/**************************************************************************** ** ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the documentation of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial Usage ** 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 Nokia. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain additional ** rights. These rights are described in the Nokia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** $QT_END_LICENSE$ ** ****************************************************************************/ //! [0] class SimpleItem : public QGraphicsItem { public: QRectF boundingRect() const { qreal penWidth = 1; return QRectF(-10 - penWidth / 2, -10 - penWidth / 2, 20 + penWidth, 20 + penWidth); } void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { painter->drawRoundedRect(-10, -10, 20, 20, 5, 5); } }; //! [0] //! [1] class CustomItem : public QGraphicsItem { ... enum { Type = UserType + 1 }; int type() const { // Enable the use of qgraphicsitem_cast with this item. return Type; } ... }; //! [1] //! [2] item->setCursor(Qt::IBeamCursor); //! [2] //! [3] item->setCursor(Qt::IBeamCursor); //! [3] //! [4] QGraphicsRectItem rect; rect.setPos(100, 100); rect.sceneTransform().map(QPointF(0, 0)); // returns QPointF(100, 100); rect.sceneTransform().inverted().map(QPointF(100, 100)); // returns QPointF(0, 0); //! [4] //! [5] QGraphicsRectItem rect; rect.setPos(100, 100); rect.deviceTransform(view->viewportTransform()).map(QPointF(0, 0)); // returns the item's (0, 0) point in view's viewport coordinates rect.deviceTransform(view->viewportTransform()).inverted().map(QPointF(100, 100)); // returns view's viewport's (100, 100) coordinate in item coordinates //! [5] //! [6] // Rotate an item 45 degrees around (0, 0). item->rotate(45); // Rotate an item 45 degrees around (x, y). item->setTransform(QTransform().translate(x, y).rotate(45).translate(-x, -y)); //! [6] //! [7] // Scale an item by 3x2 from its origin item->scale(3, 2); // Scale an item by 3x2 from (x, y) item->setTransform(QTransform().translate(x, y).scale(3, 2).translate(-x, -y)); //! [7] //! [8] QRectF CircleItem::boundingRect() const { qreal penWidth = 1; return QRectF(-radius - penWidth / 2, -radius - penWidth / 2, diameter + penWidth, diameter + penWidth); } //! [8] //! [9] QPainterPath RoundItem::shape() const { QPainterPath path; path.addEllipse(boundingRect()); return path; } //! [9] //! [10] void RoundRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { painter->drawRoundedRect(-10, -10, 20, 20, 5, 5); } //! [10] //! [11] static const int ObjectName = 0; QGraphicsItem *item = scene.itemAt(100, 50); if (item->data(ObjectName).toString().isEmpty()) { if (qgraphicsitem_cast(item)) item->setData(ObjectName, "Button"); } //! [11] //! [12] QGraphicsScene scene; QGraphicsEllipseItem *ellipse = scene.addEllipse(QRectF(-10, -10, 20, 20)); QGraphicsLineItem *line = scene.addLine(QLineF(-10, -10, 20, 20)); line->installSceneEventFilter(ellipse); // line's events are filtered by ellipse's sceneEventFilter() function. ellipse->installSceneEventFilter(line); // ellipse's events are filtered by line's sceneEventFilter() function. //! [12] //! [13] void CustomItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event) { QMenu menu; QAction *removeAction = menu.addAction("Remove"); QAction *markAction = menu.addAction("Mark"); QAction *selectedAction = menu.exec(event->screenPos()); // ... } //! [13] //! [14] CustomItem::CustomItem() { setAcceptDrops(true); ... } void CustomItem::dragEnterEvent(QGraphicsSceneDragDropEvent *event) { event->setAccepted(event->mimeData()->hasFormat("text/plain")); } //! [14] //! [15] QVariant Component::itemChange(GraphicsItemChange change, const QVariant &value) { if (change == ItemPositionChange && scene()) { // value is the new position. QPointF newPos = value.toPointF(); QRectF rect = scene()->sceneRect(); if (!rect.contains(newPos)) { // Keep the item inside the scene rect. newPos.setX(qMin(rect.right(), qMax(newPos.x(), rect.left()))); newPos.setY(qMin(rect.bottom(), qMax(newPos.y(), rect.top()))); return newPos; } } return QGraphicsItem::itemChange(change, value); } //! [15] //! [16] void CircleItem::setRadius(qreal newRadius) { if (radius != newRadius) { prepareGeometryChange(); radius = newRadius; } } //! [16] //! [17] // Group all selected items together QGraphicsItemGroup *group = scene->createItemGroup(scene->selecteditems()); // Destroy the group, and delete the group item scene->destroyItemGroup(group); //! [17] //! [QGraphicsItem type] class CustomItem : public QGraphicsItem { ... enum { Type = UserType + 1 }; int type() const { // Enable the use of qgraphicsitem_cast with this item. return Type; } ... }; //! [QGraphicsItem type] //! [18] class QGraphicsPathItem : public QAbstractGraphicsShapeItem { public: enum { Type = 2 }; int type() const { return Type; } ... }; //! [18]