JavaFX 25 · javafx.scene.control.skin.VirtualFlow · APIdia, the JavaDoc alternative

Modifier and Type	Class and Description
pack-priv static class	VirtualFlow.ArrayLinkedList<T> A List-like implementation that is exceedingly efficient for the purposes of the VirtualFlow.
pack-priv static class	VirtualFlow.ClippedContainer A simple extension to Region that ensures that anything wanting to flow outside of the bounds of the Region is clipped.

Field Summary

Modifier and Type	Field and Description
pack-priv double	absoluteOffset The offset in pixels between the top of the virtualFlow and the content it shows.
pack-priv T	accumCell A special cell used to accumulate bounds, such that we reduce object churn.
pack-priv Group	accumCellParent This group is used for holding the 'accumCell'.
private IntegerProperty	cellCount Indicates the number of cells that should be in the flow.
private ObjectProperty<Callback<VirtualFlow<T>, T>>	cellFactory
pack-priv final VirtualFlow.ArrayLinkedList<T>	cells The list of cells representing those cells which actually make up the current view.
private final Rectangle	clipRect
pack-priv VirtualFlow.ClippedContainer	clipView Control in which the cell's sheet is placed and forms the viewport.
pack-priv StackPane	corner When both the horizontal and vertical scroll bars are visible, we have to 'fill in' the bottom right corner where the two scroll bars meet.
private static final int	DEFAULT_IMPROVEMENT The default improvement for the estimation of the total size.
private final BitSet	dirtyCells
pack-priv double	estimatedSize An estimation of the total size (height for vertical, width for horizontal).
private DoubleProperty	fixedCellSize For optimisation purposes, some use cases can trade dynamic cell length for speed - if fixedCellSize is greater than zero we'll use that rather than determine it by querying the cell itself.
private boolean	fixedCellSizeEnabled
private static final double	GOLDEN_RATIO_MULTIPLIER
private VirtualScrollBar	hbar The scroll bar used for scrolling horizontally.
private boolean	isPanning
private ArrayList<Double>	itemSizeCache A list containing the cached version of the calculated size (height for vertical, width for horizontal) for a (fictive or real) cell for each element of the backing data.
pack-priv double	lastCellBreadth The breadth of the first visible cell last time we laid out.
pack-priv int	lastCellCount The number of "virtual" cells in the flow the last time it was laid out.
pack-priv double	lastCellLength The length of the first visible cell last time we laid out.
pack-priv double	lastHeight The height of the VirtualFlow the last time it was laid out.
pack-priv double	lastPosition The position last time we laid out.
pack-priv boolean	lastVertical We remember the last value for vertical the last time we laid out the flow.
pack-priv double	lastWidth The width of the VirtualFlow the last time it was laid out.
private double	lastX
private double	lastY
private double	maxPrefBreadth The maximum preferred size in the non-virtual direction.
private static final int	MIN_SCROLLING_LINES_PER_PAGE Scroll events may request to scroll about a number of "lines".
private boolean	mouseDown
private boolean	needBreadthBar
private boolean	needLengthBar
private boolean	needsCellsLayout
private boolean	needsRebuildCells
private boolean	needsReconfigureCells
private boolean	needsRecreateCells
private static final String	NEW_CELL Indicates that this is a newly created cell and we need call processCSS for it.
private BooleanProperty	pannable Indicates whether the VirtualFlow viewport is capable of being panned by the user (either via the mouse or touch events).
pack-priv final VirtualFlow.ArrayLinkedList<T>	pile A structure containing cells that can be reused later.
private DoubleProperty	position The position of the VirtualFlow within its list of cells.
private final List<T>	privateCells
private boolean	recalculating
pack-priv KeyFrame	sbTouchKF1
pack-priv KeyFrame	sbTouchKF2
pack-priv Timeline	sbTouchTimeline
pack-priv final Group	sheet The group which holds the cells.
pack-priv final ObservableList<Node>	sheetChildren
private boolean	sizeChanged
private boolean	suppressBreadthBar
private boolean	tempVisibility
private boolean	touchDetected
private VirtualScrollBar	vbar The scroll bar used to scrolling vertically.
private BooleanProperty	vertical Indicates the primary direction of virtualization.
private double	viewportBreadth The breadth of the viewport portion of the VirtualFlow as computed during the layout pass.
private double	viewportLength The length of the viewport portion of the VirtualFlow as computed during the layout pass.

Inherited from javafx.scene.layout.Region:: USE_COMPUTED_SIZE USE_PREF_SIZE

Access	Constructor and Description
public	VirtualFlow() Creates a new VirtualFlow instance.

Method Summary

Modifier and Type	Method and Description
protected void	addAllToPile() This method will remove all cells from the VirtualFlow and remove them, adding them to the 'pile' (that is, a place from where cells can be used at a later date).
pack-priv void	addLeadingCells(int currentIndex, double startOffset) Adds all the cells prior to and including the given currentIndex, until no more can be added without falling off the flow.
private void	addToPile(T cell) Puts the given cell onto the pile.
pack-priv boolean	addTrailingCells(boolean fillEmptyCells) Adds all the trailing cells that come after the last index in the cells ObservableList.
pack-priv void	adjustAbsoluteOffset() Keep the position constant and adjust the absoluteOffset to match the (new) position.
private double	Returns: the actual number of pixels that have been applied adjustByPixelAmount(double numPixels) Adjust the position based on a delta of pixels.
pack-priv void	adjustPosition() Keep the absoluteOffset constant and adjust the position to match the (new) absoluteOffset.
private void	adjustPositionToIndex(int index)
public final IntegerProperty	cellCountProperty()
public final ObjectProperty<Callback<VirtualFlow<T>, T>>	Returns: the cell factory property cellFactoryProperty() Setting a custom cell factory has the effect of deferring all cell creation, allowing for total customization of the cell.
private void	cleanPile()
private boolean	computeBarVisiblity() Returns: true if bar visibility changed
private double	computeBaseOffset(int index)
pack-priv int	computeCurrentIndex() Compute the index of the first visible cell This has package access ONLY FOR TESTING.
private int	computeCurrentIndex(int currentCellCount)
private double	computeOffsetForCell(int itemIndex) Given an item index, this function will compute and return the viewport offset from the beginning of the specified item.
protected double	computePrefHeight(double width) Overrides javafx.scene.layout.Region.computePrefHeight. Computes the preferred height of this region for the given width; Region subclasses should override this method to return an appropriate value based on their content and layout strategy.
protected double	computePrefWidth(double height) Overrides javafx.scene.layout.Region.computePrefWidth. Computes the preferred width of this region for the given height.
private double	computeViewportOffset(double position) Given a position value between 0 and 1, compute and return the viewport offset from the "current" cell associated with that position value.
private double	computeViewportOffset(double position, int localCellCount)
private void	cull()
private boolean	doesCellContainFocus(T c)
private void	fitCells() Adjusts the cells location and size if necessary.
public final DoubleProperty	fixedCellSizeProperty()
protected T	Returns: the available cell getAvailableCell(int the preferred index prefIndex) Get a cell which can be used in the layout.
public T	Returns: the cell getCell(int the index index) Return a cell for the given index.
pack-priv double	getCellBreadth(int index)
pack-priv double	getCellBreadth(T cell) Gets the breadth of a specific cell
public final int	getCellCount()
public final Callback<VirtualFlow<T>, T>	Returns: the current cell factory getCellFactory() Returns the current cell factory.
protected int	Returns: the index getCellIndex(T the cell cell) Return the index for a given cell.
pack-priv double	getCellLength(int index) Compute and return the length of the cell for the given index.
pack-priv double	getCellLength(T cell) Gets the length of a specific cell
pack-priv double	getCellPosition(T cell) Gets the layout position of the cell along the length axis
protected List<T>	Returns: the cells displayed in the current viewport getCells() Returns the list of cells displayed in the current viewport.
pack-priv double	getCellSize(int idx)
pack-priv void	getCellSizesInExpectedViewport(int the index of the cell that should be positioned at the top of the viewport in the next layout cycle. index) Make sure the sizes of the cells that are likely to be visible are known.
public T	Returns: the first visible cell getFirstVisibleCell() Locates and returns the first non-empty IndexedCell that is partially or completely visible.
protected T	Returns: first visible cell whose bounds are entirely within the viewport getFirstVisibleCellWithinViewport() Returns the first visible cell whose bounds are entirely within the viewport.
public final double	getFixedCellSize()
protected final ScrollBar	Returns: the scroll bar used for scrolling horizontally getHbar() Returns the scroll bar used for scrolling horizontally.
public T	Returns: the last visible cell getLastVisibleCell() Locates and returns the last non-empty IndexedCell that is currently partially or completely visible.
protected T	Returns: last visible cell whose bounds are entirely within the viewport getLastVisibleCellWithinViewport() Returns the last visible cell whose bounds are entirely within the viewport.
pack-priv double	getMaxCellWidth(int rowsToCount)
pack-priv final double	getMaxPrefBreadth()
pack-priv double	Returns: the size of the element; or 1 in case there are no cells yet getOrCreateCellSize(int idx) Get the size of the considered element.
private double	getOrCreateCellSize(int idx, boolean create)
public final double	getPosition()
private double	getPrefBreadth(double oppDimension)
private double	getPrefLength()
protected T	Returns: a cell for the given index inserted in the VirtualFlow container getPrivateCell(int the cell index index) Creates and returns a new cell for the given index.
protected final ScrollBar	Returns: the scroll bar used for scrolling vertically getVbar() Returns the scroll bar used for scrolling vertically.
pack-priv final double	getViewportBreadth()
public double	Returns: the viewport length in pixels getViewportLength() Returns the length of the viewport portion of the `VirtualFlow` as computed during the layout pass.
public T	Returns: the visible cell getVisibleCell(int the index index) Gets a cell for the given index if the cell has been created and laid out.
private void	initViewport()
public final boolean	isPannable()
public final boolean	isVertical()
protected void	layoutChildren() Overrides javafx.scene.Parent.layoutChildren. Invoked during the layout pass to layout the children in this `Parent`.
public final BooleanProperty	pannableProperty()
private void	positionCell(T cell, double position)
public final DoubleProperty	positionProperty()
protected void	rebuildCells() Informs the `VirtualFlow` that a layout pass should be done, and cell contents have changed.
private void	recalculateAndImproveEstimatedSize(int improve)
private void	recalculateAndImproveEstimatedSize(int improve, int oldIndex, double oldOffset) Recalculate the estimated size.
private void	recalculateEstimatedSize() Recalculate the estimated size for this list based on what we have in the cache.
protected void	reconfigureCells() Informs the `VirtualFlow` that a layout pass should be done, and the cell contents have not changed.
protected void	recreateCells() Informs the `VirtualFlow` that a layout pass should be done, and that the cell factory has changed.
private void	releaseAllPrivateCells()
private void	releaseCell(T cell) After using the accum cell, it needs to be released!
protected void	requestCellLayout() Informs the `VirtualFlow` that a layout pass should be done and only the cell layout will be requested.
public void	requestLayout() Overrides javafx.scene.Parent.requestLayout. Overridden to implement somewhat more efficient support for layout.
private void	resetIndex(VirtualFlow.ArrayLinkedList<T> the cells cells) Resets the index to -1 to all cells.
private void	resetSizeEstimates()
protected void	resizeCell(T the cell to resize cell) Resizes the given cell.
private void	scrollBarOn()
public double	Returns: the number of pixels actually moved scrollPixels(final double the delta value delta) Given a delta value representing a number of pixels, this method attempts to move the VirtualFlow in the given direction (positive is down/right, negative is up/left) the given number of pixels.
public void	scrollTo(T the cell cell) Adjusts the cells such that the selected cell will be fully visible in the viewport (but only just).
public void	scrollTo(int the index index) Adjusts the cells such that the cell in the given index will be fully visible in the viewport.
public void	scrollToBottom(T the last cell lastCell) Adjust the position of cells so that the specified cell will be positioned at the end of the viewport.
public void	scrollToTop(T the first cell firstCell) Adjust the position of cells so that the specified cell will be positioned at the start of the viewport.
public void	scrollToTop(int the index index) Adjusts the cells such that the cell in the given index will be fully visible in the viewport, and positioned at the very top of the viewport.
public final void	setCellCount(int value)
pack-priv void	setCellDirty(int index)
public final void	setCellFactory(Callback<VirtualFlow<T>, T> the new cell factory value) Sets a new cell factory to use in the VirtualFlow.
protected void	setCellIndex(T The cell whose index will be updated. cell, int The new index for the cell. index) The VirtualFlow uses this method to set a cells index (rather than calling `IndexedCell#updateIndex(int)` directly), so it is a perfect place for subclasses to override if this if of interest.
private void	setClipLayoutX(double x)
private void	setClipLayoutY(double y)
public final void	setFixedCellSize(final double value)
protected void	setHeight(double value) Overrides javafx.scene.layout.Region.setHeight.
private final void	setMaxPrefBreadth(double value)
public final void	setPannable(boolean value)
public final void	setPosition(double value)
pack-priv void	setSuppressBreadthBar(boolean suppress) Suppresses the breadth bar from appearing.
public final void	setVertical(boolean value)
private final void	setViewportBreadth(double value)
pack-priv void	setViewportLength(double value)
protected void	setWidth(double value) Overrides javafx.scene.layout.Region.setWidth.
private void	shiftDown() In case we are not rendering the first cell AND there is empty room after the last cell, the cells need to be shifted down to fill the empty area.
private void	startSBReleasedAnimation()
private boolean	tryScrollOneCell(int targetIndex, boolean downOrRight)
pack-priv void	updateCellSize(T the cell which size has to be calculated cell) Update the size of a specific cell.
pack-priv void	updateHbar()
private void	updateScrollBarsAndCells(boolean recreate)
private void	updateViewportDimensions()
public final BooleanProperty	verticalProperty()

Inherited from javafx.scene.layout.Region:: backgroundProperty borderProperty cacheShapeProperty centerShapeProperty computeMaxHeight computeMaxWidth computeMinHeight computeMinWidth getBackground getBorder getClassCssMetaData getCssMetaData getHeight getInsets getMaxHeight getMaxWidth getMinHeight getMinWidth getOpaqueInsets getPadding getPrefHeight getPrefWidth getShape getUserAgentStylesheet getWidth heightProperty insetsProperty isCacheShape isCenterShape isResizable isScaleShape isSnapToPixel layoutInArea layoutInArea layoutInArea layoutInArea maxHeight maxHeightProperty maxWidth maxWidthProperty minHeight minHeightProperty minWidth minWidthProperty opaqueInsetsProperty paddingProperty positionInArea positionInArea prefHeight prefHeightProperty prefWidth prefWidthProperty resize scaleShapeProperty setBackground setBorder setCacheShape setCenterShape setMaxHeight setMaxSize setMaxWidth setMinHeight setMinSize setMinWidth setOpaqueInsets setPadding setPrefHeight setPrefSize setPrefWidth setScaleShape setShape setSnapToPixel shapeProperty snappedBottomInset snappedLeftInset snappedRightInset snappedTopInset snapPosition snapPositionX snapPositionY snapSize snapSizeX snapSizeY snapSpace snapSpaceX snapSpaceY snapToPixelProperty widthProperty

public Class VirtualFlow<T extends IndexedCell<T>>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary