LogXLogYDomain::move(qreal dx, qreal dy)
 
 QPointF LogXLogYDomain::calculateGeometryPoint(const QPointF &point, bool &ok) const
 {
+    const qreal deltaX = m_size.width() / qAbs(m_logRightX - m_logLeftX);
+    const qreal deltaY = m_size.height() / qAbs(m_logRightY - m_logLeftY);
+    qreal x(0);
+    qreal y(0);
     if (point.x() > 0 && point.y() > 0) {
-        const qreal deltaX = m_size.width() / qAbs(m_logRightX - m_logLeftX);
-        const qreal deltaY = m_size.height() / qAbs(m_logRightY - m_logLeftY);
-        qreal x = (log10(point.x()) / log10(m_logBaseX)) * deltaX - m_logLeftX * deltaX;
-        qreal y = (log10(point.y()) / log10(m_logBaseY)) * -deltaY - m_logLeftY * -deltaY + m_size.height();
+        x = (log10(point.x()) / log10(m_logBaseX)) * deltaX - m_logLeftX * deltaX;
+        y = (log10(point.y()) / log10(m_logBaseY)) * -deltaY - m_logLeftY * -deltaY + m_size.height();
         ok = true;
-        return QPointF(x, y);
     } else {
-        qWarning() << "Logarithm of negative value is undefined. Empty layout returned.";
+        qWarning() << "Logarithms of zero and negative values are undefined.";
         ok = false;
-        return QPointF();
+        if (point.x() > 0)
+            x = (log10(point.x()) / log10(m_logBaseX)) * deltaX - m_logLeftX * deltaX;
+        else
+            x = 0;
+        if (point.y() > 0) {
+            y = (log10(point.y()) / log10(m_logBaseY)) * -deltaY - m_logLeftY * -deltaY
+                    + m_size.height();
+        } else {
+            y = m_size.height();
+        }
     }
+    return QPointF(x, y);
 }
 
 QVector<QPointF> LogXLogYDomain::calculateGeometryPoints(const QList<QPointF> &vector) const
@@ -167,7 +178,7 @@ QVector<QPointF> LogXLogYDomain::calculateGeometryPoints(const QList<QPointF> &v
             result[i].setX(x);
             result[i].setY(y);
         } else {
-            qWarning() << "Logarithm of negative value is undefined. Empty layout returned.";
+            qWarning() << "Logarithms of zero and negative values are undefined.";
             return QVector<QPointF>();
         }
     }
diff --git a/src/domain/logxydomain.cpp b/src/domain/logxydomain.cpp
index f131096c..b42d1b64 100644
--- a/src/domain/logxydomain.cpp
+++ b/src/domain/logxydomain.cpp
@@ -131,20 +131,20 @@ void LogXYDomain::move(qreal dx, qreal dy)
 
 QPointF LogXYDomain::calculateGeometryPoint(const QPointF &point, bool &ok) const
 {
+    const qreal deltaX = m_size.width() / (m_logRightX - m_logLeftX);
+    const qreal deltaY = m_size.height() / (m_maxY - m_minY);
 
+    qreal x(0);
+    qreal y = (point.y() - m_minY) * -deltaY + m_size.height();
     if (point.x() > 0) {
-        const qreal deltaX = m_size.width() / (m_logRightX - m_logLeftX);
-        const qreal deltaY = m_size.height() / (m_maxY - m_minY);
-
-        qreal x = (log10(point.x()) / log10(m_logBaseX)) * deltaX - m_logLeftX * deltaX;
-        qreal y = (point.y() - m_minY) * -deltaY + m_size.height();
+        x = (log10(point.x()) / log10(m_logBaseX)) * deltaX - m_logLeftX * deltaX;
         ok = true;
-        return QPointF(x, y);
     } else {
-        qWarning() << "Logarithm of negative value is undefined. Empty layout returned.";
+        x = 0;
+        qWarning() << "Logarithms of zero and negative values are undefined.";
         ok = false;
-        return QPointF();
     }
+    return QPointF(x, y);
 }
 
 QVector<QPointF> LogXYDomain::calculateGeometryPoints(const QList<QPointF> &vector) const
@@ -162,9 +162,10 @@ QVector<QPointF> LogXYDomain::calculateGeometryPoints(const QList<QPointF> &vect
             result[i].setX(x);
             result[i].setY(y);
         } else {
-            qWarning() << "Logarithm of negative value is undefined. Empty layout returned.";
+            qWarning() << "Logarithms of zero and negative values are undefined.";
             return QVector<QPointF>();
         }
+
     }
     return result;
 }
diff --git a/src/domain/xlogydomain.cpp b/src/domain/xlogydomain.cpp
index 7ad194b5..494e8f5b 100644
--- a/src/domain/xlogydomain.cpp
+++ b/src/domain/xlogydomain.cpp
@@ -131,19 +131,20 @@ void XLogYDomain::move(qreal dx, qreal dy)
 
 QPointF XLogYDomain::calculateGeometryPoint(const QPointF &point, bool &ok) const
 {
-    if (point.y() > 0) {
-        const qreal deltaX = m_size.width() / (m_maxX - m_minX);
-        const qreal deltaY = m_size.height() / qAbs(m_logRightY - m_logLeftY);
+    const qreal deltaX = m_size.width() / (m_maxX - m_minX);
+    const qreal deltaY = m_size.height() / qAbs(m_logRightY - m_logLeftY);
 
-        qreal x = (point.x() - m_minX) * deltaX;
-        qreal y = (log10(point.y()) / log10(m_logBaseY)) * -deltaY - m_logLeftY * -deltaY + m_size.height();
+    qreal x = (point.x() - m_minX) * deltaX;
+    qreal y(0);
+    if (point.y() > 0) {
+        y = (log10(point.y()) / log10(m_logBaseY)) * -deltaY - m_logLeftY * -deltaY + m_size.height();
         ok = true;
-        return QPointF(x, y);
     } else {
-        qWarning() << "Logarithm of negative value is undefined. Empty layout returned.";
+        y = m_size.height();
+        qWarning() << "Logarithms of zero and negative values are undefined.";
         ok = false;
-        return QPointF();
     }
+    return QPointF(x, y);
 }
 
 QVector<QPointF> XLogYDomain::calculateGeometryPoints(const QList<QPointF> &vector) const
@@ -161,7 +162,7 @@ QVector<QPointF> XLogYDomain::calculateGeometryPoints(const QList<QPointF> &vect
             result[i].setX(x);
             result[i].setY(y);
         } else {
-            qWarning() << "Logarithm of negative value is undefined. Empty layout returned.";
+            qWarning() << "Logarithms of zero and negative values are undefined.";
             return QVector<QPointF>();
         }
     }