public final class ColumnLayout extends Layout implements ILayoutExtension
In addition, the layout attempts to 'fill the space' equally i.e. to avoid large gaps at the and of the last column.
Child controls are layed out according to their 'natural' (preferred) size. For 'stretchy' controls that do not have natural preferred size, it is possible to set width and/or height hints using ColumnLayoutData objects.
ColumnLayoutData
Modifier and Type | Field and Description |
---|---|
int |
bottomMargin
Bottom margin (default is 5).
|
int |
horizontalSpacing
Horizontal spacing between columns (default is 5).
|
int |
leftMargin
Left margin (default is 5).
|
int |
maxNumColumns
Maximum number of columns (default is 3).
|
int |
minNumColumns
Minimum number of columns (default is 1).
|
int |
rightMargin
Right margin (default is 5).
|
int |
topMargin
Top margin (default is 5).
|
int |
verticalSpacing
Vertical spacing between controls (default is 5).
|
Constructor and Description |
---|
ColumnLayout()
Creates a new instance of the column layout.
|
Modifier and Type | Method and Description |
---|---|
int |
computeMaximumWidth(Composite parent,
boolean changed)
Computes the maximum width of the parent.
|
int |
computeMinimumWidth(Composite parent,
boolean changed)
Computes the minimum width of the parent.
|
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 void |
layout(Composite parent,
boolean flushCache)
Lays out the children of the specified composite
according to this layout.
|
flushCache
public int minNumColumns
public int maxNumColumns
public int horizontalSpacing
public int verticalSpacing
public int topMargin
public int leftMargin
public int bottomMargin
public int rightMargin
protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache)
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.
computeSize
in class Layout
composite
- a composite widget using this layoutwHint
- width (SWT.DEFAULT
for preferred size)hHint
- height (SWT.DEFAULT
for preferred size)flushCache
- true
means flush cached layout valuesLayout.layout(org.eclipse.swt.widgets.Composite, boolean)
,
Control.getBorderWidth()
,
Control.getBounds()
,
Control.getSize()
,
Control.pack(boolean)
,
"computeTrim, getClientArea for controls that implement them"protected void layout(Composite parent, boolean flushCache)
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.
public int computeMaximumWidth(Composite parent, boolean changed)
ILayoutExtension
computeMaximumWidth
in interface ILayoutExtension
parent
- the parent compositechanged
- true
if the cached information
should be flushed, false
otherwise.public int computeMinimumWidth(Composite parent, boolean changed)
ILayoutExtension
computeMinimumWidth
in interface ILayoutExtension
parent
- the parent compositechanged
- true
if the cached information should be
flushed, false
otherwise.
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