changes the size of grid's container on the fly to fit total width of grid's columns
| mode | boolean | true/false - enable / disable |
| max_limit | number | max allowed width, not limited by default |
| min_limit | number | min allowed width, not limited by default |
//enable auto width mode
myTreeGrid.enableAutoWidth(true);
//disable auto width mode
myTreeGrid.enableAutoWidth(true);
//enable auto width mode, set the maximal and minimal allowed width
myTreeGrid.enableAutoWidth(true,600,100);