Remove all items from layout without destroying the items.

[Szustarol]

I am aware how tab widget works.
I took a screenshot so you see how my app will look:

the tab on the left will also update its content and the part on the right will be a list of entries.
Also I plan on adding more information to the left-hand tab later on

[mrjj]

said in Remove all items from layout without destroying the items.:

how do I Unattach items from layout without removing them?

There is a TakeAt function that gives ownership back
http://doc.qt.io/qt-4.8/qlayout.html#takeAt

[Szustarol]

Okay I am getting somewhere with this, but now the container is not being repainted and everything stays on the screen (overlaps), this is my redraw function:

void clearLayout(QLayout * layout)
{
    if (layout)
    {
        while(layout->takeAt(0) != 0){}
    }
}

void MainWindow::reload()
{
    for(auto && i : this->tabs)
    {
        this->ui->tabsList->addItem(i); //redraws the panel on the left
    }
    clearLayout(this->ui->verticalLayout_2); //clears the layout
    if(selectedTab >= 0)
    {
        this->ui->verticalLayout_2->setAlignment(Qt::AlignTop); //if any tab is selected draws the coresponding panel
        this->ui->verticalLayout_2->addLayout(this->tabs.at(selectedTab)->tabContent);
    }
    else
    {
        this->ui->actionUsu_aktywny_arkusz->setEnabled(false); //if no tab is selected disable the remove tab button in the menu
    }
    this->ui->verticalLayout_2->update();//update the redrawn layout
    repaint();//repaint main window
    update();//update main window
}

here you can see as it overlaps
any ideas?

edit
i have noticed i can do this:

QLayoutItem * child;
      while((child = layout->takeAt(0)) != 0){
          child->widget()->hide();
      }

but then it crashes when i switch to another tab or click the same one again, segfault is fired at the "hide" line

[mrjj]

@Szustarol
When u take items back. they are not removed from screen. Just not owned
by layout anymore.

[Szustarol]

@mrjj
do you see any possible fix to my problem then?

[mrjj]

@Szustarol
Delete the QLayoutItem and widget when you take them out.
Then insert the new widgets.

[Szustarol]

If i do this and then want to go back to the tab I've been deleting from the app crashes.
So this'd be error in my code?
because i guess when i delete those items I cant reshow them anymore, because they are deleted right?

[mrjj]

@Szustarol
if u delete them , then yes they are gone.
but if u want to reuse them u can keep in list and reload etc.

If you crash, make sure nothing u delete is selected or active.

[Szustarol]

Okay sorry for keeping the thread dead for some time.
I have been trying your soultion, but copy constructor cannot be used so i cannot make a list of temporary objects i'd like to display.
Let's say you have a vector of QWidgets and you want to create another vector, with exactly the same QWidgets, how would you do it, because i have seriously no idea

[mrjj]

@Szustarol said in Remove all items from layout without destroying the items.:

make a list of temporary objects i'd like to display.

std::vector<QWidget *> mylist will be able to hold it those you take out.
(or Qlist)

• you want to create another vector, with exactly the same QWidgets,
  That is not really possible.