public class Composite extends Scrollable
This class may be subclassed by custom control implementors who are building controls that are constructed from aggregates of other controls.
Constructor and Description |
---|
Composite(Composite parent,
int style)
Constructs a new instance of this class given its parent
and a style value describing its behavior and appearance.
|
Modifier and Type | Method and 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 the
Adaptable 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()
Returns
true if the receiver has deferred
the performing of layout, and false otherwise. |
Control[] |
getTabList()
Gets the (possibly empty) tabbing order for the control.
|
boolean |
isLayoutDeferred()
Returns
true 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 class
SWT :
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 is
true , 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.
|
computeTrim, getClientArea, getHorizontalBar, getVerticalBar
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
addDisposeListener, addListener, checkSubclass, checkWidget, dispose, getData, getData, getDisplay, getListeners, getStyle, isDisposed, isListening, notifyListeners, removeDisposeListener, removeListener, removeListener, reskin, setData, toString
public Composite(Composite parent, int style)
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.
parent
- a widget which will be the parent of the new instance (cannot be null)style
- the style of widget to constructjava.lang.IllegalArgumentException
- SWTException
- SWT.NO_FOCUS
,
SWT.NO_RADIO_GROUP
,
Widget.getStyle()
public Control[] getChildren()
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.
SWTException
- Control.moveAbove(org.eclipse.swt.widgets.Control)
,
Control.moveBelow(org.eclipse.swt.widgets.Control)
public <T> T getAdapter(java.lang.Class<T> adapter)
Widget
Adaptable
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.
getAdapter
in interface Adaptable
getAdapter
in class Control
adapter
- the lookup classnull
if
there is no adapter associated with the given class.public void setLayout(Layout layout)
layout
- the receiver's new layout or nullSWTException
- public Layout getLayout()
SWTException
- public void setLayoutDeferred(boolean defer)
true
, 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 was
true
are remembered and when the flag is set to
false
, the layout operations are performed in an
optimized manner. Nested calls to this method are stacked.defer
- the new defer stateSWTException
- layout(boolean)
,
layout(Control[])
public boolean getLayoutDeferred()
true
if the receiver has deferred
the performing of layout, and false
otherwise.SWTException
- setLayoutDeferred(boolean)
,
isLayoutDeferred()
public boolean isLayoutDeferred()
true
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.SWTException
- setLayoutDeferred(boolean)
,
getLayoutDeferred()
public void layout()
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 invoke
Control.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.
SWTException
- public void layout(boolean changed)
true
the layout must not rely
on any information it has cached about the immediate children. If it
is false
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 use
Control.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.
changed
- true
if the layout must flush its caches, and false
otherwiseSWTException
- public void layout(boolean changed, boolean all)
true
the layout must not rely
on any information it has cached about its children. If it
is false
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 is true
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 is false
, 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 as layout(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 use
Control.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.
changed
- true
if the layout must flush its caches, and false
otherwiseall
- true
if all children in the receiver's widget tree should be laid out, and false
otherwiseSWTException
- public void layout(Control[] changed)
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 use
Control.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.
changed
- a control that has had a state change which requires a recalculation of its sizejava.lang.IllegalArgumentException
- SWTException
- public void layout(Control[] changed, int flags)
The parameter flags
may be a combination of:
When the changed
array is specified, the flags SWT.ALL
and SWT.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 flag SWT.ALL
indicates that the whole widget tree should be laid out. And the flag
SWT.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
calling Composite.setLayoutDeferred(true)
and scheduling a call
to Composite.setLayoutDeferred(false)
, which will happen when
appropriate (usually before the next event is handled). When this flag is set,
the application should not call Composite.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.
changed
- a control that has had a state change which requires a recalculation of its sizeflags
- the flags specifying how the layout should happenjava.lang.IllegalArgumentException
- SWTException
- public Point computeSize(int wHint, int hHint, boolean changed)
Control
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.
computeSize
in class Control
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
otherwiseLayout
,
Control.getBorderWidth()
,
Control.getBounds()
,
Control.getSize()
,
Control.pack(boolean)
,
"computeTrim, getClientArea for controls that implement them"public void changed(Control[] changed)
changed
- an array of controls that changed state and require a recalculation of sizejava.lang.IllegalArgumentException
- SWTException
- public int getBackgroundMode()
SWT
:
INHERIT_NONE
, INHERIT_DEFAULT
,
INHERTIT_FORCE
.SWTException
- SWT
public void setBackgroundMode(int mode)
SWT
:
INHERIT_NONE
, INHERIT_DEFAULT
,
INHERIT_FORCE
.mode
- the new background modeSWTException
- SWT
public boolean setFocus()
Control
setFocus
in class Control
true
if the control got focus, and false
if it was unable to.Control.forceFocus()
public void setTabList(Control[] tabList)
tabList
- the ordered list of controls representing the tab order or nulljava.lang.IllegalArgumentException
- SWTException
- public Control[] getTabList()
SWTException
- setTabList(org.eclipse.swt.widgets.Control[])
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are made available under the terms of the
Eclipse Public License v1.0