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Diffstat (limited to 'doc/src/snippets/code/src_gui_graphicsview_qgraphicsitem.cpp')
-rw-r--r-- | doc/src/snippets/code/src_gui_graphicsview_qgraphicsitem.cpp | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/doc/src/snippets/code/src_gui_graphicsview_qgraphicsitem.cpp b/doc/src/snippets/code/src_gui_graphicsview_qgraphicsitem.cpp new file mode 100644 index 0000000000..c4cf674995 --- /dev/null +++ b/doc/src/snippets/code/src_gui_graphicsview_qgraphicsitem.cpp @@ -0,0 +1,278 @@ +/**************************************************************************** +** +** Copyright (C) 2011 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. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** $QT_END_LICENSE$ +** +****************************************************************************/ + +//! [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<ButtonItem *>(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] + +//! [19] +QTransform xform = item->deviceTransform(view->viewportTransform()); +QRect deviceRect = xform.mapRect(rect).toAlignedRect(); +view->viewport()->scroll(dx, dy, deviceRect); +//! [19] + |