Java/SWT 鼠标悬停/单击树查看器的一列

Question

I have a TreeViewer where some cells are styled to look like links. The tree is filled with content provider and StyledCellLabelProviders . I need to know when those specific "link" cells are hovered (so I change the mouse to the hand cursor) and clicked (so I actually do something with those "links").

I failed to find a solution, so any help will be highly appreciated.

Thanks, Oren

EDIT: More explanation I have a tree and a treeviewer. There are 4 TreeColumns with a TreeViewerColumn for each. The data is filled with a content provider, and 2 types of label providers (for simple text and styled text). I need to know when the mouse is clicked on an item in the 4th column and when it hovers over it. When that happens - I need to know the cell it is clicked on, which TreeItem it belongs to, the data in this item, etc.

My problem is I can't figure this out. When I use a mouse listener, or a selection listener, they only work on the first column. I can't "reach" the 4th one.

I cannot change the column order or it won't make sense.

Any idea?

Answer 1

I would follow this approach:

1. attach a MouseMoveListener to the Tree

2. determine which TreeItem the mouse pointer is over with Tree.getItem(Point) .

   For a multi-column tree, getItem() will only return an item if the mouse position is within the first column. Either create the tree with the SWT.FULL_SELECTION style flag, or use a workaround like this to detmine the item:

    TreeItem item = tree.getItem(new Point(event.x, event.y)); int x = 0; while (item == null) { item = tree.getItem(new Point(x, event.y)); x += 5; }

   It might be necessary to add a further condition (eg x < tree.getBounds().x ) to prevent an endless loop, if no item can be found.

3. once you have the TreeItem , you can obtain the element that it shows with TreeItem::getData . Be aware that this is an implementation detail of the TreeViewer - but I am not aware that there is another way to obtain the element for a given TreeItem .