ios - Coreplot - 轴标签的坐标和大小

Question

我在 x 轴上使用日期标签，并希望使用自定义 View 突出显示特定日期。我计划使用 axis:labelWasSelected: ，将annotationFrame移动到标签位置并在轴范围更改时滚动它(在 plotSpacewillChangePlotRangeToForCoordinate: 中移动注释)(类似于 core plot Framework - How to set custom UIView in CPTPlotSpaceAnnotation )

从 plotSpacewillChangePlotRangeToForCoordinate 调用时如何获取标签的坐标？

编辑:我已经成功实现了由用户选择调用的移动注释:我保存 _selectedLabel 并在绘图范围发生变化时发送 newFrame。有两个问题:

1. 更改范围时注释框的延迟 - 看电影:https://www.youtube.com/watch?v=R66ew6GAiJU&feature=youtu.be

2. 当带注释的标签离开屏幕时，_selectedLabel 被“遗忘”。当移回屏幕时，可能会创建新标签，并且我对旧对象->框架的 _selectedLabel 引用仍保持在 x=0(离开屏幕的点)。也许有可能以某种方式获取特定标签的坐标(基于与 dateToAnnotate 的比较)？

   -(void)axis:(CPTAxis *)axis labelWasSelected:(CPTAxisLabel *)label {
           NSLog(@"labelWasSelected: %@",label);
           _selectedLabel = label;
           CGRect graphLabelFrame = [self adjustAnnotationFrameForLabel:_selectedLabel];
           [_delegate datesPlot:self didAnnotateFrame:graphLabelFrame animating:YES];
       }
   
   -(CPTPlotRange *)plotSpace:(CPTPlotSpace *)space willChangePlotRangeTo:(nonnull CPTPlotRange *)newRange forCoordinate:(CPTCoordinate)coordinate {
        CGRect graphLabelFrame = [self adjustAnnotationFrameForLabel:_selectedLabel];
       [_delegate datesPlot:self didAnnotateFrame:graphLabelFrame animating:NO];
   }
   

在委托(delegate)中:

-(void)datesPlot:(datesPlot*) plot didAnnotateFrame:(CGRect)frame animating:(BOOL)animating{
    if (animating) {
    [UIView animateWithDuration:0.3 animations:^{
        _annotationView.frame = [self.view convertRect:frame fromView:_datesHostingView];
    }];
    }
    else {
        _annotationView.frame = [self.view convertRect:frame fromView:_datesHostingView];
    }

    [_annotationView setNeedsLayout];
}

编辑2:adjustmentAnnotation - 添加间距并将框架转换为图形坐标 setNeedLayout 在转换为父 View 的坐标后由委托(delegate)调用。

-(CGRect)adjustAnnotationFrameForSelectedLabel {
    NSLog(@"selected Label:\n %@", _selectedLabel);
    float annotationMargin = 20;
    CGRect labelFrame = _selectedLabel.contentLayer.frame;
    NSLog(@"labelframe: x: %f, y: %f", labelFrame.origin.x, labelFrame.origin.y );
    //add margin for annotation to label's frame
    CGRect annotationFrame  = CGRectMake(labelFrame.origin.x-annotationMargin/2, labelFrame.origin.y-annotationMargin/2,
                                         labelFrame.size.width+annotationMargin, labelFrame.size.height+annotationMargin);
    // convert from plot area coordinates to graph (and hosting view) coordinates
    CGRect graphLabelFrame  = [self.graph convertRect:annotationFrame fromLayer:self.graph.plotAreaFrame.plotArea];
    NSLog(@"graphLabelFrame: x: %f, y: %f", graphLabelFrame.origin.x, graphLabelFrame.origin.y );
    return graphLabelFrame;

}

Answer 1

-axis:labelWasSelected: 方法的第二个参数是轴标签。标签的contentLayer是一个实际显示标签的CALayer子类。使用内置的坐标转换方法将 contentLayer 的 frame 和/或 bounds 转换为注释的 的坐标空间annotationHostLayer.