HELP! I want to zoomIn and zoomOut scribble area.

[NandiniN]

I am trying to zoomIn And zoomOut the scribble area or paint area..by the following code ,On opening the image and painting on it works fine,but when i try to zoom (view->zoomIn25%) i can zoom only the image,what i had scribbled gets disappeared..why can't i draw on widget? Please help me with the CODE to zoom the scribbleArea along with the image!!

I have
main.cpp
mainwindow.cpp
scribblearea.cpp along with the header files.

MAINWINDOW.CPP

@MainWindow::MainWindow()
{
imageLabel = new QLabel;
scribbleArea = new ScribbleArea;
setCentralWidget(scribbleArea);
imageLabel->setBackgroundRole(QPalette::Base);
imageLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
imageLabel->setScaledContents(true);

scrollArea = new QScrollArea;

scrollArea->setBackgroundRole(QPalette::Dark);
scrollArea->setWidget(imageLabel);

createActions();
createMenus();

setWindowTitle(tr("Scribble"));
resize(500, 400);

}

void MainWindow::open()
{

if (maybeSave()) {
QString fileName = QFileDialog::getOpenFileName(this,
tr("Open File"), QDir::currentPath());
if (!fileName.isEmpty()) {
scribbleArea->openImage(fileName);
QImage image(fileName);
imageLabel->setPixmap(QPixmap::fromImage(image));

    scaleFactor = 1.0;

    printAct->setEnabled(true);
    fitToWindowAct->setEnabled(true);
    updateActions();

    if (!fitToWindowAct->isChecked())
        imageLabel->adjustSize();
}

}

}
void MainWindow::zoomIn()

{

scaleImage(1.25);//"got these from":http://qt-project.org/doc/qt-4.8/widgets-imageviewer-imageviewer-cpp.html

}
void MainWindow::zoomOut()

{
scaleImage(0.8);
}
void MainWindow::createActions()

{

}
void MainWindow::createMenus()
//! [15] //! [16]
{

--
}
void MainWindow::scaleImage(double factor)

{
setCentralWidget(scrollArea);
//setCentralWidget(scribbleArea);
Q_ASSERT(imageLabel->pixmap());
scaleFactor *= factor;
imageLabel->resize(scaleFactor * imageLabel->pixmap()->size());

adjustScrollBar(scrollArea->horizontalScrollBar(), factor);

adjustScrollBar(scrollArea->verticalScrollBar(), factor);

zoomInAct->setEnabled(scaleFactor < 3.0);
zoomOutAct->setEnabled(scaleFactor > 0.333);

}
void MainWindow::adjustScrollBar(QScrollBar *scrollBar, double factor)
//! [25] //! [26]
{

}
void MainWindow::fitToWindow()
{

 }
 updateActions();

}
void MainWindow::normalSize()
{

}
void MainWindow::updateActions()
{

}@

SCRIBBLEAREA.CPP
"have made no changes to this...":http://http://qt-project.org/doc/qt-4.8/widgets-scribble-scribblearea-cpp.html

[DoctorAgony]

Hi there,

first: try to use this in a QGraphicsview. It's a little bit easier, and, you can zoom the complete view with all layers in the QGraphicsView.

For this, you have to create a QGraphicsScene, where you can put a lot of QGraphicItems (doesn't matter if pictures or self created items). And than you can show it in the view.

second: you don't have to use it, like in the example. Use "scale()", when you use the GraphicsView.

third: Use fractional numbers for the scaling values. It's more accurate.

[NandiniN]

i was trying to add zoomIn and zoomOut to Qt diagramscene example ..

added
void MainWindow::mouseMoveEvent(QMouseEvent *event)
{
}
void MainWindow::mouseReleaseEvent(QMouseEvent *event)
{
}
void MainWindow::paintEvent(QPaintEvent *event)
{
}
void MainWindow::resizeEvent(QResizeEvent *event)
{
}
void MainWindow::resizeImage(QImage *image, const QSize &newSize)
{
}
void MainWindow::drawLineTo(const QPoint &endPoint)
{
}

Still No errors nor No desired output... How to draw/paint in that already present drag and drop area.

I am implementing a paint application for now i want file->open image and
scribble on that and Zoom the complete thing.

[DoctorAgony]

Is there any code implemented?

[NandiniN]

the complete diagramscene example here-

http://harmattan-dev.nokia.com/docs/library/html/qt4/graphicsview-diagramscene.html

i tried inserting the below mentioned functions into "mainwindow.cpp" of diagramscene ..
@
void MainWindow::mousePressEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton) {
lastPoint = event->pos();
scribbling = true;
}
}

void MainWindow::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 MainWindow::paintEvent(QPaintEvent *event)
{
QPainter painter(this);
QRect dirtyRect = event->rect();
painter.drawImage(dirtyRect, image, dirtyRect);
}

void MainWindow::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 MainWindow::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 MainWindow::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;

}@