QT学习笔记之六 IconEditor

#ifndef ICONEDITOR_H
#define ICONEDITOR_H
#include <QtGui/QWidget>
#include <QImage>
#include <QWidget>
class IconEditor : public QWidget
{
Q_OBJECT
Q_PROPERTY(QColor penColor READ penClor WRITE setPenColor);
Q_PROPERTY(QImage iconImage READ iconImage WRITE setIconImage);
Q_PROPERTY(int zoomFactor READ zoomFactor WRITE setZoomFactor);
public:
IconEditor(QWidget *parent = 0);
~IconEditor();
void setPenColor(const QColor &newColor);
QColor penColor();
void setZoomFactor(int newZoom);
int zoomFactor() const;
void setIconImage(const QImage &newImage);
QImage iconImage() const;
QSize sizeHint() const;
protected:
void mousePressEvent(QMouseEvent *);
void mouseMoveEvent(QMouseEvent *);
void paintEvent(QPaintEvent *event);
private:
void setImagePixel(const QPoint &pos,bool opaque);
QRect pixelRect(int i,int j) const;
QColor curColor;
QImage image;
int zoom;
};
#endif // ICONEDITOR_H
/*
Q_PROPERTY用法：
Q_PROPERTY(type name
READ getFunction
[WRITE setFunction]
[RESET resetFunction]
[DESIGNABLE bool]
[SCRIPTABLE bool]
[STORED bool]
[USER bool])
*/

#include<QtGui>
#include "iconeditor.h"
IconEditor::IconEditor(QWidget *parent)
: QWidget(parent)
{
setAttribute(Qt::WA_StaticContents);
setSizePolicy(QSizePolicy::Minimum,QSizePolicy::Minimum);
curColor=Qt::black;
zoom=8;
image=QImage(16,16,QImage::Format_ARGB32);
image.fill(qRgba(0,0,0,0));
}
/*
Qt::WA_StaticContents 用法：
Indicates that the widget contents are north-west aligned and static.
On resize, such a widget will receive paint events only for parts of itself
that are newly visible. This flag is set or cleared by the widget's author.
*/
IconEditor::~IconEditor()
{
}
void IconEditor::setPenColor(const QColor &newColor)
{
curColor=newColor;
}
QColor IconEditor::penColor()
{
return curColor;
}
void IconEditor::setZoomFactor(int newZoom)
{
if(newZoom<1)
newZoom=1;
if(newZoom!=zoom){
zoom=newZoom;
this->update();
this->updateGeometry();    //调用update和updateGeometry进行重绘
}
}
int IconEditor::zoomFactor() const
{
return zoom;
}
void IconEditor::setIconImage(const QImage &newImage)
{
if(newImage!=image){
image=newImage.convertToFormat(QImage::Format_ARGB32);
this->update();
this->updateGeometry();
}
}
QImage IconEditor::iconImage() const
{
return image;
}
QSize IconEditor::sizeHint() const
{
QSize size=zoom*image.size();
if(zoom>=3)
size+=QSize(1,1);    //当zoom>=3时，增加一个像素用存放网格线
return size;
}
/*只要重绘就会调用这个函数*/
void IconEditor::paintEvent(QPaintEvent *event)
{
QPainter painter(this);
if(zoom>=3){
painter.setPen(palette().foreground().color());
//绘制垂直表格线
for(int i=0;i<=image.height();++i)
painter.drawLine(zoom*i,0,zoom*image.width(),zoom*i);   //(x1,y1) to (x2,y2)
//绘制水平表格线
for(int j=0;j<image.width();++j)
painter.drawLine(0,zoom*j,zoom*image.width(),zoom*j);
}
for(int i=0;i<image.width();++i){
for(int j=0;j<image.height();++j){
QRect rect=pixelRect(i,j);
if(!event->region().intersect(rect).isEmpty()){   //region区域
QColor color=QColor::fromRgba(image.pixel(i,j));   //pixel(x,y)返回(x,y)的一个像素
if(color.alpha()<255)
painter.fillRect(rect,Qt::white);
painter.fillRect(rect,color);
}
}
}
}
QRect IconEditor::pixelRect(int i,int j) const
{
if(zoom>=3){
return QRect(zoom*i+1,zoom*j+1,zoom-1,zoom-1);
}else{
return QRect(zoom*i,zoom*j,zoom,zoom);  //QRect其中一种构造函数，QRect ( int x, int y, int width, int height )
}
}
void IconEditor::mousePressEvent(QMouseEvent *event)
{
if(event->button()==Qt::LeftButton){
setImagePixel(event->pos(),true);
}else if(event->button()==Qt::RightButton){
setImagePixel(event->pos(),false);
}
}
void IconEditor::mouseMoveEvent(QMouseEvent *event)
{
if(event->buttons()& Qt::LeftButton){    //用Qt::LeftButton与buttons位或
setImagePixel(event->pos(),true);
}else if(event->buttons()& Qt::RightButton){
setImagePixel(event->pos(),false);
}
}
void IconEditor::setImagePixel(const QPoint &pos,bool opaque)
{
int i=pos.x()/zoom;
int j=pos.y()/zoom;
if(image.rect().contains(i,j)){
if(opaque){
image.setPixel(i,j,penColor().rgba());
}else{
image.setPixel(i,j,qRgba(0,0,0,0));
}
}
update(pixelRect(i,j));
}

#include <QtGui/QApplication>
#include "iconeditor.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
IconEditor *iconEditor=new IconEditor;
iconEditor->setWindowTitle("Icon Editor");
iconEditor->setIconImage(QImage(":/images/qt-logo.png"));
iconEditor->show();
return app.exec();
}