Css clipping, pie charts and hover

Question

from this: http://www.kylejlarson.com/blog/2011/how-to-create-pie-charts-with-css3/

        .pieContainer {
          height: 100px;
     }
     .pieBackground {
          background-color: grey;
          position: absolute;
          width: 100px;
          height: 100px;
          -moz-border-radius: 50px;
          -webkit-border-radius: 50px;
          -o-border-radius: 50px;
          border-radius: 50px;
          -moz-box-shadow: -1px 1px 3px #000;
          -webkit-box-shadow: -1px 1px 3px #000;
          -o-box-shadow: -1px 1px 3px #000;
          box-shadow: -1px 1px 3px #000;
     } 
 .pie {
          position: absolute;
          width: 100px;
          height: 100px;
          -moz-border-radius: 50px;
          -webkit-border-radius: 50px;
          -o-border-radius: 50px;
          border-radius: 50px;
          clip: rect(0px, 50px, 100px, 0px);
     }
     .hold {
          position: absolute;
          width: 100px;
          height: 100px;
          -moz-border-radius: 50px;
          -webkit-border-radius: 50px;
          -o-border-radius: 50px;
          border-radius: 50px;
          clip: rect(0px, 100px, 100px, 50px);
     }
#pieSliceBlue{
    -webkit-transform:rotate(0deg);
          -moz-transform:rotate(0deg);
          -o-transform:rotate(0deg);
          transform:rotate(0deg);

}
 #pieSliceBlue .pie {
          background-color: #1b458b;
          -webkit-transform:rotate(180deg);
          -moz-transform:rotate(180deg);
          -o-transform:rotate(180deg);
          transform:rotate(180deg);
     }
     #pieSliceBlue2 {
          -webkit-transform:rotate(180deg);
          -moz-transform:rotate(180deg);
          -o-transform:rotate(180deg);
          transform:rotate(180deg);
     }
     #pieSliceBlue2 .pie {
          background-color: #1b458b;
          -webkit-transform:rotate(40deg);
          -moz-transform:rotate(40deg);
          -o-transform:rotate(40deg);
          transform:rotate(40deg);
     }
     #pieSliceRed {
          -webkit-transform:rotate(220deg);
          -moz-transform:rotate(220deg);
          -o-transform:rotate(220deg);
          transform:rotate(220deg);
     }
     #pieSliceRed .pie {
          background-color: #cc0000;
          -webkit-transform:rotate(140deg);
          -moz-transform:rotate(140deg);
          -o-transform:rotate(140deg);
          transform:rotate(140deg);
     }
#pieSliceBlue .pie:hover{
    background-color: yellow;
}
#pieSliceBlue2 .pie:hover{
    background-color: yellow;
}
#pieSliceRed .pie:hover{
    background-color: yellow;
}



    <div class="pieContainer">
     <div class="pieBackground"></div>
     <div id="pieSliceBlue" class="hold"><div class="pie"></div></div>
     <div id="pieSliceBlue2" class="hold"><div class="pie"></div></div>
     <div id="pieSliceRed" class="hold"><div class="pie"></div></div>
</div>

Adding an :hover is ok for the slices blue2 and red but not for the first slice, where the hover works only on part of the slice.

http://jsfiddle.net/gvvsk/1/

Answer 1

The reason is that the pieSliceRed (the container for the .pie-div) is covering the pie-div contained in the pieSliceRed container, thus catching the hover event.

Since your solution most definately needs CSS3 support you can use pointer-events to bypass this behaviour. Try defining your css for the pieSliceRed this way instead:

#pieSliceRed {
    pointer-events: none;
    -webkit-transform:rotate(220deg);
    -moz-transform:rotate(220deg);
    -o-transform:rotate(220deg);
    transform:rotate(220deg);
}

You can read more about the pointer-events here.