C++/Qt/QLayout
extends QLayout to create border layout
<source lang="cpp"> /****************************************************************************
- 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();
}
</source>
extends QLayout to create flow layout
<source lang="cpp"> /****************************************************************************
- 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();
}
</source>
