QColorDialog always return 0 as a result

[wysota]

@wysota: Why not?

Because createEditor() is to return a persistent widget that takes place of the item for the time of editing. This is not the case here thus you are using the mechanism incorrectly.

Instead connect to the view's doubleClicked() signal and upon that signal call QColorDialog::getColor() and afterwards set the model's data using QAbstractItemModel::setData().