QGraphicsView重写-整体缩放

#include "GViewScale.h" #include <QDebug> #include <QScrollBar> GViewScale::GViewScale(QWidget *parent) : QGraphicsView(parent) { setDragMode(QGraphicsView::ScrollHandDrag); m_gs = nullptr; m_IfAddBasemap = false; m_CurScale = 1.0; m_MaxScale = 1.0; m_MinScale = 1.0; m_ViewScale = 1.0; } GViewScale::~GViewScale() { } bool GViewScale::AddBasemap(const QString &FilePath) { if(m_IfAddBasemap == true) { return true; } QPixmap pp; pp.load(FilePath); if(pp.isNull() == true) { return false; } if(pp.width() < 1280 || pp.height() < 720) { return false; } m_gs = new QGraphicsScene(); setScene(m_gs); setSceneRect(0, 0, pp.width(), pp.height()); if(m_gs->addPixmap(pp) == nullptr) { return false; } qDebug() << "ccc0" << m_gs->width() << m_gs->height() << size() << viewport()->size() << horizontalScrollBar()->value() << horizontalScrollBar()->maximum() << verticalScrollBar()->value() << verticalScrollBar()->maximum(); m_MinScale = 0.1; if(pp.width() >= 3840 || pp.height() >= 2160) { m_MaxScale = 1.0; double xb = width()*1.0/pp.width(); double yb = height()*1.0/pp.height(); m_ViewScale = xb < yb ? xb : yb; scale(m_ViewScale, m_ViewScale); m_CurScale = m_CurScale*m_ViewScale; } else { m_MaxScale = 2.0; } m_IfAddBasemap = true; qDebug() << "ccc1" << m_gs->width() << m_gs->height() << size() << viewport()->size() << horizontalScrollBar()->value() << horizontalScrollBar()->maximum() << verticalScrollBar()->value() << verticalScrollBar()->maximum(); return true; } bool GViewScale::AddWidget(QWidget *wt, const QRectF &rf) { if(m_IfAddBasemap == false) { return false; } if(wt == nullptr || sceneRect().contains(rf) == false) { return false; } wt->setParent(nullptr); if(m_gs->addWidget(wt) == nullptr) { return false; } wt->setGeometry(rf.x(), rf.y(), rf.width(), rf.height()); return true; } void GViewScale::WholeEnlarge() { if(m_IfAddBasemap == false) { return ; } if(m_CurScale >= m_MaxScale) { return ; } scale(1.1, 1.1); m_CurScale = m_CurScale*1.1; qDebug() << "+++" << m_gs->width() << m_gs->height() << size() << viewport()->size() << horizontalScrollBar()->value() << horizontalScrollBar()->maximum() << verticalScrollBar()->value() << verticalScrollBar()->maximum(); } void GViewScale::WholeShrink() { if(m_IfAddBasemap == false) { return ; } if(m_CurScale <= m_MinScale) { return ; } scale(1.0/1.1, 1.0/1.1); m_CurScale = m_CurScale*1.0/1.1; qDebug() << "---" << m_gs->width() << m_gs->height() << size() << viewport()->size() << horizontalScrollBar()->value() << horizontalScrollBar()->maximum() << verticalScrollBar()->value() << verticalScrollBar()->maximum(); } void GViewScale::WholeOriginal() { if(m_IfAddBasemap == false) { return ; } if(m_CurScale == 1.0) { return ; } scale(1.0/m_CurScale, 1.0/m_CurScale); m_CurScale = m_CurScale*1.0/m_CurScale; qDebug() << "000" << m_gs->width() << m_gs->height() << size() << viewport()->size() << horizontalScrollBar()->value() << horizontalScrollBar()->maximum() << verticalScrollBar()->value() << verticalScrollBar()->maximum(); } void GViewScale::WholeView() { if(m_IfAddBasemap == false) { return ; } if(m_CurScale == m_ViewScale) { return ; } scale(m_ViewScale/m_CurScale, m_ViewScale/m_CurScale); m_CurScale = m_CurScale*m_ViewScale/m_CurScale; }