GWT - Make CellTable Cell use HTML?

I have a CellTable where I want 开发者_如何学Cto put HTML-code in the cells. The following code is not working, the blank spaces are removed from the output.

    TextColumn<MyCell> column1 = new TextColumn<MyCell>()
    {
        @Override
        public String getValue(MyCell myCell)
        {
            String result = "     " +myCell.getValue();
            return result;
        }
    };
    table.addColumn(column1 , "Header1");

I know this could be done using css but I just want to know how to put HTML-code in the cells. Any help is appreciated!

AFAIK additional whitespace is ignored in HTML - you should use pre tag to maintain formatting.Anyway please find my column sample below. It generates nice progress bar from values contained in objects backed by data provider.

final SafeHtmlCell progressCell = new SafeHtmlCell();

    Column<UiScheduledTask, SafeHtml> progressCol = new Column<UiScheduledTask, SafeHtml>(
            progressCell) {

        @Override
        public SafeHtml getValue(UiScheduledTask value) {
            SafeHtmlBuilder sb = new SafeHtmlBuilder();
            float percent = new Float(value.getCompleted())
                    / new Float(value.getAll());
            int rounded = Math.round(percent * 100);
            sb.appendHtmlConstant("<div style='width: 100px; height: 20px; position: relative;'>");
            sb.appendHtmlConstant("<div style='z-index: 2; display: inline; width: 100px; position: absolute; left: 0px, top: 0px; text-align: center;'>"
                    + value.getCompleted()
                    + "/"
                    + value.getAll()
                    + "</div>");
            sb.appendHtmlConstant("<div style='position: absolute; left: 0; top: 0; width: 100px; z-index: 1'><div style='display: inline; float: left; width: "
                    + rounded
                    + "%; height: 20px; background-color: #82cd80;'></div>");
            sb.appendHtmlConstant("<div style='display: inline; float: right; width: "
                    + (100 - rounded)
                    + "%; height: 20px; background-color: #c54c4d;'></div></div>");
            sb.appendHtmlConstant("</div>");
            return sb.toSafeHtml();
        }
    };