QT实现橡皮擦功能.rar

#include "mainwindow.h" #include "ui_mainwindow.h" #include <QColorDialog> #include <QButtonGroup> #include <QCursor> #include <QDebug> MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); InitParam(); } MainWindow::~MainWindow() { delete ui; } void MainWindow::InitParam() { m_bPenPress = true; SetIconForButton(); CreateMenuBar(); SetBtnExclusive(); //设置scrollArea区域不能调整，当内部显示区域超过此区域时就会出现滚动条 ui->scrollArea->setWidgetResizable(false); //滑动条信号槽 connect(ui->slider, SIGNAL(valueChanged(int)), this, SLOT(SetPenOrEaraserSize())); //颜色按钮信号槽 connect(ui->btnColor, SIGNAL(clicked(bool)), this, SLOT(SetPenColor())); //橡皮擦按钮信号槽 connect(ui->btnEaraser, SIGNAL(clicked(bool)), this, SLOT(SetEaraser())); //画笔按钮信号槽 connect(ui->btnPen, SIGNAL(clicked(bool)), this, SLOT(SetPen())); //部件事件过滤的注册 ui->image->installEventFilter(this); } void MainWindow::CreateMenuBar() { //获取菜单栏句柄 QMenuBar* m_menuBar= this->menuBar(); //添加一级菜单 QMenu* m1 = m_menuBar->addMenu("文件"); //添加二级菜单 QAction* a21 = m1->addAction("Open"); QAction* a22 = m1->addAction("Save"); //设置二级菜单的快捷键 a21->setShortcut(QKeySequence("Ctrl+O")); a22->setShortcut(QKeySequence("Ctrl+S")); //添加打开/保存菜单的信号槽 connect(a21, SIGNAL(triggered()), ui->image, SLOT(Open())); connect(a22, SIGNAL(triggered()), ui->image, SLOT(Save())); } void MainWindow::SetIconForButton() { //为按钮设置图标 ui->btnPen->setIcon(QIcon(":/images/Resource/pen.png")); ui->btnPen->setIconSize(QSize(ui->btnPen->width(), ui->btnPen->height())); ui->btnEaraser->setIcon(QIcon(":/images/Resource/eraser.png")); ui->btnEaraser->setIconSize(QSize(ui->btnEaraser->width(), ui->btnEaraser->height())); //为颜色按钮设置颜色 QString strstyle = "background-color: rgba(255, 28, 107, 200)"; ui->btnColor->setStyleSheet(strstyle); } void MainWindow::SetBtnExclusive() { //设置按钮的排他属性 QButtonGroup *gp = new QButtonGroup(this); gp->addButton(ui->btnPen); gp->addButton(ui->btnEaraser); gp->setExclusive(true); } //选中画笔 void MainWindow::SetPen() { ui->image->SetPenSize(ui->slider->value()); ui->btnPen->setChecked(true); m_bPenPress = true; } //设置画笔或是橡皮擦的大小 void MainWindow::SetPenOrEaraserSize() { if(m_bPenPress) { ui->image->SetPenSize(ui->slider->value()); } else { ui->image->SetEraser(ui->slider->value()); } } //设置画笔颜色 void MainWindow::SetPenColor() { if(m_bPenPress) { ui->image->SetPenColor(QColorDialog::getColor(QColor(255, 28, 107, 200), this), ui->btnColor); } } //选中橡皮擦 void MainWindow::SetEaraser() { ui->image->SetEraser(ui->slider->value()); ui->btnEaraser->setChecked(true); m_bPenPress = false; } bool MainWindow::eventFilter(QObject *watched, QEvent *ev) { if(ui->image == watched){ if(QEvent::Enter == ev->type()){ SetCursor(); }else if(QEvent::Leave == ev->type()){ setCursor(Qt::ArrowCursor); } } return QObject::eventFilter(watched, ev); } void MainWindow::SetCursor() { QCursor *myCursor = nullptr; if(m_bPenPress) { myCursor = new QCursor(QPixmap(":/images/Resource/pen.png"),20,44); } else { myCursor = new QCursor(QPixmap(":/images/Resource/eraser.png"),2,36); } setCursor(*myCursor); }