objective-c - 默认[NSTableViewDelegate tableView :sizeToFitWidthOfColumn:] doesn't get called

Question

根据Apple's documentation on [NSTableViewDelegate tableView:sizeToFitWidthOfColumn:] :

By default, NSTableView iterates every row in the table, accesses a cell via preparedCellAtColumn:row:, and requests the cellSize to find the appropriate largest width to use.

For accurate results and performance, it’s recommended that this method is implemented when using large tables. By default, large tables use a monte carlo simulation instead of iterating every row.

这个默认行为正是我想要的，所以我选择不在我的 NSTableViewDelegate 中实现这个方法。但是，当我双击列的调整大小分隔线时，没有任何反应。我的表格 View 是基于 View 的。

Answer 1

从 OS X 10.10.2 开始，双击列分隔符时，基于 View 的表格 View 中的列仍然不会自动调整大小。

我实现了委托(delegate)来采样可见矩形的行以及下方和上方的 50 行。

- (CGFloat)tableView:(NSTableView *)tableView sizeToFitWidthOfColumn:(NSInteger)column
{
    // Note: Called on double-click of table columns separator
    // Note: As of 10.10.2, [NSTableView _sizeToFitWidthOfColumn] does nothing for view-based table views
    NSRect          visibleRect     = tableView.visibleRect;
    NSRange         rowRange        = [tableView rowsInRect:visibleRect];
    NSUInteger      numberOfRows    = tableView.numberOfRows;
    NSInteger       minRow          = rowRange.location;
    NSInteger       maxRow          = rowRange.location + rowRange.length;

    minRow  = MAX(0, minRow - 50);
    maxRow  = MIN(numberOfRows, maxRow + 50);

    NSTableColumn   *tableColumn    = [[tableView tableColumns] objectAtIndex:column];
    CGFloat         minWidth        = tableColumn.minWidth;
    CGFloat         maxWidth        = tableColumn.maxWidth;
    CGFloat         width           = minWidth;

    /*
     NSCell         *headerCell     = tableColumn.headerCell;

     if ([headerCell isKindOfClass:[NSCell class]]) {
        NSRect  bounds          = NSMakeRect(0.0f, 0.0f, maxWidth, headerCell.cellSize.height);
        CGFloat fittingWidth    = [headerCell cellSizeForBounds:bounds].width;

        if (fittingWidth > width) {
            width = fittingWidth;
        }
     }
     */
    for (NSInteger row = minRow; row < maxRow; row++) {
        NSTableCellView *tableCellView  = [tableView viewAtColumn:column row:row makeIfNecessary:YES];
        CGFloat         fittingWidth    = [tableCellView fittingSize].width;

        if (fittingWidth > width) {
            width = fittingWidth;

            if (width >= maxWidth) {
                break;
            }
        }
    }

    return MIN(maxWidth, width);
}