qt5base-lts/examples/graphicsview/flowlayout/flowlayout.cpp
Jason McDonald 5635823e17 Remove "All rights reserved" line from license headers.
As in the past, to avoid rewriting various autotests that contain
line-number information, an extra blank line has been inserted at the
end of the license text to ensure that this commit does not change the
total number of lines in the license header.

Change-Id: I311e001373776812699d6efc045b5f742890c689
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>
2012-01-30 03:54:59 +01:00

214 lines
6.4 KiB
C++

/****************************************************************************
**
** 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;
}