qgraphicsitem_p.h

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QGRAPHICSITEM_P_H
#define QGRAPHICSITEM_P_H
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of other Qt classes.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#include <QtWidgets/private/qtwidgetsglobal_p.h>
#include "qgraphicsitem.h"
#include "qset.h"
#include "qpixmapcache.h"
#include <private/qgraphicsview_p.h>
#include "qgraphicstransform.h"
#include <private/qgraphicstransform_p.h>
 
#include <QtCore/qpoint.h>
 
QT_REQUIRE_CONFIG(graphicsview);
 
QT_BEGIN_NAMESPACE
 
class QGraphicsItemPrivate;
 
class QGraphicsItemCache
{
public:
    QGraphicsItemCache() : allExposed(false) { }
 
    // ItemCoordinateCache only
    QRect boundingRect;
    QSize fixedSize;
    QPixmapCache::Key key;
 
    // DeviceCoordinateCache only
    struct DeviceData {
        DeviceData() {}
        QTransform lastTransform;
        QPoint cacheIndent;
        QPixmapCache::Key key;
    };
    QHash<QPaintDevice *, DeviceData> deviceData;
 
    // List of logical exposed rects
    QList<QRectF> exposed;
    bool allExposed;
 
    // Empty cache
    void purge();
};
 
class Q_WIDGETS_EXPORT QGraphicsItemPrivate
{
    Q_DECLARE_PUBLIC(QGraphicsItem)
public:
    enum Extra {
        ExtraToolTip,
        ExtraCursor,
        ExtraCacheData,
        ExtraMaxDeviceCoordCacheSize,
        ExtraBoundingRegionGranularity
    };
 
    enum AncestorFlag {
        NoFlag = 0,
        AncestorHandlesChildEvents = 0x1,
        AncestorClipsChildren = 0x2,
        AncestorIgnoresTransformations = 0x4,
        AncestorFiltersChildEvents = 0x8,
        AncestorContainsChildren = 0x10
    };
 
    QGraphicsItemPrivate();
    virtual ~QGraphicsItemPrivate();
 
    static const QGraphicsItemPrivate *get(const QGraphicsItem *item)
    {
        return item->d_ptr.data();
    }
    static QGraphicsItemPrivate *get(QGraphicsItem *item)
    {
        return item->d_ptr.data();
    }
 
    void updateChildWithGraphicsEffectFlagRecursively();
    void updateAncestorFlag(QGraphicsItem::GraphicsItemFlag childFlag,
                            AncestorFlag flag = NoFlag, bool enabled = false, bool root = true);
    void updateAncestorFlags();
    void setIsMemberOfGroup(bool enabled);
    void remapItemPos(QEvent *event, QGraphicsItem *item);
    QTransform genericMapFromSceneTransform(const QWidget *viewport = nullptr) const;
    QPointF genericMapFromScene(const QPointF &pos, const QWidget *viewport) const;
    inline bool itemIsUntransformable() const
    {
        return (flags & QGraphicsItem::ItemIgnoresTransformations)
            || (ancestorFlags & AncestorIgnoresTransformations);
    }
 
    void combineTransformToParent(QTransform *x, const QTransform *viewTransform = nullptr) const;
    void combineTransformFromParent(QTransform *x, const QTransform *viewTransform = nullptr) const;
    virtual void updateSceneTransformFromParent();
 
    static bool movableAncestorIsSelected(const QGraphicsItem *item);
 
    virtual void setPosHelper(const QPointF &pos);
    void setTransformHelper(const QTransform &transform);
    void prependGraphicsTransform(QGraphicsTransform *t);
    void appendGraphicsTransform(QGraphicsTransform *t);
    void setVisibleHelper(bool newVisible, bool explicitly, bool update = true,
                          bool hiddenByPanel = false);
    void setEnabledHelper(bool newEnabled, bool explicitly, bool update = true);
    bool discardUpdateRequest(bool ignoreVisibleBit = false,
                              bool ignoreDirtyBit = false, bool ignoreOpacity = false) const;
    virtual void transformChanged() {}
    int depth() const;
#if QT_CONFIG(graphicseffect)
    enum InvalidateReason {
        OpacityChanged
    };
    void invalidateParentGraphicsEffectsRecursively();
    void invalidateChildGraphicsEffectsRecursively(InvalidateReason reason);
#endif // QT_CONFIG(graphicseffect)
    void invalidateDepthRecursively();
    void resolveDepth();
    void addChild(QGraphicsItem *child);
    void removeChild(QGraphicsItem *child);
    void setParentItemHelper(QGraphicsItem *parent, const QVariant *newParentVariant,
                             const QVariant *thisPointerVariant);
    void childrenBoundingRectHelper(QTransform *x, QRectF *rect, QGraphicsItem *topMostEffectItem);
    void initStyleOption(QStyleOptionGraphicsItem *option, const QTransform &worldTransform,
                         const QRegion &exposedRegion, bool allItems = false) const;
    QRectF effectiveBoundingRect(QGraphicsItem *topMostEffectItem = nullptr) const;
    QRectF sceneEffectiveBoundingRect() const;
 
    QRectF effectiveBoundingRect(const QRectF &rect) const;
 
    virtual void resolveFont(uint inheritedMask)
    {
        for (int i = 0; i < children.size(); ++i)
            children.at(i)->d_ptr->resolveFont(inheritedMask);
    }
 
    virtual void resolvePalette(uint inheritedMask)
    {
        for (int i = 0; i < children.size(); ++i)
            children.at(i)->d_ptr->resolvePalette(inheritedMask);
    }
 
    virtual bool isProxyWidget() const;
 
    inline QVariant extra(Extra type) const
    {
        for (int i = 0; i < extras.size(); ++i) {
            const ExtraStruct &extra = extras.at(i);
            if (extra.type == type)
                return extra.value;
        }
        return QVariant();
    }
 
    inline void setExtra(Extra type, const QVariant &value)
    {
        int index = -1;
        for (int i = 0; i < extras.size(); ++i) {
            if (extras.at(i).type == type) {
                index = i;
                break;
            }
        }
 
        if (index == -1) {
            extras << ExtraStruct(type, value);
        } else {
            extras[index].value = value;
        }
    }
 
    inline void unsetExtra(Extra type)
    {
        for (int i = 0; i < extras.size(); ++i) {
            if (extras.at(i).type == type) {
                extras.removeAt(i);
                return;
            }
        }
    }
 
    struct ExtraStruct {
        ExtraStruct() { } // for QList, don't use
        ExtraStruct(Extra type, const QVariant &value)
            : type(type), value(value)
        { }
 
        Extra type;
        QVariant value;
 
        bool operator<(Extra extra) const
        { return type < extra; }
    };
 
    QList<ExtraStruct> extras;
 
    QGraphicsItemCache *maybeExtraItemCache() const;
    QGraphicsItemCache *extraItemCache() const;
    void removeExtraItemCache();
 
    void updatePaintedViewBoundingRects(bool updateChildren);
    void ensureSceneTransformRecursive(QGraphicsItem **topMostDirtyItem);
    inline void ensureSceneTransform()
    {
        QGraphicsItem *that = q_func();
        ensureSceneTransformRecursive(&that);
    }
 
    inline bool hasTranslateOnlySceneTransform()
    {
        ensureSceneTransform();
        return sceneTransformTranslateOnly;
    }
 
    inline void invalidateChildrenSceneTransform()
    {
        for (int i = 0; i < children.size(); ++i)
            children.at(i)->d_ptr->dirtySceneTransform = 1;
    }
 
    inline qreal calcEffectiveOpacity() const
    {
        qreal o = opacity;
        QGraphicsItem *p = parent;
        int myFlags = flags;
        while (p) {
            int parentFlags = p->d_ptr->flags;
 
            // If I have a parent, and I don't ignore my parent's opacity, and my
            // parent propagates to me, then combine my local opacity with my parent's
            // effective opacity into my effective opacity.
            if ((myFlags & QGraphicsItem::ItemIgnoresParentOpacity)
                || (parentFlags & QGraphicsItem::ItemDoesntPropagateOpacityToChildren)) {
                break;
            }
 
            o *= p->d_ptr->opacity;
            p = p->d_ptr->parent;
            myFlags = parentFlags;
        }
        return o;
    }
 
    inline bool isOpacityNull() const
    { return (opacity < qreal(0.001)); }
 
    static inline bool isOpacityNull(qreal opacity)
    { return (opacity < qreal(0.001)); }
 
    inline bool isFullyTransparent() const
    {
        if (isOpacityNull())
            return true;
        if (!parent)
            return false;
 
        return isOpacityNull(calcEffectiveOpacity());
    }
 
    inline qreal effectiveOpacity() const {
        if (!parent || !opacity)
            return opacity;
 
        return calcEffectiveOpacity();
    }
 
    inline qreal combineOpacityFromParent(qreal parentOpacity) const
    {
        if (parent && !(flags & QGraphicsItem::ItemIgnoresParentOpacity)
            && !(parent->d_ptr->flags & QGraphicsItem::ItemDoesntPropagateOpacityToChildren)) {
            return parentOpacity * opacity;
        }
        return opacity;
    }
 
    inline bool childrenCombineOpacity() const
    {
        if (!children.size())
            return true;
        if (flags & QGraphicsItem::ItemDoesntPropagateOpacityToChildren)
            return false;
 
        for (int i = 0; i < children.size(); ++i) {
            if (children.at(i)->d_ptr->flags & QGraphicsItem::ItemIgnoresParentOpacity)
                return false;
        }
        return true;
    }
 
    inline bool childrenClippedToShape() const
    { return (flags & QGraphicsItem::ItemClipsChildrenToShape) || children.isEmpty(); }
 
    inline bool isInvisible() const
    {
        return !visible || (childrenCombineOpacity() && isFullyTransparent());
    }
 
    inline void markParentDirty(bool updateBoundingRect = false);
 
    void setFocusHelper(Qt::FocusReason focusReason, bool climb, bool focusFromHide);
    void clearFocusHelper(bool giveFocusToParent, bool hiddenByParentPanel);
    void setSubFocus(QGraphicsItem *rootItem = nullptr, QGraphicsItem *stopItem = nullptr);
    void clearSubFocus(QGraphicsItem *rootItem = nullptr, QGraphicsItem *stopItem = nullptr);
    void resetFocusProxy();
    virtual void subFocusItemChange();
    virtual void focusScopeItemChange(bool isSubFocusItem);
 
    inline QTransform transformToParent() const;
    inline void ensureSortedChildren();
    static inline bool insertionOrder(QGraphicsItem *a, QGraphicsItem *b);
    void ensureSequentialSiblingIndex();
    inline void sendScenePosChange();
    virtual void siblingOrderChange();
 
    // Private Properties
    virtual qreal width() const;
    virtual void setWidth(qreal);
    virtual void resetWidth();
 
    virtual qreal height() const;
    virtual void setHeight(qreal);
    virtual void resetHeight();
 
    QRectF childrenBoundingRect;
    QRectF needsRepaint;
    QHash<QWidget *, QRect> paintedViewBoundingRects;
    QPointF pos;
    qreal z;
    qreal opacity;
    QGraphicsScene *scene;
    QGraphicsItem *parent;
    QList<QGraphicsItem *> children;
    struct TransformData;
    TransformData *transformData;
    QGraphicsEffect *graphicsEffect;
    QTransform sceneTransform;
    int index;
    int siblingIndex;
    int itemDepth;  // Lazily calculated when calling depth().
    QGraphicsItem *focusProxy;
    QList<QGraphicsItem **> focusProxyRefs;
    QGraphicsItem *subFocusItem;
    QGraphicsItem *focusScopeItem;
    Qt::InputMethodHints imHints;
    QGraphicsItem::PanelModality panelModality;
#ifndef QT_NO_GESTURES
    QMap<Qt::GestureType, Qt::GestureFlags> gestureContext;
#endif
 
    // Packed 32 bits
    quint32 acceptedMouseButtons : 5;
    quint32 visible : 1;
    quint32 explicitlyHidden : 1;
    quint32 enabled : 1;
    quint32 explicitlyDisabled : 1;
    quint32 selected : 1;
    quint32 acceptsHover : 1;
    quint32 acceptDrops : 1;
    quint32 isMemberOfGroup : 1;
    quint32 handlesChildEvents : 1;
    quint32 itemDiscovered : 1;
    quint32 hasCursor : 1;
    quint32 ancestorFlags : 5;
    quint32 cacheMode : 2;
    quint32 hasBoundingRegionGranularity : 1;
    quint32 isWidget : 1;
    quint32 dirty : 1;
    quint32 dirtyChildren : 1;
    quint32 localCollisionHack : 1;
    quint32 inSetPosHelper : 1;
    quint32 needSortChildren : 1;
    quint32 allChildrenDirty : 1;
    quint32 fullUpdatePending : 1;
 
    // Packed 32 bits
    quint32 flags : 20;
    quint32 paintedViewBoundingRectsNeedRepaint : 1;
    quint32 dirtySceneTransform : 1;
    quint32 geometryChanged : 1;
    quint32 inDestructor : 1;
    quint32 isObject : 1;
    quint32 ignoreVisible : 1;
    quint32 ignoreOpacity : 1;
    quint32 acceptTouchEvents : 1;
    quint32 acceptedTouchBeginEvent : 1;
    quint32 filtersDescendantEvents : 1;
    quint32 sceneTransformTranslateOnly : 1;
    quint32 notifyBoundingRectChanged : 1;
#ifdef Q_OS_WASM
    unsigned char :0; //this aligns 64bit field for wasm see QTBUG-65259
#endif
    // New 32 bits
    quint32 notifyInvalidated : 1;
    quint32 mouseSetsFocus : 1;
    quint32 explicitActivate : 1;
    quint32 wantsActive : 1;
    quint32 holesInSiblingIndex : 1;
    quint32 sequentialOrdering : 1;
    quint32 updateDueToGraphicsEffect : 1;
    quint32 scenePosDescendants : 1;
    quint32 pendingPolish : 1;
    quint32 mayHaveChildWithGraphicsEffect : 1;
    quint32 sendParentChangeNotification : 1;
    quint32 dirtyChildrenBoundingRect : 1;
    quint32 padding : 20;
 
    // Optional stacking order
    int globalStackingOrder;
    QGraphicsItem *q_ptr;
};
Q_DECLARE_TYPEINFO(QGraphicsItemPrivate::ExtraStruct, Q_RELOCATABLE_TYPE);
 
struct QGraphicsItemPrivate::TransformData
{
    QTransform transform;
    qreal scale;
    qreal rotation;
    qreal xOrigin;
    qreal yOrigin;
    QList<QGraphicsTransform *> graphicsTransforms;
    bool onlyTransform;
 
    TransformData() :
        scale(1.0), rotation(0.0),
        xOrigin(0.0), yOrigin(0.0),
        onlyTransform(true)
    { }
 
    QTransform computedFullTransform(QTransform *postmultiplyTransform = nullptr) const
    {
        if (onlyTransform) {
            if (!postmultiplyTransform || postmultiplyTransform->isIdentity())
                return transform;
            if (transform.isIdentity())
                return *postmultiplyTransform;
            return transform * *postmultiplyTransform;
        }
 
        QTransform x(transform);
        if (!graphicsTransforms.isEmpty()) {
            QMatrix4x4 m;
            for (int i = 0; i < graphicsTransforms.size(); ++i)
                graphicsTransforms.at(i)->applyTo(&m);
            x *= m.toTransform();
        }
        x.translate(xOrigin, yOrigin);
        x.rotate(rotation);
        x.scale(scale, scale);
        x.translate(-xOrigin, -yOrigin);
        if (postmultiplyTransform)
            x *= *postmultiplyTransform;
        return x;
    }
};
 
struct QGraphicsItemPaintInfo
{
    inline QGraphicsItemPaintInfo(const QTransform *const xform1, const QTransform *const xform2,
                                  const QTransform *const xform3,
                                  QRegion *r, QWidget *w, QStyleOptionGraphicsItem *opt,
                                  QPainter *p, qreal o, bool b1, bool b2)
        : viewTransform(xform1), transformPtr(xform2), effectTransform(xform3), exposedRegion(r), widget(w),
          option(opt), painter(p), opacity(o), wasDirtySceneTransform(b1), drawItem(b2)
    {}
 
    const QTransform *viewTransform;
    const QTransform *transformPtr;
    const QTransform *effectTransform;
    QRegion *exposedRegion;
    QWidget *widget;
    QStyleOptionGraphicsItem *option;
    QPainter *painter;
    qreal opacity;
    quint32 wasDirtySceneTransform : 1;
    quint32 drawItem : 1;
};
 
#if QT_CONFIG(graphicseffect)
class QGraphicsItemEffectSourcePrivate : public QGraphicsEffectSourcePrivate
{
public:
    QGraphicsItemEffectSourcePrivate(QGraphicsItem *i)
        : QGraphicsEffectSourcePrivate(), item(i), info(nullptr)
    {}
 
    void detach() override
    {
        item->d_ptr->graphicsEffect = nullptr;
        item->prepareGeometryChange();
    }
 
    const QGraphicsItem *graphicsItem() const override
    { return item; }
 
    const QWidget *widget() const override
    { return nullptr; }
 
    void update() override {
        item->d_ptr->updateDueToGraphicsEffect = true;
        item->update();
        item->d_ptr->updateDueToGraphicsEffect = false;
    }
 
    void effectBoundingRectChanged() override
    { item->prepareGeometryChange(); }
 
    bool isPixmap() const override
    {
        return item->type() == QGraphicsPixmapItem::Type
               && !(item->flags() & QGraphicsItem::ItemIsSelectable)
               && item->d_ptr->children.size() == 0;
    }
 
    const QStyleOption *styleOption() const override
    { return info ? info->option : nullptr; }
 
    QRect deviceRect() const override
    {
        if (!info || !info->widget) {
            qWarning("QGraphicsEffectSource::deviceRect: Not yet implemented, lacking device context");
            return QRect();
        }
        return info->widget->rect();
    }
 
    QRectF boundingRect(Qt::CoordinateSystem system) const override;
    void draw(QPainter *) override;
    QPixmap pixmap(Qt::CoordinateSystem system,
                   QPoint *offset,
                   QGraphicsEffect::PixmapPadMode mode) const override;
    QRectF paddedEffectRect(Qt::CoordinateSystem system, QGraphicsEffect::PixmapPadMode mode, const QRectF &sourceRect, bool *unpadded = nullptr) const;
 
    QGraphicsItem *item;
    QGraphicsItemPaintInfo *info;
    QTransform lastEffectTransform;
};
#endif // QT_CONFIG(graphicseffect)
 
inline bool qt_closestItemFirst(const QGraphicsItem *item1, const QGraphicsItem *item2)
{
    // Siblings? Just check their z-values.
    const QGraphicsItemPrivate *d1 = item1->d_ptr.data();
    const QGraphicsItemPrivate *d2 = item2->d_ptr.data();
    if (d1->parent == d2->parent)
        return qt_closestLeaf(item1, item2);
 
    // Find common ancestor, and each item's ancestor closest to the common
    // ancestor.
    int item1Depth = d1->depth();
    int item2Depth = d2->depth();
    const QGraphicsItem *p = item1;
    const QGraphicsItem *t1 = item1;
    while (item1Depth > item2Depth && (p = p->d_ptr->parent)) {
        if (p == item2) {
            // item2 is one of item1's ancestors; item1 is on top
            return !(t1->d_ptr->flags & QGraphicsItem::ItemStacksBehindParent);
        }
        t1 = p;
        --item1Depth;
    }
    p = item2;
    const QGraphicsItem *t2 = item2;
    while (item2Depth > item1Depth && (p = p->d_ptr->parent)) {
        if (p == item1) {
            // item1 is one of item2's ancestors; item1 is not on top
            return (t2->d_ptr->flags & QGraphicsItem::ItemStacksBehindParent);
        }
        t2 = p;
        --item2Depth;
    }
 
    // item1Ancestor is now at the same level as item2Ancestor, but not the same.
    const QGraphicsItem *p1 = t1;
    const QGraphicsItem *p2 = t2;
    while (t1 && t1 != t2) {
        p1 = t1;
        p2 = t2;
        t1 = t1->d_ptr->parent;
        t2 = t2->d_ptr->parent;
    }
 
    // in case we have a common ancestor, we compare the immediate children in the ancestor's path.
    // otherwise we compare the respective items' topLevelItems directly.
    return qt_closestLeaf(p1, p2);
}
 
inline bool qt_closestItemLast(const QGraphicsItem *item1, const QGraphicsItem *item2)
{
    return qt_closestItemFirst(item2, item1);
}
 
inline bool qt_closestLeaf(const QGraphicsItem *item1, const QGraphicsItem *item2)
{
    // Return true if sibling item1 is on top of item2.
    const QGraphicsItemPrivate *d1 = item1->d_ptr.data();
    const QGraphicsItemPrivate *d2 = item2->d_ptr.data();
    bool f1 = d1->flags & QGraphicsItem::ItemStacksBehindParent;
    bool f2 = d2->flags & QGraphicsItem::ItemStacksBehindParent;
    if (f1 != f2)
        return f2;
    if (d1->z != d2->z)
        return d1->z > d2->z;
    return d1->siblingIndex > d2->siblingIndex;
}
 
inline bool qt_notclosestLeaf(const QGraphicsItem *item1, const QGraphicsItem *item2)
{ return qt_closestLeaf(item2, item1); }
 
/*
   return the full transform of the item to the parent.  This include the position and all the transform data
*/
inline QTransform QGraphicsItemPrivate::transformToParent() const
{
    QTransform matrix;
    combineTransformToParent(&matrix);
    return matrix;
}
 
inline void QGraphicsItemPrivate::ensureSortedChildren()
{
    if (needSortChildren) {
        needSortChildren = 0;
        sequentialOrdering = 1;
        if (children.isEmpty())
            return;
        std::sort(children.begin(), children.end(), qt_notclosestLeaf);
        for (int i = 0; i < children.size(); ++i) {
            if (children.at(i)->d_ptr->siblingIndex != i) {
                sequentialOrdering = 0;
                break;
            }
        }
    }
}
 
inline bool QGraphicsItemPrivate::insertionOrder(QGraphicsItem *a, QGraphicsItem *b)
{
    return a->d_ptr->siblingIndex < b->d_ptr->siblingIndex;
}
 
inline void QGraphicsItemPrivate::markParentDirty(bool updateBoundingRect)
{
    QGraphicsItemPrivate *parentp = this;
#if QT_CONFIG(graphicseffect)
    if (updateBoundingRect && parentp->graphicsEffect && !parentp->inSetPosHelper) {
        parentp->notifyInvalidated = 1;
        static_cast<QGraphicsItemEffectSourcePrivate *>(parentp->graphicsEffect->d_func()
                                                        ->source->d_func())->invalidateCache();
    }
#endif
    while (parentp->parent) {
        parentp = parentp->parent->d_ptr.data();
        parentp->dirtyChildren = 1;
 
        if (updateBoundingRect) {
            parentp->dirtyChildrenBoundingRect = 1;
            // ### Only do this if the parent's effect applies to the entire subtree.
            parentp->notifyBoundingRectChanged = 1;
        }
#if QT_CONFIG(graphicseffect)
        if (parentp->graphicsEffect) {
            if (updateBoundingRect) {
                static_cast<QGraphicsItemEffectSourcePrivate *>(parentp->graphicsEffect->d_func()
                                                                ->source->d_func())->invalidateCache();
                parentp->notifyInvalidated = 1;
            }
            if (parentp->scene && parentp->graphicsEffect->isEnabled()) {
                parentp->dirty = 1;
                parentp->fullUpdatePending = 1;
            }
        }
#endif
    }
}
 
QT_END_NAMESPACE
 
#endif