Does JavaFX 8.0 TableView have a sort bug? - combobox

Question

Java 8.0 x64, Win7 x64, Clojure, Emacs.
I'm doing some stuff in Clojure with TableView wherein I'm proxying TableCell so I can render and edit arbitrary things in it. The values are the fields of a map which is inside an atom. Code is below. It makes use of plenty of utility functions and macros to make this simpler, but you get the gist. The main thing is the management of the cell's graphic and text properties.
There is a keyboard handler which is attached to the ComboBox so it knows when the user presses ENTER, etc. This handler is removed on defocus from the cell, so we don't end up with multiple handlers in the object.
In this example I have three columns, one for the name of a field (A simple cell factory which only shows text and is not editable), one for the value (fancy cell factory), and one for the type (simple cell factory). The output, using some sample data, looks like this:
When I sort the table based on Value things seem to work fine, as follows:
Normally, when the keyboard handler triggers, it calls the cell's commitEdit function, which calls its TableCell superclass commitEdit. The TableView magic behind the scenes then calls the column's onEditCommit handler, which actually commits the edit to the database. After the superclass commitEdit returns, there is nothing left to do in the cell's commitEdit. The cell's updateItem is then automatically called by TableView which replaces the ComboBox with the normal contents of the cell.
PROBLEM
When I sort the table based on the Field column one or more times, or the Type column two or more times and try to edit something with a ComboBox (in this case the color selector), it takes an extra click to get the ComboBox to drop down, and the ENTER key doesn't work, specifically as follows:
CAUSE
In the broken case, the TableCell's superclass appears to return immediately and does not call column's onCommitEdit handler, nor does the cell's updateItem get called, so the cell is not rendered back to its normal non-editing state, ie, without the ComboBox.
Normal and broken cases look like this:
The debug text output in the normal case and broken case are shown here.
The weird thing is this problem sometimes appears with the non-color ComboBox as well (the sides field is has a ComboBox editor with numbers, for example).
So is this a bug in JavaFX TableView? Or am I doing something wrong?
(defn add-handlers!
"Adds common keyboard handler and focus listener to temporary editing graphic.
graphic is typically textfield or combo-box. cell is tablecell which
is being edited. getterfn is function to get value from graphic so
it can be commited to database."
[graphic cell getterfn]
(let [focus-listener (make-focus-change-listener cell getterfn)]
(println "adding focus and keyboard listener")
(add-listener! graphic :focused focus-listener)
(.setOnKeyPressed graphic (eventhandler [e] ;; here "cell" still refers to the tablecell
(condp = (.getCode e)
KeyCode/ENTER (do (println "ENTER pressed. Removing focus listener")
(remove-listener! graphic :focused focus-listener) ;; Prevent double-commit on defocus
(.commitEdit cell (getterfn)))
KeyCode/ESCAPE (do (println "ESC pressed. Removing focus listener")
(remove-listener! graphic :focused focus-listener) ;; Prevent double-commit on defocus
(.cancelEdit cell)) ;; Removes textfield
KeyCode/TAB (let [index (.. cell getTableRow getIndex)
next-column (get-next-column cell (not (.isShiftDown e)))]
(println "TAB pressed. Removing focus listener")
(remove-listener! graphic :focused focus-listener) ;; Prevent double-commit on defocus
(.commitEdit cell (getterfn))
(.edit (.getTableView cell) index next-column))
nil))))) ;; do nothing
(defn make-combobox
"Implements dropdown combobox. 'cell' is fancy table cell in
question. 'items' is list of things for dropdown, which can be
anything that the dropdown can render and choose as the final item"
[cell initvalue & [items]]
(let [cmb (jfxnode ComboBox (observable items))
cell-factory FANCY-LISTCELL-FACTORY
blank-cell (.call cell-factory nil)]
(doto cmb
(add-handlers! cell #(.getValue cmb))
(.setValue initvalue)
(.setButtonCell blank-cell)
(.setCellFactory cell-factory))))
(defn render-cell-with-item!
"Puts correct item in cell graphic and/or text property based on item
type. Additional arguments for editing such as drop-down, are
handled in the startEdit function; this function just renders the
cell when called by updateItem or cancelEdit."
[cell item]
(cond
(instance? Node item) (set-graphic-text! cell item nil) ;; for a graphic/Node item
(instance? Boolean item) (let [[var full-accesspath] (calc-full-accesspath cell)
cb (jfxnode CheckBox
:text (str item)
:selected item
:disable (not (mutable? var)))]
(.setEditable cell false)
(set-graphic-text! cell cb nil)
(when (mutable? var)
(uni-bind! (.selectedProperty cb) var full-accesspath)))
(instance? clojure.lang.PersistentVector item) (set-graphic-text! cell (Label. "Put vector editor here") nil)
(instance? Color item) (set-graphic-text! cell (make-color-box item) (color-map-inverse item))
;; All other types go here, presumably text types, so assume editable
:else (set-graphic-text! cell nil (si/to-normstr item)))) ;; else set underlying text
(def FANCY-TABLECELL-FACTORY
"The main callback interface which constructs the actual each cell
for arbitrary types. Assumes an editable cell for text representations."
(callback [column]
(proxy [TableCell] []
(updateItem [item empty]
(proxy-super updateItem item empty)
(when (not empty)
(render-cell-with-item! this item)))
(startEdit []
(proxy-super startEdit)
;; Change to appropriate graphic when editing
(println "in proxy's startEdit. Column commitHandler is" (.getOnEditCommit column))
(let [item (apply access-db (calc-full-accesspath this))
options (get-field-options this)] ;; could be nil ...
(if-let [combo-items (:combo-items options)] ;; ... so put as argument to :combo-items
(let [cmb (make-combobox this item combo-items)]
(set-graphic-text! this cmb nil)
(.requestFocus cmb)
(.show cmb)) ;; This makes drop-down appear without clicking twice.
(when (textish? item)
(let [tf (make-textfield-editor this)]
(set-graphic-text! this tf nil) ;; just set tf as graphic; leave existing text alone
(.requestFocus tf)
(.selectAll tf))))))
(cancelEdit []
;; CancelEdit gets called either by defocus or by ESC.
;; In any case, use the item currently in the database
;; for this cell and just render as in updateItem
(proxy-super cancelEdit)
(let [item (apply access-db (calc-full-accesspath this))]
(render-cell-with-item! this item)))
(commitEdit [value]
;; Nothing to do here. All commits happen either in the textField callback or in the column edit callback
(println "in cell's commitEdit, before super")
(proxy-super commitEdit value)
(println "in cell's commitEdit, after super")))))
(defn inner-table-view*
"Make inner table view for use by inspector-view and table-view"
[var accesspath columns]
(let [obslist (observable (var-snapshot var accesspath))]
(jfxnode TableView
:user-data {:var var ;; the actual var...
:accesspath accesspath } ;; ... and how to get to the displayed data
:items obslist
:columns columns
:editable (mutable? var))))
(defn inspector-view
"Takes plain map or atom/var/ref/agent of map and displays fields
and values in JFX TableView. Compound values (ie maps, vectors,
etc., for now are just displayed as their string value. If access
is supplied, assumes m is var/ref/atom and assigns appropriate
linkage between m and view contents. The topmost available var or
map is assigned to the TableView, and the accessor for each field is
assigned to each column."
[var & {:keys [accesspath field-options]}]
(let [ismutable (mutable? var)
field-col (jfxnode TableColumn "Field"
:cell-value-factory CELL-VALUE-FACTORY
:cell-factory SIMPLE-TABLECELL-FACTORY
:user-data {:accessfn key } ;; label-only option not relevant yet
:editable false
:sortable true)
value-col (jfxnode TableColumn "Value"
:cell-value-factory CELL-VALUE-FACTORY
:cell-factory FANCY-TABLECELL-FACTORY
:user-data {:accessfn val} ;; val is fn for accessing cell values from data item
:on-edit-start (eventhandler [e] (println "editing column " (.getOldValue e) (.getNewValue e)))
:on-edit-cancel (eventhandler [e] (println "canceling column with event" e))
:on-edit-commit (eventhandler [e] (do (println "column's on-edit-commit handler calling column-commit") (column-commit e)))
:editable ismutable
:comparator columnComparator)
type-col (jfxnode TableColumn "Type"
:cell-value-factory CELL-VALUE-FACTORY
:cell-factory SIMPLE-TABLECELL-FACTORY
:user-data {:accessfn #(type (val %))}
:editable false
:sortable true)
cols [field-col value-col type-col]
tv (inner-table-view* var accesspath cols)]
;; Add options to table's userData. This is for inspector-view
;; not table-view, so we don't put this in inner-table-view
;; function
(let [userdata (.getUserData tv)
newuserdata (conj userdata {:field-options field-options})]
(.setUserData tv newuserdata))
;; Add watches, use tv instance as key so we can remove it later
;; This gets called each time db is changed.
(if (mutable? var)
(add-watch var tv (fn [k r o n] ;; Key Ref Old New
(println "Inside KRON with new var" n)
;; Capture the existing sort order and type
;; Taken from http://stackoverflow.com/questions/11096353/javafx-re-sorting-a-column-in-a-tableview
(let [sort-order (vec (.getSortOrder tv)) ;; need to remember ObservableList<TableColumn> and vectorize or it gets reset from underneath us
sort-types (map #(.getSortType %) sort-order)
sortables (map #(.isSortable %) sort-order)]
;; Here we actually put the items into the tableview after the change
(.setItems tv (observable (var-snapshot var accesspath)))
;; Sort order is now empty up so we put back what was in it
(let [new-sort-order (.getSortOrder tv)] ;; get ObservableList<TableColumn>
(.setAll new-sort-order (into-array sort-order)) ;; reset the sort order based on what was there before
;; Assign sorting to each column
(doseq [col sort-order, sort-type sort-types, sortable sortables]
(.setSortType col sort-type)
(.setSortable col sortable)))))))
tv))

Answer 1

I found the problem, which was, of course, in my code.
Because JFX reuses cells, the editable property of the cell persists even when there are different contents rendered in the cell. In my case I had a boolean member of my databased which I rendered as a checkbox. The checkbox itself was clickable, but the cell in which it was rendered was not editable. When this cell got re-rendered after sort with a different item, the non-editing state persisted and screwed up the editing of the new item, which somehow led to the drop-down box not going away properly. Actually the bug showed up in non-combobox items too, such as for text edits, etc.
So the solution was to explicitly set the editable property of the cell for each item type that is rendered.