com.trolltech.qt.gui
Class QSpacerItem

java.lang.Object
  extended by com.trolltech.qt.internal.QSignalEmitterInternal
      extended by com.trolltech.qt.QSignalEmitter
          extended by com.trolltech.qt.QtJambiObject
              extended by com.trolltech.qt.gui.QSpacerItem
All Implemented Interfaces:
QLayoutItemInterface, QtJambiInterface

public class QSpacerItem
extends QtJambiObject
implements QLayoutItemInterface

The QSpacerItem class provides blank space in a layout. Normally, you don't need to use this class directly. Qt's built-in layout managers provide the following functions for manipulating empty space in layouts:

Class
Functions
QHBoxLayout addSpacing(), addStretch(), insertSpacing(), insertStretch()
QGridLayout setRowMinimumHeight(), setRowStretch(), setColumnMinimumWidth(), setColumnStretch()

See also:
QLayout, QWidgetItem, and QLayoutItem::spacerItem().


Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.PrivateSignal0, QSignalEmitter.PrivateSignal1, QSignalEmitter.PrivateSignal2, QSignalEmitter.PrivateSignal3, QSignalEmitter.PrivateSignal4, QSignalEmitter.PrivateSignal5, QSignalEmitter.PrivateSignal6, QSignalEmitter.PrivateSignal7, QSignalEmitter.PrivateSignal8, QSignalEmitter.PrivateSignal9, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9
 
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal
 
Field Summary
 
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
currentSender
 
Constructor Summary
QSpacerItem(int w, int h)
          Constructs a spacer item with preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.
QSpacerItem(int w, int h, QSizePolicy.Policy hData)
          Constructs a spacer item with preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.
QSpacerItem(int w, int h, QSizePolicy.Policy hData, QSizePolicy.Policy vData)
          Constructs a spacer item with preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.
 
Method Summary
 Qt.Alignment alignment()
          Returns the alignment of this item.
 void changeSize(int w, int h)
          Changes this spacer item to have preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.
 void changeSize(int w, int h, QSizePolicy.Policy hData)
          Changes this spacer item to have preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.
 void changeSize(int w, int h, QSizePolicy.Policy hData, QSizePolicy.Policy vData)
          Changes this spacer item to have preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.
 QSizePolicy.ControlTypes controlTypes()
          Returns the control type(s) for the layout item.
 Qt.Orientations expandingDirections()
          Returns whether this layout item can make use of more space than sizeHint().
 QRect geometry()
          Returns the rectangle covered by this layout item.
 boolean hasHeightForWidth()
          Returns true if this layout's preferred height depends on its width; otherwise returns false.
 int heightForWidth(int arg__1)
          Returns the preferred height for this layout item, given the width w.
 void invalidate()
          Invalidates any cached information in this layout item.
 boolean isEmpty()
          Implemented in subclasses to return whether this item is empty, i.e.
 QLayout layout()
          If this item is a QLayout, it is returned as a QLayout; otherwise 0 is returned.
 QSize maximumSize()
          Implemented in subclasses to return the maximum size of this item.
 int minimumHeightForWidth(int arg__1)
          Returns the minimum height this widget needs for the given width, w.
 QSize minimumSize()
          Implemented in subclasses to return the minimum size of this item.
 void setAlignment(Qt.Alignment a)
          Sets the alignment of this item to alignment.
 void setGeometry(QRect arg__1)
          Implemented in subclasses to set this item's geometry to r.
 QSize sizeHint()
          Implemented in subclasses to return the preferred size of this item.
 QSpacerItem spacerItem()
          If this item is a QSpacerItem, it is returned as a QSpacerItem; otherwise 0 is returned.
 QWidget widget()
          If this item is a QWidget, it is returned as a QWidget; otherwise 0 is returned.
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
__qt_signalInitialization
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QSpacerItem

public QSpacerItem(int w,
                   int h,
                   QSizePolicy.Policy hData)
Constructs a spacer item with preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.

The default values provide a gap that is able to stretch if nothing else wants the space.


QSpacerItem

public QSpacerItem(int w,
                   int h)
Constructs a spacer item with preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.

The default values provide a gap that is able to stretch if nothing else wants the space.


QSpacerItem

public QSpacerItem(int w,
                   int h,
                   QSizePolicy.Policy hData,
                   QSizePolicy.Policy vData)
Constructs a spacer item with preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.

The default values provide a gap that is able to stretch if nothing else wants the space.

Method Detail

alignment

public final Qt.Alignment alignment()
Returns the alignment of this item.

See also:
setAlignment().

Specified by:
alignment in interface QLayoutItemInterface

changeSize

public final void changeSize(int w,
                             int h,
                             QSizePolicy.Policy hData)
Changes this spacer item to have preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.

The default values provide a gap that is able to stretch if nothing else wants the space.

Note that if changeSize() is called after the spacer item has been added to a layout, it is necessary to invalidate the layout in order for the spacer item's new size to take effect.

See also:
QSpacerItem::invalidate().


changeSize

public final void changeSize(int w,
                             int h)
Changes this spacer item to have preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.

The default values provide a gap that is able to stretch if nothing else wants the space.

Note that if changeSize() is called after the spacer item has been added to a layout, it is necessary to invalidate the layout in order for the spacer item's new size to take effect.

See also:
QSpacerItem::invalidate().


changeSize

public final void changeSize(int w,
                             int h,
                             QSizePolicy.Policy hData,
                             QSizePolicy.Policy vData)
Changes this spacer item to have preferred width w, preferred height h, horizontal size policy hPolicy and vertical size policy vPolicy.

The default values provide a gap that is able to stretch if nothing else wants the space.

Note that if changeSize() is called after the spacer item has been added to a layout, it is necessary to invalidate the layout in order for the spacer item's new size to take effect.

See also:
QSpacerItem::invalidate().


controlTypes

public final QSizePolicy.ControlTypes controlTypes()
Returns the control type(s) for the layout item. For a QWidgetItem, the control type comes from the widget's size policy; for a QLayoutItem, the control types is derived from the layout's contents.

See also:
QSizePolicy::controlType().

Specified by:
controlTypes in interface QLayoutItemInterface

setAlignment

public final void setAlignment(Qt.Alignment a)
Sets the alignment of this item to alignment.

Note: Item alignment is only supported by QLayoutItem subclasses where it would have a visual effect. Except for QSpacerItem, which provides blank space for layouts, all public Qt classes that inherit QLayoutItem support item alignment.

See also:
alignment().

Specified by:
setAlignment in interface QLayoutItemInterface

expandingDirections

public Qt.Orientations expandingDirections()
Returns whether this layout item can make use of more space than sizeHint(). A value of Qt::Vertical or Qt::Horizontal means that it wants to grow in only one dimension, whereas Qt::Vertical | Qt::Horizontal means that it wants to grow in both dimensions.

Specified by:
expandingDirections in interface QLayoutItemInterface

geometry

public QRect geometry()
Returns the rectangle covered by this layout item.

See also:
setGeometry().

Specified by:
geometry in interface QLayoutItemInterface

hasHeightForWidth

public boolean hasHeightForWidth()
Returns true if this layout's preferred height depends on its width; otherwise returns false. The default implementation returns false.

Reimplement this function in layout managers that support height for width.

See also:
heightForWidth(), and QWidget::heightForWidth().

Specified by:
hasHeightForWidth in interface QLayoutItemInterface

heightForWidth

public int heightForWidth(int arg__1)
Returns the preferred height for this layout item, given the width w.

The default implementation returns -1, indicating that the preferred height is independent of the width of the item. Using the function hasHeightForWidth() will typically be much faster than calling this function and testing for -1.

Reimplement this function in layout managers that support height for width. A typical implementation will look like this:

    public int heightForWidth(int w)
    {
        if (cache_dirty || cached_width != w) {
            int h = calculateHeightForWidth(w);
            cached_hfw = h;
            return h;
        }
        return cached_hfw;
    }
Caching is strongly recommended; without it layout will take exponential time.

See also:
hasHeightForWidth().

Specified by:
heightForWidth in interface QLayoutItemInterface

invalidate

public void invalidate()
Invalidates any cached information in this layout item.

Specified by:
invalidate in interface QLayoutItemInterface

isEmpty

public boolean isEmpty()
Implemented in subclasses to return whether this item is empty, i.e. whether it contains any widgets.

Specified by:
isEmpty in interface QLayoutItemInterface

layout

public QLayout layout()
If this item is a QLayout, it is returned as a QLayout; otherwise 0 is returned. This function provides type-safe casting.

Specified by:
layout in interface QLayoutItemInterface

maximumSize

public QSize maximumSize()
Implemented in subclasses to return the maximum size of this item.

Specified by:
maximumSize in interface QLayoutItemInterface

minimumHeightForWidth

public int minimumHeightForWidth(int arg__1)
Returns the minimum height this widget needs for the given width, w. The default implementation simply returns heightForWidth(w).

Specified by:
minimumHeightForWidth in interface QLayoutItemInterface

minimumSize

public QSize minimumSize()
Implemented in subclasses to return the minimum size of this item.

Specified by:
minimumSize in interface QLayoutItemInterface

setGeometry

public void setGeometry(QRect arg__1)
Implemented in subclasses to set this item's geometry to r.

See also:
geometry().

Specified by:
setGeometry in interface QLayoutItemInterface

sizeHint

public QSize sizeHint()
Implemented in subclasses to return the preferred size of this item.

Specified by:
sizeHint in interface QLayoutItemInterface

spacerItem

public QSpacerItem spacerItem()
If this item is a QSpacerItem, it is returned as a QSpacerItem; otherwise 0 is returned. This function provides type-safe casting.

Specified by:
spacerItem in interface QLayoutItemInterface

widget

public QWidget widget()
If this item is a QWidget, it is returned as a QWidget; otherwise 0 is returned. This function provides type-safe casting.

Specified by:
widget in interface QLayoutItemInterface