From 7532b52dd10c89d637688e96b315442a4f9e52b4 2016-06-29 22:22:17
From: jeandet <alexis.jeandet@member.fsf.org>
Date: 2016-06-29 22:22:17
Subject: [PATCH] Added parametric zoom on QChart.

Signed-off-by: jeandet <alexis.jeandet@member.fsf.org>

---

diff --git a/src/charts/qchart.cpp b/src/charts/qchart.cpp
index 67af761..1d4ff29 100644
--- a/src/charts/qchart.cpp
+++ b/src/charts/qchart.cpp
@@ -354,6 +354,11 @@ void QChart::zoomIn()
     d_ptr->zoomIn(2.0);
 }
 
+void QChart::zoomIn2(double factor)
+{
+    d_ptr->zoomIn2(factor);
+}
+
 /*!
  Zooms in the view to a maximum level at which \a rect is still fully visible.
  \note This is not supported for polar charts.
@@ -373,6 +378,11 @@ void QChart::zoomOut()
     d_ptr->zoomOut(2.0);
 }
 
+void QChart::zoomOut2(double factor)
+{
+    d_ptr->zoomOut2(factor);
+}
+
 /*!
  Zooms in the view by a custom \a factor.
 
@@ -834,6 +844,14 @@ void QChartPrivate::zoomIn(qreal factor)
     zoomIn(rect);
 }
 
+void QChartPrivate::zoomIn2(qreal factor)
+{
+    QRectF rect = m_presenter->geometry();
+    rect.setWidth(rect.width() / factor);
+    rect.moveCenter(m_presenter->geometry().center());
+    zoomIn(rect);
+}
+
 void QChartPrivate::zoomIn(const QRectF &rect)
 {
     if (!rect.isValid())
@@ -879,6 +897,24 @@ void QChartPrivate::zoomOut(qreal factor)
     m_presenter->setState(ChartPresenter::ShowState,QPointF());
 }
 
+void QChartPrivate::zoomOut2(qreal factor)
+{
+    const QRectF geometry = m_presenter->geometry();
+
+    QRectF r;
+    QSizeF size = geometry.size();
+    size.setWidth(size.width()/factor);
+    r.setSize(size);
+    r.moveCenter(QPointF(geometry.size().width()/2 ,geometry.size().height()/2));
+    if (!r.isValid())
+        return;
+
+    QPointF zoomPoint(r.center().x() / geometry.width(), r.center().y() / geometry.height());
+    m_presenter->setState(ChartPresenter::ZoomOutState,zoomPoint);
+    m_dataset->zoomOutDomain(r);
+    m_presenter->setState(ChartPresenter::ShowState,QPointF());
+}
+
 void QChartPrivate::scroll(qreal dx, qreal dy)
 {
     if (dx < 0) m_presenter->setState(ChartPresenter::ScrollLeftState,QPointF());
diff --git a/src/charts/qchart.h b/src/charts/qchart.h
index 40b53a8..21ee8fd 100644
--- a/src/charts/qchart.h
+++ b/src/charts/qchart.h
@@ -147,7 +147,9 @@ public:
     QEasingCurve animationEasingCurve() const;
 
     void zoomIn();
+    void zoomIn2(double factor);
     void zoomOut();
+    void zoomOut2(double factor);
 
     void zoomIn(const QRectF &rect);
     void zoom(qreal factor);
diff --git a/src/charts/qchart_p.h b/src/charts/qchart_p.h
index 1f11b3c..05441c7 100644
--- a/src/charts/qchart_p.h
+++ b/src/charts/qchart_p.h
@@ -68,7 +68,9 @@ public:
 
     void init();
     void zoomIn(qreal factor);
+    void zoomIn2(qreal factor);
     void zoomOut(qreal factor);
+    void zoomOut2(qreal factor);
     void zoomIn(const QRectF &rect);
     void zoomReset();
     bool isZoomed();