HG_REPOSITORIES/LPP/INSTRUMENTATION/USERS/JEANDET/qtcharts Commit - r972:23d12d63b029

Prevent slice label pointing straight down (because it looks bad).

Jani Honkonen -

r972:23d12d63b029

parent child

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r972:23d12d63b029

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src/piechart/piesliceitem.cpp +11 -3

             /****************************************************************************
             **
             ** Copyright (C) 2012 Digia Plc
             ** All rights reserved.
             ** For any questions to Digia, please use contact form at http://qt.digia.com
             **
             ** This file is part of the Qt Commercial Charts Add-on.
             **
             ** $QT_BEGIN_LICENSE$
             ** Licensees holding valid Qt Commercial licenses may use this file in
             ** accordance with the Qt Commercial License Agreement provided with the
             ** Software or, alternatively, in accordance with the terms contained in
             ** a written agreement between you and Digia.
             **
             ** If you have questions regarding the use of this file, please use
             ** contact form at http://qt.digia.com
             ** $QT_END_LICENSE$
             **
             ****************************************************************************/
             #include "piesliceitem_p.h"
             #include "piechartitem_p.h"
             #include "qpieseries.h"
             #include "qpieslice.h"
             #include "chartpresenter_p.h"
             #include <QPainter>
             #include <QDebug>
             #include <qmath.h>
             #include <QGraphicsSceneEvent>
             #include <QTime>
             QTCOMMERCIALCHART_BEGIN_NAMESPACE
             #define PI 3.14159265 // TODO: is this defined in some header?
             QPointF offset(qreal angle, qreal length)
             {
                 qreal dx = qSin(angle*(PI/180)) * length;
                 qreal dy = qCos(angle*(PI/180)) * length;
                 return QPointF(dx, -dy);
             }
             PieSliceItem::PieSliceItem(QGraphicsItem* parent)
                 :QGraphicsObject(parent)
             {
                 setAcceptHoverEvents(true);
                 setAcceptedMouseButtons(Qt::MouseButtonMask);
                 setZValue(ChartPresenter::PieSeriesZValue);
             }
             PieSliceItem::~PieSliceItem()
             {
             }
             QRectF PieSliceItem::boundingRect() const
             {
                 return m_boundingRect;
             }
             QPainterPath PieSliceItem::shape() const
             {
                 // Don't include the label and label arm.
                 // This is used to detect a mouse clicks. We do not want clicks from label.
                 return m_slicePath;
             }
             void PieSliceItem::paint(QPainter* painter, const QStyleOptionGraphicsItem* /*option*/, QWidget* /*widget*/)
             {
                 painter->save();
                 painter->setClipRect(parentItem()->boundingRect());
                 painter->setPen(m_data.m_slicePen);
                 painter->setBrush(m_data.m_sliceBrush);
                 painter->drawPath(m_slicePath);
                 painter->restore();
                 if (m_data.m_isLabelVisible) {
                     painter->setClipRect(parentItem()->boundingRect());
                     painter->setPen(m_data.m_labelPen);
                     painter->drawPath(m_labelArmPath);
             		// the pen color will affect the font color as well
                     painter->setFont(m_data.m_labelFont);
                     painter->drawText(m_labelTextRect.bottomLeft(), m_data.m_labelText);
                 }
             }
             void PieSliceItem::hoverEnterEvent(QGraphicsSceneHoverEvent* /*event*/)
             {
                 emit hoverEnter(); // TODO: refactor emit hover(somebooleanvalue)
             }
             void PieSliceItem::hoverLeaveEvent(QGraphicsSceneHoverEvent* /*event*/)
             {
                 emit hoverLeave(); // TODO: refactor emit hover(somebooleanvalue)
             }
             void PieSliceItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
             {
                 emit clicked(event->buttons());
             }
             void PieSliceItem::setSliceData(PieSliceData sliceData)
             {
                 m_data = sliceData;
             }
             void PieSliceItem::updateGeometry()
             {
                 if (m_data.m_radius <= 0)
                     return;
                 prepareGeometryChange();
                 // update slice path
                 qreal centerAngle;
                 QPointF armStart;
                 m_slicePath = slicePath(m_data.m_center, m_data.m_radius, m_data.m_startAngle, m_data.m_angleSpan, &centerAngle, &armStart);
                 // update text rect
                 m_labelTextRect = labelTextRect(m_data.m_labelFont, m_data.m_labelText);
                 // update label arm path
                 QPointF labelTextStart;
                 m_labelArmPath = labelArmPath(armStart, centerAngle, m_data.m_radius * m_data.m_labelArmLengthFactor, m_labelTextRect.width(), &labelTextStart);
                 // update text position
                 m_labelTextRect.moveBottomLeft(labelTextStart);
                 // update bounding rect
                 if (m_data.m_isLabelVisible)
                     m_boundingRect = m_slicePath.boundingRect().united(m_labelArmPath.boundingRect()).united(m_labelTextRect);
                 else
                     m_boundingRect = m_slicePath.boundingRect();
             }
             QPointF PieSliceItem::sliceCenter(QPointF point, qreal radius, QPieSlice *slice)
             {
                 if (slice->isExploded()) {
                     qreal centerAngle = slice->startAngle() + ((slice->endAngle() - slice->startAngle())/2);
                     qreal len = radius * slice->explodeDistanceFactor();
                     qreal dx = qSin(centerAngle*(PI/180)) * len;
                     qreal dy = -qCos(centerAngle*(PI/180)) * len;
                     point += QPointF(dx, dy);
                 }
                 return point;
             }
-            QPainterPath PieSliceItem::slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, qreal* centerAngle, QPointF* armStart)
+            QPainterPath PieSliceItem::slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, qreal *centerAngle, QPointF* armStart)
             {
                 // calculate center angle
                 *centerAngle = startAngle + (angleSpan/2);
                 // calculate slice rectangle
                 QRectF rect(center.x()-radius, center.y()-radius, radius*2, radius*2);
                 // slice path
                 // TODO: draw the shape so that it might have a hole in the center
                 QPainterPath path;
                 path.moveTo(rect.center());
                 path.arcTo(rect, -startAngle + 90, -angleSpan);
                 path.closeSubpath();
                 // calculate label arm start point
                 *armStart = center;
                 *armStart += offset(*centerAngle, radius + PIESLICE_LABEL_GAP);
                 return path;
             }
-            QPainterPath PieSliceItem::labelArmPath(QPointF start, qreal angle, qreal length, qreal textWidth, QPointF* textStart)
+            QPainterPath PieSliceItem::labelArmPath(QPointF start, qreal angle, qreal length, qreal textWidth, QPointF *textStart)
             {
+                // prevent label arm pointing straight down because it will look bad
+                if (angle < 180 && angle > 170)
+                    angle = 170;
+                if (angle > 180 && angle < 190)
+                    angle = 190;
+                // line from slice to label
                 qreal dx = qSin(angle*(PI/180)) * length;
                 qreal dy = -qCos(angle*(PI/180)) * length;
                 QPointF parm1 = start + QPointF(dx, dy);
+                // line to underline the label
                 QPointF parm2 = parm1;
                 if (angle < 180) { // arm swings the other way on the left side
                      parm2 += QPointF(textWidth, 0);
                      *textStart = parm1;
                 }
                 else {
                      parm2 += QPointF(-textWidth,0);
                      *textStart = parm2;
                 }
                 // elevate the text position a bit so that it does not hit the line
-                *textStart += QPointF(0, -5);
+                *textStart += QPointF(0, -3);
                 QPainterPath path;
                 path.moveTo(start);
                 path.lineTo(parm1);
                 path.lineTo(parm2);
                 return path;
             }
             QRectF PieSliceItem::labelTextRect(QFont font, QString text)
             {
                 QFontMetricsF fm(font);
                 return fm.boundingRect(text);
             }
             #include "moc_piesliceitem_p.cpp"
             QTCOMMERCIALCHART_END_NAMESPACE

src/piechart/piesliceitem_p.h +3 -3

             /****************************************************************************
             **
             ** Copyright (C) 2012 Digia Plc
             ** All rights reserved.
             ** For any questions to Digia, please use contact form at http://qt.digia.com
             **
             ** This file is part of the Qt Commercial Charts Add-on.
             **
             ** $QT_BEGIN_LICENSE$
             ** Licensees holding valid Qt Commercial licenses may use this file in
             ** accordance with the Qt Commercial License Agreement provided with the
             ** Software or, alternatively, in accordance with the terms contained in
             ** a written agreement between you and Digia.
             **
             ** If you have questions regarding the use of this file, please use
             ** contact form at http://qt.digia.com
             ** $QT_END_LICENSE$
             **
             ****************************************************************************/
             #ifndef PIESLICEITEM_H
             #define PIESLICEITEM_H
             #include "qchartglobal.h"
             #include "charttheme_p.h"
             #include "qpieseries.h"
             #include "pieslicedata_p.h"
             #include <QGraphicsItem>
             #include <QRectF>
             #include <QColor>
             #include <QPen>
             #define PIESLICE_LABEL_GAP 5
             QTCOMMERCIALCHART_BEGIN_NAMESPACE
             class PieChartItem;
             class PieSliceLabel;
             class QPieSlice;
             class PieSliceItem : public QGraphicsObject
             {
                 Q_OBJECT
             public:
                 PieSliceItem(QGraphicsItem* parent = 0);
                 ~PieSliceItem();
             public: // from QGraphicsItem
                 QRectF boundingRect() const;
                 QPainterPath shape() const;
                 void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
                 void hoverEnterEvent(QGraphicsSceneHoverEvent *event);
                 void hoverLeaveEvent(QGraphicsSceneHoverEvent *event);
                 void mousePressEvent(QGraphicsSceneMouseEvent *event);
             Q_SIGNALS:
                 void clicked(Qt::MouseButtons buttons);
                 void hoverEnter();
                 void hoverLeave();
             public:
                 void setSliceData(PieSliceData sliceData);
                 void updateGeometry();
                 static QPointF sliceCenter(QPointF point, qreal radius, QPieSlice *slice);
-                static QPainterPath slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, qreal* centerAngle, QPointF* armStart);
+                QPainterPath slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, qreal *centerAngle, QPointF *armStart);
-                static QPainterPath labelArmPath(QPointF start, qreal angle, qreal length, qreal textWidth, QPointF* textStart);
+                QPainterPath labelArmPath(QPointF start, qreal angle, qreal length, qreal textWidth, QPointF *textStart);
-                static QRectF labelTextRect(QFont font, QString text);
+                QRectF labelTextRect(QFont font, QString text);
             private:
                 PieSliceData m_data;
                 QRectF m_boundingRect;
                 QPainterPath m_slicePath;
                 QPainterPath m_labelArmPath;
                 QRectF m_labelTextRect;
             };
             QTCOMMERCIALCHART_END_NAMESPACE
             #endif // PIESLICEITEM_H

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