### What problem does this feature solve? 期望鼠标 hover 图表时正常显示和更新 crosshair,click 时锁定当前位置,crosshair 不再跟随鼠标移动更新位置。 且鼠标移出 canvas 后, crosshair 保持锁定。 再次 click 解除锁定; ### What does the proposed API look like? none