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* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package javafx.scene.control;
import javafx.beans.property.
ReadOnlyIntegerProperty;
import javafx.beans.property.
ReadOnlyIntegerWrapper;
import javafx.beans.property.
ReadOnlyObjectProperty;
import javafx.beans.property.
ReadOnlyObjectWrapper;
import javafx.collections.
ListChangeListener;
/**
* SelectionModel is an abstract class used by UI controls to provide a
* consistent API for maintaining selection.
*
* @param <T> The type of the item contained in the control that can be selected.
* @since JavaFX 2.0
*/
public abstract class
SelectionModel<T> {
/***************************************************************************
* *
* Selection Properties *
* *
**************************************************************************/
/**
* <p>Refers to the selected index property, which is used to indicate
* the currently selected index value in the selection model. The selected
* index is either -1,
* to represent that there is no selection, or an integer value that is within
* the range of the underlying data model size.
*
* <p>The selected index property is most commonly used when the selection
* model only allows single selection, but is equally applicable when in
* multiple selection mode. When in this mode, the selected index will always
* represent the last selection made.
*
* <p>Note that in the case of multiple selection, it is possible to add
* a {@link ListChangeListener} to the collection returned by
* {@link MultipleSelectionModel#getSelectedIndices()} to be informed whenever
* the selection changes, and this will also work in the case of single selection.
*/
public final
ReadOnlyIntegerProperty selectedIndexProperty() { return
selectedIndex.
getReadOnlyProperty(); }
private
ReadOnlyIntegerWrapper selectedIndex = new
ReadOnlyIntegerWrapper(this, "selectedIndex", -1);
protected final void
setSelectedIndex(int
value) {
selectedIndex.
set(
value); }
/**
* <p>Returns the integer value indicating the currently selected index in
* this model. If there are multiple items selected, this will return the
* most recent selection made.
*
* <p>Note that the returned value is a snapshot in time - if you wish to
* observe the selection model for changes to the selected index, you can
* add a ChangeListener as such:
*
* <pre><code>
* SelectionModel sm = ...;
* InvalidationListener listener = ...;
* sm.selectedIndexProperty().addListener(listener);
* </code></pre>
*/
public final int
getSelectedIndex() { return
selectedIndexProperty().
get(); }
/**
* <p>Refers to the selected item property, which is used to indicate
* the currently selected item in the selection model. The selected item is
* either null,
* to represent that there is no selection, or an Object that is retrieved
* from the underlying data model of the control the selection model is
* associated with.
*
* <p>The selected item property is most commonly used when the selection
* model is set to be single selection, but is equally applicable when in
* multiple selection mode. When in this mode, the selected item will always
* represent the last selection made.
*/
public final
ReadOnlyObjectProperty<T>
selectedItemProperty() { return
selectedItem.
getReadOnlyProperty(); }
private
ReadOnlyObjectWrapper<T>
selectedItem = new
ReadOnlyObjectWrapper<T>(this, "selectedItem");
protected final void
setSelectedItem(T
value) {
selectedItem.
set(
value); }
/**
* Returns the currently selected object (which resides in the selected index
* position). If there are multiple items selected, this will return the
* object contained at the index returned by getSelectedIndex() (which is
* always the index to the most recently selected item).
*
* <p>Note that the returned value is a snapshot in time - if you wish to
* observe the selection model for changes to the selected item, you can
* add a ChangeListener as such:
*
* <pre><code>
* SelectionModel sm = ...;
* InvalidationListener listener = ...;
* sm.selectedItemProperty().addListener(listener);
* </code></pre>
*/
public final T
getSelectedItem() { return
selectedItemProperty().
get(); }
/***************************************************************************
* *
* Constructor *
* *
**************************************************************************/
/**
* Creates a default SelectionModel instance.
*/
public
SelectionModel() { }
/***************************************************************************
* *
* Selection API *
* *
**************************************************************************/
/**
* A method that clears any selection prior to setting the selection to the
* given index. The purpose of this method is to avoid having to call
* {@link #clearSelection()} first, meaning that observers that are listening to
* the {@link #selectedIndexProperty() selected index} property will not
* see the selected index being temporarily set to -1.
*
* @param index The index that should be the only selected index in this
* selection model.
*/
public abstract void
clearAndSelect(int
index);
/**
* <p>This will select the given index in the selection model, assuming the
* index is within the valid range (i.e. greater than or equal to zero, and
* less than the total number of items in the underlying data model).
*
* <p>If there is already one or more indices selected in this model, calling
* this method will <b>not</b> clear these selections - to do so it is
* necessary to first call {@link #clearSelection()}.
*
* <p>If the index is already selected, it will not be selected again, or
* unselected. However, if multiple selection is implemented, then calling
* select on an already selected index will have the effect of making the index
* the new selected index (as returned by {@link #getSelectedIndex()}.
*
* @param index The position of the item to select in the selection model.
*/
public abstract void
select(int
index);
/**
* <p>This method will attempt to select the index that contains the given
* object. It will iterate through the underlying data model until it finds
* an item whose value is equal to the given object. At this point it will
* stop iterating - this means that this method will not select multiple
* indices.
*
* @param obj The object to attempt to select in the underlying data model.
*/
public abstract void
select(T
obj);
/**
* <p>This method will clear the selection of the item in the given index.
* If the given index is not selected, nothing will happen.
*
* @param index The selected item to deselect.
*/
public abstract void
clearSelection(int
index);
/**
* <p>Clears the selection model of all selected indices.
*/
public abstract void
clearSelection();
/**
* <p>Convenience method to inform if the given index is currently selected
* in this SelectionModel. Is functionally equivalent to calling
* <code>getSelectedIndices().contains(index)</code>.
*
* @param index The index to check as to whether it is currently selected
* or not.
* @return True if the given index is selected, false otherwise.
*/
public abstract boolean
isSelected(int
index);
/**
* This method is available to test whether there are any selected
* indices/items. It will return true if there are <b>no</b> selected items,
* and false if there are.
*
* @return Will return true if there are <b>no</b> selected items, and false
* if there are.
*/
public abstract boolean
isEmpty();
/**
* <p>This method will attempt to select the index directly before the current
* focused index. If clearSelection is not called first, this method
* will have the result of selecting the previous index, whilst retaining
* the selection of any other currently selected indices.</p>
*
* <p>Calling this method will only succeed if:</p>
*
* <ul>
* <li>There is currently a lead/focused index.
* <li>The lead/focus index is not the first index in the control.
* <li>The previous index is not already selected.
* </ul>
*
* <p>If any of these conditions is false, no selection event will take
* place.</p>
*/
public abstract void
selectPrevious();
/**
* <p>This method will attempt to select the index directly after the current
* focused index. If clearSelection is not called first, this method
* will have the result of selecting the next index, whilst retaining
* the selection of any other currently selected indices.</p>
*
* <p>Calling this method will only succeed if:</p>
*
* <ul>
* <li>There is currently a lead/focused index.
* <li>The lead/focus index is not the last index in the control.
* <li>The next index is not already selected.
* </ul>
*
* <p>If any of these conditions is false, no selection event will take
* place.</p>
*/
public abstract void
selectNext();
/**
* <p>This method will attempt to select the first index in the control. If
* clearSelection is not called first, this method
* will have the result of selecting the first index, whilst retaining
* the selection of any other currently selected indices.</p>
*
* <p>If the first index is already selected, calling this method will have
* no result, and no selection event will take place.</p>
*/
public abstract void
selectFirst();
/**
* <p>This method will attempt to select the last index in the control. If
* clearSelection is not called first, this method
* will have the result of selecting the last index, whilst retaining
* the selection of any other currently selected indices.</p>
*
* <p>If the last index is already selected, calling this method will have
* no result, and no selection event will take place.</p>
*/
public abstract void
selectLast();
}