Extjs 4 Grid hover effect

I am working with extjs 4 n rails. i have grid that has column as filename which is hyperlink. i want to display image开发者_如何学JAVA on hover effect of filename. the image is saved as binary in database. now i want to display image on hover effect of filename in grid.

i would put a listener on mouseover in the view and then show it as an ordinary <img src='your url'> in a tooltip or other container

viewConfig: {stripeRows: false, trackOver:true},
selType: 'cellmodel',
columns: [
  {text: "Filename", dataIndex: 'filename', 
    listeners: {
      'mouseover': function(){
        //show your container
      }
    }
  },