[Grid] Column ignores custom reversed comparator implementation #3926
Description
Description
I use the grid.setComparator(<>) method to supply comparator to the grid. My comparator has custom reverse comparator - I do NOT want the default one. Vaadin ignores my reverse comparator and uses own reverse comparator.
Here is setComparator method and here is getComparator method.
I need the setComparator to do something like this:
public Column<T> setComparator(Comparator<T> comparator) {
Objects.requireNonNull(comparator, "Comparator must not be null");
setSortable(true);
this.comparator = comparator::compare;
this.reverseComparator = comparator.reversed()::compare; // <----- new line here
return this;
}and the getComparator to do:
public SerializableComparator<T> getComparator(
SortDirection sortDirection) {
Objects.requireNonNull(comparator,
"No comparator defined for sorted column.");
setSortable(true);
boolean reverse = sortDirection != SortDirection.ASCENDING;
return reverse ? reverseComparator : comparator; <----- change here
}Reason: I need to implement "favorites" functionality - a set of rows that is up even if the order is descending. The "natural" way to implement it would be to use reverse comparator for that.
Expected outcome
If I supply a comparator with custom reverse comparator, vaadin should use that one to to compare rows.
Minimal reproducible example
Grid<Integer> grid2 = new Grid<>();
Comparator<Integer> comparator = new Comparator<Integer>() {
@Override
public int compare(Integer o1, Integer o2) {
return Comparator
.comparing(this::isFavorite)
.thenComparing(getNestedComparator())
.compare(o1, o2);
}
@Override
public Comparator<Integer> reversed() {
return Comparator
.comparing(this::isFavorite)
.thenComparing(getNestedComparator().reversed());
}
private Comparator<Integer> getNestedComparator() {
return Comparator.naturalOrder();
}
private boolean isFavorite(Integer t) {
return t % 2 == 0;
}
};
Column<Integer> c = grid2.addColumn(i -> String.valueOf(i)).setHeader("Text");
c.setComparator(comparator);
grid2.setItems(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);Steps to reproduce
Try to sort the above grid. Odd numbers should be always on top. It should be:
- Ascending: 1 3 5 7 9 <<- favorites | less important ->> 2 4 6 8 10
- Descending: 9 7 5 3 1 <<- favorites | less important ->> 10 8 6 4
It is:
- Ascending: 1 3 5 7 9 <<- favorites | less important ->> 2 4 6 8 10
- Descending: 10 8 6 4 2 < | favorites are fown ->> 9 7 5 3 1
Environment
Vaadin version(s):
OS:
Browsers
No response
Environment
Vaadin version(s):
OS:
Browsers
No response