org.openide.util

Class HelpCtx

java.lang.Object

org.openide.util.HelpCtx

public final class HelpCtx
extends Object

Provides help for any window or other feature in the system. It is designed to be JavaHelp-compatible and to use the same tactics when assigning help to JComponent instances.

See Also:

JavaHelp Integration API

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	HelpCtx.Displayer Service to display a HelpCtx in a help viewer.
static interface	HelpCtx.Provider An object implementing this interface is willing to answer the HelpCtx.findHelp() query itself.

Field Summary

Fields

Modifier and Type	Field and Description
static HelpCtx	DEFAULT_HELP Default help page.

Constructor Summary

Constructors

Constructor and Description
HelpCtx(Class<?> clazz) Deprecated. Too easily breaks IDs after code refactoring. Rather use HelpCtx.HelpCtx(String) with a constant value known to be in the JavaHelp map.
HelpCtx(String helpID) Create a help context by tag.
HelpCtx(URL helpCtx) Deprecated. Does not work nicely with JavaHelp.

Method Summary

Modifier and Type	Method and Description
boolean	display() Displays the help page in a supported viewer, if any.
boolean	equals(Object obj)
static HelpCtx	findHelp(Component comp) Find the help ID for a component.
static HelpCtx	findHelp(Object instance) Finds help context for a generic object.
URL	getHelp() Get a URL to the help page, if applicable.
String	getHelpID() Get the ID of the help page, if applicable.
int	hashCode()
static void	setHelpIDString(JComponent comp, String helpID) Set the help ID for a component.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_HELP

public static final HelpCtx DEFAULT_HELP

Default help page. This (hopefully) points to a note explaining to the user that no help is available. Precisely, the Help ID is set to org.openide.util.HelpCtx.DEFAULT_HELP.

Constructor Detail

HelpCtx

@Deprecated
public HelpCtx(URL helpCtx)

Deprecated. Does not work nicely with JavaHelp.

Create a help context by URL.

Parameters:

helpCtx - URL to point help to

HelpCtx

public HelpCtx(String helpID)

Create a help context by tag. You must provide an ID of the desired help for the item. The ID should refer to an already installed help; this can be easily installed by specifying a JavaHelp help set for the module (see the JavaHelp API for details).

Parameters:

helpID - the JavaHelp ID of the help

HelpCtx

@Deprecated
public HelpCtx(Class<?> clazz)

Deprecated. Too easily breaks IDs after code refactoring. Rather use HelpCtx.HelpCtx(String) with a constant value known to be in the JavaHelp map.

Create a help context by class. Assigns the name of a class as the ID.

Parameters:

clazz - the class to take the name from

Method Detail

getHelp

public URL getHelp()

Get a URL to the help page, if applicable.

Returns:

a URL to the page, or null if the target was specified by ID

getHelpID

public String getHelpID()

Get the ID of the help page, if applicable.

Returns:

the JavaHelp ID string, or null if specified by URL

display

public boolean display()

Displays the help page in a supported viewer, if any.

Returns:

true if this help was displayed successfully

Since:

8.21

See Also:

HelpCtx.Displayer.display(org.openide.util.HelpCtx)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

setHelpIDString

public static void setHelpIDString(JComponent comp,
                                   String helpID)

Set the help ID for a component.

Parameters:

comp - the visual component to associate help to

helpID - help ID, or null if the help ID should be removed

findHelp

public static HelpCtx findHelp(Component comp)

Find the help ID for a component. If the component implements HelpCtx.Provider, its method HelpCtx.Provider.getHelpCtx() is called. If the component has help attached by HelpCtx.setHelpIDString(javax.swing.JComponent, java.lang.String), it returns that. Otherwise it checks the parent component recursively.

Parameters:

comp - the component to find help for

Returns:

the help for that component (never null)

findHelp

public static HelpCtx findHelp(Object instance)

Finds help context for a generic object. Right now checks for HelpCtx.Provider and handles java.awt.Component in a special way compatible with JavaHelp. Also BeanDescriptor's are checked for a string-valued attribute helpID, as per the JavaHelp specification (but no help sets will be loaded).

Parameters:

instance - to search help for

Returns:

the help for the object or HelpCtx.DEFAULT_HELP if HelpCtx cannot be found

Since:

4.3