| /**************************************************************************** |
| ** |
| ** Copyright (C) 2016 The Qt Company Ltd. |
| ** Contact: https://www.qt.io/licensing/ |
| ** |
| ** This file is part of the documentation of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:BSD$ |
| ** Commercial License Usage |
| ** Licensees holding valid commercial Qt licenses may use this file in |
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| ** information use the contact form at https://www.qt.io/contact-us. |
| ** |
| ** BSD License Usage |
| ** Alternatively, 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 |
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| ** the documentation and/or other materials provided with the |
| ** distribution. |
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| ** 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 |
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| ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." |
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| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| //! [0] |
| class SimpleItem : public QGraphicsItem |
| { |
| public: |
| QRectF boundingRect() const override |
| { |
| qreal penWidth = 1; |
| return QRectF(-10 - penWidth / 2, -10 - penWidth / 2, |
| 20 + penWidth, 20 + penWidth); |
| } |
| |
| void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, |
| QWidget *widget) override |
| { |
| painter->drawRoundedRect(-10, -10, 20, 20, 5, 5); |
| } |
| }; |
| //! [0] |
| |
| |
| //! [1] |
| class CustomItem : public QGraphicsItem |
| { |
| public: |
| enum { Type = UserType + 1 }; |
| |
| int type() const override |
| { |
| // 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] |
| |
| |
| //! [18] |
| class QGraphicsPathItem : public QAbstractGraphicsShapeItem |
| { |
| public: |
| enum { Type = 2 }; |
| int type() const override { return Type; } |
| ... |
| }; |
| //! [18] |
| |
| //! [19] |
| QTransform xform = item->deviceTransform(view->viewportTransform()); |
| QRect deviceRect = xform.mapRect(rect).toAlignedRect(); |
| view->viewport()->scroll(dx, dy, deviceRect); |
| //! [19] |
| |
| //! [20] |
| item->setTransform(QTransform().rotate(angle), true); |
| //! [20] |
| |
| //! [21] |
| setTransform(QTransform::fromScale(sx, sy), true); |
| //! [21] |
| |
| //! [22] |
| setTransform(QTransform().shear(sh, sv), true); |
| //! [22] |
| |
| //! [23] |
| setTransform(QTransform::fromTranslate(dx, dy), true); |
| //! [23] |