CODEWITHSUNDEEP
gwt
Fedy2
Fedy2

Reputation: 3207

GWT cell rendering based on selection state

I've a custom image cell in a CellTree. I want to render two different images depending on the row/node selection state, for example if the row/node is selected I want to render image A if not selected image B. The images couple is different for each node.

What is the best way to get the selection state in the render method of the cell?

Upvotes: 0

Views: 246

Answers (1)

Chris Lercher
Chris Lercher

Reputation: 37778

CSS solution

If you can work with background images here, the easiest and most efficient solution would be CSS based.

Take a look at /com/google/gwt/user/cellview/client/CellTree.css (in gwt-user.jar). There you see the css classes ".cellTreeItem" and ".cellTreeSelectedItem". The latter one already has an image. You could assign it your own, and for ".cellTreeItem" a different one.

For general information how to adjust CellTable/CellTree/... styles, see e.g. https://stackoverflow.com/a/6387210/291741

Cell solution

You could construct your cell with the SelectionModel like

public MyCell(SelectionModel selectionModel) {
  this.selectionModel = selectionModel;
}

public void render(final Cell.Context context, final Node value,
    final SafeHtmlBuilder sb) {

  if (selectionModel.isSelected(...
}

However, you will probably need to retrigger the cell rendering when the selection changes. It's probably possible, but I've never done that.

Upvotes: 1

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