在NSTableView中只为填充行绘制网格线？ [英] Draw grid lines in NSTableView only for populated rows?

问题描述

如何在NSTableView中只为填充的行绘制网格线？当我将网格样式掩码设置为NSTableViewSolidHorizo​​ntalGridStyleMask时，它会为所有行绘制网格线，无论是否填充。

我正在寻找一些示例代码来执行此操作。

解决方案

我认为你必须子类 NSTableView 并覆盖 drawRow：clipRect： 。另一种可能性是覆盖 drawGridInClipRect： ，但这有点更笨拙，因为你必须手动选择行。 / p>

这应该让你走正确的方向：

   - void drawRow：（NSInteger）rowIndex clipRect：（NSRect）clipRect {
 //首先做默认绘图
 [super drawRow：rowIndex clipRect：clipRect]; 
 
 //检查此行中任何单元格中是否有内容
 BOOL doesHaveContent = NO; 
 int numCols = [self numberOfColumns]; 
 int colIndex; 
 for（colIndex = 0; colIndex< numCols; colIndex ++）{
 NSCell * cell = [self preparedCellAtColumn：colIndex 
 row：rowIndex]; 
 if（[cell objectValue]！= nil）{
 doesHaveContent = YES; 
 break; 
} 
} 
 
 if（doesHaveContent）{
 NSRect rowRect = [self rectOfRow：rowIndex]; 
 NSBezierPath * gridPath = [NSBezierPath bezierPath]; 
 //忽略clipRect，因为这不是很多绘图
 [gridPath moveToPoint：rowRect.origin]; 
 [gridPath lineToPoint：NSMakePoint（rowRect.origin.x + rowRect.size.width，
 rowRect.origin.y）]; 
 [gridPath moveToPoint：NSMakePoint（rowRect.origin.x，
 rowRect.origin.y + rowRect.size.height）]; 
 [gridPath lineToPoint：NSMakePoint（rowRect.origin.x + rowRect.size.width，
 rowRect.origin.y + rowRect.size.height）]; 
 [myGridColor set]; 
 [gridPath stroke]; 
 //你也可以这样做：
 // [myGridColor set]; 
 // [[NSBezierPath bezierPathWithRect：rowRect] stroke]; 
} 
} 
  

另一种可能性是自定义 NSCell ;如果它有内容，每个单元格可以围绕自身绘制一个特殊的边框。这不会画一条线穿过整个行，虽然，如果在行中有一些单元格是空的。

How can I draw grid lines in an NSTableView only for rows that are populated? When I set the grid style mask to NSTableViewSolidHorizontalGridStyleMask, it draws grid lines for all rows whether populated or not.

I'm looking for a bit of sample code to do this.

解决方案

I think you will have to subclass NSTableView and override drawRow:clipRect:. Another possibility would be overriding drawGridInClipRect:, but that's a bit more unwieldy, because you'll have to manually pick out the rows.

This should get you going in the right direction:

- (void)drawRow:(NSInteger)rowIndex clipRect:(NSRect)clipRect {
    // First do the default drawing
    [super drawRow:rowIndex clipRect:clipRect];

    // Check if there's content in any of the cells in this row
    BOOL doesHaveContent = NO;
    int numCols = [self numberOfColumns];
    int colIndex;
    for( colIndex = 0; colIndex < numCols; colIndex++ ){
        NSCell * cell = [self preparedCellAtColumn:colIndex 
                                               row:rowIndex];
        if( [cell objectValue] != nil ){
            doesHaveContent = YES;
            break;
        }
    }

    if( doesHaveContent ){
        NSRect rowRect = [self rectOfRow:rowIndex];
        NSBezierPath * gridPath = [NSBezierPath bezierPath];
        // Ignoring clipRect because this isn't a lot of drawing
        [gridPath moveToPoint:rowRect.origin];
        [gridPath lineToPoint:NSMakePoint(rowRect.origin.x + rowRect.size.width,
                                          rowRect.origin.y)];
        [gridPath moveToPoint:NSMakePoint(rowRect.origin.x,
                                          rowRect.origin.y + rowRect.size.height)];
        [gridPath lineToPoint:NSMakePoint(rowRect.origin.x + rowRect.size.width,
                                          rowRect.origin.y + rowRect.size.height)];
        [myGridColor set];
        [gridPath stroke];
        // You could also just do:
        // [myGridColor set];
        // [[NSBezierPath bezierPathWithRect:rowRect] stroke];
    }
}

Yet another possibility would be to have a custom NSCell; each cell could draw a special border around itself if it had content. This wouldn't draw a line across the whole row, though, if there were some cells in the row that were empty.

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