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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "flowlayout.h"
#include <QtMath>
FlowLayout::FlowLayout(QGraphicsLayoutItem *parent) : QGraphicsLayout(parent)
{
QSizePolicy sp = sizePolicy();
sp.setHeightForWidth(true);
setSizePolicy(sp);
}
void FlowLayout::insertItem(int index, QGraphicsLayoutItem *item)
{
item->setParentLayoutItem(this);
if (index > m_items.count() || index < 0)
index = m_items.count();
m_items.insert(index, item);
invalidate();
}
int FlowLayout::count() const
{
return m_items.count();
}
QGraphicsLayoutItem *FlowLayout::itemAt(int index) const
{
return m_items.value(index);
}
void FlowLayout::removeAt(int index)
{
m_items.removeAt(index);
invalidate();
}
qreal FlowLayout::spacing(Qt::Orientation o) const
{
return m_spacing[int(o) - 1];
}
void FlowLayout::setSpacing(Qt::Orientations o, qreal spacing)
{
if (o & Qt::Horizontal)
m_spacing[0] = spacing;
if (o & Qt::Vertical)
m_spacing[1] = spacing;
}
void FlowLayout::setGeometry(const QRectF &geom)
{
QGraphicsLayout::setGeometry(geom);
doLayout(geom, true);
}
qreal FlowLayout::doLayout(const QRectF &geom, bool applyNewGeometry) const
{
qreal left, top, right, bottom;
getContentsMargins(&left, &top, &right, &bottom);
const qreal maxw = geom.width() - left - right;
qreal x = 0;
qreal y = 0;
qreal maxRowHeight = 0;
QSizeF pref;
for (QGraphicsLayoutItem *item : m_items) {
pref = item->effectiveSizeHint(Qt::PreferredSize);
maxRowHeight = qMax(maxRowHeight, pref.height());
qreal next_x;
next_x = x + pref.width();
if (next_x > maxw) {
if (qFuzzyIsNull(x)) {
pref.setWidth(maxw);
} else {
x = 0;
next_x = pref.width();
}
y += maxRowHeight + spacing(Qt::Vertical);
maxRowHeight = 0;
}
if (applyNewGeometry)
item->setGeometry(QRectF(QPointF(left + x, top + y), pref));
x = next_x + spacing(Qt::Horizontal);
}
maxRowHeight = qMax(maxRowHeight, pref.height());
return top + y + maxRowHeight + bottom;
}
QSizeF FlowLayout::minSize(const QSizeF &constraint) const
{
QSizeF size(0, 0);
qreal left, top, right, bottom;
getContentsMargins(&left, &top, &right, &bottom);
if (constraint.width() >= 0) { // height for width
const qreal height = doLayout(QRectF(QPointF(0,0), constraint), false);
size = QSizeF(constraint.width(), height);
} else if (constraint.height() >= 0) { // width for height?
// not supported
} else {
for (const QGraphicsLayoutItem *item : std::as_const(m_items))
size = size.expandedTo(item->effectiveSizeHint(Qt::MinimumSize));
size += QSizeF(left + right, top + bottom);
}
return size;
}
QSizeF FlowLayout::prefSize() const
{
qreal left, right;
getContentsMargins(&left, nullptr, &right, nullptr);
qreal maxh = 0;
qreal totalWidth = 0;
for (const QGraphicsLayoutItem *item : std::as_const(m_items)) {
if (totalWidth > 0)
totalWidth += spacing(Qt::Horizontal);
QSizeF pref = item->effectiveSizeHint(Qt::PreferredSize);
totalWidth += pref.width();
maxh = qMax(maxh, pref.height());
}
maxh += spacing(Qt::Vertical);
const qreal goldenAspectRatio = 1.61803399;
qreal w = qSqrt(totalWidth * maxh * goldenAspectRatio) + left + right;
return minSize(QSizeF(w, -1));
}
QSizeF FlowLayout::maxSize() const
{
qreal totalWidth = 0;
qreal totalHeight = 0;
for (const QGraphicsLayoutItem *item : std::as_const(m_items)) {
if (totalWidth > 0)
totalWidth += spacing(Qt::Horizontal);
if (totalHeight > 0)
totalHeight += spacing(Qt::Vertical);
QSizeF pref = item->effectiveSizeHint(Qt::PreferredSize);
totalWidth += pref.width();
totalHeight += pref.height();
}
qreal left, top, right, bottom;
getContentsMargins(&left, &top, &right, &bottom);
return QSizeF(left + totalWidth + right, top + totalHeight + bottom);
}
QSizeF FlowLayout::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
QSizeF sh = constraint;
switch (which) {
case Qt::PreferredSize:
sh = prefSize();
break;
case Qt::MinimumSize:
sh = minSize(constraint);
break;
case Qt::MaximumSize:
sh = maxSize();
break;
default:
break;
}
return sh;
}
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