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public  class  java.awt.Checkbox
    extends  java.awt.Component  (II-§1.10)
{
        // Constructors
    public Checkbox();	§1.5.1
    public Checkbox(String  label);	§1.5.2
    public Checkbox(String  label, CheckboxGroup  group,  §1.5.3
                                        boolean  state);

        // Methods
    public void addNotify();	§1.5.4
    public CheckboxGroup getCheckboxGroup();	§1.5.5
    public String getLabel();	§1.5.6
    public boolean getState();	§1.5.7
    protected String paramString();	§1.5.8
    public void setCheckboxGroup(CheckboxGroup  g);	§1.5.9
    public void setLabel(String  label);	§1.5.10
    public void setState(boolean  state);	§1.5.11
}

For example, the code:

setLayout(new GridLayout(3, 1));
add(new Checkbox("one", null, true));
add(new Checkbox("two"));
add(new Checkbox("three"));

produces the following three check boxes:

The button labelled one is "on". The other two are "off".

When the check box is clicked,¹ AWT sends an action event (II-§1.14.11) to the check box. This event's target is the check box, and its object is a Boolean (I-§1.1) giving the new state of the check box. An application should override the action method (II-§1.10.1) of the check box or of one of its containing windows in order to cause some action to occur.

Optionally, several checkboxes can be grouped together into a CheckboxGroup (II-§1.6). At most one button in a group can be in the "on" state at any given time. Pushing a check box to turn it "on" forces any other check box in the group that is "on" to become "off".

Creates a check box with no label. The check box is set to "off" and is not part of any check box group.

Creates a check box with the specified label. The check box is set to "off" and is not part of any check box group.

Parameters:

label - a string label for the check box, or null for no label.

Creates a check box with the specified label, in the specified check box group, and set to the specified state.

Parameters:

label - a string label for the check box, or null for no label

group - this check box's check box group, or null for no group

state - the initial state of the check box: true indicates "on"; false indicates "off"

This method calls the createCheckbox method (II-§1.41.5) of the check box's toolkit (II-§1.10.20) in order to create a CheckboxPeer (II-§3.4) for this button. This peer allows the application to change the look of a check box without changing its functionality.

Most applications do not call this method directly.

Overrides:

addNotify in class Component (II-§1.10.2).

Determines this check box's group.

Returns:

thischeck box's group, or null if it is not part of a check box group.

See Also:

setCheckboxGroup (II-§1.5.9).

Returns:

the label of this check box, or null if this check box has no label.

See Also:

setLabel (II-§1.5.10).

Determines if this check box is "on" or "off."

Returns:

the state of this check box. The value true indicates "on", false indicates "off".

See Also:

setState (II-§1.5.11).

Returns the parameter string representing the state of this check box. This string is useful for debugging.

Returns:

the parameter string of this check box.

Overrides:

paramString in class Component (II-§1.10.51).

Sets the group of this check box to be the specified check box group. If this check box is already in a different check box group, it is first taken out of that group.

Parameters:

g - the new check box group, or null to remove the check box from any check box group

See Also:

getCheckboxGroup (II-§1.5.5).

Sets this check box's label to be the string argument.

Parameters:

label - the new label, or null for no label

See Also:

getLabel (II-§1.5.6).

Sets this check box to the specifed boolean state: true indicates "on"; false indicates "off".

Parameters:

state - the boolean state of the check box.

See Also:

getState (II-§1.5.7).

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