diff options
Diffstat (limited to 'tests/manual/examples/widgets/graphicsview/flowlayout/flowlayout.cpp')
-rw-r--r-- | tests/manual/examples/widgets/graphicsview/flowlayout/flowlayout.cpp | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/tests/manual/examples/widgets/graphicsview/flowlayout/flowlayout.cpp b/tests/manual/examples/widgets/graphicsview/flowlayout/flowlayout.cpp new file mode 100644 index 0000000000..ab5f4717b3 --- /dev/null +++ b/tests/manual/examples/widgets/graphicsview/flowlayout/flowlayout.cpp @@ -0,0 +1,170 @@ +// 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; +} |