Qt 流式布局
Qt 流动布局,实现自适应
flowlayout.h
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, 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 The Qt Company Ltd 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."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef FLOWLAYOUT_H
#define FLOWLAYOUT_H
#include <QLayout>
#include <QRect>
#include <QStyle>
//! [0]
class FlowLayout : public QLayout
{
public:
explicit FlowLayout(QWidget *parent, int margin = -1, int hSpacing = -1, int vSpacing = -1);
explicit FlowLayout(int margin = -1, int hSpacing = -1, int vSpacing = -1);
~FlowLayout();
void addItem(QLayoutItem *item) override;
int horizontalSpacing() const;
int verticalSpacing() const;
Qt::Orientations expandingDirections() const override;
bool hasHeightForWidth() const override;
int heightForWidth(int) const override;
int count() const override;
QLayoutItem *itemAt(int index) const override;
QSize minimumSize() const override;
void setGeometry(const QRect &rect) override;
QSize sizeHint() const override;
QLayoutItem *takeAt(int index) override;
private:
int doLayout(const QRect &rect, bool testOnly) const;
int smartSpacing(QStyle::PixelMetric pm) const;
QList<QLayoutItem *> itemList;
int m_hSpace;
int m_vSpace;
};
//! [0]
#endif // FLOWLAYOUT_H
/*
demo
//Qt 流式布局
if(true){
FlowLayout *flowLayout = new FlowLayout;
flowLayout->addWidget(ui->btn_info_1);
flowLayout->addWidget(ui->btn_info_2);
flowLayout->addWidget(ui->btn_info_3);
flowLayout->addWidget(ui->btn_info_4);
flowLayout->addWidget(ui->btn_info_5);
flowLayout->addWidget(ui->btn_info_6);
flowLayout->addWidget(ui->btn_info_7);
ui->groupBox__function->setLayout(flowLayout);
}
*/
flowlayout.cpp
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, 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 The Qt Company Ltd 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 <QtWidgets>
#include "flowlayout.h"
//! [1]
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);
}
//! [1]
//! [2]
FlowLayout::~FlowLayout()
{
QLayoutItem *item;
while ((item = takeAt(0)))
delete item;
}
//! [2]
//! [3]
void FlowLayout::addItem(QLayoutItem *item)
{
itemList.append(item);
}
//! [3]
//! [4]
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);
}
}
//! [4]
//! [5]
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;
}
//! [5]
//! [6]
Qt::Orientations FlowLayout::expandingDirections() const
{
return 0;
}
//! [6]
//! [7]
bool FlowLayout::hasHeightForWidth() const
{
return true;
}
int FlowLayout::heightForWidth(int width) const
{
int height = doLayout(QRect(0, 0, width, 0), true);
return height;
}
//! [7]
//! [8]
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;
}
//! [8]
//! [9]
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;
//! [9]
//! [10]
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);
//! [10]
//! [11]
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;
}
//! [11]
//! [12]
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();
}
}
//! [12]
//实际使用案例如下,此处使用时,根据自定义规则,实现了先后优先级
//Qt 流式布局
if(true){
FlowLayout *flowLayout = new FlowLayout;
auto childs = ui->groupBox__flow->children();
QList<QWidget*> gs;
for(auto child:childs){
if(child->objectName().startsWith("gro")){gs.append((QWidget*)child);}
else if(child->objectName().startsWith("gri")){continue;}
else{flowLayout->addWidget((QWidget*)child);}
}
for(auto child:gs){flowLayout->addWidget(child);}
ui->groupBox__flow->setLayout(flowLayout);
}
//
