capi:list-panel selection-callback issues

Situation

I use list-panels to show items depending on the selection in a previous list-panel.

For example: list-panel 1 shows body regions. Depending on the selection of the body region in list-panel 1, the second list-panel has to show a list of possible sub-regions for that body region.

If a sub-region is selected, a third list-panel shows the muscles in that sub-region.

All data is displayed in the lists, however, there seems to be a challenge with selection.

I’m using LispWorks 7.0 Pro (32-bit) in a Mac (OS X 10.10.5 Yosemite)

One item in the list-panel

If there is only one possible sub-region, it is displayed in the second list-panel.

Then the user may decide if he/she wants to see the muscles for this sub-region or not.

Say, the user wants to see more and selects it … nothing happens because the selection-callback is not activated.

Thus, if the list-panel only has one item, you first have to click somewhere in the list-panel to deselect the item (the retract callback is called then) and the select it again. Then the selection-callback is activated, which in my case populates the third list-panel with muscle names.

Multiple items in the list-panel

When there are many sub-region, they are displayed in the second list-panel, with the first item in grey (auto selected by the system).

However, the user did not select this one, so the muscle list-panel doesn’t show any items.

When the user clicks on this ‘grey’ item, the selection-callback is not called.

Again, first the users needs to select an item he/she doesn’t want to see and then select the first item again.

Only then is the selection-callback called.

The CAPI User Manual on page 338 writes:

“With interaction :single-selection, the choice can only have one item selected at a time. When a new selection is made, the old selection is cleared and its selection-callback is called.

The selection-callback is also called when the user invokes the selection gesture on the selected item.”

The last sentence suggests that when clicking on a selected item, the selection-callback is called again?

Which it isn’t.

Question: how to let the list-panel call the selection-callback of an item even if it was already selected by the user, or the system?

i.e. it always calls the selection-callback even when selected before.

Or even shorter, when selecting an item in a list-panel with the mouse, always call the selection-callback.

The code below from the user manual is presenting this issue.

Just click on the selected item. The selection-callback is not fired.

Example 1 - one item

(capi:contain (make-instance

'capi:list-panel

:items '(:grey)

:print-function 'string-capitalize

:interaction :single-selection

:selection-callback

#'(lambda (data interface) (capi:display-message "~S" data))))

Example 2 - multiple items

(setq capi-test (capi:contain (make-instance

'capi:list-panel

:items '(:red :blue :green)

:print-function 'string-capitalize

:interaction :single-selection

:selection-callback

#'(lambda (data interface) (capi:display-message "~S" data)))))

When you use the following function to change the selection:

(capi:apply-in-pane-process

list #'(setf capi:choice-selected-item) ':green capi-test)

This does not activate the selection-callback. Try now to click on the newly selected item. The selection-callback is not called.

After many hours of trying, I ran out of ideas.

Any hints and tips would be greatly appreciated.

Thanks,

Kris