scribblearea.cpp

利用Qt写的白板程序

/****************************************************************************
**
** Copyright (C) 2005-2008 Trolltech ASA. All rights reserved.
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** This file is part of the example classes of the Qt Toolkit.
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****************************************************************************/

#include <QtGui>

#include "scribblearea.h"

ScribbleArea::ScribbleArea(QWidget *parent)
    : QWidget(parent)
{
    setAttribute(Qt::WA_StaticContents);
    modified = false;
    scribbling = false;
    myPenWidth = 1;
    myPenColor = Qt::blue;
}

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

    QSize newSize = loadedImage.size().expandedTo(size());
    resizeImage(&loadedImage, newSize);
    image = loadedImage;
    modified = false;
    update();
    return true;
}

bool ScribbleArea::saveImage(const QString &fileName, const char *fileFormat)
{
    QImage visibleImage = image;
    resizeImage(&visibleImage, size());

    if (visibleImage.save(fileName, fileFormat)) {
        modified = false;
        return true;
    } else {
        return false;
    }
}

void ScribbleArea::setPenColor(const QColor &newColor)
{
    myPenColor = newColor;
}

void ScribbleArea::setPenWidth(int newWidth)
{
    myPenWidth = newWidth;
}

void ScribbleArea::clearImage()
{
    image.fill(qRgb(255, 255, 255));
    modified = true;
    update();
}

void ScribbleArea::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton) {
        lastPoint = event->pos();
        scribbling = true;
    }
}

void ScribbleArea::mouseMoveEvent(QMouseEvent *event)
{
    if ((event->buttons() & Qt::LeftButton) && scribbling)
        drawLineTo(event->pos());
}

void ScribbleArea::mouseReleaseEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton && scribbling) {
        drawLineTo(event->pos());
        scribbling = false;
    }
}

void ScribbleArea::paintEvent(QPaintEvent * /* event */)
{
    QPainter painter(this);
    painter.drawImage(QPoint(0, 0), image);
}

void ScribbleArea::resizeEvent(QResizeEvent *event)
{
    if (width() > image.width() || height() > image.height()) {
        int newWidth = qMax(width() + 128, image.width());
        int newHeight = qMax(height() + 128, image.height());
        resizeImage(&image, QSize(newWidth, newHeight));
        update();
    }
    QWidget::resizeEvent(event);
}

void ScribbleArea::drawLineTo(const QPoint &endPoint)
{
    QPainter painter(&image);
    painter.setPen(QPen(myPenColor, myPenWidth, Qt::SolidLine, Qt::RoundCap,
                        Qt::RoundJoin));
    painter.drawLine(lastPoint, endPoint);
    modified = true;

    int rad = (myPenWidth / 2) + 2;
    update(QRect(lastPoint, endPoint).normalized()
                                     .adjusted(-rad, -rad, +rad, +rad));
    lastPoint = endPoint;
}

void ScribbleArea::resizeImage(QImage *image, const QSize &newSize)
{
    if (image->size() == newSize)
        return;

    QImage newImage(newSize, QImage::Format_RGB32);
    newImage.fill(qRgb(255, 255, 255));
    QPainter painter(&newImage);
    painter.drawImage(QPoint(0, 0), *image);
    *image = newImage;
}

void ScribbleArea::print()
{
    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);
    }

}

/********************添加的函数********************/

/*
 * 读取共享去关于手的轨迹的数据
 */
/* 读取共享区的轨迹数据 */
QPoint ScribbleArea::trackPosition()
{
	//用于共享内存的变量
	int shm_id, i;
	key_t key;
	HandTrack *p_Track;
	HandTrack Track;


	//Qt相关的变量
	QPoint point;
	int x, y;


	//创建key
	key = ftok(PATH_HANDTRACK, 0);
	if (key == -1)
		perror("ftok error");

	//得到共享区的id号
	shm_id = shmget(key, HANDTRACK_SHM_SIZE,0660);
	if (shm_id == -1) {
		perror("shemget error");
		exit(0);
	}
	//链接共享区
	p_Track = (HandTrack *)shmat(shm_id, 0, 0);

	//给共享区上锁
	pthread_rwlock_rdlock(&(p_Track->rwlock));

	//读取数据
	Track.direction = (*p_Track).direction;
	Track.distance = (*p_Track).distance;

	//数据读取完毕，给共享区解锁
	pthread_rwlock_unlock(&(p_Track->rwlock));

	//断开共享内存的链接
	if (shmdt(p_Track) == -1)
		perror("in file trackRead.cpp detach error");

	x = lastPoint.x();
	y = lastPoint.y();

	switch(Track.direction) {
		case 0:
			y += Track.distance;
			break;
		case 1:
			y -= Track.distance;
			break;
		case 2:
			x -= Track.distance;
			break;
		case 3:
			x += Track.distance;
			break;
	}

	point.setX(x);
	point.setY(y);

	return point;
}



/*
 * 读取共享区的手的坐标的数据，并初始化lastPoint
 */
void ScribbleArea::InitPoint()
{
	//用于共享内存的变量
	int shm_id, i;
	key_t key;

	Hand *p_Hand;

	//用于Qt的变量
	int x, y;

	//创建key
	key = ftok(PATH_HAND, 0);
	if (key == -1)
		perror("ftok error");

	//得到共享区的id号
	shm_id = shmget(key, HAND_SHM_SIZE,0660);
	if (shm_id == -1) {
		perror("shemget error");
		exit(0);
	}
	//链接共享区
	p_Hand = (Hand *)shmat(shm_id, 0, 0);

	//给共享区上锁
	pthread_rwlock_rdlock(&(p_Hand->rwlock));

	//读取数据
	x = (*p_Hand).x;
	y = (*p_Hand).y;

	//数据读取完毕，给共享区解锁
	pthread_rwlock_unlock(&(p_Track->rwlock));

	//断开共享内存的链接
	if (shmdt(p_Track) == -1)
		perror("in file trackRead.cpp detach error");

	//初始化lastPoint
	lastPoint.setX(x);
	lastPoint.setY(y);

}

void sigusr(int signo)
{
	QPoint endPoint;

	switch (signo) {
		case SIGDRAW:
			endPoint = trackPosition();
			drawLineTo(endPoint);
			break;
		case SIGSTART:
			InitPoint();
			break;
	}
}