Qt实现的实时显示CPU使用率

#include "usagechart.h" UsageChart::UsageChart(QWidget *parent) : QWidget(parent) { initVariables(); } void UsageChart::initVariables() { m_bUseAntialiasing=true; m_bShowHLine=true; m_bShowPoint=true; m_hLineClr=Qt::black; m_strTitle="Demo"; } void UsageChart::paintEvent(QPaintEvent *e) { QPainter painter; painter.begin(this); if(m_bUseAntialiasing) { painter.setRenderHints(QPainter::Antialiasing|QPainter::TextAntialiasing); } resetVariables(&painter); drawBackground(&painter); drawBox(&painter); drawText(&painter); drawGraph(&painter); drawTitle(&painter); } /*! The following is painting used private functions */ void UsageChart::resetVariables(QPainter *painter) { QPointF topRectTopLeftPot(0,0); QPointF topRectBottomRightPot(width(),height()/3*2); m_topRect=QRectF(topRectTopLeftPot,topRectBottomRightPot); QPointF bottomRectTopLeftPot(0,height()/3*2); QPointF bottomRectBottomRightPot(width(),height()); m_bottomRect=QRectF(bottomRectTopLeftPot,bottomRectBottomRightPot); m_leftSpace=(qreal)width()/10; m_topSpace=(qreal)height()/10; } void UsageChart::drawBackground(QPainter *painter) { painter->save(); painter->setPen(Qt::NoPen); QLinearGradient topGradient(m_topRect.topLeft(),m_topRect.bottomLeft()); topGradient.setColorAt(0.0,QColor(110,110,110)); topGradient.setColorAt(1.0,QColor(190,190,190)); painter->setBrush(topGradient); painter->drawRect(m_topRect); QLinearGradient bottomGradient(m_bottomRect.topLeft(),m_bottomRect.bottomLeft()); bottomGradient.setColorAt(0.0,QColor(190,190,190)); bottomGradient.setColorAt(1.0,QColor(130,130,130)); painter->setBrush(bottomGradient); painter->drawRect(m_bottomRect); painter->restore(); } void UsageChart::drawBox(QPainter *painter) { painter->save(); QPointF topLeftPot(m_leftSpace,m_topSpace); QPointF bottomRightPot(width()-m_leftSpace,height()-m_topSpace); painter->setPen(Qt::black); painter->setBrush(Qt::NoBrush); m_boxRect=QRectF(topLeftPot,bottomRightPot); painter->drawRect(m_boxRect); if(m_bShowHLine) { painter->setPen(m_hLineClr); qreal increment=(qreal)m_boxRect.height()/10; qreal startY=m_boxRect.topLeft().y(); qreal boxWidth=m_boxRect.width(); for(int i=0;i<9;i++) { startY+=increment; QPointF leftPot(m_boxRect.topLeft().x(),startY); QPointF rightPot(m_boxRect.topRight().x(),startY); painter->setPen(Qt::DotLine); painter->drawLine(leftPot,rightPot); } } painter->restore(); } void UsageChart::drawText(QPainter *painter) { painter->save(); int value=100; qreal increment=(qreal)m_boxRect.height()/10; qreal startY=m_boxRect.topLeft().y(); QString strValue; for(int i=0;i<=10;i++) { strValue=tr("%1%").arg(value); qreal textWidth=fontMetrics().width(strValue); qreal textHeight=fontMetrics().height(); QPointF textPot(m_boxRect.topLeft().x()-TEXT_BOX_SPACE-textWidth,startY+textHeight/2); painter->drawText(textPot,strValue); value-=10; startY+=increment; } painter->restore(); } void UsageChart::drawGraph(QPainter *painter) { painter->save(); qreal startX=m_boxRect.topRight().x(); QVector<QPointF> potVec; painter->save(); painter->setPen(Qt::NoPen); potVec.push_back(QPointF(startX,m_boxRect.bottomRight().y())); for(int i=0;i<m_dataVec.count();i++) { qreal x=startX; qreal y=m_boxRect.bottomRight().y()-(qreal)m_dataVec.at(i)*(m_boxRect.height()/100); QPointF dataPot(x,y); potVec.push_back(dataPot); startX-=X_INCREMENT; qDebug() << m_dataVec.at(i) << ":"<< y; } potVec.push_back(QPointF(startX,m_boxRect.bottomRight().y())); painter->restore(); QLinearGradient graphGradient(m_boxRect.topLeft(),m_boxRect.bottomLeft()); graphGradient.setColorAt(0.0,QColor(240,67,51)); graphGradient.setColorAt(0.4,QColor(208,94,49)); graphGradient.setColorAt(1.0,QColor(85,255,0)); painter->setBrush(graphGradient); painter->setPen(Qt::NoPen); painter->drawConvexPolygon(QPolygonF(potVec)); // draw points if(m_bShowPoint) { painter->setOpacity(0.5); for(int i=1;i<potVec.count()-1;i++) { QPointF dataPot=potVec.at(i); QRadialGradient potGradient(dataPot,POINT_RADIUS,dataPot); potGradient.setColorAt(0.0,QColor(180,180,180)); potGradient.setColorAt(0.5,QColor(143,123,23)); potGradient.setColorAt(1.0,QColor(180,180,180)); painter->setBrush(potGradient); painter->drawEllipse(dataPot,POINT_RADIUS,POINT_RADIUS); } } painter->restore(); } void UsageChart::drawTitle(QPainter *painter) { painter->save(); qreal titleX=(qreal)width()/2; qreal titleY=m_topSpace/2; qreal textWidth=fontMetrics().width(m_strTitle); qreal textHeight=fontMetrics().height(); QFont titleFont; titleFont.setBold(true); titleFont.setPointSize(10); painter->setFont(titleFont); QPointF textPot(titleX-textWidth/2,titleY/2+textHeight/2); painter->drawText(textPot,m_strTitle); painter->restore(); } /*! public slot functions */ void UsageChart::addData(qreal data) { m_dataVec.push_front(data); updateVector(); } void UsageChart::updateVector() { int allowDataCount=m_boxRect.width()/X_INCREMENT; if(m_dataVec.count()>allowDataCount) { m_dataVec.remove(allowDataCount,1); } update(); }