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java.lang.Object | +----multilizer.BidiGridBagLayout
BidiGridBagLayout
class is a flexible layout
manager that aligns components vertically and horizontally,
without requiring that the components be of the same size.
Each BidiGridBagLayout
object maintains a dynamic
rectangular grid of cells, with each component occupying
one or more cells, called its display area.
Each component managed by a grid bag layout is associated
with an instance of
BidiGridBagConstraints
that specifies how the component is laid out within its display area.
How a BidiGridBagLayout
object places a set of components
depends on the BidiGridBagConstraints
object associated
with each component, and on the minimum size
and the preferred size of the components' containers.
To use a grid bag layout effectively, you must customize one or more
of the BidiGridBagConstraints
objects that are associated
with its components. You customize a BidiGridBagConstraints
object by setting one or more of its instance variables:
gridx
,
gridy
gridx = 0
,
gridy = 0
.
Use BidiGridBagConstraints.RELATIVE
(the default value)
to specify that the component be just placed
just to the right of (for gridx
)
or just below (for gridy
)
the component that was added to the container
just before this component was added.
gridwidth
,
gridheight
gridwidth
)
or column (for gridheight
)
in the component's display area.
The default value is 1.
Use BidiGridBagConstraints.REMAINDER
to specify
that the component be the last one in its row (for gridwidth
)
or column (for gridheight
).
Use BidiGridBagConstraints.RELATIVE
to specify
that the component be the next to last one
in its row (for gridwidth
)
or column (for gridheight
).
fill
BidiGridBagConstraints.NONE
(the default),
BidiGridBagConstraints.HORIZONTAL
(make the component wide enough to fill its display area
horizontally, but don't change its height),
BidiGridBagConstraints.VERTICAL
(make the component tall enough to fill its display area
vertically, but don't change its width), and
BidiGridBagConstraints.BOTH
(make the component fill its display area entirely).
ipadx
,
ipady
(ipadx * 2)
pixels (since the padding
applies to both sides of the component). Similarly, the height of
the component will be at least the minimum height plus
(ipady * 2)
pixels.
insets
anchor
BidiGridBagConstraints.CENTER
(the default),
BidiGridBagConstraints.NORTH
,
BidiGridBagConstraints.NORTHEAST
,
BidiGridBagConstraints.EAST
,
BidiGridBagConstraints.SOUTHEAST
,
BidiGridBagConstraints.SOUTH
,
BidiGridBagConstraints.SOUTHWEST
,
BidiGridBagConstraints.WEST
, and
BidiGridBagConstraints.NORTHWEST
.
weightx
,
weighty
weightx
) and column (weighty
),
all the components clump together in the center of their container.
This is because when the weight is zero (the default),
the BidiGridBagLayout
object puts any extra space
between its grid of cells and the edges of the container.
The following figure shows ten components (all buttons) managed by a grid bag layout:
Each of the ten components has the fill
field
of its associated BidiGridBagConstraints
object
set to GridBagConstraints.BOTH
.
In addition, the components have the following non-default constraints:
weightx = 1.0
weightx = 1.0
,
gridwidth = BidiGridBagConstraints.REMAINDER
gridwidth = BidiGridBagConstraints.REMAINDER
gridwidth = BidiGridBagConstraints.RELATIVE
gridwidth = BidiGridBagConstraints.REMAINDER
gridheight = 2
,
weighty = 1.0
gridwidth = BidiGridBagConstraints.REMAINDER
Here is the code that implements the example shown above:
import java.awt.*; import java.util.*; import java.applet.Applet; public class BidiGridBagEx1 extends Applet { protected void makebutton( String name, BidiGridBagLayout gridbag, BidiGridBagConstraints c) { Button button = new Button(name); gridbag.setConstraints(button, c); add(button); } public void init() { BidiGridBagLayout gridbag = new BidiGridBagLayout(); BidiGridBagConstraints c = new BidiGridBagConstraints(); setFont(new Font("Helvetica", Font.PLAIN, 14)); setLayout(gridbag); c.fill = BidiGridBagConstraints.BOTH; c.weightx = 1.0; makebutton("Button1", gridbag, c); makebutton("Button2", gridbag, c); makebutton("Button3", gridbag, c); c.gridwidth = BidiGridBagConstraints.REMAINDER; //end row makebutton("Button4", gridbag, c); c.weightx = 0.0; //reset to the default makebutton("Button5", gridbag, c); //another row c.gridwidth = BidiGridBagConstraints.RELATIVE; //next-to-last in row makebutton("Button6", gridbag, c); c.gridwidth = BidiGridBagConstraints.REMAINDER; //end row makebutton("Button7", gridbag, c); c.gridwidth = 1; //reset to the default c.gridheight = 2; c.weighty = 1.0; makebutton("Button8", gridbag, c); c.weighty = 0.0; //reset to the default c.gridwidth = BidiGridBagConstraints.REMAINDER; //end row c.gridheight = 1; //reset to the default makebutton("Button9", gridbag, c); makebutton("Button10", gridbag, c); setSize(300, 100); } public static void main(String args[]) { Frame f = new Frame("Bidirectional GridBag Layout Example"); BidiGridBagEx1 ex1 = new BidiGridBagEx1(); ex1.init(); f.add("Center", ex1); f.pack(); f.setSize(f.getPreferredSize()); f.show(); } }
(x, y)
.
target
container
using this grid bag layout.
target
container using this grid bag layout.
protected static final int MAXGRIDSIZE
protected static final int MINSIZE
protected static final int PREFERREDSIZE
protected Hashtable comptable
protected BidiGridBagConstraints defaultConstraints
protected BidiGridBagLayoutInfo layoutInfo
protected boolean leftToRight
public int columnWidths[]
public int rowHeights[]
public double columnWeights[]
public double rowWeights[]
public BidiGridBagLayout()
public void mirror(Container container)
public void setConstraints(Component comp, BidiGridBagConstraints constraints)
public BidiGridBagConstraints getConstraints(Component comp)
BidiGridBagConstraints
object is returned.
protected BidiGridBagConstraints lookupConstraints(Component comp)
BidiGridBagConstraints
object used by the layout mechanism.
public Point getLayoutOrigin()
public int[][] getLayoutDimensions()
Most applications do not call this method directly.
public double[][] getLayoutWeights()
Most applications do not call this method directly.
public Point location(int x, int y)
(x, y)
. Each cell is identified
by its column index (ranging from 0 to the number of columns
minus 1) and its row index (ranging from 0 to the number of
rows minus 1).
If the (x, y)
point lies
outside the grid, the following rules are used.
The column index is returned as zero if x
lies to the
left of the layout, and as the number of columns if x
lies
to the right of the layout. The row index is returned as zero
if y
lies above the layout,
and as the number of rows if y
lies
below the layout.
public void addLayoutComponent(String name, Component comp)
public void addLayoutComponent(Component comp, Object constraints)
public void removeLayoutComponent(Component comp)
Most applications do not call this method directly.
public Dimension preferredLayoutSize(Container parent)
target
container using this grid bag layout.
Most applications do not call this method directly.
public Dimension minimumLayoutSize(Container parent)
target
container
using this grid bag layout.
Most applications do not call this method directly.
public Dimension maximumLayoutSize(Container target)
public float getLayoutAlignmentX(Container parent)
public float getLayoutAlignmentY(Container parent)
public void invalidateLayout(Container target)
public void layoutContainer(Container parent)
GridBagLayout
object.
Most applications do not call this method directly.
public String toString()
protected BidiGridBagLayoutInfo GetLayoutInfo(Container parent, int sizeflag)
protected void AdjustForGravity(BidiGridBagConstraints constraints, Rectangle r)
protected Dimension GetMinSize(Container parent, BidiGridBagLayoutInfo info)
protected void ArrangeGrid(Container parent)
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