Class EnvController

java.lang.Object
  |
  +--EnvController

public class EnvController

extends java.lang.Object

Environment-Based Applications:
The EnvController class implements the methods used by the File menu defined in EnvApplFrame.

Version:

1 December 2002

See Also:

EnvAppFrame

Field Summary

protected CreateEnvDialog	createEnvDialog
protected EnvFileChooser	fileChooser
protected EnvDataFileHandler	fileHandler
protected EnvAppFrame	parentFrame

Constructor Summary

EnvController(EnvAppFrame frame, EnvDataFileHandler fileHandler)
Creates a new environment controller tied to the specified frame.

Method Summary

void	createNewEnv() Creates a new empty environment and invokes the environment editor.
void	editEnv(Environment env) Enables editing of the existing environment.
protected void	invokeEditor(Environment env) Invokes the appropriate environment editor.
void	openFile() Reads a new environment from a saved data file.
void	saveFile(Environment env) Saves an environment to a data file.
boolean	supportsEnvEditing() Indicates whether this controller supports environment editing.
boolean	supportsFileIO() Indicates whether this controller supports file i/o.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

parentFrame

protected EnvAppFrame parentFrame

createEnvDialog

protected CreateEnvDialog createEnvDialog

fileChooser

protected EnvFileChooser fileChooser

fileHandler

protected EnvDataFileHandler fileHandler

Constructor Detail

EnvController

public EnvController(EnvAppFrame frame,
                     EnvDataFileHandler fileHandler)

Creates a new environment controller tied to the specified frame. (Precondition: frame is not null. )

Parameters:

frame - the frame that uses this controller

fileHandler - object that can read and write an environment; null if this controller should not support file i/o

Method Detail

supportsFileIO

public boolean supportsFileIO()

Indicates whether this controller supports file i/o.

Returns:

true if this controller was constructed with a non-null environment data file handler

supportsEnvEditing

public boolean supportsEnvEditing()

Indicates whether this controller supports environment editing. Should only be redefined in subclasses that also redefine the invokeEditor method.

createNewEnv

public void createNewEnv()

Creates a new empty environment and invokes the environment editor. (Precondition: supportsEnvEditing() == true

invokeEditor

protected void invokeEditor(Environment env)

Invokes the appropriate environment editor. Should be redefined in subclasses that support an environment editor to construct and run the editor.

Parameters:

env - the environment to edit

editEnv

public void editEnv(Environment env)

Enables editing of the existing environment. Subclasses that support environment editing should ensure that the application is not actively running and modifying the environment while the environment is being edited. For example, if the parent frame is an ActiveEnvFrame, the subclass should call the frame's stop method.

openFile

public void openFile()

Reads a new environment from a saved data file. Gets file via file chooser dialog, reads contents using the specified file handler. On error, brings up dialog and continues using previous environment.

saveFile

public void saveFile(Environment env)

Saves an environment to a data file.

Parameters:

env - the environment to save to the file