Module javafx.controls
Package javafx.scene.control.cell

Class CheckBoxTreeTableCell<S,T>

  • Type Parameters:
    S - The type of the TreeTableView generic type
    T - The type of the elements contained within the TreeTableColumn.
    All Implemented Interfaces:
    Styleable, EventTarget, Skinnable

    public class CheckBoxTreeTableCell<S,T>
extends TreeTableCell<S,T>
    A class containing a TreeTableCell implementation that draws a CheckBox node inside the cell, optionally with a label to indicate what the checkbox represents.

    By default, the CheckBoxTreeTableCell is rendered with a CheckBox centred in the TreeTableColumn. If a label is required, it is necessary to provide a non-null StringConverter instance to the CheckBoxTreeTableCell(Callback, StringConverter) constructor.

    To construct an instance of this class, it is necessary to provide a Callback that, given an object of type T, will return an ObservableProperty<Boolean> that represents whether the given item is selected or not. This ObservableValue will be bound bidirectionally (meaning that the CheckBox in the cell will set/unset this property based on user interactions, and the CheckBox will reflect the state of the ObservableValue, if it changes externally).

    Note that the CheckBoxTreeTableCell renders the CheckBox 'live', meaning that the CheckBox is always interactive and can be directly toggled by the user. This means that it is not necessary that the cell enter its editing state (usually by the user double-clicking on the cell). A side-effect of this is that the usual editing callbacks (such as on edit commit) will not be called. If you want to be notified of changes, it is recommended to directly observe the boolean properties that are manipulated by the CheckBox.

    Since:
    JavaFX 8.0

    • Constructor Detail

      • CheckBoxTreeTableCell

        public CheckBoxTreeTableCell​()
        Creates a default CheckBoxTreeTableCell.

      • CheckBoxTreeTableCell

        public CheckBoxTreeTableCell​(Callback<Integer,ObservableValue<Boolean>> getSelectedProperty)
        Creates a default CheckBoxTreeTableCell with a custom Callback to retrieve an ObservableValue for a given cell index.
        Parameters:
        getSelectedProperty - A Callback that will return an ObservableValue given an index from the TreeTableColumn.

      • CheckBoxTreeTableCell

        public CheckBoxTreeTableCell​(Callback<Integer,ObservableValue<Boolean>> getSelectedProperty,
                             StringConverter<T> converter)
        Creates a CheckBoxTreeTableCell with a custom string converter.
        Parameters:
        getSelectedProperty - A Callback that will return a ObservableValue given an index from the TreeTableColumn.
        converter - A StringConverter that, given an object of type T, will return a String that can be used to represent the object visually.

    • Method Detail

      • forTreeTableColumn

        public static <S> Callback<TreeTableColumn<S,Boolean>,TreeTableCell<S,Boolean>> forTreeTableColumn​(TreeTableColumn<S,Boolean> column)
        Creates a cell factory for use in a TreeTableColumn cell factory. This method requires that the TreeTableColumn be of type Boolean.

        When used in a TreeTableColumn, the CheckBoxCell is rendered with a CheckBox centered in the column.

        The ObservableValue<Boolean> contained within each cell in the column will be bound bidirectionally. This means that the CheckBox in the cell will set/unset this property based on user interactions, and the CheckBox will reflect the state of the ObservableValue<Boolean>, if it changes externally).

        Type Parameters:
        S - The type of the TreeTableView generic type
        Parameters:
        column - the TreeTableColumn of type Boolean
        Returns:
        A Callback that will return a TreeTableCell that is able to work on the type of element contained within the TreeTableColumn.

      • forTreeTableColumn

        public static <S,T> Callback<TreeTableColumn<S,T>,TreeTableCell<S,T>> forTreeTableColumn​(Callback<Integer,ObservableValue<Boolean>> getSelectedProperty)
        Creates a cell factory for use in a TreeTableColumn cell factory. This method requires that the TreeTableColumn be of type ObservableValue<Boolean>.

        When used in a TreeTableColumn, the CheckBoxCell is rendered with a CheckBox centered in the column.

        Type Parameters:
        S - The type of the TreeTableView generic type
        T - The type of the elements contained within the TreeTableColumn instance.
        Parameters:
        getSelectedProperty - A Callback that, given an object of type TreeTableColumn<S,T>, will return an ObservableValue<Boolean> that represents whether the given item is selected or not. This ObservableValue<Boolean> will be bound bidirectionally (meaning that the CheckBox in the cell will set/unset this property based on user interactions, and the CheckBox will reflect the state of the ObservableValue<Boolean>, if it changes externally).
        Returns:
        A Callback that will return a TreeTableCell that is able to work on the type of element contained within the TreeTableColumn.

      • forTreeTableColumn

        public static <S,T> Callback<TreeTableColumn<S,T>,TreeTableCell<S,T>> forTreeTableColumn​(Callback<Integer,ObservableValue<Boolean>> getSelectedProperty,
                                                                                         boolean showLabel)
        Creates a cell factory for use in a TreeTableColumn cell factory. This method requires that the TreeTableColumn be of type ObservableValue<Boolean>.

        When used in a TreeTableColumn, the CheckBoxCell is rendered with a CheckBox centered in the column.

        Type Parameters:
        S - The type of the TreeTableView generic type
        T - The type of the elements contained within the TreeTableColumn instance.
        Parameters:
        getSelectedProperty - A Callback that, given an object of type TreeTableColumn<S,T>, will return an ObservableValue<Boolean> that represents whether the given item is selected or not. This ObservableValue<Boolean> will be bound bidirectionally (meaning that the CheckBox in the cell will set/unset this property based on user interactions, and the CheckBox will reflect the state of the ObservableValue<Boolean>, if it changes externally).
        showLabel - In some cases, it may be desirable to show a label in the TreeTableCell beside the CheckBox. By default a label is not shown, but by setting this to true the item in the cell will also have toString() called on it. If this is not the desired behavior, consider using forTreeTableColumn(javafx.util.Callback, javafx.util.StringConverter), which allows for you to provide a callback that specifies the label for a given row item.
        Returns:
        A Callback that will return a TreeTableCell that is able to work on the type of element contained within the TreeTableColumn.

      • forTreeTableColumn

        public static <S,T> Callback<TreeTableColumn<S,T>,TreeTableCell<S,T>> forTreeTableColumn​(Callback<Integer,ObservableValue<Boolean>> getSelectedProperty,
                                                                                         StringConverter<T> converter)
        Creates a cell factory for use in a TreeTableColumn cell factory. This method requires that the TreeTableColumn be of type ObservableValue<Boolean>.

        When used in a TreeTableColumn, the CheckBoxCell is rendered with a CheckBox centered in the column.

        Type Parameters:
        S - The type of the TreeTableView generic type
        T - The type of the elements contained within the TreeTableColumn instance.
        Parameters:
        getSelectedProperty - A Callback that, given an object of type TreeTableColumn<S,T>, will return an ObservableValue<Boolean> that represents whether the given item is selected or not. This ObservableValue<Boolean> will be bound bidirectionally (meaning that the CheckBox in the cell will set/unset this property based on user interactions, and the CheckBox will reflect the state of the ObservableValue<Boolean>, if it changes externally).
        converter - A StringConverter that, give an object of type T, will return a String that can be used to represent the object visually. The default implementation in forTreeTableColumn(Callback, boolean) (when showLabel is true) is to simply call .toString() on all non-null items (and to just return an empty string in cases where the given item is null).
        Returns:
        A Callback that will return a TreeTableCell that is able to work on the type of element contained within the TreeTableColumn.

      • setSelectedStateCallback

        public final void setSelectedStateCallback​(Callback<Integer,ObservableValue<Boolean>> value)
        Sets the Callback that is bound to by the CheckBox shown on screen.
        Parameters:
        value - the Callback that is bound to by the CheckBox shown on screen

      • updateItem

        public void updateItem​(T item,
                       boolean empty)
        The updateItem method should not be called by developers, but it is the best method for developers to override to allow for them to customise the visuals of the cell. To clarify, developers should never call this method in their code (they should leave it up to the UI control, such as the ListView control) to call this method. However, the purpose of having the updateItem method is so that developers, when specifying custom cell factories (again, like the ListView cell factory), the updateItem method can be overridden to allow for complete customisation of the cell.

        It is very important that subclasses of Cell override the updateItem method properly, as failure to do so will lead to issues such as blank cells or cells with unexpected content appearing within them. Here is an example of how to properly override the updateItem method: 

         protected void updateItem(T item, boolean empty) {
     super.updateItem(item, empty);

     if (empty || item == null) {
         setText(null);
         setGraphic(null);
     } else {
         setText(item.toString());
     }
 }

        Note in this code sample two important points:

        1. We call the super.updateItem(T, boolean) method. If this is not done, the item and empty properties are not correctly set, and you are likely to end up with graphical issues.
        2. We test for the empty condition, and if true, we set the text and graphic properties to null. If we do not do this, it is almost guaranteed that end users will see graphical artifacts in cells unexpectedly.
        Overrides:
        updateItem in class Cell<T>
        Parameters:
        item - The new item for the cell.
        empty - whether or not this cell represents data from the list. If it is empty, then it does not represent any domain data, but is a cell being used to render an "empty" row.