##// END OF EJS Templates
Optimize polar chart radius calculation a bit....
Optimize polar chart radius calculation a bit. Current algorithm still results in an occasional extra unneeded iteration, as it uses only crude approximation for radius reduction. However, any speedup gained by accurately calculating needed reduction would be very minor compared to approximations used, so it doesn't seem worth the effort to figure out the complex math. Change-Id: If670a1b058a85cd0305b93f62e6388b463bafd0d Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

File last commit:

r2540:18da5db7d538
r2542:189023d9a551
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horizontalaxis.cpp
223 lines | 8.8 KiB | text/x-c | CppLexer
/ src / axis / horizontalaxis.cpp
/****************************************************************************
**
** Copyright (C) 2013 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 "horizontalaxis_p.h"
#include "qabstractaxis_p.h"
#include "chartpresenter_p.h"
#include <qmath.h>
#include <QDebug>
QTCOMMERCIALCHART_BEGIN_NAMESPACE
HorizontalAxis::HorizontalAxis(QAbstractAxis *axis, QGraphicsItem *item, bool intervalAxis)
: CartesianChartAxis(axis, item, intervalAxis)
{
}
HorizontalAxis::~HorizontalAxis()
{
}
void HorizontalAxis::updateGeometry()
{
const QVector<qreal> &layout = ChartAxisElement::layout();
if (layout.isEmpty())
return;
QStringList labelList = labels();
QList<QGraphicsItem *> lines = gridItems();
QList<QGraphicsItem *> labels = labelItems();
QList<QGraphicsItem *> shades = shadeItems();
QList<QGraphicsItem *> arrow = arrowItems();
QGraphicsTextItem *title = titleItem();
Q_ASSERT(labels.size() == labelList.size());
Q_ASSERT(layout.size() == labelList.size());
const QRectF &axisRect = axisGeometry();
const QRectF &gridRect = gridGeometry();
//arrow
QGraphicsLineItem *arrowItem = static_cast<QGraphicsLineItem *>(arrow.at(0));
if (axis()->alignment() == Qt::AlignTop)
arrowItem->setLine(gridRect.left(), axisRect.bottom(), gridRect.right(), axisRect.bottom());
else if (axis()->alignment() == Qt::AlignBottom)
arrowItem->setLine(gridRect.left(), axisRect.top(), gridRect.right(), axisRect.top());
qreal width = 0;
//title
QRectF titleBoundingRect;
QString titleText = axis()->titleText();
qreal availableSpace = axisRect.height() - labelPadding();
if (!titleText.isEmpty() && titleItem()->isVisible()) {
availableSpace -= titlePadding() * 2.0;
qreal minimumLabelHeight = ChartPresenter::textBoundingRect(axis()->labelsFont(), "...").height();
QString truncatedTitle = ChartPresenter::truncatedText(axis()->titleFont(), titleText, qreal(0.0),
gridRect.width(), Qt::Horizontal, titleBoundingRect);
qreal titleSpace = availableSpace - minimumLabelHeight;
if (titleSpace < titleBoundingRect.height()) {
// Need to also truncate title vertically (multiline title)
bool skip = false;
if (truncatedTitle.endsWith("...")) {
if (truncatedTitle.size() == 3)
skip = true; // Already truncated to minimum
else
truncatedTitle.chop(3);
}
if (!skip)
truncatedTitle = ChartPresenter::truncatedText(axis()->titleFont(), truncatedTitle, qreal(0.0),
titleSpace, Qt::Vertical, titleBoundingRect);
}
title->setHtml(truncatedTitle);
titleBoundingRect = title->boundingRect();
QPointF center = gridRect.center() - titleBoundingRect.center();
if (axis()->alignment() == Qt::AlignTop)
title->setPos(center.x(), axisRect.top() + titlePadding());
else if (axis()->alignment() == Qt::AlignBottom)
title->setPos(center.x(), axisRect.bottom() - titleBoundingRect.height() - titlePadding());
availableSpace -= titleBoundingRect.height();
}
for (int i = 0; i < layout.size(); ++i) {
//items
QGraphicsLineItem *gridItem = static_cast<QGraphicsLineItem*>(lines.at(i));
QGraphicsLineItem *tickItem = static_cast<QGraphicsLineItem*>(arrow.at(i + 1));
QGraphicsTextItem *labelItem = static_cast<QGraphicsTextItem *>(labels.at(i));
//grid line
gridItem->setLine(layout[i], gridRect.top(), layout[i], gridRect.bottom());
//label text wrapping
QString text = labelList.at(i);
QRectF boundingRect;
labelItem->setHtml(ChartPresenter::truncatedText(axis()->labelsFont(), text, axis()->labelsAngle(),
availableSpace, Qt::Vertical, boundingRect));
//label transformation origin point
const QRectF& rect = labelItem->boundingRect();
QPointF center = rect.center();
labelItem->setTransformOriginPoint(center.x(), center.y());
qreal heightDiff = rect.height() - boundingRect.height();
//ticks and label position
if (axis()->alignment() == Qt::AlignTop) {
labelItem->setPos(layout[i] - center.x(), axisRect.bottom() - rect.height() + (heightDiff / 2.0) - labelPadding());
tickItem->setLine(layout[i], axisRect.bottom(), layout[i], axisRect.bottom() - labelPadding());
} else if (axis()->alignment() == Qt::AlignBottom) {
labelItem->setPos(layout[i] - center.x(), axisRect.top() - (heightDiff / 2.0) + labelPadding());
tickItem->setLine(layout[i], axisRect.top(), layout[i], axisRect.top() + labelPadding());
}
//label in between
bool forceHide = false;
if (intervalAxis() && (i + 1) != layout.size()) {
qreal leftBound = qMax(layout[i], gridRect.left());
qreal rightBound = qMin(layout[i + 1], gridRect.right());
const qreal delta = rightBound - leftBound;
// Hide label in case visible part of the category at the grid edge is too narrow
if (delta < boundingRect.width()
&& (leftBound == gridRect.left() || rightBound == gridRect.right())) {
forceHide = true;
} else {
labelItem->setPos(leftBound + (delta / 2.0) - center.x(), labelItem->pos().y());
}
}
//label overlap detection - compensate one pixel for rounding errors
if (labelItem->pos().x() < width || forceHide ||
labelItem->pos().x() < (axisRect.left() - 1.0) ||
(labelItem->pos().x() + boundingRect.width() - 1.0) > axisRect.right()){
labelItem->setVisible(false);
} else {
labelItem->setVisible(true);
width = boundingRect.width() + labelItem->pos().x();
}
//shades
if ((i + 1) % 2 && i > 1) {
QGraphicsRectItem *rectItem = static_cast<QGraphicsRectItem *>(shades.at(i / 2 - 1));
qreal leftBound = qMax(layout[i - 1], gridRect.left());
qreal rightBound = qMin(layout[i], gridRect.right());
rectItem->setRect(leftBound, gridRect.top(), rightBound - leftBound, gridRect.height());
if (rectItem->rect().width() <= 0.0)
rectItem->setVisible(false);
else
rectItem->setVisible(true);
}
// check if the grid line and the axis tick should be shown
qreal x = gridItem->line().p1().x();
if (x < gridRect.left() || x > gridRect.right()) {
gridItem->setVisible(false);
tickItem->setVisible(false);
} else {
gridItem->setVisible(true);
tickItem->setVisible(true);
}
}
//begin/end grid line in case labels between
if (intervalAxis()) {
QGraphicsLineItem *gridLine;
gridLine = static_cast<QGraphicsLineItem *>(lines.at(layout.size()));
gridLine->setLine(gridRect.right(), gridRect.top(), gridRect.right(), gridRect.bottom());
gridLine->setVisible(true);
gridLine = static_cast<QGraphicsLineItem*>(lines.at(layout.size()+1));
gridLine->setLine(gridRect.left(), gridRect.top(), gridRect.left(), gridRect.bottom());
gridLine->setVisible(true);
}
}
QSizeF HorizontalAxis::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
Q_UNUSED(constraint);
QSizeF sh(0,0);
if (axis()->titleText().isEmpty() || !titleItem()->isVisible())
return sh;
switch (which) {
case Qt::MinimumSize: {
QRectF titleRect = ChartPresenter::textBoundingRect(axis()->titleFont(), "...");
sh = QSizeF(titleRect.width(), titleRect.height() + (titlePadding() * 2.0));
break;
}
case Qt::MaximumSize:
case Qt::PreferredSize: {
QRectF titleRect = ChartPresenter::textBoundingRect(axis()->titleFont(), axis()->titleText());
sh = QSizeF(titleRect.width(), titleRect.height() + (titlePadding() * 2.0));
break;
}
default:
break;
}
return sh;
}
QTCOMMERCIALCHART_END_NAMESPACE