How to take window from QWorkspace?

[8Observer8]

Hi,

I try to take window from QWorkspace. But it doesn't work:


m_tablePanel = (TabelPanel *)(workspace->windowList()).at(0);

Thank you!

[wysota]

Please define what you mean by "it doesn't work".

[8Observer8]

I cannot update my Plot.

9452

I'm a little ashamed for my code. But this is my first MDI program.

There is a little code:



m_tablePanel = (TabelPanel *)(workspace->windowList()).at(0);
m_plotPanel = (PlotPanel *)(workspace->windowList()).at(1);

connect(m_tablePanel, SIGNAL(itemChanged(QStandardItem *)), this, SLOT(updatePanel(QStandardItem*)));




void MainWindow::updatePanel(QStandardItem *item)
{
m_plotPanel->updatePanel(model);
}

[wysota]

Maybe you can't update your plot but it doesn't mean the method doesn't work. Especially that you have an ugly C cast instead of qobject_cast or something similar. How do you know that the first item in the list is an instance of TablePanel and the second one is an instance of PlotPanel?

[8Observer8]

I want to take instance of TablePanel and PlotPanel from workspace. I don't know how to do it.

It's doesn't work:



m_tablePanel = qobject_cast<TabelPanel *>((workspace->windowList()).at(0));
m_plotPanel = qobject_cast<PlotPanel *>((workspace->windowList()).at(1));



How do you know that the first item in the list is an instance of TablePanel and the second one is an instance of PlotPanel?

I added the Table then the Plot.



workspace->addWindow(tablePanel);
workspace->addWindow(plotPanel);


Slot of MainWindow updatePanel() doesn't work.


connect(m_tablePanel, SIGNAL(itemChanged(QStandardItem *)), this, SLOT(updatePanel(QStandardItem*)));

[wysota]

I want to take instance of TablePanel and PlotPanel from workspace. I don't know how to do it.

It's doesn't work:



m_tablePanel = qobject_cast<TabelPanel *>((workspace->windowList()).at(0));
m_plotPanel = qobject_cast<PlotPanel *>((workspace->windowList()).at(1));

Define "doesn't work". Does the program crash or do you get a result different than what you expected to get?


Slot of MainWindow updatePanel() doesn't work.
The slot doesn't get called or it behaves differently to what you expected?

[8Observer8]

I set a breakpoint in updatePanel() SLOT


void MainWindow::updatePanel(QStandardItem *item)
{
m_plotPanel->updatePanel(model);
}

[wysota]

You set a breakpoint and?

[8Observer8]

You set a breakpoint and?

Then I change value in the table. But nothing happens.

[wysota]

Apparently your signal-slot connection is invalid.

TablePanel class is unlikely to have a signal itemChanged() carrying a QStandardItem pointer unless you added such signal to the class yourself.

[8Observer8]

Thanks! Now the breakpoint works.



connect(model, SIGNAL(itemChanged(QStandardItem *)), this, SLOT(updatePanel(QStandardItem*)));


But the Plot is not redrawn.

plotpanel.cpp


#include "plotpanel.h"
#include <QHBoxLayout>
#include <QDebug>
#include <qwt_plot_curve.h>
#include <qwt_symbol.h>

PlotPanel::PlotPanel(QWidget *parent) :
QDialog(parent)
{
plot = new QwtPlot;

QHBoxLayout *mainLayout = new QHBoxLayout;

mainLayout->addWidget(plot);

this->setLayout(mainLayout);
}

void PlotPanel::updatePanel(QStandardItemModel *model)
{
plot->setAxisScale(QwtPlot::yLeft, 0.0, 10);
plot->setAxisScale(QwtPlot::xBottom, 0.0, 10);

QwtPlotCurve *curve = new QwtPlotCurve;
curve->setTitle(tr("Points"));
curve->setPen(QPen(Qt::blue, 4));
curve->setRenderHint(QwtPlotItem::RenderAntialiased, true);

QwtSymbol *symbol = new QwtSymbol(QwtSymbol::Ellipse, QBrush(Qt::yellow),
QPen(Qt::red, 2), QSize(8, 8));
curve->setSymbol(symbol);

QPolygonF points;

double x, y;
for (int row = 0; row < model->rowCount(); row++) {
QModelIndex index = model->index(row, 0);
x = model->data(index).toDouble();

index = model->index(row, 1);
y = model->data(index).toDouble();

points << QPointF(x, y);
}

curve->setSamples(points);
curve->attach(plot);

// this->update();
}

[wysota]

I don't see you calling replot() on the plot anywhere.

[8Observer8]

Thanks! Thanks! Thanks! :)

There is an another problem. I wanna see the new plot. How to delete the old plot?

9458

[wysota]

Why not reuse the old curve instead?

[8Observer8]

Maybe I must delete the old curve? How to do it? I don't understand...

[wysota]

If you want to remove the old curve then detach it from the plot and delete it.

[8Observer8]

How to get the old curve?

[wysota]

You can store it in some member variable and then retrieve it later when you need it.

[8Observer8]

Nice! It works! Thank you much :)

9459

This program is still left unfinished. But it may be useful for someone.

[8Observer8]

I made a loading (saving) table from (to) a xml-file:

Table.xml


<Table nrows="5" ncols="2">
<point x="0.02" y="0.33"/>
<point x="0.56" y="1.12"/>
<point x="2.22" y="2.33"/>
<point x="6.23" y="4.87"/>
<point x="9.55" y="8.23"/>
</Table>


9461

[8Observer8]

I replace QWorkspace -> QMdiArea



//workspace = new QWorkspace;
mdiArea = new QMdiArea;
//setCentralWidget( workspace );
setCentralWidget( mdiArea );

createActions();
createMenus();
createToolbars();

showScenePanel();
showControlPanel();

scenePanel = new ScenePanel;
//scenePanel = qobject_cast<ScenePanel *>((workspace->windowList()).at(0));
scenePanel = qobject_cast<ScenePanel *>((mdiArea->subWindowList()).at(0));
controlPanel = new ControlPanel;
//controlPanel = qobject_cast<ControlPanel *>((workspace->windowList()).at(1));
controlPanel = qobject_cast<ControlPanel *>((mdiArea->subWindowList()).at(1));

scenePanel->setWindowIcon(QIcon(":/Icons/Scene.png")); // <---- RED LINE
controlPanel->setWindowIcon(QIcon(":/Icons/Control.png"));



But the program crashes at run time (on the red line)

[Santosh Reddy]

Comment lines #15 and #18 in the above code

[8Observer8]

I did it. The program isn't crushed.

But I see:

9467

My Project:

[Santosh Reddy]

Here is corrected code...

[wysota]

QList<QMdiSubWindow*> windows = mdi->subWindowList();
windows.at(0)->setWindowIcon(QIcon(":/Icons/Scene.png"));
windows.at(1)->setWindowIcon(QIcon(":/Icons/Control.png"));

[8Observer8]

I have ran it with "QWorkspase". It worked normally.



QList<QMdiSubWindow*> windows = mdi->subWindowList();
windows.at(0)->setWindowIcon(QIcon(":/Icons/Scene.png"));
windows.at(1)->setWindowIcon(QIcon(":/Icons/Control.png"));

Thanks! It works.

But program works illegal.

Added after 5 minutes:

How to do that:



scenePanel = qobject_cast<ScenePanel *>(windows.at(0));
controlPanel = qobject_cast<ControlPanel *>(windows.at(1));



Here is corrected code...

Thank you very much :)

Added after 40 minutes:

In addition, instead:


scenePanel->resize(500, 500);

I wrote


sceneWindow->resize(500, 500);

Guys, thanks for help! I am happy :D

[wysota]

How to do that:



scenePanel = qobject_cast<ScenePanel *>(windows.at(0));
controlPanel = qobject_cast<ControlPanel *>(windows.at(1));

This won't work because the returned widget is an instance of QMdiSubWindow and not your widget.

[8Observer8]

Santosh Reddy have corrected:

mainwindow.h


#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "controlpanel.h"
#include "scenepanel.h"

class QAction;
class QMdiSubWindow;
class QMdiArea;
class QMenu;

class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);

signals:

public slots:

private:
void createActions();
void createMenus();
void createToolbars();

QMdiArea *mdiArea;

QAction *sceneAction;
QAction *controlAction;

ScenePanel *scenePanel;
ControlPanel *controlPanel;

QMdiSubWindow * sceneWindow;
QMdiSubWindow * controlWindow;

private slots:
void showScenePanel();
void showControlPanel();
};

#endif // MAINWINDOW_H


mainwindow.cpp


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

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent)
{
this->setWindowTitle(tr("mdiLine"));
mdiArea = new QMdiArea;
setCentralWidget( mdiArea );

createActions();
createMenus();
createToolbars();

scenePanel = new ScenePanel;
scenePanel->setWindowIcon(QIcon(":/Icons/Scene.png"));
sceneWindow = mdiArea->addSubWindow(scenePanel);
sceneWindow->resize(500, 500);

controlPanel = new ControlPanel;
controlPanel->setWindowIcon(QIcon(":/Icons/Control.png"));
controlWindow = mdiArea->addSubWindow(controlPanel);

connect(controlPanel, SIGNAL(drawLine(QVector3D,QVector3D)), scenePanel, SLOT(drawLine(QVector3D,QVector3D)));

showScenePanel();
showControlPanel();
}

void MainWindow::createActions() {
sceneAction = new QAction( QIcon(":/Icons/Scene.png"), tr("&Scene"), this );
sceneAction->setStatusTip( tr("Scene Panel") );
connect( sceneAction, SIGNAL(triggered()), this, SLOT(showScenePanel()) );

controlAction = new QAction( QIcon(":/Icons/Control.png"), tr("&Control"), this );
controlAction->setStatusTip( tr("Control Panel") );
connect( controlAction, SIGNAL(triggered()), this, SLOT(showControlPanel()) );
}

void MainWindow::createMenus() {
QMenu *menu;
menu = menuBar()->addMenu( tr("&Panels") );
menu->addAction( sceneAction );
menu->addAction( controlAction );
}

void MainWindow::createToolbars() {
QToolBar *toolbar;

toolbar = addToolBar( tr("Panels") );
toolbar->addAction( sceneAction );
toolbar->addAction( controlAction );
}

void MainWindow::showScenePanel()
{
sceneWindow->show();
}

void MainWindow::showControlPanel()
{
controlWindow->show();
}