в 14:21, 25 мая 2010

2010-05-25T14:21:06Z

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2010-05-25T10:24:58Z

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==Create pixmal with QPixmap, save to png file==

<source lang="cpp">
Foundations of Qt Development\Chapter07\paths\main.cpp
/*
* Copyright (c) 2006-2007, Johan Thelin
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of APress nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <QApplication>
#include <QPainter>
#include <QPainterPath>
#include <QPixmap>
int main( int argc, char **argv )
{
QApplication app( argc, argv );

QPixmap pixmap( 200, 200 );
pixmap.fill( Qt::white );

QPainterPath path;

path.addEllipse( 80, 80, 80, 80 );

path.moveTo( 120, 120 );
path.lineTo( 120, 40 );
path.arcTo( 40, 40, 160, 160, 90, 90 );
path.lineTo( 120, 120 );

QFont font = QApplication::font();
font.setPixelSize( 40 );

path.addText( 20, 180, font, "Path" );

QPainter painter( &pixmap );
painter.setRenderHint( QPainter::Antialiasing );

painter.setPen( Qt::black );
painter.setBrush( Qt::gray );

painter.drawPath( path );

pixmap.save( "path.png" );

return 0;
}

</source>

==Create screen shot==

<source lang="cpp">
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef SCREENSHOT_H
#define SCREENSHOT_H
#include <QPixmap>
#include <QWidget>
QT_BEGIN_NAMESPACE
class QCheckBox;
class QGridLayout;
class QGroupBox;
class QHBoxLayout;
class QLabel;
class QPushButton;
class QSpinBox;
class QVBoxLayout;
QT_END_NAMESPACE

class Screenshot : public QWidget
{
Q_OBJECT
public:
Screenshot();
protected:
void resizeEvent(QResizeEvent *event);
private slots:
void newScreenshot();
void saveScreenshot();
void shootScreen();
void updateCheckBox();
private:
void createOptionsGroupBox();
void createButtonsLayout();
QPushButton *createButton(const QString &text, QWidget *receiver,
const char *member);
void updateScreenshotLabel();
QPixmap originalPixmap;
QLabel *screenshotLabel;
QGroupBox *optionsGroupBox;
QSpinBox *delaySpinBox;
QLabel *delaySpinBoxLabel;
QCheckBox *hideThisWindowCheckBox;
QPushButton *newScreenshotButton;
QPushButton *saveScreenshotButton;
QPushButton *quitScreenshotButton;
QVBoxLayout *mainLayout;
QGridLayout *optionsGroupBoxLayout;
QHBoxLayout *buttonsLayout;
};

#endif

#include <QtGui>
#include "screenshot.h"

Screenshot::Screenshot()
{
screenshotLabel = new QLabel;
screenshotLabel->setSizePolicy(QSizePolicy::Expanding,
QSizePolicy::Expanding);
screenshotLabel->setAlignment(Qt::AlignCenter);
screenshotLabel->setMinimumSize(240, 160);
createOptionsGroupBox();
createButtonsLayout();
mainLayout = new QVBoxLayout;
mainLayout->addWidget(screenshotLabel);
mainLayout->addWidget(optionsGroupBox);
mainLayout->addLayout(buttonsLayout);
setLayout(mainLayout);
shootScreen();
delaySpinBox->setValue(5);
setWindowTitle(tr("Screenshot"));
resize(300, 200);
}

void Screenshot::resizeEvent(QResizeEvent * /* event */)
{
QSize scaledSize = originalPixmap.size();
scaledSize.scale(screenshotLabel->size(), Qt::KeepAspectRatio);
if (!screenshotLabel->pixmap()
|| scaledSize != screenshotLabel->pixmap()->size())
updateScreenshotLabel();
}

void Screenshot::newScreenshot()
{
if (hideThisWindowCheckBox->isChecked())
hide();
newScreenshotButton->setDisabled(true);
QTimer::singleShot(delaySpinBox->value() * 1000, this, SLOT(shootScreen()));
}

void Screenshot::saveScreenshot()
{
QString format = "png";
QString initialPath = QDir::currentPath() + tr("/untitled.") + format;
QString fileName = QFileDialog::getSaveFileName(this, tr("Save As"),
initialPath,
tr("%1 Files (*.%2);;All Files (*)")
.arg(format.toUpper())
.arg(format));
if (!fileName.isEmpty())
originalPixmap.save(fileName, format.toAscii());
}

void Screenshot::shootScreen()
{
if (delaySpinBox->value() != 0)
qApp->beep();
originalPixmap = QPixmap(); // clear image for low memory situations
// on embedded devices.
originalPixmap = QPixmap::grabWindow(QApplication::desktop()->winId());
updateScreenshotLabel();
newScreenshotButton->setDisabled(false);
if (hideThisWindowCheckBox->isChecked())
show();
}

void Screenshot::updateCheckBox()
{
if (delaySpinBox->value() == 0) {
hideThisWindowCheckBox->setDisabled(true);
hideThisWindowCheckBox->setChecked(false);
}
else
hideThisWindowCheckBox->setDisabled(false);
}

void Screenshot::createOptionsGroupBox()
{
optionsGroupBox = new QGroupBox(tr("Options"));
delaySpinBox = new QSpinBox;
delaySpinBox->setSuffix(tr(" s"));
delaySpinBox->setMaximum(60);
connect(delaySpinBox, SIGNAL(valueChanged(int)), this, SLOT(updateCheckBox()));
delaySpinBoxLabel = new QLabel(tr("Screenshot Delay:"));
hideThisWindowCheckBox = new QCheckBox(tr("Hide This Window"));
optionsGroupBoxLayout = new QGridLayout;
optionsGroupBoxLayout->addWidget(delaySpinBoxLabel, 0, 0);
optionsGroupBoxLayout->addWidget(delaySpinBox, 0, 1);
optionsGroupBoxLayout->addWidget(hideThisWindowCheckBox, 1, 0, 1, 2);
optionsGroupBox->setLayout(optionsGroupBoxLayout);
}

void Screenshot::createButtonsLayout()
{
newScreenshotButton = createButton(tr("New Screenshot"),
this, SLOT(newScreenshot()));
saveScreenshotButton = createButton(tr("Save Screenshot"),
this, SLOT(saveScreenshot()));
quitScreenshotButton = createButton(tr("Quit"), this, SLOT(close()));
buttonsLayout = new QHBoxLayout;
buttonsLayout->addStretch();
buttonsLayout->addWidget(newScreenshotButton);
buttonsLayout->addWidget(saveScreenshotButton);
buttonsLayout->addWidget(quitScreenshotButton);
}

QPushButton *Screenshot::createButton(const QString &text, QWidget *receiver,
const char *member)
{
QPushButton *button = new QPushButton(text);
button->connect(button, SIGNAL(clicked()), receiver, member);
return button;
}

void Screenshot::updateScreenshotLabel()
{
screenshotLabel->setPixmap(originalPixmap.scaled(screenshotLabel->size(),
Qt::KeepAspectRatio,
Qt::SmoothTransformation));
}

#include <QApplication>
#include "screenshot.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Screenshot screenshot;
screenshot.show();
return app.exec();
}

</source>

==Set mask for QPixmap==

<source lang="cpp">
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtGui>
int main()
{
int x, y;
{
QPixmap alpha("image-with-alpha.png");
QPixmap alphacopy = alpha;
alphacopy.setMask(alphacopy.mask());
}

}

</source>

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