使用 Three20 重新排序超出表格范围的行/单元格时，表格视图不会滚动

Question

When I re-order rows/cells in my Three20 TTTableViewController (editing a table and moving individual cells up or down) it does not scroll with the cell being moved beyond the bounds of the tableview. When I do drag the cell up beyond the bounds it automatically animates the cell upwards and out of the view without scrolling with it. This makes it impossible to effectively re-order cells to positions outside of what is currently visible.

I have tested this with and without Three20 and it only doesn't scroll the table when ordering with the Three20 implementation.

Answer 1

Apparently Three20's TTTableView implementation overrides UIScrollView 's

- (void)setContentSize:(CGSize)size;

and

- (void)setContentOffset:(CGPoint)point;

These are meant to prevent the contentOffset from being changed incorrectly with a change in content size or height of the table, although it inadvertently prevents the table from scrolling when moving rows in editing mode.

I commented out these methods and the functionality I needed became available.

Answer 2

Three20 likes to control scrolling behavior with the setContentOffset and setContentSize method overrides. Scrolling behavior is controlled with a scrollEnabled property.

TTTableViews are scrollEnabled = YES, but at the time this method is called scrollEnabled = NO and needs to be reset when reordering rows.

• (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath { tableView.scrollEnabled = YES; }