src/gui/graphicsview/qgraphicsscene.cpp File Reference

#include "qgraphicsscene.h"
#include "qgraphicsitem.h"
#include "qgraphicsitem_p.h"
#include "qgraphicsscene_p.h"
#include "qgraphicssceneevent.h"
#include "qgraphicsview.h"
#include <private/qobject_p.h>
#include <QtCore/qcoreapplication.h>
#include <QtCore/qlist.h>
#include <QtCore/qrect.h>
#include <QtCore/qset.h>
#include <QtCore/qtimer.h>
#include <QtGui/qevent.h>
#include <QtGui/qmatrix.h>
#include <QtGui/qpainter.h>
#include <QtGui/qpolygon.h>
#include <QtGui/qstyleoption.h>
#include <QtGui/qtooltip.h>
#include <math.h>
#include <qdebug.h>
#include "moc_qgraphicsscene.cpp"

Include dependency graph for qgraphicsscene.cpp:

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Functions
static int	intmaxlog (int n)
bool	qt_closestLeaf (const QGraphicsItem *item1, const QGraphicsItem *item2)
bool	qt_closestItemFirst (const QGraphicsItem *item1, const QGraphicsItem *item2)

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Function Documentation

static int intmaxlog

(

int

n

)

[inline, static]

Definition at line 291 of file qgraphicsscene.cpp.

References qMax().

Referenced by QGraphicsScenePrivate::_q_generateBspTree().

{
    return  (n > 0 ? qMax(int(::log(float(n))), 5) : 0);
}

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bool qt_closestItemFirst	(	const QGraphicsItem *	item1,
		const QGraphicsItem *	item2
	)

Definition at line 697 of file qgraphicsscene.cpp.

References QVector< T >::at(), QGraphicsItem::d_ptr, QVector< T >::first(), i, QGraphicsItemPrivate::parent, QVector< T >::prepend(), qt_closestLeaf(), QVector< T >::resize(), and QVector< T >::size().

Referenced by QGraphicsScenePrivate::sortItems().

{
    // Siblings? Just check their z-values.
    if (item1->d_ptr->parent == item2->d_ptr->parent)
        return qt_closestLeaf(item1, item2);

    // Find item1's ancestors. If item2 is among them, return true (item1 is
    // above item2).
    QVector<const QGraphicsItem *> ancestors1;
    const QGraphicsItem *parent1 = item1;
    do {
        if (parent1 == item2)
            return true;
        ancestors1.prepend(parent1);
    } while ((parent1 = parent1->d_ptr->parent));

    // Find item2's ancestors. If item1 is among them, return false (item2 is
    // above item1).
    QVector<const QGraphicsItem *> ancestors2;
    const QGraphicsItem *parent2 = item2;
    do {
        if (parent2 == item1)
            return false;
        ancestors2.prepend(parent2);
    } while ((parent2 = parent2->d_ptr->parent));

    // Truncate the largest ancestor list.
    int size1 = ancestors1.size();
    int size2 = ancestors2.size();
    if (size1 > size2) {
        ancestors1.resize(size2);
    } else if (size2 > size1) {
        ancestors2.resize(size1);
    }

    // Compare items from the two ancestors lists and find a match. Then
    // compare item1's and item2's toplevels relative to the common ancestor.
    for (int i = ancestors1.size() - 2; i >= 0; --i) {
        const QGraphicsItem *a1 = ancestors1.at(i);
        const QGraphicsItem *a2 = ancestors2.at(i);
        if (a1 == a2)
            return qt_closestLeaf(ancestors1.at(i + 1), ancestors2.at(i + 1));
    }

    // No common ancestor? Then just compare the items' toplevels directly.
    return qt_closestLeaf(ancestors1.first(), ancestors2.first());
}

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bool qt_closestLeaf	(	const QGraphicsItem *	item1,
		const QGraphicsItem *	item2
	)			[inline]

Definition at line 687 of file qgraphicsscene.cpp.

References QGraphicsItem::d_ptr, and QGraphicsItemPrivate::z.

Referenced by qt_closestItemFirst().

{
    qreal z1 = item1->d_ptr->z;
    qreal z2 = item2->d_ptr->z;
    return z1 != z2 ? z1 > z2 : item1 > item2;
}

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