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Diffstat (limited to 'examples/charts/chartsgallery/callout.cpp')
-rw-r--r-- | examples/charts/chartsgallery/callout.cpp | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/examples/charts/chartsgallery/callout.cpp b/examples/charts/chartsgallery/callout.cpp new file mode 100644 index 00000000..2169286c --- /dev/null +++ b/examples/charts/chartsgallery/callout.cpp @@ -0,0 +1,111 @@ +// Copyright (C) 2023 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only + +#include "callout.h" + +#include <QChart> +#include <QFontMetrics> +#include <QGraphicsSceneMouseEvent> +#include <QMouseEvent> +#include <QPainter> + +Callout::Callout(QChart *chart) + : QGraphicsItem(chart) + , m_chart(chart) +{ +} + +QRectF Callout::boundingRect() const +{ + QPointF anchor = mapFromParent(m_chart->mapToPosition(m_anchor)); + QRectF rect; + rect.setLeft(qMin(m_rect.left(), anchor.x())); + rect.setRight(qMax(m_rect.right(), anchor.x())); + rect.setTop(qMin(m_rect.top(), anchor.y())); + rect.setBottom(qMax(m_rect.bottom(), anchor.y())); + return rect; +} + +void Callout::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) +{ + Q_UNUSED(option); + Q_UNUSED(widget); + QPainterPath path; + path.addRoundedRect(m_rect, 5, 5); + + QPointF anchor = mapFromParent(m_chart->mapToPosition(m_anchor)); + if (!m_rect.contains(anchor) && !m_anchor.isNull()) { + QPointF point1, point2; + + // establish the position of the anchor point in relation to m_rect + bool above = anchor.y() <= m_rect.top(); + bool aboveCenter = anchor.y() > m_rect.top() && anchor.y() <= m_rect.center().y(); + bool belowCenter = anchor.y() > m_rect.center().y() && anchor.y() <= m_rect.bottom(); + bool below = anchor.y() > m_rect.bottom(); + + bool onLeft = anchor.x() <= m_rect.left(); + bool leftOfCenter = anchor.x() > m_rect.left() && anchor.x() <= m_rect.center().x(); + bool rightOfCenter = anchor.x() > m_rect.center().x() && anchor.x() <= m_rect.right(); + bool onRight = anchor.x() > m_rect.right(); + + // get the nearest m_rect corner. + qreal x = (onRight + rightOfCenter) * m_rect.width(); + qreal y = (below + belowCenter) * m_rect.height(); + bool cornerCase = (above && onLeft) || (above && onRight) || (below && onLeft) || (below && onRight); + bool vertical = qAbs(anchor.x() - x) > qAbs(anchor.y() - y); + + qreal x1 = x + leftOfCenter * 10 - rightOfCenter * 20 + cornerCase * !vertical * (onLeft * 10 - onRight * 20); + qreal y1 = y + aboveCenter * 10 - belowCenter * 20 + cornerCase * vertical * (above * 10 - below * 20);; + point1.setX(x1); + point1.setY(y1); + + qreal x2 = x + leftOfCenter * 20 - rightOfCenter * 10 + cornerCase * !vertical * (onLeft * 20 - onRight * 10);; + qreal y2 = y + aboveCenter * 20 - belowCenter * 10 + cornerCase * vertical * (above * 20 - below * 10);; + point2.setX(x2); + point2.setY(y2); + + path.moveTo(point1); + path.lineTo(anchor); + path.lineTo(point2); + path = path.simplified(); + } + painter->setBrush(QColor(255, 255, 255)); + painter->drawPath(path); + painter->drawText(m_textRect, m_text); +} + +void Callout::mousePressEvent(QGraphicsSceneMouseEvent *event) +{ + event->setAccepted(true); +} + +void Callout::mouseMoveEvent(QGraphicsSceneMouseEvent *event) +{ + if (event->buttons() & Qt::LeftButton){ + setPos(mapToParent(event->pos() - event->buttonDownPos(Qt::LeftButton))); + event->setAccepted(true); + } else { + event->setAccepted(false); + } +} + +void Callout::setText(const QString &text) +{ + m_text = text; + QFontMetrics metrics(m_font); + m_textRect = metrics.boundingRect(QRect(0, 0, 150, 150), Qt::AlignLeft, m_text); + m_textRect.translate(5, 5); + prepareGeometryChange(); + m_rect = m_textRect.adjusted(-5, -5, 5, 5); +} + +void Callout::setAnchor(QPointF point) +{ + m_anchor = point; +} + +void Callout::updateGeometry() +{ + prepareGeometryChange(); + setPos(m_chart->mapToPosition(m_anchor) + QPoint(10, -50)); +} |