io Programmo 39/IOPROG_39.ISO/SOFT/sdkjava40.exe/data1.cab/fg_Samples/Samples/afc11/JNotepad/src/CommandFeature.java

Java Source | 2000-05-04 | 6.6 KB | 200 lines

/*
 * (C) Copyright 1995 - 1999 Microsoft Corporation.  All rights reserved.
 */
import com.ms.ui.*;
import com.ms.ui.event.*;
import com.ms.fx.*;
import java.util.*;
/**
 *    Application message mapping module. This module intercepts all menu commands, toolbar
 *    commands, and accelerator key commands, identifies what command they are in one place,
 *    and routes them to the appropriate place. This allows the developer to put all
 *    code designed to identify user commands and put it in one spot. No need to duplicate
 *    menu item command routing in different parts of the code.
 *    <p>
 *    This module also implements ICommandFeedback, which allows parts of the app to enable
 *    and disable menu items/toolbar buttons. All the items which can send that command
 *    are disabled, even if they are on totally different controls. One simple call
 *    enables and disables all controls that can send a particular item.
 *    <p>
 *    This component is implemented as a plugin feature through the IComponentFeature
 *    interface. Subclass this and do your command processing in actionPerformed.
 *    <p>
 *    @see    IFeature
 *    @see    ICommandFeedback
 *    @see    IComponentFeature
 *
 *    @version    1.0, 8/6/97
 */
public abstract class CommandFeature implements IComponentFeature, ICommandFeedback, IUIActionListener{
    /**
    *    An object which handles text-related commands
    */
    ITextOperationTarget textTarget;
    /**
    *    An object which handles file-related commands
    */
    IFileOperationTarget fileTarget;
    /**
    *    Vector of components which generate commands
    */
    Vector talkerVector;
/**
 *    Creates a new ComponentFeature.
 */
    public CommandFeature(){
        talkerVector = new Vector(4);
    }
/**
 *    Public init function. Part of the IFeature interface. Sets the objects
 *    which will receive the commands processed.
 *
 *    @param    tTarget    object to receive text-related commands
 *    @param    fTarget    object to receive file-related commands
 */
    public void init(ITextOperationTarget tTarget,
                     IFileOperationTarget fTarget){
        textTarget = tTarget;
        fileTarget = fTarget;
    }
/**
 *    Adds a component to the list of objects that are listened to for
 *    command events. These objects are referred to as "talkers".
 *
 *    @param    talker    Object to listen to for command events.
 */
    public void addTalker(IUIComponent talker){
        if (talker != null){
            talkerVector.addElement(talker);
        }
    }
/**
 *    Called to activate the feature.
 *    Registers the feature as active and attaches listeners to the
 *    components which have been added as talkers. Part of the IFeature interface.
 *    Once this class has been registered, it is listening to the commands
 *    performed on all of the elements in talkerVector.
 */
    public void register(){
        Enumeration enum = talkerVector.elements();
        while (enum.hasMoreElements()){
            Object comp = enum.nextElement();
            if (comp instanceof IUISelector){
                ((IUISelector)comp).addActionListener(this);
            }else if (comp instanceof IActionTalker)
                ((IActionTalker)comp).addActionListener(this);
        }
    }
/**
 *    Called when the feature is no longer
 *    active on the current objects. Removes listeners from the talkers.
 *    Part of the IFeature interface.
 */
    public void unregister(){
        Enumeration enum = talkerVector.elements();
        while (enum.hasMoreElements()){
            Object comp = (Object)enum.nextElement();
            if (comp instanceof IUISelector){
                ((IUISelector)comp).removeActionListener(this);
            }else if (comp instanceof IActionTalker)
                ((IActionTalker)comp).removeActionListener(this);
        }
    }
/**
 *    Called to reset the state of the
 *    feature after it is removed. There is no state to reset, so this
 *    method does nothing. Part of the IFeature interface.
 */
    public void reset(){
    }
/**
 *    Enables or disables a command. All talker objects which support the
 *    passed command will disable it (normally by graying it out).
 *
 *    @param    command    Name of command to disable or enable.
 *    @param    on    true if the control is to be enabled, false if it is to be disabled
 */
    public void enableCommand(String command,
                              boolean on){
        Enumeration e = talkerVector.elements();
        while (e.hasMoreElements()){
            Object obj = (Object)e.nextElement();
            // if the element supports ICommandFeedback, try to enable/disable
            // this command
            if (obj instanceof ICommandFeedback)
                ((ICommandFeedback)obj).enableCommand(command, on);
        }
    }
/**
 *    Checks whether a control is enabled or not.
 *
 *    @param    command    Name of command to check
 */
    public boolean isEnabled(String command){
        Enumeration e = talkerVector.elements();
        while (e.hasMoreElements()){
            Object obj = (Object)e.nextElement();
            if (obj instanceof ICommandFeedback)
                if (!((ICommandFeedback)obj).isEnabled(command))
                    return false;
        }
        return true;
    }
/**
 *    Checks or unchecks a check menu item or a check box button. All talker
 *    controls will check or uncheck the item.
 *
 *    @param    command    Name of command to check or uncheck
 *    @param    on    true if the command is to be checked, false if it is to be unchecked
 */
    public void setChecked(String command, boolean on){
        Enumeration e = talkerVector.elements();
        while (e.hasMoreElements()){
            Object obj = (Object)e.nextElement();
            if (obj instanceof ICommandFeedback)
                ((ICommandFeedback)obj).setChecked(command, on);
        }
    }
/**
 *    Adds a file to the Most Recently Used (MRU) file list of all the
 *    talker components.
 *
 *    @param    filename    Name of file to add
 */
    public void addToMRUList(String filename){
        Enumeration e = talkerVector.elements();
        while (e.hasMoreElements()){
            Object obj = (Object)e.nextElement();
            if (obj instanceof ICommandFeedback)
                ((ICommandFeedback)obj).addToMRUList(filename);
        }
    }
/**
 *    Called when a control in the system changes color. Notifies all
 *    talker components of this change.
 *
 *    @param    comp    Component who had a color change
 *    @param    color    Color that the component was changed to
 *    @param    whichPart    Which part of the component had a color change. This can
 *                        be either FOREGROUND or BACKGROUND.
 */
    public void    notifyColorChange(Object comp,
                                  FxColor color,
                                  int whichPart){
        Enumeration e = talkerVector.elements();
        while (e.hasMoreElements()){
            Object obj = (Object)e.nextElement();
            if (obj instanceof ICommandFeedback)
                ((ICommandFeedback)obj).notifyColorChange(comp,color,whichPart);
        }
    }
/**
 *    Called whenever a command is performed. Override this in a subclass
 *    to perform custom command processing for your application.
 *
 *    @param    evt    Action that was performed.
 */
    public abstract void actionPerformed(UIActionEvent evt);
}