Sorting QTreeView() columns by clicking on header
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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.
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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.
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And how do you use this type?
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@Mary02
Maybe this was worth mentioning in the first place, since this is the only column you say does not sort? Did you put aqDebug()statement into your method to verify it is getting called? -
@Mary02
That is why I would put aqDebug()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 asQVariants, why would it even be interested in/now about your enum type during its sorting? -
@Mary02
That is why I would put aqDebug()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 asQVariants, why would it even be interested in/now about your enum type during its sorting?@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
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.@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
intand use that for any comparison purposes. Is that not sufficient/working for your case? -
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?
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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?
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@Christian-Ehrlicher
I use a QTreeView.
