zoukankan      html  css  js  c++  java
  • Qt之自定义布局管理器(QBorderLayout)

    简述

    QBorderLayout,顾名思义-边框布局,实现了排列子控件包围中央区域的布局。

    具体实现要求不再赘述,请参考前几节内容。

    实现

    QBorderLayout主要采用QLayout和QWidgetItem实现,而窗口使用了QWidget,中央窗体使用QTextBrowser,四周以QLabel排列。

    效果

    这里写图片描述

    源码

    QBorderLayout.h

    #ifndef QBORDERLAYOUT_H
    #define QBORDERLAYOUT_H
    
    #include <QLayout>
    #include <QRect>
    
    class QBorderLayout : public QLayout
    {
    public:
        enum Position {West, North, South, East, Center};
    
        explicit QBorderLayout(QWidget *parent, int margin = 0, int spacing = -1);
        QBorderLayout(int spacing = -1);
        ~QBorderLayout();
    
        void addItem(QLayoutItem *item) Q_DECL_OVERRIDE;
        void addWidget(QWidget *widget, Position position);
        Qt::Orientations expandingDirections() const Q_DECL_OVERRIDE;
        bool hasHeightForWidth() const Q_DECL_OVERRIDE;
        int count() const Q_DECL_OVERRIDE;
        QLayoutItem *itemAt(int index) const Q_DECL_OVERRIDE;
        QSize minimumSize() const Q_DECL_OVERRIDE;
        void setGeometry(const QRect &rect) Q_DECL_OVERRIDE;
        QSize sizeHint() const Q_DECL_OVERRIDE;
        QLayoutItem *takeAt(int index) Q_DECL_OVERRIDE;
    
        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 // QBORDERLAYOUT_H

    QBorderLayout.cpp

    #include "QBorderLayout.h"
    
    QBorderLayout::QBorderLayout(QWidget *parent, int margin, int spacing)
        : QLayout(parent)
    {
        setMargin(margin);
        setSpacing(spacing);
    }
    
    QBorderLayout::QBorderLayout(int spacing)
    {
        setSpacing(spacing);
    }
    
    QBorderLayout::~QBorderLayout()
    {
        QLayoutItem *l;
        while ((l = takeAt(0)))
            delete l;
    }
    
    void QBorderLayout::addItem(QLayoutItem *item)
    {
        add(item, West);
    }
    
    void QBorderLayout::addWidget(QWidget *widget, Position position)
    {
        add(new QWidgetItem(widget), position);
    }
    
    Qt::Orientations QBorderLayout::expandingDirections() const
    {
        return Qt::Horizontal | Qt::Vertical;
    }
    
    bool QBorderLayout::hasHeightForWidth() const
    {
        return false;
    }
    
    int QBorderLayout::count() const
    {
        return list.size();
    }
    
    QLayoutItem *QBorderLayout::itemAt(int index) const
    {
        ItemWrapper *wrapper = list.value(index);
        if (wrapper)
            return wrapper->item;
        else
            return 0;
    }
    
    QSize QBorderLayout::minimumSize() const
    {
        return calculateSize(MinimumSize);
    }
    
    void QBorderLayout::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 QBorderLayout::sizeHint() const
    {
        return calculateSize(SizeHint);
    }
    
    QLayoutItem *QBorderLayout::takeAt(int index)
    {
        if (index >= 0 && index < list.size()) {
            ItemWrapper *layoutStruct = list.takeAt(index);
            return layoutStruct->item;
        }
        return 0;
    }
    
    void QBorderLayout::add(QLayoutItem *item, Position position)
    {
        list.append(new ItemWrapper(item, position));
    }
    
    QSize QBorderLayout::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;
    }

    使用

    中央窗体使用QTextBrowser,四周以QLabel排列开来。

    QTextBrowser *pCentralWidget = new QTextBrowser(this);
    pCentralWidget->setPlainText(tr("Central Widget"));
    
    QBorderLayout *pLayout = new QBorderLayout();
    pLayout->addWidget(pCentralWidget, QBorderLayout::Center);
    pLayout->addWidget(createLabel("North"), QBorderLayout::North);
    pLayout->addWidget(createLabel("West"), QBorderLayout::West);
    pLayout->addWidget(createLabel("East 1"), QBorderLayout::East);
    pLayout->addWidget(createLabel("East 2") , QBorderLayout::East);
    pLayout->addWidget(createLabel("South"), QBorderLayout::South);
    setLayout(pLayout);
    
    QLabel *MainWindow::createLabel(const QString &text)
    {
        QLabel *pLabel = new QLabel(this);
        pLabel->setText(text);
        pLabel->setFrameStyle(QFrame::Box | QFrame::Raised);
        return pLabel;
    }
  • 相关阅读:
    js处理富文本编辑器转义、去除转义、去除HTML标签
    web sec tools / Arachni
    OS + Linux IP / Inside IP / Outside IP
    OS + Linux SMB / Samba
    OS + Linux NTP Server
    my live / PC NAS / weiliantong QNAP TS-532X 4.5.1.1495 / cipanzhenlie / raid / Synology
    summarise() regrouping output 警告
    binary_crossentropy和BinaryCrossentropy的区别
    损失函数BinaryCrossentropy例子说明
    理解功能强大的sed替换命令
  • 原文地址:https://www.cnblogs.com/itrena/p/5938329.html
Copyright © 2011-2022 走看看