README.en.md

QListView

1. Custom Widget Item

Run CustomWidgetItem.py

use setIndexWidget(QModelIndex, QWidget) to set custom QWidget

2. Custom Widget Sort Item

Run CustomWidgetSortItem.py

1. set QListView proxy model, use QSortFilterProxyModel
2. rewrite lessThan method to sort

3, Custom Role And Sort

Run SortItemByRole.py

Demand:

1. 5 categories(Tang, Song, Yuan, Ming, Qing) and Unclassified
2. selected Tang, the result is Tang, Song, Yuan, Ming, Qing, Unclassified
3. selected Song, the result is Song, Tang, Yuan, Ming, Qing, Unclassified
4. selected Yuan, the result is Yuan, Tang, Song, Ming, Qing, Unclassified
5. Cancel sorting then Restore, like: Unclassified, Tang, Tang, Ming, Qing, Unclassified, Song, Yuan, Unclassified

Method:

1. define IdRole = Qt.UserRole + 1 Used to restore default sort
2. define ClassifyRole = Qt.UserRole + 2 Used for sorting by sorting number
3. define 5 classify id

   NameDict = {
       'Tang': ['Tang', 0],
       'Song': ['Song', 1],
       'Yuan': ['Yuan', 2],
       'Ming': ['Ming', 3],
       'Qing': ['Qing', 4],
   }
   IndexDict = {
       0: 'Tang',
       1: 'Song',
       2: 'Yuan',
       3: 'Ming',
       4: 'Qing',
   }

4. item setData(id, IdRole) Used to restore default sort
5. item setData(cid, ClassifyRole) Used to record classification
6. inherit QSortFilterProxyModel and add setSortIndex(self, index) mthod, The purpose is to keep some classify always top

   def setSortIndex(self, index):
       self._topIndex = index

7. inherit QSortFilterProxyModel and rewrite lessThan mthod, if classify id is equal to top id, then modify it -1

   if self.sortRole() == ClassifyRole and \
           source_left.column() == self.sortColumn() and \
           source_right.column() == self.sortColumn():
       # get classify id
       leftIndex = source_left.data(ClassifyRole)
       rightIndex = source_right.data(ClassifyRole)
   
       # AscendingOrder
       if self.sortOrder() == Qt.AscendingOrder:
           # keep always top
           if leftIndex == self._topIndex:
               leftIndex = -1
           if rightIndex == self._topIndex:
               rightIndex = -1
   
           return leftIndex < rightIndex

8. restore default sort

   self.fmodel.setSortRole(IdRole)     
   self.fmodel.sort(0)                 

9. sort by classify id, must reset setSortRole to other

   self.fmodel.setSortIndex(1)
   self.fmodel.setSortRole(IdRole)
   self.fmodel.setSortRole(ClassifyRole)
   self.fmodel.sort(0)