Can Qt open a bottle?

[sivrisinek]

Hi there,

i have the frequently annoying question (problem) which probably many have faced before:

" hide a tab page "

1) without using removeTab() (because it will be deleted)
2) without using setTabEnabled() (because with CTRL+TAB one can indeed open it!!!!)
3) without using QWidgetStack (because it is a part of Qt3)

is there a solution for this problem? Please notice the nice BUG in point (2). If you would like to care for data integration, this might be a problem or not?

Qt does all those fascinating things like driving a car but can not open a bottle (or close it if you would prefer)?



please excuse me for this way of articulation of the problem.

[wysota]

1) without using removeTab() (because it will be deleted)

It will not be deleted. You can store a pointer to it and reinsert the tab later on.

3) without using QWidgetStack (because it is a part of Qt3)

See QStackedWidget.

[sivrisinek]

It will not be deleted. You can store a pointer to it and reinsert the tab later on.


See QStackedWidget.

What can I do to get the pointer to a specified tabpage? There is not a member method of QTabWidget which returns a QWidget* to the removed page. Or at least I can not find it.

Here the question is not to hide the whole tab widget; just a single page of it.
---

My Qt Version is 4.2.2, that's why QStackedWidget was documented to belong to Qt3 I guess.

[sivrisinek]

it is very important for us to hide the page (and not re-instantiate it) as it has much more complex widgets inside and not few buttons and labels..

[Raccoon29]

There is not a member method of QTabWidget which returns a QWidget* to the removed page.

If you know the index of the page to be removed, you might use QTabWidget::widget(int index) to retrieve the tab's pointer before removing it.
Then you can easily restore it with QTabWidget::addTab(QWidget*,QString) or QTabWidget::insertTab(int,QWidget*,QString).
I never tested it, but it should work. Shouldn't it?

EDIT: at the moment is impossible to hide litterally the tab, so this trick seems required. Anyway since you save a pointer to the page, probably its content shall be saved to the restoring too.

[sivrisinek]

If you know the index of the page to be removed, you might use QTabWidget::widget(int index) to retrieve the tab's pointer before removing it.
Then you can easily restore it with QTabWidget::addTab(QWidget*,QString) or QTabWidget::insertTab(int,QWidget*,QString).
I never tested it, but it should work. Shouldn't it?

EDIT: at the moment is impossible to hide litterally the tab, so this trick seems required. Anyway since you save a pointer to the page, probably its content shall be saved to the restoring too.

Thanks a lot this did really work.

[jpujolf]

If anyone want an "embeded" solution to this problem, can freely use QExtendedTabWidget

Have fun.

[luf]

yes, qt can open a bottle if you make a serial port device with a robot arm, program a nice gui with image recognition through a webcam, that finds the bottle and opens it...

shouldn't take more than a few hours I guess

For a TabWidget that can add/remove pages, but still remember them, use a stackedwidget where you keep the widgets always, and use a TabBar with indexing, where you update the index when you add/remove tabs.

I have not tested the below code, as it's a rewrite of something I did a few months ago, but you will get a hint on where to start off.

header:

class MyWidget : public QWidget
{
    Q_OBJECT
public:
    MyWidget(QWidget *parent);
};
 
class QMyCustomTabBar : public QTabBar
{
    Q_OBJECT
public:
    QMyCustomTabBar(QWidget *parent);
    QList <unsigned short int> TabPage;
 
public slots:
    PageToView(int index);
    RemoveTabWithNo(unsigned short int stackedpagenumber);
    InsertTabWithNo(unsigned short int stackedpagenumber, const QString &TabString);
 
signals:
    SendPageToView(unsigned int index);
};

class MyWidget : public QWidget
{
    Q_OBJECT
public:
    MyWidget(QWidget *parent);
};

class QMyCustomTabBar : public QTabBar
{
    Q_OBJECT
public:
    QMyCustomTabBar(QWidget *parent);
    QList <unsigned short int> TabPage;

public slots:
    PageToView(int index);
    RemoveTabWithNo(unsigned short int stackedpagenumber);
    InsertTabWithNo(unsigned short int stackedpagenumber, const QString &TabString);

signals:
    SendPageToView(unsigned int index);
};

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source:

MyWidget::MyWidget(QWidget *parent) : QWidget (parent)
{
    QStackedWidget *myStacked = new QStackedWidget(this);
    myStacked->addWidget(widget1);
    myStacked->addWidget(widget2);
    myStacked->addWidget(widget3);
 
    QMyCustomTabBar *myCustomTabBar = new QMyCustomTabBar(this);
    connect (myCustomTabBar, SIGNAL(SendPageToView(int)), myStacked, SLOT(setCurrentIndex(int)));
    // then use RemoveTabWithNo and InsertTabWithNo to remove/insert.
    // subclass checkbox'es or add slots for checkbox'es if you need those to enable disable
}
 
QMyCustomTabBar::QMyCustomTabBar(QWidget *parent) : QTabBar (parent)
{
    connect (this, SIGNAL(currentChanged(int)), this, SLOT(PageToView(int)));
}
 
void QMyCustomTabBar::PageToView(int index)
{
    if (index < this->TabPage.count())
    {
        emit(SendPageToView(TabPage[index]));
    }
}
void QMyCustomTabBar::RemoveTabWithNo(unsigned short int stackedpagenumber)
{
    for (int i = 0;i < this->TabPage.count(); i++)
    {
        if (TabPage[i] == stackedpagenumber)
        {
            TabPage.removeAt(i);
            this->removeTab(i);
            return;
        }
    }
}
 
void QMyCustomTabBar::InsertTabWithNo(unsigned short int stackedpagenumber, const QString &TabString)
{
    // see if we have a tab we need to insert it before...
    for (int i = 0;i < this->TabPage.count(); i++)
    {
        if (TabPage[i] > stackedpagenumber)
        {
            TabPage.insert(i, stackedpagenumber);
            this->insertTab(i, TabString);
            return;
        }
    }
    // if not, we should insert at the end
    this->TabPage.append(stackedpagenumber);
    this->addTab(TabString);
}

MyWidget::MyWidget(QWidget *parent) : QWidget (parent)
{
    QStackedWidget *myStacked = new QStackedWidget(this);
    myStacked->addWidget(widget1);
    myStacked->addWidget(widget2);
    myStacked->addWidget(widget3);

    QMyCustomTabBar *myCustomTabBar = new QMyCustomTabBar(this);
    connect (myCustomTabBar, SIGNAL(SendPageToView(int)), myStacked, SLOT(setCurrentIndex(int)));
    // then use RemoveTabWithNo and InsertTabWithNo to remove/insert.
    // subclass checkbox'es or add slots for checkbox'es if you need those to enable disable
}

QMyCustomTabBar::QMyCustomTabBar(QWidget *parent) : QTabBar (parent)
{
    connect (this, SIGNAL(currentChanged(int)), this, SLOT(PageToView(int)));
}

void QMyCustomTabBar::PageToView(int index)
{
    if (index < this->TabPage.count())
    {
        emit(SendPageToView(TabPage[index]));
    }
}
void QMyCustomTabBar::RemoveTabWithNo(unsigned short int stackedpagenumber)
{
    for (int i = 0;i < this->TabPage.count(); i++)
    {
        if (TabPage[i] == stackedpagenumber)
        {
            TabPage.removeAt(i);
            this->removeTab(i);
            return;
        }
    }
}

void QMyCustomTabBar::InsertTabWithNo(unsigned short int stackedpagenumber, const QString &TabString)
{
    // see if we have a tab we need to insert it before...
    for (int i = 0;i < this->TabPage.count(); i++)
    {
        if (TabPage[i] > stackedpagenumber)
        {
            TabPage.insert(i, stackedpagenumber);
            this->insertTab(i, TabString);
            return;
        }
    }
    // if not, we should insert at the end
    this->TabPage.append(stackedpagenumber);
    this->addTab(TabString);
}

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[sivrisinek]

Thanks a lot for the answers.

Have fun.