Class Composite
- java.lang.Object
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- org.eclipse.swt.widgets.Widget
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- org.eclipse.swt.widgets.Control
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- org.eclipse.swt.widgets.Scrollable
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- org.eclipse.swt.widgets.Composite
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- Direct Known Subclasses:
Browser
,Canvas
,CBanner
,CCombo
,Combo
,CoolBar
,CTabFolder
,DateTime
,ExpandBar
,Grid
,Group
,RichTextEditor
,SashForm
,ScrolledComposite
,Spinner
,TabFolder
,Table
,ToolBar
,Tree
,ViewForm
public class Composite extends Scrollable
Instances of this class are controls which are capable of containing other controls.- Styles:
- NO_FOCUS, NO_RADIO_GROUP
- Events:
- (none)
This class may be subclassed by custom control implementors who are building controls that are constructed from aggregates of other controls.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
changed(Control[] changed)
Clears any data that has been cached by a Layout for all widgets that are in the parent hierarchy of the changed control up to and including the receiver.Point
computeSize(int wHint, int hHint, boolean changed)
Returns the preferred size of the receiver.<T> T
getAdapter(java.lang.Class<T> adapter)
Implementation of theAdaptable
interface.int
getBackgroundMode()
Returns the receiver's background drawing mode.Control[]
getChildren()
Returns a (possibly empty) array containing the receiver's children.Layout
getLayout()
Returns layout which is associated with the receiver, or null if one has not been set.boolean
getLayoutDeferred()
Returnstrue
if the receiver has deferred the performing of layout, andfalse
otherwise.Control[]
getTabList()
Gets the (possibly empty) tabbing order for the control.boolean
isLayoutDeferred()
Returnstrue
if the receiver or any ancestor up to and including the receiver's nearest ancestor shell has deferred the performing of layouts.void
layout()
If the receiver has a layout, asks the layout to lay out (that is, set the size and location of) the receiver's children.void
layout(boolean changed)
If the receiver has a layout, asks the layout to lay out (that is, set the size and location of) the receiver's children.void
layout(boolean changed, boolean all)
If the receiver has a layout, asks the layout to lay out (that is, set the size and location of) the receiver's children.void
layout(Control[] changed)
Forces a lay out (that is, sets the size and location) of all widgets that are in the parent hierarchy of the changed control up to and including the receiver.void
layout(Control[] changed, int flags)
Forces a lay out (that is, sets the size and location) of all widgets that are in the parent hierarchy of the changed control up to and including the receiver.void
setBackgroundMode(int mode)
Sets the background drawing mode to the argument which should be one of the following constants defined in classSWT
:INHERIT_NONE
,INHERIT_DEFAULT
,INHERIT_FORCE
.boolean
setFocus()
Causes the receiver to have the keyboard focus, such that all keyboard events will be delivered to it.void
setLayout(Layout layout)
Sets the layout which is associated with the receiver to be the argument which may be null.void
setLayoutDeferred(boolean defer)
If the argument istrue
, causes subsequent layout operations in the receiver or any of its children to be ignored.void
setTabList(Control[] tabList)
Sets the tabbing order for the specified controls to match the order that they occur in the argument list.-
Methods inherited from class org.eclipse.swt.widgets.Scrollable
computeTrim, getClientArea, getHorizontalBar, getVerticalBar
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Methods inherited from class org.eclipse.swt.widgets.Control
addControlListener, addDragDetectListener, addFocusListener, addGestureListener, addHelpListener, addKeyListener, addMenuDetectListener, addMouseListener, addTouchListener, addTraverseListener, computeSize, forceFocus, getAccessible, getBackground, getBackgroundImage, getBorderWidth, getBounds, getCursor, getEnabled, getFont, getForeground, getLayoutData, getLocation, getMenu, getMonitor, getOrientation, getParent, getShell, getSize, getToolTipText, getTouchEnabled, getVisible, isEnabled, isFocusControl, isReparentable, isVisible, moveAbove, moveBelow, pack, pack, redraw, redraw, removeControlListener, removeDragDetectListener, removeFocusListener, removeGestureListener, removeHelpListener, removeKeyListener, removeMenuDetectListener, removeMouseListener, removeTouchListener, removeTraverseListener, requestLayout, setBackground, setBackgroundImage, setBounds, setBounds, setCursor, setData, setEnabled, setFont, setForeground, setLayoutData, setLocation, setLocation, setMenu, setOrientation, setParent, setRedraw, setSize, setSize, setToolTipText, setTouchEnabled, setVisible, toControl, toControl, toDisplay, toDisplay, update
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Methods inherited from class org.eclipse.swt.widgets.Widget
addDisposeListener, addListener, checkSubclass, checkWidget, dispose, getData, getData, getDisplay, getListeners, getStyle, isDisposed, isListening, notifyListeners, removeDisposeListener, removeListener, removeListener, reskin, setData, toString
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Constructor Detail
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Composite
public Composite(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 theint
"|" operator) two or more of thoseSWT
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 widget which will be the parent of the new instance (cannot be null)style
- the style of widget 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
- See Also:
SWT.NO_FOCUS
,SWT.NO_RADIO_GROUP
,Widget.getStyle()
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Method Detail
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getChildren
public Control[] getChildren()
Returns a (possibly empty) array containing the receiver's children. Children are returned in the order that they are drawn. The topmost control appears at the beginning of the array. Subsequent controls draw beneath this control and appear later in the array.Note: This is not the actual structure used by the receiver to maintain its list of children, so modifying the array will not affect the receiver.
- Returns:
- an array of children
- 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:
Control.moveAbove(org.eclipse.swt.widgets.Control)
,Control.moveBelow(org.eclipse.swt.widgets.Control)
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getAdapter
public <T> T getAdapter(java.lang.Class<T> adapter)
Description copied from class:Widget
Implementation of theAdaptable
interface.IMPORTANT: This method is not part of the RWT public API. It is marked public only so that it can be shared within the packages provided by RWT. It should never be accessed from application code.
- Specified by:
getAdapter
in interfaceAdaptable
- Overrides:
getAdapter
in classControl
- Parameters:
adapter
- the lookup class- Returns:
- an object that can be cast to the given class or
null
if there is no adapter associated with the given class.
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setLayout
public void setLayout(Layout layout)
Sets the layout which is associated with the receiver to be the argument which may be null.- Parameters:
layout
- the receiver's new layout or null- 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
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getLayout
public Layout getLayout()
Returns layout which is associated with the receiver, or null if one has not been set.- Returns:
- the receiver's layout or null
- 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
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setLayoutDeferred
public void setLayoutDeferred(boolean defer)
If the argument istrue
, causes subsequent layout operations in the receiver or any of its children to be ignored. No layout of any kind can occur in the receiver or any of its children until the flag is set to false. Layout operations that occurred while the flag wastrue
are remembered and when the flag is set tofalse
, the layout operations are performed in an optimized manner. Nested calls to this method are stacked.- Parameters:
defer
- the new defer 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:
- 1.3
- See Also:
layout(boolean)
,layout(Control[])
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getLayoutDeferred
public boolean getLayoutDeferred()
Returnstrue
if the receiver has deferred the performing of layout, andfalse
otherwise.- Returns:
- the receiver's deferred layout 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
- See Also:
setLayoutDeferred(boolean)
,isLayoutDeferred()
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isLayoutDeferred
public boolean isLayoutDeferred()
Returnstrue
if the receiver or any ancestor up to and including the receiver's nearest ancestor shell has deferred the performing of layouts. Otherwise,false
is returned.- Returns:
- the receiver's deferred layout 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
- See Also:
setLayoutDeferred(boolean)
,getLayoutDeferred()
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layout
public void layout()
If the receiver has a layout, asks the layout to lay out (that is, set the size and location of) the receiver's children. If the receiver does not have a layout, do nothing.Use of this method is discouraged since it is the least-efficient way to trigger a layout. The use of
layout(true)
discards all cached layout information, even from controls which have not changed. It is much more efficient to invokeControl.requestLayout()
on every control which has changed in the layout than it is to invoke this method on the layout itself.This is equivalent to calling
layout(true)
.Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint.
- 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
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layout
public void layout(boolean changed)
If the receiver has a layout, asks the layout to lay out (that is, set the size and location of) the receiver's children. If the argument istrue
the layout must not rely on any information it has cached about the immediate children. If it isfalse
the layout may (potentially) optimize the work it is doing by assuming that none of the receiver's children has changed state since the last layout. If the receiver does not have a layout, do nothing.It is normally more efficient to invoke
Control.requestLayout()
on every control which has changed in the layout than it is to invoke this method on the layout itself. Clients are encouraged to useControl.requestLayout()
where possible instead of calling this method.If a child is resized as a result of a call to layout, the resize event will invoke the layout of the child. The layout will cascade down through all child widgets in the receiver's widget tree until a child is encountered that does not resize. Note that a layout due to a resize will not flush any cached information (same as
layout(false)
).Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint.
- Parameters:
changed
-true
if the layout must flush its caches, andfalse
otherwise- 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
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layout
public void layout(boolean changed, boolean all)
If the receiver has a layout, asks the layout to lay out (that is, set the size and location of) the receiver's children. If the changed argument istrue
the layout must not rely on any information it has cached about its children. If it isfalse
the layout may (potentially) optimize the work it is doing by assuming that none of the receiver's children has changed state since the last layout. If the all argument istrue
the layout will cascade down through all child widgets in the receiver's widget tree, regardless of whether the child has changed size. The changed argument is applied to all layouts. If the all argument isfalse
, the layout will not cascade down through all child widgets in the receiver's widget tree. However, if a child is resized as a result of a call to layout, the resize event will invoke the layout of the child. Note that a layout due to a resize will not flush any cached information (same aslayout(false)
).It is normally more efficient to invoke
Control.requestLayout()
on every control which has changed in the layout than it is to invoke this method on the layout itself. Clients are encouraged to useControl.requestLayout()
where possible instead of calling this method.Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint.
- Parameters:
changed
-true
if the layout must flush its caches, andfalse
otherwiseall
-true
if all children in the receiver's widget tree should be laid out, andfalse
otherwise- 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
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layout
public void layout(Control[] changed)
Forces a lay out (that is, sets the size and location) of all widgets that are in the parent hierarchy of the changed control up to and including the receiver. The layouts in the hierarchy must not rely on any information cached about the changed control or any of its ancestors. The layout may (potentially) optimize the work it is doing by assuming that none of the peers of the changed control have changed state since the last layout. If an ancestor does not have a layout, skip it.It is normally more efficient to invoke
Control.requestLayout()
on every control which has changed in the layout than it is to invoke this method on the layout itself. Clients are encouraged to useControl.requestLayout()
where possible instead of calling this method.Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint.
- Parameters:
changed
- a control that has had a state change which requires a recalculation of its size- Throws:
java.lang.IllegalArgumentException
-- ERROR_INVALID_ARGUMENT - if the changed array is null any of its controls are null or have been disposed
- ERROR_INVALID_PARENT - if any control in changed is not in the widget tree of the receiver
SWTException
-- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
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layout
public void layout(Control[] changed, int flags)
Forces a lay out (that is, sets the size and location) of all widgets that are in the parent hierarchy of the changed control up to and including the receiver.The parameter
flags
may be a combination of:- SWT.ALL
- all children in the receiver's widget tree should be laid out
- SWT.CHANGED
- the layout must flush its caches
- SWT.DEFER
- layout will be deferred
When the
changed
array is specified, the flagsSWT.ALL
andSWT.CHANGED
have no effect. In this case, the layouts in the hierarchy must not rely on any information cached about the changed control or any of its ancestors. The layout may (potentially) optimize the work it is doing by assuming that none of the peers of the changed control have changed state since the last layout. If an ancestor does not have a layout, skip it.When the
changed
array is not specified, the flagSWT.ALL
indicates that the whole widget tree should be laid out. And the flagSWT.CHANGED
indicates that the layouts should flush any cached information for all controls that are laid out.The
SWT.DEFER
flag always causes the layout to be deferred by callingComposite.setLayoutDeferred(true)
and scheduling a call toComposite.setLayoutDeferred(false)
, which will happen when appropriate (usually before the next event is handled). When this flag is set, the application should not callComposite.setLayoutDeferred()
.Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint.
- Parameters:
changed
- a control that has had a state change which requires a recalculation of its sizeflags
- the flags specifying how the layout should happen- Throws:
java.lang.IllegalArgumentException
-- ERROR_INVALID_ARGUMENT - if any of the controls in changed is null or has been disposed
- ERROR_INVALID_PARENT - if any control in changed is not in the widget tree of the receiver
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:
- 1.3
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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 befalse
, so layout manager caches can be retained.- Overrides:
computeSize
in classControl
- Parameters:
wHint
- the width hint (can beSWT.DEFAULT
)hHint
- the height hint (can beSWT.DEFAULT
)changed
-true
if the control's contents have changed, andfalse
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"
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changed
public void changed(Control[] changed)
Clears any data that has been cached by a Layout for all widgets that are in the parent hierarchy of the changed control up to and including the receiver. If an ancestor does not have a layout, it is skipped.- Parameters:
changed
- an array of controls that changed state and require a recalculation of size- Throws:
java.lang.IllegalArgumentException
-- ERROR_INVALID_ARGUMENT - if the changed array is null any of its controls are null or have been disposed
- ERROR_INVALID_PARENT - if any control in changed is not in the widget tree of the receiver
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:
- 1.0
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getBackgroundMode
public int getBackgroundMode()
Returns the receiver's background drawing mode. This will be one of the following constants defined in classSWT
:INHERIT_NONE
,INHERIT_DEFAULT
,INHERTIT_FORCE
.- Returns:
- the background mode
- 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:
- 1.1
- See Also:
SWT
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setBackgroundMode
public void setBackgroundMode(int mode)
Sets the background drawing mode to the argument which should be one of the following constants defined in classSWT
:INHERIT_NONE
,INHERIT_DEFAULT
,INHERIT_FORCE
.- Parameters:
mode
- the new background mode- 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:
- 1.1
- See Also:
SWT
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setFocus
public boolean setFocus()
Description copied from class:Control
Causes the receiver to have the keyboard focus, such that all keyboard events will be delivered to it. Focus reassignment will respect applicable platform constraints.- Overrides:
setFocus
in classControl
- Returns:
true
if the control got focus, andfalse
if it was unable to.- See Also:
Control.forceFocus()
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setTabList
public void setTabList(Control[] tabList)
Sets the tabbing order for the specified controls to match the order that they occur in the argument list.- Parameters:
tabList
- the ordered list of controls representing the tab order or null- Throws:
java.lang.IllegalArgumentException
-- ERROR_INVALID_ARGUMENT - if a widget in the tabList is null or has been disposed
- ERROR_INVALID_PARENT - if widget in the tabList is not in the same widget tree
SWTException
-- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
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getTabList
public Control[] getTabList()
Gets the (possibly empty) tabbing order for the control.- Returns:
- tabList the ordered list of controls representing the tab order
- 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:
setTabList(org.eclipse.swt.widgets.Control[])
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