C++Qt实现拖拽按钮插入指定位置并重新排序

#include "applicationlistwidget.h" #include "ui_applicationlistwidget.h" #include <QDebug> ApplicationListWidget::ApplicationListWidget(QWidget *parent) : QListWidget(parent), ui(new Ui::ApplicationListWidget), m_leftPress(false), m_mouseMoved(false), m_dragItem(nullptr), m_shotLabel(nullptr), m_shotLine(nullptr) { ui->setupUi(this); initWidget(); } ApplicationListWidget::~ApplicationListWidget() { if(m_shotLabel) { m_shotLabel->close(); m_shotLabel->deleteLater(); m_shotLabel = nullptr; } if(m_shotLine) { m_shotLine->close(); m_shotLine->deleteLater(); m_shotLine = nullptr; } delete ui; } void ApplicationListWidget::initWidget() { setViewMode(QListView::IconMode); setResizeMode(QListView::Adjust); setGridSize(QSize(122, 110)); setStyleSheet( "QListWidget{border:0px;}" "QListView::item{width:95;height:93px;}"); } bool ApplicationListWidget::AddItem(YYXX yyxx) { ApplicationItem *itemWidget = new ApplicationItem; itemWidget->setData(yyxx); QListWidgetItem *item = new QListWidgetItem; addItem(item); this->setItemWidget(item, itemWidget); return true; } void ApplicationListWidget::mousePressEvent(QMouseEvent *event) { if(event->button() == Qt::LeftButton) { m_leftPress = true; m_startPos = event->pos(); m_dragItem = itemAt(event->pos()); } //QListWidget::mousePressEvent(event); } void ApplicationListWidget::mouseMoveEvent(QMouseEvent *event) { if(m_dragItem == nullptr) { return ; } m_mouseMoved = true; if(m_shotLabel == nullptr) { InitShotLabel(); } if(m_shotLine == nullptr) { InitShotLine(); } QListWidgetItem *item = itemAt(event->pos()); if(ApplicationItem *hoverWidget = ItemWidget(item)) { m_hoverRect = visualItemRect(item); m_shotLine->move(mapToGlobal(QPoint(m_hoverRect.x(), m_hoverRect.y() + 1))); m_shotLine->setVisible(m_hoverRect.contains(event->pos())); } QRect rect = visualItemRect(m_dragItem); if(ApplicationItem *newWidget = ItemWidget(m_dragItem)) { m_shotLabel->move(mapToGlobal(event->pos() - newWidget->mapFromParent(m_startPos))); if(rect.contains(event->pos()) || event->pos().isNull()) { setCursor(Qt::ForbiddenCursor); } else { setCursor(Qt::ArrowCursor); } if(m_shotLabel->isHidden()) { m_shotLabel->show(); } } QListWidget::mouseMoveEvent(event); } void ApplicationListWidget::mouseReleaseEvent(QMouseEvent *event) { if(event->button() == Qt::LeftButton) { m_leftPress = false; if(!m_mouseMoved) { emit ClickedItem(ItemWidget(m_dragItem)); return; } m_mouseMoved = false; MouseRelease(event); if(m_shotLabel) { m_shotLabel->close(); m_shotLabel->deleteLater(); m_shotLabel = nullptr; } if(m_shotLine) { m_shotLine->close(); m_shotLine->deleteLater(); m_shotLine = nullptr; } } setCursor(Qt::ArrowCursor); QListWidget::mouseReleaseEvent(event); } void ApplicationListWidget::InitShotLabel() { m_shotLabel = new QLabel; m_shotLabel->setWindowOpacity(0.8); m_shotLabel->setWindowFlags(Qt::FramelessWindowHint | Qt::Tool | Qt::WindowStaysOnTopHint); m_shotLabel->setAttribute(Qt::WA_TransparentForMouseEvents, true); if(ApplicationItem *oldWidget = ItemWidget(m_dragItem)) { m_shotLabel->setPixmap(oldWidget->grab()); m_shotLabel->resize(visualItemRect(m_dragItem).size()); } m_shotLabel->show(); } void ApplicationListWidget::InitShotLine() { m_shotLine = new QLabel(this); m_shotLine->setObjectName(QStringLiteral("ShotLine")); m_shotLine->setWindowFlags(Qt::FramelessWindowHint | Qt::Tool | Qt::WindowStaysOnTopHint); m_shotLine->setAttribute(Qt::WA_TransparentForMouseEvents, true); m_shotLine->setStyleSheet("QLabel#ShotLine{background:blue;}"); if(ApplicationItem *oldWidget = ItemWidget(m_dragItem)) { m_shotLine->resize(visualItemRect(m_dragItem).size().width(), 2); } m_shotLine->show(); } void ApplicationListWidget::MouseRelease(QMouseEvent *event) { QListWidgetItem *item = itemAt(m_hoverRect.topLeft()); if(item == nullptr || m_dragItem == nullptr || item == m_dragItem) { return; } int insertPos = row(item); int oldPos = row(m_dragItem); if (oldPos < insertPos) { insertPos += 1; } if(ApplicationItem *oldWidget = ItemWidget(m_dragItem)) { ApplicationItem *widgetItem = new ApplicationItem; widgetItem->setData(oldWidget->GetData()); QListWidgetItem *newItem = new QListWidgetItem; this->insertItem(insertPos, newItem); this->setItemWidget(newItem, widgetItem); this->setCurrentItem(newItem); oldWidget->deleteLater(); } m_dragItem = this->takeItem(row(m_dragItem)); if(m_dragItem) { delete m_dragItem; m_dragItem = nullptr; } } ApplicationItem *ApplicationListWidget::ItemWidget(QListWidgetItem *item) { return dynamic_cast<ApplicationItem *>(this->itemWidget(item)); }