Package org.eclipse.ui.handlers

Class RadioState

java.lang.Object
org.eclipse.core.commands.common.EventManager
org.eclipse.core.commands.State
org.eclipse.jface.commands.PersistentState
org.eclipse.ui.handlers.RadioState
All Implemented Interfaces:
IExecutableExtension
public final class RadioState extends PersistentState implements IExecutableExtension
This state supports a radio-button like command, where the value of the parameterized command is stored as state. The command must define a state using the STATE_ID id and a string commandParameter using the PARAMETER_ID id. Menu contributions supplied by org.eclipse.ui.menus can then set the PARAMETER_ID.

When parsing from the registry, this state understands two parameters: default, which is the default value for this item; and persisted, which is whether the state should be persisted between sessions. The default parameter has no default value and must be specified in one of its forms, and the persisted parameter defaults to true. If only one parameter is passed (i.e., using the class name followed by a colon), then it is assumed to be the default parameter.

Since:
3.5
See Also:

  • Field Details

    • STATE_ID

      public static final String STATE_ID
      The state ID for a radio state understood by the system.
      See Also:

    • PARAMETER_ID

      public static final String PARAMETER_ID
      The parameter ID for a radio state understood by the system.
      See Also:

  • Constructor Details

    • RadioState

      public RadioState()
      This constructor creates a persisted instance.

  • Method Details

    • setInitializationData

      public void setInitializationData(IConfigurationElement config, String propertyName, Object data)
      Description copied from interface: IExecutableExtension
      This method is called by the implementation of the method IConfigurationElement.createExecutableExtension on a newly constructed extension, passing it its relevant configuration information. Most executable extensions only make use of the first two call arguments.

      Regular executable extensions specify their Java implementation class name as an attribute of the configuration element for the extension. For example 

           <action run="com.example.BaseAction"/>

      In the above example, this method would be called with a reference to the <action> element (first argument), and "run" as the name of the attribute that defined this executable extension (second argument).

      The last parameter is for the specific use of extension adapters and is typically not used by regular executable extensions.

      There are two supported ways of associating additional adapter-specific data with the configuration in a way that is transparent to the extension point implementor:

      (1) by specifying adapter data as part of the implementation class attribute value. The Java class name can be followed by a ":" separator, followed by any adapter data in string form. For example, if the extension point specifies an attribute "run" to contain the name of the extension implementation, an adapter can be configured as 

           <action run="com.example.ExternalAdapter:./cmds/util.exe -opt 3"/>

      (2) by converting the attribute used to specify the executable extension to a child element of the original configuration element, and specifying the adapter data in the form of xml markup. Using this form, the example above would become 

           <action>
         <run class="com.xyz.ExternalAdapter">
             <parameter name="exec" value="./cmds/util.exe"/>
             <parameter name="opt"  value="3"/>
         </run>
     </action>

      Form (2) will typically only be used for extension points that anticipate the majority of extensions configured into it will in fact be in the form of adapters.

      In either case, the specified adapter class is instantiated using its 0-argument public constructor. The adapter data is passed as the last argument of this method. The data argument is defined as Object. It can have the following values:

      • null, if no adapter data was supplied
      • in case (1), the initialization data string is passed as a String
      • in case (2), the initialization data is passed as a Hashtable containing the actual parameter names and values (both Strings)
      Specified by:
      setInitializationData in interface IExecutableExtension
      Parameters:
      config - the configuration element used to trigger this execution. It can be queried by the executable extension for specific configuration properties
      propertyName - the name of an attribute of the configuration element used on the createExecutableExtension(String) call. This argument can be used in the cases where a single configuration element is used to define multiple executable extensions.
      data - adapter data in the form of a String, a Hashtable, or null.
      See Also:

    • load

      public void load(IPreferenceStore store, String preferenceKey)
      Description copied from class: PersistentState
      Loads this state from the preference store, given the location at which to look. This method must be symmetric with a call to PersistentState.save(IPreferenceStore, String).
      Specified by:
      load in class PersistentState
      Parameters:
      store - The store from which to read; must not be null.
      preferenceKey - The key at which the state is stored; must not be null.

    • save

      public void save(IPreferenceStore store, String preferenceKey)
      Description copied from class: PersistentState
      Saves this state to the preference store, given the location at which to write. This method must be symmetric with a call to PersistentState.load(IPreferenceStore, String).
      Specified by:
      save in class PersistentState
      Parameters:
      store - The store to which the state should be written; must not be null.
      preferenceKey - The key at which the state should be stored; must not be null.

    • setValue

      public void setValue(Object value)
      Description copied from class: State
      Sets the value for this state object.
      Overrides:
      setValue in class State
      Parameters:
      value - The value to set; may be anything.