GridLayout (Eclipse Remote Application Platform API Reference)

java.lang.Object
- org.eclipse.swt.widgets.Layout
- - org.eclipse.swt.layout.GridLayout

```
public final class GridLayout
extends Layout
```
Instances of this class lay out the control children of a Composite in a grid.
GridLayout has a number of configuration fields, and the controls it lays out can have an associated layout data object, called GridData. The power of GridLayout lies in the ability to configure GridData for each control in the layout.

The following code creates a shell managed by a GridLayout with 3 columns:
```
    Display display = new Display();
    Shell shell = new Shell(display);
    GridLayout gridLayout = new GridLayout();
    gridLayout.numColumns = 3;
    shell.setLayout(gridLayout);
 
```
The numColumns field is the most important field in a GridLayout. Widgets are laid out in columns from left to right, and a new row is created when numColumns + 1 controls are added to the Composite.
Since: 1.0 See Also: GridData, GridLayout snippets, SWT Example: LayoutExample, Sample code and further information










Field Summary

Fields 

Modifier and Type
Field and Description


int
horizontalSpacing
horizontalSpacing specifies the number of pixels between the right
 edge of one cell and the left edge of its neighbouring cell to
 the right.



boolean
makeColumnsEqualWidth
makeColumnsEqualWidth specifies whether all columns in the layout
 will be forced to have the same width.



int
marginBottom
marginBottom specifies the number of pixels of vertical margin
 that will be placed along the bottom edge of the layout.



int
marginHeight
marginHeight specifies the number of pixels of vertical margin
 that will be placed along the top and bottom edges of the layout.



int
marginLeft
marginLeft specifies the number of pixels of horizontal margin
 that will be placed along the left edge of the layout.



int
marginRight
marginRight specifies the number of pixels of horizontal margin
 that will be placed along the right edge of the layout.



int
marginTop
marginTop specifies the number of pixels of vertical margin
 that will be placed along the top edge of the layout.



int
marginWidth
marginWidth specifies the number of pixels of horizontal margin
 that will be placed along the left and right edges of the layout.



int
numColumns
numColumns specifies the number of cell columns in the layout.



int
verticalSpacing
verticalSpacing specifies the number of pixels between the bottom
 edge of one cell and the top edge of its neighbouring cell underneath.










Constructor Summary

Constructors 

Constructor and Description


GridLayout()
Constructs a new instance of this class
 with a single column.



GridLayout(int numColumns,
          boolean makeColumnsEqualWidth)
Constructs a new instance of this class given the
 number of columns, and whether or not the columns
 should be forced to have the same width.










Method Summary

Methods 

Modifier and Type
Method and Description


protected Point
computeSize(Composite composite,
           int wHint,
           int hHint,
           boolean flushCache)
Computes and returns the size of the specified composite's client area
 according to this layout.



protected boolean
flushCache(Control control)
Instruct the layout to flush any cached values
 associated with the control specified in the argument 
 control.



protected void
layout(Composite composite,
      boolean flushCache)
Lays out the children of the specified composite according to this
 layout.



java.lang.String
toString()
Returns a string containing a concise, human-readable
 description of the receiver.







Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait














Field Detail





numColumns
public int numColumns
numColumns specifies the number of cell columns in the layout.
 If numColumns has a value less than 1, the layout will not
 set the size and position of any controls.

 The default value is 1.







makeColumnsEqualWidth
public boolean makeColumnsEqualWidth
makeColumnsEqualWidth specifies whether all columns in the layout
 will be forced to have the same width.

 The default value is false.







marginWidth
public int marginWidth
marginWidth specifies the number of pixels of horizontal margin
 that will be placed along the left and right edges of the layout.

 The default value is 5.







marginHeight
public int marginHeight
marginHeight specifies the number of pixels of vertical margin
 that will be placed along the top and bottom edges of the layout.

 The default value is 5.







marginLeft
public int marginLeft
marginLeft specifies the number of pixels of horizontal margin
 that will be placed along the left edge of the layout.

 The default value is 0.







marginTop
public int marginTop
marginTop specifies the number of pixels of vertical margin
 that will be placed along the top edge of the layout.

 The default value is 0.







marginRight
public int marginRight
marginRight specifies the number of pixels of horizontal margin
 that will be placed along the right edge of the layout.

 The default value is 0.







marginBottom
public int marginBottom
marginBottom specifies the number of pixels of vertical margin
 that will be placed along the bottom edge of the layout.

 The default value is 0.







horizontalSpacing
public int horizontalSpacing
horizontalSpacing specifies the number of pixels between the right
 edge of one cell and the left edge of its neighbouring cell to
 the right.

 The default value is 5.







verticalSpacing
public int verticalSpacing
verticalSpacing specifies the number of pixels between the bottom
 edge of one cell and the top edge of its neighbouring cell underneath.

 The default value is 5.









Constructor Detail





GridLayout
public GridLayout()
Constructs a new instance of this class
 with a single column.







GridLayout
public GridLayout(int numColumns,
          boolean makeColumnsEqualWidth)
Constructs a new instance of this class given the
 number of columns, and whether or not the columns
 should be forced to have the same width.
 If numColumns has a value less than 1, the layout will not
 set the size and position of any controls.
Parameters:
numColumns - the number of columns in the grid
makeColumnsEqualWidth - whether or not the columns will have equal width









Method Detail





computeSize
protected Point computeSize(Composite composite,
                int wHint,
                int hHint,
                boolean flushCache)
Description copied from class: Layout
Computes and returns the size of the specified composite's client area
 according to this layout.
 
 This method computes the size that the client area of the composite must
 be in order to position all children at their preferred size inside the
 composite according to the layout algorithm encoded by this layout.
 
 
 When a width or height hint is supplied, it is used to constrain the
 result. For example, if a width hint is provided that is less than the
 width of the client area, the layout may choose to wrap and increase
 height, clip, overlap, or otherwise constrain the children.
 

Specified by:
computeSize in class Layout
Parameters:
composite - a composite widget using this layout
wHint - width (SWT.DEFAULT for preferred size)
hHint - height (SWT.DEFAULT for preferred size)
flushCache - true means flush cached layout values
Returns:
a point containing the computed size (width, height)
See Also:
Layout.layout(org.eclipse.swt.widgets.Composite, boolean), 
Control.getBorderWidth(), 
Control.getBounds(), 
Control.getSize(), 
Control.pack(boolean), 
"computeTrim, getClientArea for controls that implement them"







flushCache
protected boolean flushCache(Control control)
Description copied from class: Layout
Instruct the layout to flush any cached values
 associated with the control specified in the argument 
 control.

Overrides:
flushCache in class Layout
Parameters:
control - a control managed by this layout
Returns:
true if the Layout has flushed all cached information associated with control







layout
protected void layout(Composite composite,
          boolean flushCache)
Description copied from class: Layout
Lays out the children of the specified composite according to this
 layout.
 
 This method positions and sizes the children of a composite using the
 layout algorithm encoded by this layout. Children of the composite are
 positioned in the client area of the composite. The position of the
 composite is not altered by this method.
 
 
 When the flush cache hint is true, the layout is instructed to flush any
 cached values associated with the children. Typically, a layout will
 cache the preferred sizes of the children to avoid the expense of
 computing these values each time the widget is laid out.
 
 
 When layout is triggered explicitly by the programmer the flush cache
 hint is true. When layout is triggered by a resize, either caused by the
 programmer or by the user, the hint is false.
 

Specified by:
layout in class Layout
Parameters:
composite - a composite widget using this layout
flushCache - true means flush cached layout values







toString
public java.lang.String toString()
Returns a string containing a concise, human-readable
 description of the receiver.

Overrides:
toString in class java.lang.Object
Returns:
a string representation of the layout

Modifier and Type	Field and Description
`int`	`horizontalSpacing` horizontalSpacing specifies the number of pixels between the right edge of one cell and the left edge of its neighbouring cell to the right.
`boolean`	`makeColumnsEqualWidth` makeColumnsEqualWidth specifies whether all columns in the layout will be forced to have the same width.
`int`	`marginBottom` marginBottom specifies the number of pixels of vertical margin that will be placed along the bottom edge of the layout.
`int`	`marginHeight` marginHeight specifies the number of pixels of vertical margin that will be placed along the top and bottom edges of the layout.
`int`	`marginLeft` marginLeft specifies the number of pixels of horizontal margin that will be placed along the left edge of the layout.
`int`	`marginRight` marginRight specifies the number of pixels of horizontal margin that will be placed along the right edge of the layout.
`int`	`marginTop` marginTop specifies the number of pixels of vertical margin that will be placed along the top edge of the layout.
`int`	`marginWidth` marginWidth specifies the number of pixels of horizontal margin that will be placed along the left and right edges of the layout.
`int`	`numColumns` numColumns specifies the number of cell columns in the layout.
`int`	`verticalSpacing` verticalSpacing specifies the number of pixels between the bottom edge of one cell and the top edge of its neighbouring cell underneath.

Modifier and Type	Method and Description
`protected Point`	`computeSize(Composite composite, int wHint, int hHint, boolean flushCache)` Computes and returns the size of the specified composite's client area according to this layout.
`protected boolean`	`flushCache(Control control)` Instruct the layout to flush any cached values associated with the control specified in the argument `control`.
`protected void`	`layout(Composite composite, boolean flushCache)` Lays out the children of the specified composite according to this layout.
`java.lang.String`	`toString()` Returns a string containing a concise, human-readable description of the receiver.

Class GridLayout

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

numColumns

makeColumnsEqualWidth

marginWidth

marginHeight

marginLeft

marginTop

marginRight

marginBottom

horizontalSpacing

verticalSpacing

Constructor Detail

GridLayout

GridLayout

Method Detail

computeSize

flushCache

layout

toString