Sorting QTreeView() columns by clicking on header

Mary02

I've used

treeView->setSortingEnabled(true);

to sort the view by clicking the view's horizontal header and it doesn't work only for last column. When I click the last column there appears sort indicator (when I click its direction change up/down) but the column doesn't sort. The rest of the columns work good.
What can I do to fix it? I've not found such a problem anywhere.

JonB

@Mary02
If it is only the last column, in case it is relevant what type of data does that hold? And what type of model is it attached to?

Mary02

In last column I hold QMetaType. I created enum class MyType where I assign numbers to value and declare AMetaType MyType. I added also

inline bool operator<(MyType left, MyType right) {
return static_cast<std::underlying_type_t<MyType>>(left) < static_cast<std::underlying_type_t<MyType>>(right);
}

for use in context where the enum needs to be sortable but sorting still doesn't work.

JonB

@Mary02
Maybe this was worth mentioning in the first place, since this is the only column you say does not sort? Did you put a qDebug() statement into your method to verify it is getting called?

Christian Ehrlicher

And how do you use this type?

Mary02

@JonB
I put qDebug() and my method is not even called.

JonB

@Mary02
That is why I would put a qDebug() in! So now you know why your method has no effect. As @Christian-Ehrlicher asked, you now have to show/explain how/where you use your type and why you think that method should be called during sorting. Qt treats the data in model columns/rows as QVariants, why would it even be interested in/now about your enum type during its sorting?

Mary02

@JonB
Ok, I am brand new in Qt/C++. As you mentioned Qt treats data in model as QVariant, I used qDebug() to print the data from the last column, converting it to QVariant, and it turned out that instead of my values, there are empty fields. It's strange because another column that also contains my own variable types displays the correct values after conversion.

JonB

@Mary02 said in Sorting QTreeView() columns by clicking on header:

also contains my own variable types displays the correct values after conversion

And does that call an inline bool operator<(MyType left, MyType right) method you have written for that type? Or does not, and just happens to output in anticipated order so you would not know?

I am brand new in Qt/C++

Then what made you write that less-than method for your type, and what makes you think anything will call it?

And btw: I would assume that for an enumerated type left to its own devices Qt will treat an enumerated type value as an int and use that for any comparison purposes. Is that not sufficient/working for your case?

Christian Ehrlicher

Again: how do you use this enum? Do you have a QStandardItemModel, a custom model derived from QAbstractItemModel or do you use a QTreeWidget instead a QTreeView?

Mary02

@Christian-Ehrlicher
I use a QTreeView.

JonB

@Mary02
This does not answer the question. What model do you use, and how do you think your enumerated type/its comparison operator are involved?