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Chapter 19 java.awt Reference |
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CardLayout
Name
CardLayout
![[Graphic: Figure from the text]](./figs/cardlay.gif)
Description
The CardLayout LayoutManager provides the means to manage multiple components, displaying one at a time. Components are displayed in the order in which they are added to the layout, or in an arbitrary order by using an assignable name.
Class Definition
public class java.awt.CardLayout
extends java.lang.Object
implements java.awt.LayoutManager2, java.io.Serializable {
// Constructors
public CardLayout();
public CardLayout (int hgap, int vgap);
// Instance Methods
public void addLayoutComponent (Component comp,
Object constraints); 
public void addLayoutComponent (String name, Component component); 
public void first (Container parent);
public int getHgap();
public abstract float getLayoutAlignmentX(Container target);
public abstract float getLayoutAlignmentY(Container target);
public int getVgap();
public abstract void invalidateLayout(Container target);
public void last (Container parent);
public void layoutContainer (Container target);
public abstract Dimension maximumLayoutSize(Container target);
public Dimension minimumLayoutSize (Container target);
public void next (Container parent);
public Dimension preferredLayoutSize (Container target);
public void previous (Container parent);
public void removeLayoutComponent (Component component);
public void setHgap (int hgap);
public void setVgap (int vgap);
public void show (Container parent, String name);
public String toString();
}
Constructors
CardLayout
public CardLayout()
- Description
-
Constructs a CardLayout object.
public CardLayout (int hgap, int vgap)
- Parameters
-
- hgap
-
Horizontal space around left and right of container
- vgap
-
Vertical space around top and bottom of container
- hgap
- Description
-
Constructs a CardLayout object with the values specified as the gaps around the container managed by this instance of CardLayout.
Instance Methods
addLayoutComponent
public void addLayoutComponent (Component comp, Object constraints)
- Parameters
-
- comp
-
The component being added.
- constraints
-
An object describing the constraints on this component.
- comp
- Implements
-
LayoutManager2.addLayoutComponent()
- Description
-
Adds the component comp to a container subject to the given constraints. This is a more generalized version of addLayoutComponent(String, Component). It corresponds to java.awt.Container's add(Component, Object). In practice, it is used the same in Java 1.1 as in Java 1.0.2, except with the parameters swapped:
Panel p = new Panel(); p.setLayoutManager(new CardLayout()); p.add(new Button("OK"), "Don Julio");
addLayoutComponent
public void addLayoutComponent (String name, Component component)
- Parameters
-
- name
-
Name of the component to add.
- component
-
The actual component being added.
- name
- Implements
-
LayoutManager.addLayoutComponent()
- Description
-
Places component under the layout's management, assigning it the given name. This has been replaced in version 1.1 with the more general addLayoutComponent(Component, Object).
first
public void first (Container parent)
- Parameters
-
- parent
-
The container whose displayed component is changing.
- parent
- Throws
-
- IllegalArgumentException
-
If the LayoutManager of parent is not CardLayout.
- IllegalArgumentException
- Description
-
Sets the container to display the first component in parent.
getHgap
public int getHgap()
- Returns
-
The horizontal gap for this CardLayout instance.
getLayoutAlignmentX
public abstract float getLayoutAlignmentX (Container target)
- Parameters
-
- target
-
The container to inspect.
- target
- Returns
-
The value .5 for all containers.
- Description
-
This method returns the preferred alignment of the given container target. A return value of 0 is left aligned, .5 is centered, and 1 is right aligned.
getLayoutAlignmentY
public abstract float getLayoutAlignmentY (Container target)
- Parameters
-
- target
-
The container to inspect.
- target
- Returns
-
The value .5 for all containers.
- Description
-
This method returns the preferred alignment of the given container target. A return value of 0 is top aligned, .5 is centered, and 1 is bottom aligned.
getVgap
public int getVgap()
- Returns
-
The vertical gap for this CardLayout instance.
invalidateLayout
public abstract void invalidateLayout (Container target)
- Parameters
-
- target
-
The container to invalidate.
- target
- Description
-
Does nothing.
last
public void last (Container parent)
- Parameters
-
- parent
-
The container whose displayed component is changing.
- parent
- Throws
-
- IllegalArgumentException
-
If the LayoutManager of parent is not CardLayout.
- IllegalArgumentException
- Description
-
Sets the container to display the final component in parent.
layoutContainer
public void layoutContainer (Container target)
- Parameters
-
- target
-
The container that needs to be redrawn.
- target
- Implements
-
LayoutManager.layoutContainer()
- Description
-
Displays the currently selected component contained within target.
maximumLayoutSize
public abstract Dimension maximumLayoutSize (Container target)
- Parameters
-
- target
-
The container to inspect.
- target
- Returns
-
A Dimension whose horizontal and vertical components are Integer.MAX_VALUE.
- Description
-
For CardLayout, a maximal Dimension is always returned.
minimumLayoutSize
public Dimension minimumLayoutSize (Container target)
- Parameters
-
- target
-
The container whose size needs to be calculated.
- target
- Returns
-
Minimum Dimension of the container target.
- Implements
-
LayoutManager.minimumLayoutSize()
- Description
-
Calculates minimum size of the target container.
next
public void next (Container parent)
- Parameters
-
- parent
-
The container whose displayed component is changing.
- parent
- Throws
-
- IllegalArgumentException
-
If the LayoutManager of parent is not CardLayout.
- IllegalArgumentException
- Description
-
Sets the container to display the following component in the parent.
preferredLayoutSize
public Dimension preferredLayoutSize (Container target)
- Parameters
-
- target
-
The container whose size needs to be calculated.
- target
- Returns
-
Preferred Dimension of the container target.
- Implements
-
LayoutManager.preferredLayoutSize()
- Description
-
Calculates preferred size of the target container.
previous
public void previous (Container parent)
- Parameters
-
- parent
-
The container whose displayed component is changing.
- parent
- Throws
-
- IllegalArgumentException
-
If the LayoutManager of parent is not CardLayout.
- IllegalArgumentException
- Description
-
Sets the container to display the prior component in parent.
removeLayoutComponent
public void removeLayoutComponent (Component component)
- Parameters
-
- component
-
Component to stop tracking.
- component
- Implements
-
LayoutManager.removeLayoutComponent()
- Description
-
Removes component from the layout manager's internal tables.
setHgap
public void setHgap (int hgap)
- Parameters
-
- hgap
-
The horizontal gap value.
- hgap
- Description
-
Sets the horizontal gap for the left and right of the container.
setVgap
public void setVgap (int vgap)
- Parameters
-
- vgap
-
The vertical gap value.
- vgap
- Description
-
Sets the vertical gap for the top and bottom of the container.
show
public void show (Container parent, String name)
- Parameters
-
- parent
-
The container whose displayed component is changing.
- name
-
Name of component to display.
- parent
- Throws
-
- IllegalArgumentException
-
If LayoutManager of parent is not CardLayout.
- IllegalArgumentException
- Description
-
Sets the container to display the component name in parent.
toString
public String toString()
- Returns
-
A string representation of the CardLayout object.
- Overrides
-
Object.toString()
See Also
Component, Container, Dimension, LayoutManager, LayoutManager2, Object, String
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