org.eclipse.swt.widgets

Class Combo

java.lang.Object

org.eclipse.swt.widgets.Widget

org.eclipse.swt.widgets.Control

org.eclipse.swt.widgets.Scrollable

org.eclipse.swt.widgets.Composite

org.eclipse.swt.widgets.Combo

All Implemented Interfaces:

Drawable

public class Combo
extends Composite

Instances of this class are controls that allow the user to choose an item from a list of items, or optionally enter a new value by typing it into an editable text field. Often, Combos are used in the same place where a single selection List widget could be used but space is limited. A Combo takes less space than a List widget and shows similar information.

Note: Since Combos can contain both a list and an editable text field, it is possible to confuse methods which access one versus the other (compare for example, clearSelection() and deselectAll()). The API documentation is careful to indicate either "the receiver's list" or the "the receiver's text field" to distinguish between the two cases.

Note that although this class is a subclass of Composite, it does not make sense to add children to it, or set a layout on it.

Styles:

DROP_DOWN, READ_ONLY, SIMPLE

Events:

DefaultSelection, Modify, Selection, Verify, OrientationChange

Note: Only one of the styles DROP_DOWN and SIMPLE may be specified.

IMPORTANT: This class is not intended to be subclassed.

See Also:

List, Combo snippets, SWT Example: ControlExample, Sample code and further information

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static int	CBID_EDIT
(package private) static int	CBID_LIST
(package private) int	cbtHook
(package private) static TCHAR	ComboClass
(package private) static int	ComboProc
(package private) static int	EditProc
(package private) boolean	ignoreCharacter
(package private) boolean	ignoreDefaultSelection
(package private) boolean	ignoreModify
(package private) boolean	ignoreResize
static int	LIMIT the operating system limit for the number of characters that the text field in an instance of this class can hold
(package private) static int	ListProc
(package private) boolean	lockText
(package private) boolean	noSelection
(package private) int	scrollWidth
(package private) static int	VISIBLE_COUNT
(package private) int	visibleCount

Fields inherited from class org.eclipse.swt.widgets.Composite

backgroundMode, layout, layoutCount, lpwp, tabList

Fields inherited from class org.eclipse.swt.widgets.Scrollable

horizontalBar, verticalBar

Fields inherited from class org.eclipse.swt.widgets.Control

accessible, background, backgroundImage, cursor, drawCount, font, foreground, handle, layoutData, menu, parent, region, toolTipText

Fields inherited from class org.eclipse.swt.widgets.Widget

CANVAS, data, DEFAULT_HEIGHT, DEFAULT_WIDTH, DISABLED, display, DISPOSE_SENT, DISPOSED, DRAG_DETECT, DRAW_BACKGROUND, eventTable, FOREIGN_HANDLE, HIDDEN, IGNORE_WM_CHANGEUISTATE, KEYED_DATA, LAYOUT_CHANGED, LAYOUT_CHILD, LAYOUT_NEEDED, MAJOR, MINOR, MOVE_DEFERRED, MOVE_OCCURRED, PARENT_BACKGROUND, RELEASED, RESIZE_DEFERRED, RESIZE_OCCURRED, SKIN_NEEDED, state, style, THEME_BACKGROUND, TRACK_MOUSE

Constructor Summary

Constructors

Constructor and Description
Combo(Composite parent, int style) Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(java.lang.String string) Adds the argument to the end of the receiver's list.
void	add(java.lang.String string, int index) Adds the argument to the receiver's list at the given zero-relative index.
void	addModifyListener(ModifyListener listener) Adds the listener to the collection of listeners who will be notified when the receiver's text is modified, by sending it one of the messages defined in the ModifyListener interface.
void	addSelectionListener(SelectionListener listener) Adds the listener to the collection of listeners who will be notified when the user changes the receiver's selection, by sending it one of the messages defined in the SelectionListener interface.
void	addVerifyListener(VerifyListener listener) Adds the listener to the collection of listeners who will be notified when the receiver's text is verified, by sending it one of the messages defined in the VerifyListener interface.
(package private) int	callWindowProc(int hwnd, int msg, int wParam, int lParam)
(package private) int	CBTProc(int nCode, int wParam, int lParam)
(package private) boolean	checkHandle(int hwnd)
(package private) static int	checkStyle(int style)
protected void	checkSubclass() Checks that this class can be subclassed.
void	clearSelection() Sets the selection in the receiver's text field to an empty selection starting just before the first character.
Point	computeSize(int wHint, int hHint, boolean changed) Returns the preferred size of the receiver.
void	copy() Copies the selected text.
(package private) void	createHandle()
(package private) void	createWidget()
void	cut() Cuts the selected text.
(package private) int	defaultBackground()
(package private) void	deregister()
void	deselect(int index) Deselects the item at the given zero-relative index in the receiver's list.
void	deselectAll() Deselects all selected items in the receiver's list.
(package private) boolean	dragDetect(int hwnd, int x, int y, boolean filter, boolean[] detect, boolean[] consume)
Point	getCaretLocation() Returns a point describing the location of the caret relative to the receiver.
int	getCaretPosition() Returns the character position of the caret.
java.lang.String	getItem(int index) Returns the item at the given, zero-relative index in the receiver's list.
int	getItemCount() Returns the number of items contained in the receiver's list.
int	getItemHeight() Returns the height of the area which would be used to display one of the items in the receiver's list.
java.lang.String[]	getItems() Returns a (possibly empty) array of Strings which are the items in the receiver's list.
boolean	getListVisible() Returns true if the receiver's list is visible, and false otherwise.
(package private) java.lang.String	getNameText()
int	getOrientation() Returns the orientation of the receiver.
Point	getSelection() Returns a Point whose x coordinate is the character position representing the start of the selection in the receiver's text field, and whose y coordinate is the character position representing the end of the selection.
int	getSelectionIndex() Returns the zero-relative index of the item which is currently selected in the receiver's list, or -1 if no item is selected.
java.lang.String	getText() Returns a string containing a copy of the contents of the receiver's text field, or an empty string if there are no contents.
int	getTextHeight() Returns the height of the receivers's text field.
int	getTextLimit() Returns the maximum number of characters that the receiver's text field is capable of holding.
int	getVisibleItemCount() Gets the number of items that are visible in the drop down portion of the receiver's list.
(package private) boolean	hasFocus()
int	indexOf(java.lang.String string) Searches the receiver's list starting at the first item (index 0) until an item is found that is equal to the argument, and returns the index of that item.
int	indexOf(java.lang.String string, int start) Searches the receiver's list starting at the given, zero-relative index until an item is found that is equal to the argument, and returns the index of that item.
(package private) int	mbcsToWcsPos(int mbcsPos)
void	paste() Pastes text from clipboard.
(package private) void	register()
void	remove(int index) Removes the item from the receiver's list at the given zero-relative index.
(package private) void	remove(int index, boolean notify)
void	remove(int start, int end) Removes the items from the receiver's list which are between the given zero-relative start and end indices (inclusive).
void	remove(java.lang.String string) Searches the receiver's list starting at the first item until an item is found that is equal to the argument, and removes that item from the list.
void	removeAll() Removes all of the items from the receiver's list and clear the contents of receiver's text field.
void	removeModifyListener(ModifyListener listener) Removes the listener from the collection of listeners who will be notified when the receiver's text is modified.
void	removeSelectionListener(SelectionListener listener) Removes the listener from the collection of listeners who will be notified when the user changes the receiver's selection.
void	removeVerifyListener(VerifyListener listener) Removes the listener from the collection of listeners who will be notified when the control is verified.
void	select(int index) Selects the item at the given zero-relative index in the receiver's list.
(package private) boolean	sendKeyEvent(int type, int msg, int wParam, int lParam, Event event)
(package private) void	setBackgroundImage(int hBitmap)
(package private) void	setBackgroundPixel(int pixel)
(package private) void	setBounds(int x, int y, int width, int height, int flags)
void	setFont(Font font) Sets the font that the receiver will use to paint textual information to the font specified by the argument, or to the default font for that kind of control if the argument is null.
(package private) void	setForegroundPixel(int pixel)
void	setItem(int index, java.lang.String string) Sets the text of the item in the receiver's list at the given zero-relative index to the string argument.
void	setItems(java.lang.String[] items) Sets the receiver's list to be the given array of items.
void	setListVisible(boolean visible) Marks the receiver's list as visible if the argument is true, and marks it invisible otherwise.
void	setOrientation(int orientation) Sets the orientation of the receiver, which must be one of the constants SWT.LEFT_TO_RIGHT or SWT.RIGHT_TO_LEFT.
(package private) void	setScrollWidth()
(package private) void	setScrollWidth(int scrollWidth)
(package private) void	setScrollWidth(int newWidth, boolean grow)
(package private) void	setScrollWidth(TCHAR buffer, boolean grow)
void	setSelection(Point selection) Sets the selection in the receiver's text field to the range specified by the argument whose x coordinate is the start of the selection and whose y coordinate is the end of the selection.
void	setText(java.lang.String string) Sets the contents of the receiver's text field to the given string.
void	setTextLimit(int limit) Sets the maximum number of characters that the receiver's text field is capable of holding to be the argument.
(package private) void	setToolTipText(Shell shell, java.lang.String string)
void	setVisibleItemCount(int count) Sets the number of items that are visible in the drop down portion of the receiver's list.
(package private) void	subclass()
(package private) boolean	translateTraversal(MSG msg)
(package private) boolean	traverseEscape()
(package private) boolean	traverseReturn()
(package private) void	unsubclass()
(package private) void	updateDropDownHeight()
(package private) void	updateOrientation()
(package private) java.lang.String	verifyText(java.lang.String string, int start, int end, Event keyEvent)
(package private) int	wcsToMbcsPos(int wcsPos)
(package private) int	widgetExtStyle()
(package private) int	widgetStyle()
(package private) TCHAR	windowClass()
(package private) int	windowProc()
(package private) int	windowProc(int hwnd, int msg, int wParam, int lParam)
(package private) LRESULT	WM_CTLCOLOR(int wParam, int lParam)
(package private) LRESULT	WM_GETDLGCODE(int wParam, int lParam)
(package private) LRESULT	WM_KILLFOCUS(int wParam, int lParam)
(package private) LRESULT	WM_LBUTTONDOWN(int wParam, int lParam)
(package private) LRESULT	WM_SETFOCUS(int wParam, int lParam)
(package private) LRESULT	WM_SIZE(int wParam, int lParam)
(package private) LRESULT	WM_UPDATEUISTATE(int wParam, int lParam)
(package private) LRESULT	WM_WINDOWPOSCHANGING(int wParam, int lParam)
(package private) LRESULT	wmChar(int hwnd, int wParam, int lParam)
(package private) LRESULT	wmClipboard(int hwndText, int msg, int wParam, int lParam)
(package private) LRESULT	wmCommandChild(int wParam, int lParam)
(package private) LRESULT	wmIMEChar(int hwnd, int wParam, int lParam)
(package private) LRESULT	wmKeyDown(int hwnd, int wParam, int lParam)
(package private) LRESULT	wmSysKeyDown(int hwnd, int wParam, int lParam)

Methods inherited from class org.eclipse.swt.widgets.Composite

_getChildren, _getTabList, changed, checkBuffered, checkComposited, computeTabList, copyArea, drawBackground, findDeferredControl, findMenus, fixChildren, fixTabList, getBackgroundMode, getChildren, getChildrenCount, getLayout, getLayoutDeferred, getTabList, hooksKeys, isLayoutDeferred, layout, layout, layout, layout, layout, markLayout, minimumSize, redrawChildren, releaseChildren, releaseParent, releaseWidget, removeControl, resizeChildren, resizeChildren, resizeEmbeddedHandle, reskinChildren, sendResize, setBackgroundMode, setBounds, setFocus, setLayout, setLayoutDeferred, setResizeChildren, setTabGroupFocus, setTabList, toolTipText, translateMnemonic, updateBackgroundColor, updateBackgroundImage, updateBackgroundMode, updateFont, updateLayout, updateLayout, updateUIState, WM_ERASEBKGND, WM_GETFONT, WM_NCHITTEST, WM_PAINT, WM_PARENTNOTIFY, WM_PRINTCLIENT, WM_SETFONT, WM_SYSCOLORCHANGE, WM_SYSCOMMAND, wmNCPaint, wmNotify

Methods inherited from class org.eclipse.swt.widgets.Scrollable

computeTrim, createScrollBar, destroyScrollBar, getClientArea, getHorizontalBar, getScrollbarsMode, getVerticalBar, scrolledHandle, WM_HSCROLL, WM_MOUSEWHEEL, WM_VSCROLL, wmScroll, wmScrollWheel

Methods inherited from class org.eclipse.swt.widgets.Control

addControlListener, addDragDetectListener, addFocusListener, addGestureListener, addHelpListener, addKeyListener, addMenuDetectListener, addMouseListener, addMouseMoveListener, addMouseTrackListener, addMouseWheelListener, addPaintListener, addTouchListener, addTraverseListener, binarySearch, borderHandle, checkBackground, checkBorder, checkGesture, checkMirrored, computeSize, computeTabGroup, computeTabRoot, defaultFont, defaultForeground, destroyWidget, dragDetect, dragDetect, dragDetect, drawBackground, drawBackground, drawBackground, drawImageBackground, drawThemeBackground, enableDrag, enableWidget, fillBackground, fillImageBackground, fillThemeBackground, findBackgroundControl, findBrush, findCursor, findImageControl, findMnemonic, findThemeControl, fixFocus, forceFocus, forceResize, getAccessible, getBackground, getBackgroundImage, getBackgroundPixel, getBorderWidth, getBounds, getClipboardText, getCodePage, getCursor, getDragDetect, getDrawing, getEnabled, getFont, getForeground, getForegroundPixel, getLayoutData, getLocation, getMenu, getMonitor, getParent, getPath, getRegion, getShell, getSize, getToolTipText, getTouchEnabled, getVisible, hasCursor, internal_dispose_GC, internal_new_GC, isActive, isEnabled, isFocusAncestor, isFocusControl, isReparentable, isShowing, isTabGroup, isTabItem, isVisible, mapEvent, menuShell, mnemonicHit, mnemonicMatch, moveAbove, moveBelow, new_Accessible, new_GC, pack, pack, print, printWidget, redraw, redraw, redraw, releaseHandle, removeControlListener, removeDragDetectListener, removeFocusListener, removeGestureListener, removeHelpListener, removeKeyListener, removeMenuDetectListener, removeMouseListener, removeMouseMoveListener, removeMouseTrackListener, removeMouseWheelListener, removePaintListener, removeTouchListener, removeTraverseListener, sendFocusEvent, sendGestureEvent, sendMove, sendTouchEvent, setBackground, setBackground, setBackgroundImage, setBounds, setBounds, setCapture, setCursor, setCursor, setDefaultFont, setDragDetect, setEnabled, setForeground, setLayoutData, setLocation, setLocation, setMenu, setParent, setRadioFocus, setRadioSelection, setRedraw, setRegion, setSavedFocus, setSize, setSize, setTabItemFocus, setToolTipText, setTouchEnabled, setVisible, showWidget, sort, toControl, toControl, toDisplay, toDisplay, topHandle, translateAccelerator, translateMnemonic, traverse, traverse, traverse, traverse, traverse, traverseGroup, traverseItem, traverseMnemonic, traversePage, update, update, updateImages, widgetCreateStruct, widgetParent, WM_ACTIVATE, WM_CAPTURECHANGED, WM_CHANGEUISTATE, WM_CHAR, WM_CLEAR, WM_CLOSE, WM_COMMAND, WM_CONTEXTMENU, WM_CUT, WM_DESTROY, WM_DRAWITEM, WM_ENDSESSION, WM_ENTERIDLE, WM_GESTURE, WM_GETMINMAXINFO, WM_GETOBJECT, WM_HELP, WM_HOTKEY, WM_IME_CHAR, WM_IME_COMPOSITION_START, WM_IME_COMPOSITION, WM_IME_ENDCOMPOSITION, WM_INITMENUPOPUP, WM_INPUTLANGCHANGE, WM_KEYDOWN, WM_KEYUP, WM_LBUTTONDBLCLK, WM_LBUTTONUP, WM_MBUTTONDBLCLK, WM_MBUTTONDOWN, WM_MBUTTONUP, WM_MEASUREITEM, WM_MENUCHAR, WM_MENUSELECT, WM_MOUSEACTIVATE, WM_MOUSEHOVER, WM_MOUSEHWHEEL, WM_MOUSELEAVE, WM_MOUSEMOVE, WM_MOVE, WM_NCACTIVATE, WM_NCCALCSIZE, WM_NCLBUTTONDOWN, WM_NCPAINT, WM_NOTIFY, WM_PALETTECHANGED, WM_PASTE, WM_PRINT, WM_QUERYENDSESSION, WM_QUERYNEWPALETTE, WM_QUERYOPEN, WM_RBUTTONDBLCLK, WM_RBUTTONDOWN, WM_RBUTTONUP, WM_SETCURSOR, WM_SETREDRAW, WM_SETTINGCHANGE, WM_SHOWWINDOW, WM_SYSCHAR, WM_SYSKEYDOWN, WM_SYSKEYUP, WM_TABLET_FLICK, WM_TIMER, WM_TOUCH, WM_UNDO, WM_UNINITMENUPOPUP, WM_WINDOWPOSCHANGED, WM_XBUTTONDBLCLK, WM_XBUTTONDOWN, WM_XBUTTONUP, wmColorChild, wmDrawChild, wmMeasureChild, wmNotifyChild, wmScrollChild

Methods inherited from class org.eclipse.swt.widgets.Widget

_addListener, addDisposeListener, addListener, checkBits, checkOpened, checkOrientation, checkParent, checkWidget, DeferWindowPos, dispose, error, filters, findItem, fixMnemonic, fixMnemonic, getData, getData, getDisplay, getListeners, getName, getStyle, hooks, isDisposed, isListening, isValidSubclass, isValidThread, notifyListeners, postEvent, postEvent, release, removeDisposeListener, removeListener, removeListener, reskin, reskinWidget, sendDragEvent, sendDragEvent, sendEvent, sendEvent, sendEvent, sendEvent, sendKeyEvent, sendMouseEvent, sendMouseEvent, sendMouseWheelEvent, sendSelectionEvent, sendSelectionEvent, setData, setData, setInputState, setKeyState, setLocationMask, SetWindowPos, showMenu, showMenu, toString, updateMenuLocation, wmCaptureChanged, wmContextMenu, wmKeyUp, wmKillFocus, wmLButtonDblClk, wmLButtonDown, wmLButtonUp, wmMButtonDblClk, wmMButtonDown, wmMButtonUp, wmMouseHover, wmMouseHWheel, wmMouseLeave, wmMouseMove, wmMouseWheel, wmPaint, wmPrint, wmRButtonDblClk, wmRButtonDown, wmRButtonUp, wmSetFocus, wmSysChar, wmSysKeyUp, wmXButtonDblClk, wmXButtonDown, wmXButtonUp

Methods inherited from class java.lang.Object

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

Field Detail

noSelection

boolean noSelection

ignoreDefaultSelection

boolean ignoreDefaultSelection

ignoreCharacter

boolean ignoreCharacter

ignoreModify

boolean ignoreModify

ignoreResize

boolean ignoreResize

lockText

boolean lockText

scrollWidth

int scrollWidth

visibleCount

int visibleCount

cbtHook

int cbtHook

VISIBLE_COUNT

static final int VISIBLE_COUNT

See Also:

Constant Field Values

LIMIT

public static final int LIMIT

the operating system limit for the number of characters that the text field in an instance of this class can hold

CBID_LIST

static final int CBID_LIST

See Also:

Constant Field Values

CBID_EDIT

static final int CBID_EDIT

See Also:

Constant Field Values

EditProc

static int EditProc

ListProc

static int ListProc

ComboProc

static final int ComboProc

ComboClass

static final TCHAR ComboClass

Constructor Detail

Combo

public Combo(Composite parent,
     int style)

Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

Parameters:

parent - a composite control which will be the parent of the new instance (cannot be null)

style - the style of control to construct

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
• ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass

See Also:

SWT.DROP_DOWN, SWT.READ_ONLY, SWT.SIMPLE, Widget.checkSubclass(), Widget.getStyle()

Method Detail

add

public void add(java.lang.String string)

Adds the argument to the end of the receiver's list.

Parameters:

string - the new item

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the string is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

add(String,int)

add

public void add(java.lang.String string,
       int index)

Adds the argument to the receiver's list at the given zero-relative index.

Note: To add an item at the end of the list, use the result of calling getItemCount() as the index or use add(String).

Parameters:

string - the new item

index - the index for the item

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the string is null
• ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list (inclusive)

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

add(String)

addModifyListener

public void addModifyListener(ModifyListener listener)

Adds the listener to the collection of listeners who will be notified when the receiver's text is modified, by sending it one of the messages defined in the ModifyListener interface.

Parameters:

listener - the listener which should be notified

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

ModifyListener, removeModifyListener(org.eclipse.swt.events.ModifyListener)

addSelectionListener

public void addSelectionListener(SelectionListener listener)

Adds the listener to the collection of listeners who will be notified when the user changes the receiver's selection, by sending it one of the messages defined in the SelectionListener interface.

widgetSelected is called when the user changes the combo's list selection. widgetDefaultSelected is typically called when ENTER is pressed the combo's text area.

Parameters:

listener - the listener which should be notified

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

SelectionListener, removeSelectionListener(org.eclipse.swt.events.SelectionListener), SelectionEvent

addVerifyListener

public void addVerifyListener(VerifyListener listener)

Adds the listener to the collection of listeners who will be notified when the receiver's text is verified, by sending it one of the messages defined in the VerifyListener interface.

Parameters:

listener - the listener which should be notified

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.1

See Also:

VerifyListener, removeVerifyListener(org.eclipse.swt.events.VerifyListener)

callWindowProc

int callWindowProc(int hwnd,
                 int msg,
                 int wParam,
                 int lParam)

Overrides:

callWindowProc in class Scrollable

CBTProc

int CBTProc(int nCode,
          int wParam,
          int lParam)

checkHandle

boolean checkHandle(int hwnd)

Overrides:

checkHandle in class Control

checkSubclass

protected void checkSubclass()

Description copied from class: Widget

Checks that this class can be subclassed.

The SWT class library is intended to be subclassed only at specific, controlled points (most notably, Composite and Canvas when implementing new widgets). This method enforces this rule unless it is overridden.

IMPORTANT: By providing an implementation of this method that allows a subclass of a class which does not normally allow subclassing to be created, the implementer agrees to be fully responsible for the fact that any such subclass will likely fail between SWT releases and will be strongly platform specific. No support is provided for user-written classes which are implemented in this fashion.

The ability to subclass outside of the allowed SWT classes is intended purely to enable those not on the SWT development team to implement patches in order to get around specific limitations in advance of when those limitations can be addressed by the team. Subclassing should not be attempted without an intimate and detailed understanding of the hierarchy.

Overrides:

checkSubclass in class Composite

checkStyle

static int checkStyle(int style)

clearSelection

public void clearSelection()

Sets the selection in the receiver's text field to an empty selection starting just before the first character. If the text field is editable, this has the effect of placing the i-beam at the start of the text.

Note: To clear the selected items in the receiver's list, use deselectAll().

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

deselectAll()

computeSize

public Point computeSize(int wHint,
                int hHint,
                boolean changed)

Description copied from class: Control

Returns the preferred size of the receiver.

The preferred size of a control is the size that it would best be displayed at. The width hint and height hint arguments allow the caller to ask a control questions such as "Given a particular width, how high does the control need to be to show all of the contents?" To indicate that the caller does not wish to constrain a particular dimension, the constant SWT.DEFAULT is passed for the hint.

If the changed flag is true, it indicates that the receiver's contents have changed, therefore any caches that a layout manager containing the control may have been keeping need to be flushed. When the control is resized, the changed flag will be false, so layout manager caches can be retained.

Overrides:

computeSize in class Composite

Parameters:

wHint - the width hint (can be SWT.DEFAULT)

hHint - the height hint (can be SWT.DEFAULT)

changed - true if the control's contents have changed, and false otherwise

Returns:

the preferred size of the control.

See Also:

Layout, Control.getBorderWidth(), Control.getBounds(), Control.getSize(), Control.pack(boolean), "computeTrim, getClientArea for controls that implement them"

copy

public void copy()

Copies the selected text.

The current selection is copied to the clipboard.

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

2.1

createHandle

void createHandle()

Overrides:

createHandle in class Composite

createWidget

void createWidget()

Overrides:

createWidget in class Scrollable

cut

public void cut()

Cuts the selected text.

The current selection is first copied to the clipboard and then deleted from the widget.

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

2.1

defaultBackground

int defaultBackground()

Overrides:

defaultBackground in class Control

deregister

void deregister()

Overrides:

deregister in class Control

deselect

public void deselect(int index)

Deselects the item at the given zero-relative index in the receiver's list. If the item at the index was already deselected, it remains deselected. Indices that are out of range are ignored.

Parameters:

index - the index of the item to deselect

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

deselectAll

public void deselectAll()

Deselects all selected items in the receiver's list.

Note: To clear the selection in the receiver's text field, use clearSelection().

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

clearSelection()

dragDetect

boolean dragDetect(int hwnd,
                 int x,
                 int y,
                 boolean filter,
                 boolean[] detect,
                 boolean[] consume)

Overrides:

dragDetect in class Widget

getCaretLocation

public Point getCaretLocation()

Returns a point describing the location of the caret relative to the receiver.

Returns:

a point, the location of the caret

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.8

getCaretPosition

public int getCaretPosition()

Returns the character position of the caret.

Indexing is zero based.

Returns:

the position of the caret

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.8

getItem

public java.lang.String getItem(int index)

Returns the item at the given, zero-relative index in the receiver's list. Throws an exception if the index is out of range.

Parameters:

index - the index of the item to return

Returns:

the item at the given index

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getItemCount

public int getItemCount()

Returns the number of items contained in the receiver's list.

Returns:

the number of items

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getItemHeight

public int getItemHeight()

Returns the height of the area which would be used to display one of the items in the receiver's list.

Returns:

the height of one item

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getItems

public java.lang.String[] getItems()

Returns a (possibly empty) array of Strings which are the items in the receiver's list.

Note: This is not the actual structure used by the receiver to maintain its list of items, so modifying the array will not affect the receiver.

Returns:

the items in the receiver's list

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getListVisible

public boolean getListVisible()

Returns true if the receiver's list is visible, and false otherwise.

If one of the receiver's ancestors is not visible or some other condition makes the receiver not visible, this method may still indicate that it is considered visible even though it may not actually be showing.

Returns:

the receiver's list's visibility state

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.4

getNameText

java.lang.String getNameText()

Overrides:

getNameText in class Widget

setListVisible

public void setListVisible(boolean visible)

Marks the receiver's list as visible if the argument is true, and marks it invisible otherwise.

If one of the receiver's ancestors is not visible or some other condition makes the receiver not visible, marking it visible may not actually cause it to be displayed.

Parameters:

visible - the new visibility state

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.4

getOrientation

public int getOrientation()

Returns the orientation of the receiver.

Overrides:

getOrientation in class Control

Returns:

the orientation style

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

2.1.2

getSelection

public Point getSelection()

Returns a Point whose x coordinate is the character position representing the start of the selection in the receiver's text field, and whose y coordinate is the character position representing the end of the selection. An "empty" selection is indicated by the x and y coordinates having the same value.

Indexing is zero based. The range of a selection is from 0..N where N is the number of characters in the widget.

Returns:

a point representing the selection start and end

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getSelectionIndex

public int getSelectionIndex()

Returns the zero-relative index of the item which is currently selected in the receiver's list, or -1 if no item is selected.

Returns:

the index of the selected item

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getText

public java.lang.String getText()

Returns a string containing a copy of the contents of the receiver's text field, or an empty string if there are no contents.

Returns:

the receiver's text

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getTextHeight

public int getTextHeight()

Returns the height of the receivers's text field.

Returns:

the text height

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

getTextLimit

public int getTextLimit()

Returns the maximum number of characters that the receiver's text field is capable of holding. If this has not been changed by setTextLimit(), it will be the constant Combo.LIMIT.

Returns:

the text limit

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

LIMIT

getVisibleItemCount

public int getVisibleItemCount()

Gets the number of items that are visible in the drop down portion of the receiver's list.

Note: This operation is a hint and is not supported on platforms that do not have this concept.

Returns:

the number of items that are visible

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.0

hasFocus

boolean hasFocus()

Overrides:

hasFocus in class Control

indexOf

public int indexOf(java.lang.String string)

Searches the receiver's list starting at the first item (index 0) until an item is found that is equal to the argument, and returns the index of that item. If no item is found, returns -1.

Parameters:

string - the search item

Returns:

the index of the item

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the string is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

indexOf

public int indexOf(java.lang.String string,
          int start)

Searches the receiver's list starting at the given, zero-relative index until an item is found that is equal to the argument, and returns the index of that item. If no item is found or the starting index is out of range, returns -1.

Parameters:

string - the search item

start - the zero-relative index at which to begin the search

Returns:

the index of the item

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the string is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

mbcsToWcsPos

int mbcsToWcsPos(int mbcsPos)

paste

public void paste()

Pastes text from clipboard.

The selected text is deleted from the widget and new text inserted from the clipboard.

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

2.1

register

void register()

Overrides:

register in class Control

remove

public void remove(int index)

Removes the item from the receiver's list at the given zero-relative index.

Parameters:

index - the index for the item

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

remove

void remove(int index,
          boolean notify)

remove

public void remove(int start,
          int end)

Removes the items from the receiver's list which are between the given zero-relative start and end indices (inclusive).

Parameters:

start - the start of the range

end - the end of the range

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_RANGE - if either the start or end are not between 0 and the number of elements in the list minus 1 (inclusive)

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

remove

public void remove(java.lang.String string)

Searches the receiver's list starting at the first item until an item is found that is equal to the argument, and removes that item from the list.

Parameters:

string - the item to remove

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the string is null
• ERROR_INVALID_ARGUMENT - if the string is not found in the list

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

removeAll

public void removeAll()

Removes all of the items from the receiver's list and clear the contents of receiver's text field.

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

removeModifyListener

public void removeModifyListener(ModifyListener listener)

Removes the listener from the collection of listeners who will be notified when the receiver's text is modified.

Parameters:

listener - the listener which should no longer be notified

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

ModifyListener, addModifyListener(org.eclipse.swt.events.ModifyListener)

removeSelectionListener

public void removeSelectionListener(SelectionListener listener)

Removes the listener from the collection of listeners who will be notified when the user changes the receiver's selection.

Parameters:

listener - the listener which should no longer be notified

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

SelectionListener, addSelectionListener(org.eclipse.swt.events.SelectionListener)

removeVerifyListener

public void removeVerifyListener(VerifyListener listener)

Removes the listener from the collection of listeners who will be notified when the control is verified.

Parameters:

listener - the listener which should no longer be notified

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.1

See Also:

VerifyListener, addVerifyListener(org.eclipse.swt.events.VerifyListener)

sendKeyEvent

boolean sendKeyEvent(int type,
                   int msg,
                   int wParam,
                   int lParam,
                   Event event)

Overrides:

sendKeyEvent in class Widget

select

public void select(int index)

Selects the item at the given zero-relative index in the receiver's list. If the item at the index was already selected, it remains selected. Indices that are out of range are ignored.

Parameters:

index - the index of the item to select

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

setBackgroundImage

void setBackgroundImage(int hBitmap)

Overrides:

setBackgroundImage in class Control

setBackgroundPixel

void setBackgroundPixel(int pixel)

Overrides:

setBackgroundPixel in class Control

setBounds

void setBounds(int x,
             int y,
             int width,
             int height,
             int flags)

Overrides:

setBounds in class Control

setFont

public void setFont(Font font)

Description copied from class: Control

Sets the font that the receiver will use to paint textual information to the font specified by the argument, or to the default font for that kind of control if the argument is null.

Overrides:

setFont in class Control

Parameters:

font - the new font (or null)

setForegroundPixel

void setForegroundPixel(int pixel)

Overrides:

setForegroundPixel in class Control

setItem

public void setItem(int index,
           java.lang.String string)

Sets the text of the item in the receiver's list at the given zero-relative index to the string argument.

Parameters:

index - the index for the item

string - the new text for the item

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)
• ERROR_NULL_ARGUMENT - if the string is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

setItems

public void setItems(java.lang.String[] items)

Sets the receiver's list to be the given array of items.

Parameters:

items - the array of items

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the items array is null
• ERROR_INVALID_ARGUMENT - if an item in the items array is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

setOrientation

public void setOrientation(int orientation)

Sets the orientation of the receiver, which must be one of the constants SWT.LEFT_TO_RIGHT or SWT.RIGHT_TO_LEFT.

Overrides:

setOrientation in class Control

Parameters:

orientation - new orientation style

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

2.1.2

setScrollWidth

void setScrollWidth()

setScrollWidth

void setScrollWidth(int scrollWidth)

setScrollWidth

void setScrollWidth(TCHAR buffer,
                  boolean grow)

setScrollWidth

void setScrollWidth(int newWidth,
                  boolean grow)

setSelection

public void setSelection(Point selection)

Sets the selection in the receiver's text field to the range specified by the argument whose x coordinate is the start of the selection and whose y coordinate is the end of the selection.

Parameters:

selection - a point representing the new selection start and end

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the point is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

setText

public void setText(java.lang.String string)

Sets the contents of the receiver's text field to the given string.

This call is ignored when the receiver is read only and the given string is not in the receiver's list.

Note: The text field in a Combo is typically only capable of displaying a single line of text. Thus, setting the text to a string containing line breaks or other special characters will probably cause it to display incorrectly.

Parameters:

string - the new text

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the string is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

setTextLimit

public void setTextLimit(int limit)

Sets the maximum number of characters that the receiver's text field is capable of holding to be the argument.

To reset this value to the default, use setTextLimit(Combo.LIMIT). Specifying a limit value larger than Combo.LIMIT sets the receiver's limit to Combo.LIMIT.

Parameters:

limit - new text limit

Throws:

java.lang.IllegalArgumentException -

• ERROR_CANNOT_BE_ZERO - if the limit is zero

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

LIMIT

setToolTipText

void setToolTipText(Shell shell,
                  java.lang.String string)

Overrides:

setToolTipText in class Control

setVisibleItemCount

public void setVisibleItemCount(int count)

Sets the number of items that are visible in the drop down portion of the receiver's list.

Note: This operation is a hint and is not supported on platforms that do not have this concept.

Parameters:

count - the new number of items to be visible

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.0

subclass

void subclass()

Overrides:

subclass in class Control

translateTraversal

boolean translateTraversal(MSG msg)

Overrides:

translateTraversal in class Composite

traverseEscape

boolean traverseEscape()

Overrides:

traverseEscape in class Control

traverseReturn

boolean traverseReturn()

Overrides:

traverseReturn in class Control

unsubclass

void unsubclass()

Overrides:

unsubclass in class Control

updateDropDownHeight

void updateDropDownHeight()

updateOrientation

void updateOrientation()

Overrides:

updateOrientation in class Composite

verifyText

java.lang.String verifyText(java.lang.String string,
                          int start,
                          int end,
                          Event keyEvent)

wcsToMbcsPos

int wcsToMbcsPos(int wcsPos)

widgetExtStyle

int widgetExtStyle()

Overrides:

widgetExtStyle in class Scrollable

widgetStyle

int widgetStyle()

Overrides:

widgetStyle in class Composite

windowClass

TCHAR windowClass()

Overrides:

windowClass in class Scrollable

windowProc

int windowProc()

Overrides:

windowProc in class Scrollable

windowProc

int windowProc(int hwnd,
             int msg,
             int wParam,
             int lParam)

Overrides:

windowProc in class Control

WM_CTLCOLOR

LRESULT WM_CTLCOLOR(int wParam,
                  int lParam)

Overrides:

WM_CTLCOLOR in class Control

WM_GETDLGCODE

LRESULT WM_GETDLGCODE(int wParam,
                    int lParam)

Overrides:

WM_GETDLGCODE in class Composite

WM_KILLFOCUS

LRESULT WM_KILLFOCUS(int wParam,
                   int lParam)

Overrides:

WM_KILLFOCUS in class Control

WM_LBUTTONDOWN

LRESULT WM_LBUTTONDOWN(int wParam,
                     int lParam)

Overrides:

WM_LBUTTONDOWN in class Composite

WM_SETFOCUS

LRESULT WM_SETFOCUS(int wParam,
                  int lParam)

Overrides:

WM_SETFOCUS in class Control

WM_SIZE

LRESULT WM_SIZE(int wParam,
              int lParam)

Overrides:

WM_SIZE in class Composite

WM_UPDATEUISTATE

LRESULT WM_UPDATEUISTATE(int wParam,
                       int lParam)

Overrides:

WM_UPDATEUISTATE in class Composite

WM_WINDOWPOSCHANGING

LRESULT WM_WINDOWPOSCHANGING(int wParam,
                           int lParam)

Overrides:

WM_WINDOWPOSCHANGING in class Control

wmChar

LRESULT wmChar(int hwnd,
             int wParam,
             int lParam)

Overrides:

wmChar in class Widget

wmClipboard

LRESULT wmClipboard(int hwndText,
                  int msg,
                  int wParam,
                  int lParam)

wmCommandChild

LRESULT wmCommandChild(int wParam,
                     int lParam)

Overrides:

wmCommandChild in class Control

wmIMEChar

LRESULT wmIMEChar(int hwnd,
                int wParam,
                int lParam)

Overrides:

wmIMEChar in class Widget

wmKeyDown

LRESULT wmKeyDown(int hwnd,
                int wParam,
                int lParam)

Overrides:

wmKeyDown in class Widget

wmSysKeyDown

LRESULT wmSysKeyDown(int hwnd,
                   int wParam,
                   int lParam)

Overrides:

wmSysKeyDown in class Widget