Class JScrollPane

java.lang.Object

vaadinx.awt.Component

vaadinx.awt.Container

vaadinx.swing.JComponent

vaadinx.swing.JScrollPane

All Implemented Interfaces:

ImageObserver, MenuContainer, Serializable, Accessible, ScrollPaneConstants

public class JScrollPane
extends JComponent
implements ScrollPaneConstants, Accessible

Emulator for JScrollPane. Per D_jscrollpane, a thin delegating shell over the SJScrollPane surrogate (extends Vaadin Scroller). The scrollbar-policy ints field-shadow JDK-faithfully (R_swing_is_truth store-then-drive); the setScrollDirection push to the surrogate is skipped when the current viewport content is auto-scrolling (per SD_sjscrollpane's setContent override on the surrogate side), so user code reading back its policy ints sees what it set even when wrapping a Grid / TextArea.

R_leaf_peer_lockdown-locked-down: no protected (Component peer) ctor — every public ctor funnels through a private (SJScrollPane) ctor that hard-codes the surrogate. JScrollPane is a leaf in the public javax.swing.* hierarchy, so user-code subclasses extend the public form and inherit the locked-in peer.

JViewport and JScrollBar are emulator-only shadow JDK components (per D_viewport_scrollbar_shadows — Vaadin has no separate viewport object; Vaadin Scroller's web component owns scrollbar rendering internally). The shadow ports field-shadow their JDK state for round-trip but never fire listeners (no Vaadin source for scroll-position events without a custom DOM stack — R_match_swing_errors sub-bucket (a) until a migration target asks).

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected JViewport	columnHeader
protected JScrollBar	horizontalScrollBar
protected int	horizontalScrollBarPolicy
protected Component	lowerLeft
protected Component	lowerRight
protected JViewport	rowHeader
protected Component	upperLeft
protected Component	upperRight
protected JScrollBar	verticalScrollBar
protected int	verticalScrollBarPolicy
protected JViewport	viewport

Fields inherited from class JComponent

TOOL_TIP_TEXT_KEY, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, FILL_CHROME, FILL_DEFAULT, LEFT_ALIGNMENT, listenerList, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Fields inherited from interface ScrollPaneConstants

COLUMN_HEADER, HORIZONTAL_SCROLLBAR, HORIZONTAL_SCROLLBAR_ALWAYS, HORIZONTAL_SCROLLBAR_AS_NEEDED, HORIZONTAL_SCROLLBAR_NEVER, HORIZONTAL_SCROLLBAR_POLICY, LOWER_LEADING_CORNER, LOWER_LEFT_CORNER, LOWER_RIGHT_CORNER, LOWER_TRAILING_CORNER, ROW_HEADER, UPPER_LEADING_CORNER, UPPER_LEFT_CORNER, UPPER_RIGHT_CORNER, UPPER_TRAILING_CORNER, VERTICAL_SCROLLBAR, VERTICAL_SCROLLBAR_ALWAYS, VERTICAL_SCROLLBAR_AS_NEEDED, VERTICAL_SCROLLBAR_NEVER, VERTICAL_SCROLLBAR_POLICY, VIEWPORT

Constructor Summary

Constructors

Constructor	Description
JScrollPane()
JScrollPane(int vsbPolicy, int hsbPolicy)
JScrollPane(Component view)
JScrollPane(Component view, int vsbPolicy, int hsbPolicy)

Method Summary

Modifier and Type	Method	Description
AccessibleContext	getAccessibleContext()
JViewport	getColumnHeader()
Component	getCorner(String key)
JScrollBar	getHorizontalScrollBar()
int	getHorizontalScrollBarPolicy()
JViewport	getRowHeader()
ScrollPaneUI	getUI()
String	getUIClassID()
JScrollBar	getVerticalScrollBar()
int	getVerticalScrollBarPolicy()
JViewport	getViewport()	Returns the JViewport that wraps the viewport view.
Border	getViewportBorder()
Component	getViewportView()	The wrapped emulator component, or null if none was set.
boolean	isWheelScrollingEnabled()
void	setColumnHeader(JViewport columnHeader)	Stores the header viewport and fires "columnHeader"; nothing is rendered.
void	setColumnHeaderView(Component view)
void	setCorner(String key, Component corner)	Stores the corner and fires the key-named bound property; nothing is rendered — see setColumnHeader(JViewport).
void	setHorizontalScrollBar(JScrollBar sb)	Replace the horizontal scrollbar.
void	setHorizontalScrollBarPolicy(int policy)
void	setLayout(LayoutManager mgr)	Accepts only null, throwing the JDK's own ClassCastException and message for anything else — javax.swing.JScrollPane.setLayout takes a ScrollPaneLayout or null and rejects the rest, so tolerating a BorderLayout here would let code run that fails on the desktop (R_match_swing_errors).
void	setRowHeader(JViewport rowHeader)	Stores and fires; nothing is rendered — see setColumnHeader(JViewport).
void	setRowHeaderView(Component view)
void	setUI(ScrollPaneUI ui)
void	setVerticalScrollBar(JScrollBar sb)
void	setVerticalScrollBarPolicy(int policy)
void	setViewport(JViewport vp)	Replace the JViewport.
void	setViewportBorder(Border viewportBorder)
void	setViewportView(Component view)	Set the wrapped component.
void	setWheelScrollingEnabled(boolean handleWheel)
void	updateUI()
protected void	validateTree()	setViewportView attaches the view through Scroller.setContent (one-content-slot per SD_sjscrollpane), bypassing Container.addImpl — the view never enters this JScrollPane's components list.

Methods inherited from class JComponent

addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, paramString, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class Container

add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, addSlotChild, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, fireHierarchyEvent, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, peerContentElement, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeSlotChild, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, transferFocusDownCycle, validate

Methods inherited from class Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, applyBackgroundToPeer, applyVisibleToPeer, awtListeners, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, defaultFillCssClass, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, fireComponentEvent, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isShowing, isThemeDefault, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, peerIs, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setMixingCutoutShape, setName, setSize, setSize, show, show, size, suppressMouseBridge, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, withPeer, withPeerOnLiveUI

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

verticalScrollBarPolicy

protected int verticalScrollBarPolicy

horizontalScrollBarPolicy

protected int horizontalScrollBarPolicy

viewport

protected JViewport viewport

horizontalScrollBar

protected JScrollBar horizontalScrollBar

verticalScrollBar

protected JScrollBar verticalScrollBar

columnHeader

protected JViewport columnHeader

rowHeader

protected JViewport rowHeader

lowerLeft

protected Component lowerLeft

lowerRight

protected Component lowerRight

upperLeft

protected Component upperLeft

upperRight

protected Component upperRight

Constructor Details

JScrollPane

public JScrollPane()

JScrollPane

public JScrollPane(Component view)

JScrollPane

public JScrollPane(int vsbPolicy,
 int hsbPolicy)

JScrollPane

public JScrollPane(Component view,
 int vsbPolicy,
 int hsbPolicy)

Method Details

setViewportView

public void setViewportView(Component view)

Set the wrapped component. Field-shadows the emulator-side reference, delegates to SJScrollPane.setContent(com.vaadin.flow.component.Component) (which applies the auto-scroll guard per SD_sjscrollpane), then re-pushes the scrollbar policy via pushPolicyToSurrogate() — the push is a no-op when content is auto-scrolling.

getViewportView

public Component getViewportView()

The wrapped emulator component, or null if none was set.

getViewport

public JViewport getViewport()

Returns the JViewport that wraps the viewport view. Eagerly constructed in the ctor (added to Container.components so the JDK tree shape round-trips). Per D_viewport_scrollbar_shadows, the JViewport is an emulator-only shadow JDK component — its getView / setView round-trip the wrapped component, but viewport-position / extent-size APIs are round-trip-only (no Vaadin counterpart).

setViewport

public void setViewport(JViewport vp)

Replace the JViewport. JDK contract: the new viewport's view becomes the JScrollPane's viewport view. The old viewport is detached from Container.components and the new one inserted at the same index (viewport always lives at index 0 — JDK ordering).

getHorizontalScrollBar

public JScrollBar getHorizontalScrollBar()

getVerticalScrollBar

public JScrollBar getVerticalScrollBar()

setHorizontalScrollBar

public void setHorizontalScrollBar(JScrollBar sb)

Replace the horizontal scrollbar. JDK accepts user-supplied JScrollBar instances (rare; common in subclassed L&F-aware code). The old scrollbar is detached from Container.components and the new one inserted at the same JDK index (2 — after viewport and verticalScrollBar). No DOM impact: Vaadin Scroller renders its own scrollbar; the shadow's inert Div peer stays out of the peer DOM.

setVerticalScrollBar

public void setVerticalScrollBar(JScrollBar sb)

getVerticalScrollBarPolicy

public int getVerticalScrollBarPolicy()

setVerticalScrollBarPolicy

public void setVerticalScrollBarPolicy(int policy)

getHorizontalScrollBarPolicy

public int getHorizontalScrollBarPolicy()

setHorizontalScrollBarPolicy

public void setHorizontalScrollBarPolicy(int policy)

setViewportBorder

public void setViewportBorder(Border viewportBorder)

getViewportBorder

public Border getViewportBorder()

setColumnHeaderView

public void setColumnHeaderView(Component view)

setRowHeaderView

public void setRowHeaderView(Component view)

setColumnHeader

public void setColumnHeader(JViewport columnHeader)

Stores the header viewport and fires "columnHeader"; nothing is rendered. A Vaadin Scroller has one content slot and no header/corner grid, so the JDK's add(columnHeader, COLUMN_HEADER) has no target — the declined effect. State and notification are owed regardless (R_decline_effect_only, D_owed_events).

getColumnHeader

public JViewport getColumnHeader()

setRowHeader

public void setRowHeader(JViewport rowHeader)

Stores and fires; nothing is rendered — see setColumnHeader(JViewport).

getRowHeader

public JViewport getRowHeader()

setCorner

public void setCorner(String key,
 Component corner)

Stores the corner and fires the key-named bound property; nothing is rendered — see setColumnHeader(JViewport). Invalid keys throw IllegalArgumentException as in the JDK (R_match_swing_errors).

getCorner

public Component getCorner(String key)

setWheelScrollingEnabled

public void setWheelScrollingEnabled(boolean handleWheel)

isWheelScrollingEnabled

public boolean isWheelScrollingEnabled()

setLayout

public void setLayout(LayoutManager mgr)

Accepts only null, throwing the JDK's own ClassCastException and message for anything else — javax.swing.JScrollPane.setLayout takes a ScrollPaneLayout or null and rejects the rest, so tolerating a BorderLayout here would let code run that fails on the desktop (R_match_swing_errors).

The JDK's accept-branch has nothing to accept, and costs nothing: SB-Emulators ports no ScrollPaneLayout (its viewport / header / corner orchestration is R_vaadin_first drop-and-WARN per D_jscrollpane, the peer being one content slot), and javax.swing.ScrollPaneLayout is not a vaadinx.awt.LayoutManager, so a migrator's surviving call would not compile either way.

Overrides:

setLayout in class Container

Parameters:

mgr - must be null

Throws:

ClassCastException - for any non-null manager

validateTree

protected void validateTree()

setViewportView attaches the view through Scroller.setContent (one-content-slot per SD_sjscrollpane), bypassing Container.addImpl — the view never enters this JScrollPane's components list. The inherited Container.validateTree() walks components only, so without this override an inner panel created with new JPanel() then setLayout(new BoxLayout(...)) keeps the FlowLayout CSS the SJPanel ctor wrote at construction time — its BoxLayout never gets a layoutContainer pass. Recursing into the viewportView closes that gap.

Overrides:

validateTree in class Container

getUIClassID

public String getUIClassID()

Overrides:

getUIClassID in class JComponent

updateUI

public void updateUI()

Overrides:

updateUI in class JComponent

getUI

public ScrollPaneUI getUI()

Overrides:

getUI in class JComponent

setUI

public void setUI(ScrollPaneUI ui)

getAccessibleContext

public AccessibleContext getAccessibleContext()

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class Component