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  1. JDK
  2. JDK-8251481

TableCell accessing row: NPE on auto-sizing

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    Details

    • Type: Bug
    • Status: Open
    • Priority: P4
    • Resolution: Unresolved
    • Affects Version/s: 8u261, 9.0.4, openjfx14
    • Fix Version/s: tbd
    • Component/s: javafx

      Description

      The example has a custom TableCell that uses the row's item to configure its own visuals. To reproduce the NPE, compile and run

      - note that the cells' content is not fully visible (no wonder, we set the column's pref too small ;)
      - double click the column's resize region to adjust its width
      - expected: column width extended to fit the cell content
      - actual: NPE thrown (and column width unchanged)

      Technically, the reason is that the row is actually null (due to the cell context not completely setup for measuring its size requirement JDK-8251480).

      This behavior is unexpected: client code shouldn't be required to bother with implementation details for certain use-cases but rely on a fully configured cell context if !cell.empty.

      The example:

          public class TableColumnAutoSizingNPE extends Application {
          
              private Parent createContent() {
                  TableView<String> table = new TableView<>(FXCollections.observableArrayList
                          ("short name", "and now really really longish name that exceeds all"));
                  TableColumn<String, String> name = new TableColumn<>("Name");
                  // just for control (without, it will throw initially)
                  name.setPrefWidth(100);
                  name.setCellValueFactory(cc -> new SimpleStringProperty(cc.getValue()));
                  name.setCellFactory(cc -> new TableCell<String, String>() {
          
                      @Override
                      protected void updateItem(String item, boolean empty) {
                          super.updateItem(item, empty);
                          if (empty) {
                              setText("");
                          } else {
                              // access item of tableRow:
                              // NPE on autosizing because row is null
                              setText(item + getTableRow().getItem());
                          }
                      }
                      
                  });
                  table.getColumns().addAll(name);
                  BorderPane content = new BorderPane(table);
                  return content;
              }
          
              @Override
              public void start(Stage stage) throws Exception {
                  stage.setScene(new Scene(createContent(), 400, 200));
                  //stage.setTitle(FXUtils.version());
                  stage.show();
              }
          
              public static void main(String[] args) {
                  launch(args);
              }
          
          }

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              Assignee:
              aghaisas Ajit Ghaisas
              Reporter:
              fastegal Jeanette Winzenburg
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                Dates

                Created:
                Updated: