C++/Qt/QLayout
extends QLayout to create border layout
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef BORDERLAYOUT_H
#define BORDERLAYOUT_H
#include <QLayout>
#include <QRect>
#include <QWidgetItem>
class BorderLayout : public QLayout
{
public:
enum Position { West, North, South, East, Center };
BorderLayout(QWidget *parent, int margin = 0, int spacing = -1);
BorderLayout(int spacing = -1);
~BorderLayout();
void addItem(QLayoutItem *item);
void addWidget(QWidget *widget, Position position);
Qt::Orientations expandingDirections() const;
bool hasHeightForWidth() const;
int count() const;
QLayoutItem *itemAt(int index) const;
QSize minimumSize() const;
void setGeometry(const QRect &rect);
QSize sizeHint() const;
QLayoutItem *takeAt(int index);
void add(QLayoutItem *item, Position position);
private:
struct ItemWrapper
{
ItemWrapper(QLayoutItem *i, Position p) {
item = i;
position = p;
}
QLayoutItem *item;
Position position;
};
enum SizeType { MinimumSize, SizeHint };
QSize calculateSize(SizeType sizeType) const;
QList<ItemWrapper *> list;
};
#endif
#include <QtGui>
#include "borderlayout.h"
BorderLayout::BorderLayout(QWidget *parent, int margin, int spacing)
: QLayout(parent)
{
setMargin(margin);
setSpacing(spacing);
}
BorderLayout::BorderLayout(int spacing)
{
setSpacing(spacing);
}
BorderLayout::~BorderLayout()
{
QLayoutItem *l;
while ((l = takeAt(0)))
delete l;
}
void BorderLayout::addItem(QLayoutItem *item)
{
add(item, West);
}
void BorderLayout::addWidget(QWidget *widget, Position position)
{
add(new QWidgetItem(widget), position);
}
Qt::Orientations BorderLayout::expandingDirections() const
{
return Qt::Horizontal | Qt::Vertical;
}
bool BorderLayout::hasHeightForWidth() const
{
return false;
}
int BorderLayout::count() const
{
return list.size();
}
QLayoutItem *BorderLayout::itemAt(int index) const
{
ItemWrapper *wrapper = list.value(index);
if (wrapper)
return wrapper->item;
else
return 0;
}
QSize BorderLayout::minimumSize() const
{
return calculateSize(MinimumSize);
}
void BorderLayout::setGeometry(const QRect &rect)
{
ItemWrapper *center = 0;
int eastWidth = 0;
int westWidth = 0;
int northHeight = 0;
int southHeight = 0;
int centerHeight = 0;
int i;
QLayout::setGeometry(rect);
for (i = 0; i < list.size(); ++i) {
ItemWrapper *wrapper = list.at(i);
QLayoutItem *item = wrapper->item;
Position position = wrapper->position;
if (position == North) {
item->setGeometry(QRect(rect.x(), northHeight, rect.width(),
item->sizeHint().height()));
northHeight += item->geometry().height() + spacing();
} else if (position == South) {
item->setGeometry(QRect(item->geometry().x(),
item->geometry().y(), rect.width(),
item->sizeHint().height()));
southHeight += item->geometry().height() + spacing();
item->setGeometry(QRect(rect.x(),
rect.y() + rect.height() - southHeight + spacing(),
item->geometry().width(),
item->geometry().height()));
} else if (position == Center) {
center = wrapper;
}
}
centerHeight = rect.height() - northHeight - southHeight;
for (i = 0; i < list.size(); ++i) {
ItemWrapper *wrapper = list.at(i);
QLayoutItem *item = wrapper->item;
Position position = wrapper->position;
if (position == West) {
item->setGeometry(QRect(rect.x() + westWidth, northHeight,
item->sizeHint().width(), centerHeight));
westWidth += item->geometry().width() + spacing();
} else if (position == East) {
item->setGeometry(QRect(item->geometry().x(), item->geometry().y(),
item->sizeHint().width(), centerHeight));
eastWidth += item->geometry().width() + spacing();
item->setGeometry(QRect(
rect.x() + rect.width() - eastWidth + spacing(),
northHeight, item->geometry().width(),
item->geometry().height()));
}
}
if (center)
center->item->setGeometry(QRect(westWidth, northHeight,
rect.width() - eastWidth - westWidth,
centerHeight));
}
QSize BorderLayout::sizeHint() const
{
return calculateSize(SizeHint);
}
QLayoutItem *BorderLayout::takeAt(int index)
{
if (index >= 0 && index < list.size()) {
ItemWrapper *layoutStruct = list.takeAt(index);
return layoutStruct->item;
}
return 0;
}
void BorderLayout::add(QLayoutItem *item, Position position)
{
list.append(new ItemWrapper(item, position));
}
QSize BorderLayout::calculateSize(SizeType sizeType) const
{
QSize totalSize;
for (int i = 0; i < list.size(); ++i) {
ItemWrapper *wrapper = list.at(i);
Position position = wrapper->position;
QSize itemSize;
if (sizeType == MinimumSize)
itemSize = wrapper->item->minimumSize();
else // (sizeType == SizeHint)
itemSize = wrapper->item->sizeHint();
if (position == North || position == South || position == Center)
totalSize.rheight() += itemSize.height();
if (position == West || position == East || position == Center)
totalSize.rwidth() += itemSize.width();
}
return totalSize;
}
#ifndef WINDOW_H
#define WINDOW_H
#include <QWidget>
QT_BEGIN_NAMESPACE
class QLabel;
QT_END_NAMESPACE
class Window : public QWidget
{
Q_OBJECT
public:
Window();
private:
QLabel *createLabel(const QString &text);
};
#endif
#include <QtGui>
#include "borderlayout.h"
#include "window.h"
Window::Window()
{
QTextBrowser *centralWidget = new QTextBrowser;
centralWidget->setPlainText(tr("Central widget"));
BorderLayout *layout = new BorderLayout;
layout->addWidget(centralWidget, BorderLayout::Center);
layout->addWidget(createLabel("North"), BorderLayout::North);
layout->addWidget(createLabel("West"), BorderLayout::West);
layout->addWidget(createLabel("East 1"), BorderLayout::East);
layout->addWidget(createLabel("East 2") , BorderLayout::East);
layout->addWidget(createLabel("South"), BorderLayout::South);
setLayout(layout);
setWindowTitle(tr("Border Layout"));
}
QLabel *Window::createLabel(const QString &text)
{
QLabel *label = new QLabel(text);
label->setFrameStyle(QFrame::Box | QFrame::Raised);
return label;
}
#include <QApplication>
#include "window.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Window window;
window.show();
return app.exec();
}
extends QLayout to create flow layout
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef FLOWLAYOUT_H
#define FLOWLAYOUT_H
#include <QLayout>
#include <QRect>
#include <QWidgetItem>
class FlowLayout : public QLayout
{
public:
FlowLayout(QWidget *parent, int margin = -1, int hSpacing = -1, int vSpacing = -1);
FlowLayout(int margin = -1, int hSpacing = -1, int vSpacing = -1);
~FlowLayout();
void addItem(QLayoutItem *item);
int horizontalSpacing() const;
int verticalSpacing() const;
Qt::Orientations expandingDirections() const;
bool hasHeightForWidth() const;
int heightForWidth(int) const;
int count() const;
QLayoutItem *itemAt(int index) const;
QSize minimumSize() const;
void setGeometry(const QRect &rect);
QSize sizeHint() const;
QLayoutItem *takeAt(int index);
private:
int doLayout(const QRect &rect, bool testOnly) const;
int smartSpacing(QStyle::PixelMetric pm) const;
QList<QLayoutItem *> itemList;
int m_hSpace;
int m_vSpace;
};
#endif
#include <QtGui>
#include "flowlayout.h"
FlowLayout::FlowLayout(QWidget *parent, int margin, int hSpacing, int vSpacing)
: QLayout(parent), m_hSpace(hSpacing), m_vSpace(vSpacing)
{
setContentsMargins(margin, margin, margin, margin);
}
FlowLayout::FlowLayout(int margin, int hSpacing, int vSpacing)
: m_hSpace(hSpacing), m_vSpace(vSpacing)
{
setContentsMargins(margin, margin, margin, margin);
}
FlowLayout::~FlowLayout()
{
QLayoutItem *item;
while ((item = takeAt(0)))
delete item;
}
void FlowLayout::addItem(QLayoutItem *item)
{
itemList.append(item);
}
int FlowLayout::horizontalSpacing() const
{
if (m_hSpace >= 0) {
return m_hSpace;
} else {
return smartSpacing(QStyle::PM_LayoutHorizontalSpacing);
}
}
int FlowLayout::verticalSpacing() const
{
if (m_vSpace >= 0) {
return m_vSpace;
} else {
return smartSpacing(QStyle::PM_LayoutVerticalSpacing);
}
}
int FlowLayout::count() const
{
return itemList.size();
}
QLayoutItem *FlowLayout::itemAt(int index) const
{
return itemList.value(index);
}
QLayoutItem *FlowLayout::takeAt(int index)
{
if (index >= 0 && index < itemList.size())
return itemList.takeAt(index);
else
return 0;
}
Qt::Orientations FlowLayout::expandingDirections() const
{
return 0;
}
bool FlowLayout::hasHeightForWidth() const
{
return true;
}
int FlowLayout::heightForWidth(int width) const
{
int height = doLayout(QRect(0, 0, width, 0), true);
return height;
}
void FlowLayout::setGeometry(const QRect &rect)
{
QLayout::setGeometry(rect);
doLayout(rect, false);
}
QSize FlowLayout::sizeHint() const
{
return minimumSize();
}
QSize FlowLayout::minimumSize() const
{
QSize size;
QLayoutItem *item;
foreach (item, itemList)
size = size.expandedTo(item->minimumSize());
size += QSize(2*margin(), 2*margin());
return size;
}
int FlowLayout::doLayout(const QRect &rect, bool testOnly) const
{
int left, top, right, bottom;
getContentsMargins(&left, &top, &right, &bottom);
QRect effectiveRect = rect.adjusted(+left, +top, -right, -bottom);
int x = effectiveRect.x();
int y = effectiveRect.y();
int lineHeight = 0;
QLayoutItem *item;
foreach (item, itemList) {
QWidget *wid = item->widget();
int spaceX = horizontalSpacing();
if (spaceX == -1)
spaceX = wid->style()->layoutSpacing(
QSizePolicy::PushButton, QSizePolicy::PushButton, Qt::Horizontal);
int spaceY = verticalSpacing();
if (spaceY == -1)
spaceY = wid->style()->layoutSpacing(
QSizePolicy::PushButton, QSizePolicy::PushButton, Qt::Vertical);
int nextX = x + item->sizeHint().width() + spaceX;
if (nextX - spaceX > effectiveRect.right() && lineHeight > 0) {
x = effectiveRect.x();
y = y + lineHeight + spaceY;
nextX = x + item->sizeHint().width() + spaceX;
lineHeight = 0;
}
if (!testOnly)
item->setGeometry(QRect(QPoint(x, y), item->sizeHint()));
x = nextX;
lineHeight = qMax(lineHeight, item->sizeHint().height());
}
return y + lineHeight - rect.y() + bottom;
}
int FlowLayout::smartSpacing(QStyle::PixelMetric pm) const
{
QObject *parent = this->parent();
if (!parent) {
return -1;
} else if (parent->isWidgetType()) {
QWidget *pw = static_cast<QWidget *>(parent);
return pw->style()->pixelMetric(pm, 0, pw);
} else {
return static_cast<QLayout *>(parent)->spacing();
}
}
#ifndef WINDOW_H
#define WINDOW_H
#include <QWidget>
QT_BEGIN_NAMESPACE
class QLabel;
QT_END_NAMESPACE
class Window : public QWidget
{
Q_OBJECT
public:
Window();
};
#endif
#include <QtGui>
#include "flowlayout.h"
#include "window.h"
Window::Window()
{
FlowLayout *flowLayout = new FlowLayout;
flowLayout->addWidget(new QPushButton(tr("Short")));
flowLayout->addWidget(new QPushButton(tr("Longer")));
flowLayout->addWidget(new QPushButton(tr("Different text")));
flowLayout->addWidget(new QPushButton(tr("More text")));
flowLayout->addWidget(new QPushButton(tr("Even longer button text")));
setLayout(flowLayout);
setWindowTitle(tr("Flow Layout"));
}
#include <QApplication>
#include "window.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Window window;
window.show();
return app.exec();
}