QT下简易画板实现

以你之姓@ 2022-06-09 07:17 250阅读 0赞

//maindow.h

\#ifndef MAINWINDOW\_H  
\#define MAINWINDOW\_H

\#include"paintwidget.h"  
\#include <QMainWindow>  
\#include<QScrollArea>

\#include<QComboBox>  //颜色组合框头

namespace Ui \{  
    class MainWindow;  
\}

class MainWindow : public QMainWindow  
\{  
    Q\_OBJECT

public:  
    explicit MainWindow(QWidget \*parent = 0);  
    ~MainWindow();

void doNew();  //新建文件操作  
    void doOpen();  //打开文件操作  
    bool doFileSave();  //保存文件操作  
    bool doFileSaveAs();  //文件另存为操作

void creatColorComboBox(QComboBox\*comboBox);  //构建颜色组合框

private:  
    Ui::MainWindow \*ui;  
    PaintWidget\*area;  
    QScrollArea\*scrollArea;

bool isSaved;  //标志文件是否保存过  
    QString curFile;  //保存当前文件的路径  
    bool maybeSave();  //是否保存文件

bool saveFile(QString fileName);  //实现文件的存储

protected:  
    void changeEvent(QEvent \*e);  
    void closeEvent(QCloseEvent\*);

private slots:  
    void on\_action\_triggered();  
    void on\_brushColorComboBox\_currentIndexChanged(int index);  
    void on\_penColorComboBox\_currentIndexChanged(int index);  
    void on\_penWidthSpinBox\_valueChanged(int );  
    void on\_penStyleComboBox\_currentIndexChanged(QString );  
    void on\_shapeComboBox\_currentIndexChanged(QString );  
    void on\_action\_28\_triggered();  
    void on\_action\_26\_triggered();  
    void on\_action\_24\_triggered();  
    void on\_action\_23\_triggered();  
    void on\_action\_22\_triggered();  
    void on\_action\_21\_triggered();  
    void on\_action\_20\_triggered();  
    void on\_action\_P\_triggered();  
    void on\_action\_X\_triggered();  
    void on\_action\_A\_triggered();  
    void on\_action\_S\_triggered();  
    void on\_action\_O\_triggered();  
    void on\_action\_N\_triggered();  
\};

\#endif // MAINWINDOW\_H

//paintwidget.h

\#ifndef PAINTWIDGET\_H  
\#define PAINTWIDGET\_H

\#include <QWidget>  
\#include<QMouseEvent>  
\#include<QPoint>

class PaintWidget : public QWidget  
\{  
    Q\_OBJECT  
public:  
    //explicit PaintWidget();

PaintWidget();  
    void setImageSize(int width,int height);  //声明改变画布大小函数  
    void setImageColor(QColor color);  //声明改变画布颜色函数

bool isModified() const\{return modified;\}  //判断画布内容是否被更改过  
    bool saveImage(const QString&fileName,const char\*fileFormat); //保存图片  
    bool openImage(const QString&fileName);  //打开图片

QSize getImageSize();

void doPrint();  //打印菜单功能函数声明

//工具菜单功能函数声明  
    void zoomIn();  //放大  
    void zoomOut();  //缩小  
    void zoom\_1();  //还原  
    void doRotate();  //旋转  
    void doShear();  //拉伸  
    void doClear();  //清空

//画笔颜色  
    void setPenStyle(Qt::PenStyle style);  //设置画笔风格  
    void setPenWidth(int width);  //设置画笔宽度  
    void setPenColor(QColor color);  //设置画笔颜色  
    void setBrushColor(QColor color);  //设置填充颜色

enum ShapeType  //枚举变量，几个图形的选择  
    \{  
        None,  
        Line,  
        Rectangle,  
        Ellipse,  
        ERASE  
    \};  
    void setShape(ShapeType shape);  //设置要绘制的图形

protected:  
    void paintEvent(QPaintEvent\*);  //重绘事件

void mousePressEvent(QMouseEvent\*);  //鼠标按下事件  
    void mouseMoveEvent(QMouseEvent\*);  //鼠标移动事件  
    void mouseReleaseEvent(QMouseEvent\*);  //鼠标释放事件  
    void paint(QImage&theImage);

private:  
    QImage image;  //QImage类对象，用于在其上绘图  
    QRgb backColor;  //QRgb颜色对象，存储image的背景色

QPoint lastPoint,endPoint;  //定义两个坐标对象存放鼠标指针的前后两个坐标

bool modified;  //标志画布是否被更改过

//工具变量声明  
    qreal scale;  //缩放量  
    int angle;  //角度  
    qreal shear;  //拉伸量

//画笔填充变量  
    QColor penColor;  //画笔颜色  
    QColor brushColor;  //填充颜色  
    int penWidth;  //画笔宽度  
    Qt::PenStyle penStyle;  //画笔风格  
    ShapeType curShape;  //当前图形

QImage tempImage;  //临时绘图区  
    bool isDrawing;  //是否在绘制特殊图形

signals:

public slots:

\};

\#endif // PAINTWIDGET\_H

//donewdialog.h

\#ifndef DONEWDIALOG\_H  
\#define DONEWDIALOG\_H

\#include <QDialog>

namespace Ui \{  
    class DoNewDialog;  
\}

class DoNewDialog : public QDialog  
\{  
    Q\_OBJECT

public:  
    explicit DoNewDialog(QWidget \*parent = 0);  
    ~DoNewDialog();  
    int getWidth();  //用于返回画布的宽  
    int getHeight();  //用于返回画笔的高  
    QColor getBackColor();  //用于返回画布的背景色

protected:  
    void changeEvent(QEvent \*e);

private:  
    Ui::DoNewDialog \*ui;  
    QColor backColor;  //用于保存画布的背景色

private slots:  
    void on\_toolButton\_clicked();  
\};

\#endif // DONEWDIALOG\_H

//mainwindow.cpp

\#include <QtGui/QApplication>  
\#include "mainwindow.h"  
\#include <QTextCodec>

int main(int argc, char \*argv\[\])  
\{  
    QApplication a(argc, argv);  
    QTextCodec::setCodecForTr(QTextCodec::codecForLocale());  
    MainWindow w;  
    w.show();

return a.exec();  
\}

//paintwidget.cpp

\#include "paintwidget.h"  
\#include<QPainter>

\#include<QPrintDialog>  
\#include<QPrinter>

/\*构造函数初始化对象\*/  
PaintWidget::PaintWidget()

\{  
    image=QImage(400,300,QImage::Format\_RGB32);  //画布的初始化大小设为400\*300，使用32位颜色  
    backColor=qRgb(255,255,255);  //画布初始化背景色使用白色  
    image.fill(backColor);

modified=false;  
    //modified=true;

scale=1;  
    angle=0;  
    shear=0;

penColor=Qt::black;  
    brushColor=Qt::black;  
    penWidth=1;  
    penStyle=Qt::SolidLine;  
    curShape=None;

isDrawing=false;

/\*定义重绘函数\*/  
void PaintWidget::paintEvent(QPaintEvent\*)  
\{  
    QPainter painter(this);  
    //painter.drawImage(0,0,image);

//更改重绘事件函数  
    painter.scale(scale,scale);  
    if(isDrawing)  //如果正在绘制特殊图形，则显示临时绘图区上的内容  
    \{  
        painter.drawImage(0,0,tempImage);  
    \}  
    else  
    \{  
        if(angle)  
        \{  
            QImage copyImage=image;  //新建临时的copyImage，利用它进行旋转操作  
            QPainter pp(&copyImage);  
            QPointF center(copyImage.width()/2.0,copyImage.height()/2.0);  
            pp.translate(center);  
            pp.rotate(angle);  
            pp.translate(-center);  
            pp.drawImage(0,0,image);  
            image=copyImage;  //只会复制图片上的内容，不会复制坐标系统  
            angle=0;  //完成旋转后将角度值重新设为0

/\*QPointF center(image.width()/2.0,image.height()/2.0);  
            painter.translate(center);  
            painter.rotate(angle);  
            painter.translate(-center);\*/

\}  
        if(shear)  
        \{  
            //painter.shear(shear,shear);  
            QImage copyImage=image;  
            QPainter pp(&copyImage);  
            pp.shear(shear,shear);  
            pp.drawImage(0,0,image);  
            image=copyImage;  
            shear=0;  
        \}  
        painter.drawImage(0,0,image);

QSize PaintWidget::getImageSize()  
\{  
    return image.size()\*scale;  
\}

/\*定义鼠标按下、移动、释放函数\*/  
void PaintWidget::mousePressEvent(QMouseEvent\*event)  
\{  
    if(event->button()==Qt::LeftButton)  //当鼠标左键按下  
    \{  
        lastPoint=event->pos();  //获得鼠标指针当前坐标作为起始坐标  
        isDrawing=true;  
    \}  
\}

void PaintWidget::mouseMoveEvent(QMouseEvent\*event)  
\{  
    if(event->buttons()&Qt::LeftButton)  //如果鼠标左键按着的同时移动鼠标  
    \{  
        endPoint=event->pos();  //获得鼠标指针当前坐标作为终止坐标

if(curShape==None || curShape==ERASE)  //如果不进行特殊图形绘制，则直接在image上绘制  
        \{  
            isDrawing=false;  
            paint(image);  //绘制图形

\}  
        else  //如果绘制特殊图形，则再临时绘图区tempImage上绘制  
        \{  
            tempImage=image;  //每次绘制tempImage前用上一次image中的图片对其进行填充  
            paint(tempImage);  
        \}  
    \}  
\}

void PaintWidget::mouseReleaseEvent(QMouseEvent\*event)  
\{  
    if(event->button()==Qt::LeftButton)  //如果鼠标左键释放  
    \{  
        endPoint=event->pos();  //获得鼠标指针当前坐标作为终止坐标  
        isDrawing=false;  
        paint(image);  //绘制图形

\}  
\}

void PaintWidget::paint(QImage&theImage)  
\{  
    QPainter pp(&theImage);  //在theImage上绘图

/\*  
    pp.drawLine(lastPoint,endPoint);  //由起始坐标和终止坐标绘制直线  
    update();  //进行更新界面显示，可引起窗口重绘事件，重绘窗口  
    \*/

//    QPainter pp(&theImage);  //在zheImage上绘图  
    QPen pen=QPen();  
    pen.setColor(penColor);  
    pen.setStyle(penStyle);  
    pen.setWidth(penWidth);  
    QBrush brush=QBrush(brushColor);  
    pp.setPen(pen);  
    pp.setBrush(brush);  
    QRect rect;

int x,y,w,h;  
    x=lastPoint.x()/scale;  
    y=lastPoint.y()/scale;  
    w=(endPoint.x()-x)/scale;  
    h=(endPoint.y()-y)/scale;

switch(curShape)  
    \{  
    case None:  //不绘制特殊图形  
        \{  
            pp.drawLine(lastPoint/scale,endPoint/scale);  //由起始坐标和终止坐标绘制直线  
            lastPoint=endPoint;  //让终止坐标变为起始坐标  
            break;  
        \}  
    case Line:  //绘制直线  
        \{  
            pp.drawLine(lastPoint/scale,endPoint/scale);  
            break;  
        \}  
    case Rectangle:  //绘制矩形  
        \{  
            pp.drawRect(x,y,w,h);  
            break;  
        \}  
    case Ellipse:  //绘制椭圆  
        \{  
            pp.drawEllipse(x,y,w,h);  
            break;  
        \}  
    case ERASE:  //橡皮擦  
        \{  
            rect=QRect(lastPoint,QPoint(lastPoint.x()+10,lastPoint.y()+10));  //橡皮擦大小  
            pp.eraseRect(rect);  
            lastPoint=endPoint;  
            break;  
        \}  
    \}  
    update();  //进行更新界面显示，可引起窗口重绘事件，重绘窗口  
    modified=true;  
\}

void PaintWidget::setImageSize(int width,int height)  
\{  
    QImage newImage(width,height,QImage::Format\_RGB32);  
    image=newImage;  
    update();  
\}

void PaintWidget::setImageColor(QColor color)  
\{  
    backColor=color.rgb();  //因为image的背景色要用QRgb类型的颜色，所以这里进行了转换  
    image.fill(backColor);  
    update();  
\}

bool PaintWidget::saveImage(const QString&fileName,const char\*fileFormat)  
\{  
    QImage visibleImage=image;

if(visibleImage.save(fileName,fileFormat))  //实现了文件存储  
    \{  
        modified=false;  
        return true;  
    \}  
    else  
    \{  
        return false;  
    \}  
\}

bool PaintWidget::openImage(const QString&fileName)  
\{  
    QImage loadedImage;  
    if(!loadedImage.load(fileName))  
        return false;

QSize newSize=loadedImage.size();  
    setImageSize(newSize.width(),newSize.height());  
    image=loadedImage;

modified=false;  
    update();  
    return true;  
\}

void PaintWidget::doPrint()  
\{  
    QPrinter printer(QPrinter::HighResolution);

QPrintDialog\*printDialog=new QPrintDialog(&printer,this);  
    if(printDialog->exec()==QDialog::Accepted)  
    \{  
        QPainter painter(&printer);  
        QRect rect=painter.viewport();  
        QSize size=image.size();  
        size.scale(rect.size(),Qt::KeepAspectRatio);  
        painter.setViewport(rect.x(),rect.y(),size.width(),size.height());  
        painter.setWindow(image.rect());  
        painter.drawImage(0,0,image);

\}  
\}

//编辑菜单功能函数定义

void PaintWidget::zoomIn()  
\{  
    scale\*=1.2;  
    update();  
\}

void PaintWidget::zoomOut()  
\{  
    scale/=1.2;  
    update();  
\}

void PaintWidget::zoom\_1()  
\{  
    scale=1;  
    update();  
\}

void PaintWidget::doRotate()  
\{  
    angle+=90;  
    update();  
\}

void PaintWidget::doShear()  
\{  
    shear=0.2;  
    update();  
\}

void PaintWidget::doClear()  
\{  
    image.fill(backColor);  //用现在的画布背景色进行填充  
    update();  
\}

//画笔填充函数定义  
void PaintWidget::setPenStyle(Qt::PenStyle style)  
\{  
    penStyle=style;  
\}

void PaintWidget::setPenWidth(int width)  
\{  
    penWidth=width;  
\}

void PaintWidget::setPenColor(QColor color)  
\{  
    penColor=color;  
\}

void PaintWidget::setBrushColor(QColor color)  
\{  
    brushColor=color;  
\}

void PaintWidget::setShape(ShapeType shape)  
\{  
    curShape=shape;  
\}

//donewdialog.cpp

\#include "donewdialog.h"  
\#include "ui\_donewdialog.h"

\#include<QColorDialog>  
\#include<QDebug>  
DoNewDialog::DoNewDialog(QWidget \*parent) :  
    QDialog(parent),  
    ui(new Ui::DoNewDialog)  
\{  
    ui->setupUi(this);  
    //初始化  
    backColor=Qt::white;  
\}

DoNewDialog::~DoNewDialog()  
\{  
    delete ui;  
\}

//定义  
void DoNewDialog::changeEvent(QEvent \*e)  
\{  
    QDialog::changeEvent(e);  
    switch(e->type())  
    \{  
    case QEvent::LanguageChange:  
        ui->retranslateUi(this);  
        break;  
    default:  
        break;  
    \}  
\}

int DoNewDialog::getWidth()  
\{  
    return ui->widthSpinBox->text().toInt();  
\}

int DoNewDialog::getHeight()  
\{  
    return ui->heightSpinBox->text().toInt();  
\}

QColor DoNewDialog::getBackColor()  
\{  
    return backColor;  
\}

void DoNewDialog::on\_toolButton\_clicked()  
\{  
    QColor newColor=QColorDialog::getColor();  //从颜色对话框获得颜色  
    if(newColor.isValid())  //如果得到的是可用的颜色  
    \{  
        backColor=newColor;

QPalette palette=ui->textBrowser->palette();  //显示这个颜色  
        palette.setColor(QPalette::Base,backColor);  
        ui->textBrowser->setPalette(palette);  
        update();  
    \}

FROM:http://lizhigg.love.blog.163.com/blog/static/62611781201222105550184/

http://blog.csdn.net/imxiangzi/article/details/49310573