Qt基于paintEvent自定义CharView

Qt基于paintEvent自定义CharView

鼠标拖动，缩放，区域缩放， 针对x轴，直接上代码

charview.h

#ifndef CHARVIEW_H
#define CHARVIEW_H#include <QWidget>
#include <QPainter>
#include <QPaintEvent>
#include <QResizeEvent>
#include <QMouseEvent>
#include <QWheelEvent>
#include <QPointF>class ScaleNode
{
public:QPointF pointScaleOne;QPointF pointScaleTwo;QPointF pointScaleText;double scaleValue;bool bShowScaleText;ScaleNode* nextNode;ScaleNode(){bShowScaleText = false;nextNode = nullptr;}
};class CharView: public QWidget
{
public:CharView(QWidget *parent = nullptr);~CharView();virtual void paintAxisX(QPainter &painter);virtual void paintAxisY(QPainter &painter);virtual void paintCursor(QPainter &painter);virtual void paintData(QPainter &painter);virtual void paintMouseRightMove(QPainter &painter);void UpdeScaleNode();void InitScaleNode();void MouseLeftMoveUpdateStartEndValue();//鼠标左键拖动更新void MouseRightMoveUpdateStartEndValue();//鼠标右键选择更新void MouseWheelUpdateStartEndValue(int flag);//鼠标缩放更新private:void DeleteNode(ScaleNode* node);
protected:virtual void paintEvent(QPaintEvent* event) override;virtual void resizeEvent(QResizeEvent* event) override;virtual void mouseMoveEvent(QMouseEvent* event) override;virtual void mousePressEvent(QMouseEvent* event) override;//鼠标左键按住拖动移动， 右键区域放大virtual void mouseReleaseEvent(QMouseEvent* event) override;virtual void wheelEvent(QWheelEvent* event) override;//滚动鼠标滑轮放大缩小virtual void mouseDoubleClickEvent(QMouseEvent* event) override;//双击恢复默认public:int leftBorder;int topBorder;int rightBorder;int bottomBorder;double scaleValue;int scaleLength;//刻度线高度int scaleTextScaleLength;//带text的刻度线高度int scaleTextHeight;//刻度text高度int scaleTextWidth;//刻度text宽度int scaleTextBorder;//刻度text边距int scaleCnt;//刻度数量double scaleWidth;//刻度宽度int scaleCntShowText;//每多少个刻度显示刻度textdouble startScaleValueInit;//默认刻度开始值double endScaleValueInit;//默认刻度结束值double startScaleValue;//当前刻度开始值double endScaleValue;//当前刻度结束值double everyWidthValue;//每个宽度的值ScaleNode* scaleNodeBegin;//第一个刻度QPointF currentPointF;//当前鼠标位置bool bShowCursor;//是否实现游标bool bPressLeft;//是否鼠标左键按下bool bPressRight;//是否鼠标右键按下QPointF pressPointF;//鼠标左键按下时坐标bool bPressRightMove;//鼠标是否按下移动};#endif // CHARVIEW_H

CharView.cpp

#include "charview.h"#include <QDebug>
CharView::CharView(QWidget *parent):QWidget(parent)
{setMouseTracking(true);setStyleSheet("background-color:rgb(255,255,255);");InitScaleNode();
}CharView::~CharView()
{DeleteNode(scaleNodeBegin);
}void CharView::DeleteNode(ScaleNode *node)
{if(node->nextNode)DeleteNode(node->nextNode);delete node;node = nullptr;
}void CharView::UpdeScaleNode()
{scaleValue = ((double)(endScaleValue - startScaleValue))/scaleCnt;scaleWidth = ((double)(width() - leftBorder - rightBorder))/scaleCnt;everyWidthValue = ((double)(endScaleValue - startScaleValue))/(width() - leftBorder - rightBorder);ScaleNode* node = scaleNodeBegin;int var=0;while(node){node->pointScaleOne = QPointF(leftBorder + var*scaleWidth, height() - bottomBorder);node->pointScaleTwo = QPointF(leftBorder + var*scaleWidth, height() - bottomBorder - scaleLength);node->pointScaleText = QPointF(leftBorder + var*scaleWidth - scaleTextWidth/2,  height() - bottomBorder + scaleTextBorder);node->scaleValue = startScaleValue + var*scaleValue;if(var%scaleCntShowText == 0){node->pointScaleTwo = QPointF((double)(leftBorder + var*scaleWidth), height() - bottomBorder - scaleTextScaleLength);node->bShowScaleText = true;}var++;node = node->nextNode;}}void CharView::InitScaleNode()
{bPressRightMove = false;bPressLeft = false;bPressRight = false;bShowCursor = true;leftBorder = 50;topBorder = 10;rightBorder = 50;bottomBorder = 20;scaleCntShowText = 5;startScaleValueInit = 0;endScaleValueInit = 3000000000;startScaleValue = startScaleValueInit;endScaleValue = endScaleValueInit;scaleCnt = 30;scaleLength = 2;scaleTextScaleLength = 4;scaleTextBorder = 5;scaleTextWidth = 100;scaleTextHeight = fontMetrics().height();ScaleNode* nodeTmp=nullptr;for (int var = 0; var <= scaleCnt; ++var) {ScaleNode* node = new ScaleNode;if(nodeTmp)nodeTmp->nextNode = node;nodeTmp = node;if(var == 0)scaleNodeBegin = node;}
}void CharView::MouseWheelUpdateStartEndValue(int flag)
{double zoomValue = (endScaleValue - startScaleValue)/10;if(flag > 0){endScaleValue -= zoomValue;}else{endScaleValue += zoomValue;}double everyWidthValueOld = everyWidthValue;double centerX = currentPointF.x() - leftBorder;everyWidthValue = ((double)(endScaleValue - startScaleValue))/(width() - leftBorder - rightBorder);startScaleValue = startScaleValue + centerX*everyWidthValueOld - centerX*everyWidthValue ;endScaleValue = endScaleValue + centerX*everyWidthValueOld - centerX*everyWidthValue ;if(startScaleValue <=0)startScaleValue = 0;
}void CharView::MouseLeftMoveUpdateStartEndValue()
{double offsetX  =  currentPointF.x() - pressPointF.x();pressPointF = currentPointF;double offsetValue = offsetX*everyWidthValue;if(startScaleValue - offsetValue <=0 && offsetX > 0){startScaleValue = 0;offsetValue = startScaleValue;}else{startScaleValue = startScaleValue - offsetValue;}endScaleValue = endScaleValue - offsetValue;}void CharView::MouseRightMoveUpdateStartEndValue()
{if(currentPointF.x() < leftBorder || currentPointF.x() > width() - rightBorder ||pressPointF.x() < leftBorder || pressPointF.x() > width() - rightBorder|| !bPressRight)return;endScaleValue = startScaleValue + (currentPointF.x() - leftBorder)*everyWidthValue;startScaleValue = startScaleValue + (pressPointF.x() - leftBorder)*everyWidthValue;
}void CharView::paintEvent(QPaintEvent *event)
{//界面大小改变，只改变刻度实际宽度， 刻度开始结束值不变//鼠标缩放，刻度实际宽度改变， 刻度开始结束值改变//鼠标拖动，刻度实际宽度不变， 刻度开始结束值改变//绘制前计算更新刻度UpdeScaleNode();QPainter painter(this);// painter.setRenderHint(QPainter::Antialiasing);//加上会加粗//绘制游标paintAxisX(painter);paintAxisY(painter);//绘制数据paintData(painter);paintMouseRightMove(painter);//绘制游标if(bShowCursor)paintCursor(painter);
}void CharView::paintMouseRightMove(QPainter &painter)
{if(currentPointF.x() < leftBorder || currentPointF.x() > width() - rightBorder ||pressPointF.x() < leftBorder || pressPointF.x() > width() - rightBorder|| !bPressRight)return;QPen pen;pen.setStyle(Qt::DashLine);pen.setColor(QColor(236,132,251));pen.setWidth(1);painter.setPen(pen);double w = currentPointF.x() - pressPointF.x();double y = currentPointF.y() - pressPointF.y();painter.drawRect(pressPointF.x(),pressPointF.y(), w, y);
}void CharView::paintAxisX(QPainter &painter)
{QPen pen;pen.setStyle(Qt::SolidLine);pen.setColor(Qt::black);pen.setWidth(1);painter.setPen(pen);int y = height() - bottomBorder;painter.drawLine(QPointF(leftBorder, y),QPointF(width() - rightBorder, y));ScaleNode* node = scaleNodeBegin;while(node){painter.drawLine(node->pointScaleOne,node->pointScaleTwo);if(node->bShowScaleText)painter.drawText(node->pointScaleText.x(), node->pointScaleText.y(), scaleTextWidth, scaleTextHeight,Qt::AlignCenter, QString::number(node->scaleValue, 'f', 0));node = node->nextNode;}
}void CharView::paintAxisY(QPainter &painter)
{}void CharView::paintCursor(QPainter &painter)
{if(currentPointF.x() < leftBorder || currentPointF.x() > width() - rightBorder)return;QPen pen;pen.setStyle(Qt::DashLine);pen.setColor(QColor(236,132,251));pen.setWidth(1);painter.setPen(pen);painter.drawLine(QPointF(currentPointF.x(), 0), QPointF(currentPointF.x(), height() - bottomBorder));double number = (currentPointF.x() - leftBorder)*everyWidthValue + startScaleValue;painter.drawText(currentPointF.x(), height() - bottomBorder - scaleTextHeight, scaleTextWidth, scaleTextHeight,Qt::AlignLeft, QString::number(number, 'f', 0));
}void CharView::paintData(QPainter &painter)
{//testdouble value1 = 1240000000;double value2 = 1590000000;double x1 = leftBorder + (value1 - startScaleValue)/everyWidthValue;double x2 = leftBorder + (value2 - startScaleValue)/everyWidthValue;QPointF point1(x1, 100);QPointF point2(x2, 200);QPen pen;pen.setStyle(Qt::SolidLine);pen.setColor(Qt::black);pen.setWidth(1);painter.setPen(pen);painter.drawLine(point1,point2);
}void CharView::resizeEvent(QResizeEvent *event)
{UpdeScaleNode();return QWidget::resizeEvent(event);
}void CharView::mouseMoveEvent(QMouseEvent *event)
{currentPointF = event->localPos();if(bPressLeft){if(currentPointF != pressPointF)MouseLeftMoveUpdateStartEndValue();}else if(bPressRight){bPressRightMove = true;}update();return QWidget::mouseMoveEvent(event);
}void CharView::mousePressEvent(QMouseEvent *event)
{if(!bPressLeft && event->button() == Qt::LeftButton){bPressLeft = true;pressPointF = event->localPos();}else if(!bPressRight && event->button() == Qt::RightButton){bPressRight = true;pressPointF = event->localPos();}return QWidget::mousePressEvent(event);
}void CharView::mouseReleaseEvent(QMouseEvent *event)
{if(bPressRight){if(bPressRightMove && currentPointF != pressPointF)MouseRightMoveUpdateStartEndValue();bPressRight = false;bPressRightMove = false;update();}bPressLeft = false;return QWidget::mouseReleaseEvent(event);
}void CharView::wheelEvent(QWheelEvent *event)
{MouseWheelUpdateStartEndValue(event->delta());update();return QWidget::wheelEvent(event);
}void CharView::mouseDoubleClickEvent(QMouseEvent *event)
{startScaleValue = startScaleValueInit;endScaleValue = endScaleValueInit;return QWidget::mouseDoubleClickEvent(event);
}