《QT实用小工具·四十六》多边形窗口

本文主要是介绍《QT实用小工具·四十六》多边形窗口，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1、概述
源码放在文章末尾

该项目实现了可以移动的多边形窗口，项目demo演示如下所示：
在这里插入图片描述
项目部分代码如下所示：

#include "polygonwindow.h"#include <QBitmap>
#include <QQuickItem>
#include <QQmlFile>
#include <QSGSimpleTextureNode>class PolygonItem : public QQuickItem
{
public:PolygonItem(QQuickItem *parent = nullptr) : QQuickItem (parent) {setFlag(ItemHasContents);}void setTexture(QSGTexture *texture);protected:virtual QSGNode *updatePaintNode(QSGNode *node, UpdatePaintNodeData *);private:QScopedPointer<QSGTexture> m_texture;
};void PolygonItem::setTexture(QSGTexture *texture)
{m_texture.reset(texture);
}QSGNode* PolygonItem::updatePaintNode(QSGNode *node, UpdatePaintNodeData *)
{QSGSimpleTextureNode *n = static_cast<QSGSimpleTextureNode *>(node);if (n) {if (!m_texture.isNull()) {n->setTexture(m_texture.data());n->setFiltering(QSGTexture::Linear);n->setRect(boundingRect());}} else {n = new QSGSimpleTextureNode();if (!m_texture.isNull()) {n->setTexture(m_texture.data());n->setFiltering(QSGTexture::Linear);n->setRect(boundingRect());}}return n;
}class PolygonWindowPrivate
{
public:QPoint m_startPos;QPoint m_oldPos;QUrl m_source;QPixmap m_background;QScopedPointer<PolygonItem> m_centerItem;
};PolygonWindow::PolygonWindow(QWindow *parent): QQuickWindow (parent)
{d = new PolygonWindowPrivate;setOpacity(0.8);setColor(Qt::transparent);setFlags(flags() | Qt::Window | Qt::FramelessWindowHint);connect(this, &QQuickWindow::widthChanged, this, [this](int) {changeTexture();});connect(this, &QQuickWindow::heightChanged, this, [this](int) {changeTexture();});connect(this, &QQuickWindow::sceneGraphInitialized, this, [this]() {d->m_centerItem.reset(new PolygonItem(contentItem()));changeTexture();});
}PolygonWindow::~PolygonWindow()
{delete d;
}QUrl PolygonWindow::source() const
{return d->m_source;
}void PolygonWindow::setSource(const QUrl &source)
{if (source != d->m_source) {d->m_source = source;d->m_background = QQmlFile::urlToLocalFileOrQrc(source);changeTexture();emit sourceChanged();}
}void PolygonWindow::mousePressEvent(QMouseEvent *event)
{d->m_startPos = event->globalPos();d->m_oldPos = position();event->ignore();QQuickWindow::mousePressEvent(event);
}void PolygonWindow::mouseReleaseEvent(QMouseEvent *event)
{d->m_oldPos = position();QQuickWindow::mouseReleaseEvent(event);
}void PolygonWindow::mouseMoveEvent(QMouseEvent *event)
{if (event->buttons() & Qt::LeftButton) {setPosition(d->m_oldPos - d->m_startPos + event->globalPos());}QQuickWindow::mouseMoveEvent(event);
}void PolygonWindow::changeTexture()
{auto texture = d->m_background.scaled(size(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);if (!texture.isNull()) {d->m_background = texture;setMask(QRegion(d->m_background.mask()));if (d->m_centerItem) {d->m_centerItem->setSize(size());d->m_centerItem->setTexture(createTextureFromImage(d->m_background.toImage(), TextureHasAlphaChannel));}}update();
}