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Diffstat (limited to 'examples/widgets/graphicsview/flowlayout/flowlayout.cpp')
| -rw-r--r-- | examples/widgets/graphicsview/flowlayout/flowlayout.cpp | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/examples/widgets/graphicsview/flowlayout/flowlayout.cpp b/examples/widgets/graphicsview/flowlayout/flowlayout.cpp new file mode 100644 index 0000000000..3f787109eb --- /dev/null +++ b/examples/widgets/graphicsview/flowlayout/flowlayout.cpp @@ -0,0 +1,213 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** 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 +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its 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 +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "flowlayout.h" +#include <QtWidgets/qwidget.h> +#include <QtCore/qmath.h> + +FlowLayout::FlowLayout() +{ + m_spacing[0] = 6; + m_spacing[1] = 6; + QSizePolicy sp = sizePolicy(); + sp.setHeightForWidth(true); + setSizePolicy(sp); +} + +void FlowLayout::insertItem(int index, QGraphicsLayoutItem *item) +{ + item->setParentLayoutItem(this); + if (uint(index) > uint(m_items.count())) + 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 (int i = 0; i < m_items.count(); ++i) { + QGraphicsLayoutItem *item = m_items.at(i); + pref = item->effectiveSizeHint(Qt::PreferredSize); + maxRowHeight = qMax(maxRowHeight, pref.height()); + + qreal next_x; + next_x = x + pref.width(); + if (next_x > maxw) { + if (x == 0) { + 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 { + QGraphicsLayoutItem *item; + foreach (item, m_items) + size = size.expandedTo(item->effectiveSizeHint(Qt::MinimumSize)); + size += QSize(left + right, top + bottom); + } + return size; +} + +QSizeF FlowLayout::prefSize() const +{ + qreal left, right; + getContentsMargins(&left, 0, &right, 0); + + QGraphicsLayoutItem *item; + qreal maxh = 0; + qreal totalWidth = 0; + foreach (item, 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 +{ + QGraphicsLayoutItem *item; + qreal totalWidth = 0; + qreal totalHeight = 0; + foreach (item, 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; +} |