How to disable the entire widget except for a specific widget in a multi-layered nested widget？

John Van

If the parent widget is disabled, all child widgets will become disabled.

Pl45m4

@John-Van said in How to disable the entire widget except for a specific widget in a multi-layered nested widget？:

After setParent (nulliptr), the position of the widget will change, which is not what I expected.

If you don't want/like the solutions and suggestions we provided, the final answer to your question:

How to disable the entire widget except for a specific widget in a multi-layered nested widget ?

is short and simple:

You cannot.

@JonB said in How to disable the entire widget except for a specific widget in a multi-layered nested widget？:

More work but (presumably) doable.

Easy ;-)

QString activeWidget = "button_not2disable"; // objectname

for (auto &w : findChildren<QWidget *>(QRegularExpression(QString("^(?!%1)\\w+").arg(activeWidget)), Qt::FindChildrenRecursively) )
      w->setDisabled(true);

Edit:
Fixed RegEx
Solution only valid if your widgets are direct children of current class... else it disables one parent, which also disables your target widget...

Edit_2:

Fixed recursion :))
Now also works when target is some layers deep in the QObject tree behind other widgets, which have to stay enabled

    // ###########################################################
    /// Disable everything recursively, except target widget
    QString targetWidgetName = "button_42"; // objectname of widget that should be active

    for (auto &w : findChildren<QWidget *>(QRegularExpression(QString("^(?!%1)\\w+").arg(targetWidgetName)), Qt::FindChildOption::FindChildrenRecursively) ) {
        qDebug() << w->objectName() << "disabled";
        w->setDisabled(true);
    }

    // ############################################################
    /// enable everything needed by moving upwards the parent-child hierarchy starting from target
    auto target = findChild<QWidget * >(targetWidgetName);
    while (target->parentWidget() != nullptr) {

        target = target->parentWidget();
        qDebug() << target->objectName() << "enabled";
        target->setDisabled(false);
    }

Axel Spoerl

@John-Van said in How to disable the entire widget except for a specific widget in a multi-layered nested widget？:

If the parent widget is disabled, all child widgets will become disabled.

That's expected and can't be changed.
You need one top level (=parentless) widget, to display a window.
If you disable the top level widget, and display one of its children, call setParent(nullptr), then enable and show it. It will become a top level widget of its own. If you want to restore the previous order, you need to set its old parent and also embed into its previous layout if it was part of one.

Pl45m4

@John-Van

What @Axel-Spoerl described above sounds a little like my solution for this topic here. In addition you can disable the parent, while the child is shown as standalone widget.

Another solution:
Don't disable the whole parent widget. Disable only parts of it.
You can disable a QGroupBox for example, which then does not disable other widgets in the same window that are not part of your groupbox.

John Van

@Axel-Spoerl After setParent (nulliptr), the position of the widget will change, which is not what I expected.

JonB

@John-Van
Then what did you expect? If a widget has a parent it is positioned with respect to its parent. If it has no parent it is not positioned with respect to the parent it used to have but no longer has, it is now a "top level" widget. If you want it positioned relative to some other widget (e.g. its old parent) you would have to move it appropriately yourself.

You can't disable the parent of a non-disabled child/descendant, since disabling a parent by definition disables its descendants. As @Pl45m4 says, it sounds like what you might really mean is to disable all other children of a parent keeping only one child enabled. More work but (presumably) doable.

Pl45m4

@John-Van said in How to disable the entire widget except for a specific widget in a multi-layered nested widget？:

After setParent (nulliptr), the position of the widget will change, which is not what I expected.

If you don't want/like the solutions and suggestions we provided, the final answer to your question:

How to disable the entire widget except for a specific widget in a multi-layered nested widget ?

is short and simple:

You cannot.

@JonB said in How to disable the entire widget except for a specific widget in a multi-layered nested widget？:

More work but (presumably) doable.

Easy ;-)

QString activeWidget = "button_not2disable"; // objectname

for (auto &w : findChildren<QWidget *>(QRegularExpression(QString("^(?!%1)\\w+").arg(activeWidget)), Qt::FindChildrenRecursively) )
      w->setDisabled(true);

Edit:
Fixed RegEx
Solution only valid if your widgets are direct children of current class... else it disables one parent, which also disables your target widget...

Edit_2:

Fixed recursion :))
Now also works when target is some layers deep in the QObject tree behind other widgets, which have to stay enabled

    // ###########################################################
    /// Disable everything recursively, except target widget
    QString targetWidgetName = "button_42"; // objectname of widget that should be active

    for (auto &w : findChildren<QWidget *>(QRegularExpression(QString("^(?!%1)\\w+").arg(targetWidgetName)), Qt::FindChildOption::FindChildrenRecursively) ) {
        qDebug() << w->objectName() << "disabled";
        w->setDisabled(true);
    }

    // ############################################################
    /// enable everything needed by moving upwards the parent-child hierarchy starting from target
    auto target = findChild<QWidget * >(targetWidgetName);
    while (target->parentWidget() != nullptr) {

        target = target->parentWidget();
        qDebug() << target->objectName() << "enabled";
        target->setDisabled(false);
    }

John Van

@Pl45m4
Sad. It seems like I have to iterate through child widgets and disable it.
Thank you all.

Pl45m4

@John-Van

Check my updated post. No guarantee that the regex works, but worth a try.