All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class edu.mit.ai.psg.jevaESUI.JevaESUI

java.lang.Object
   |
   +----java.awt.Component
           |
           +----java.awt.Container
                   |
                   +----java.awt.Panel
                           |
                           +----java.applet.Applet
                                   |
                                   +----edu.mit.ai.psg.jevaESUI.JevaESUI

public class JevaESUI
extends Applet
implements ActionListener

JevaESUI is the user interface for the JevaES Java Expression & Statement evaluator. JevaESUI can be used as

an application: main starts a top read-eval-print-loop (repl) window. Good for quickly trying out some class in the classpath.
an applet: provides a button which starts a repl window when pressed. (AWT panes haven't worked well nested in browsers.)
a breakpoint/stub: an application may call JevaESUI.repl(..) providing an environment of current names, and a repl window appears in which the user can evaluate Java expression and statements in that environment, including calling other stubs (which create new windows), returning values, and throwing exceptions.

In any situation, results can be explored in an outline tree using Jexa, and objects found in Jexa can become parameters of statements and expressions.

Author:: CarlManning, caroma@ai.mit.edu
Copyright (c) 1997, 1998 Massachusetts Institute of Technology
See Also:: JevaES, Jexa

DontRedirectSystemOutAndErr: option bits fit into a 32 bit int.
err: PrintWriter stream for printing errors to result pane.
NoThrowDeclarations: default empty array argument for repl(...
out: PrintWriter stream for printing to result pane.
results: Vector of result values from expressions typed at the window
systemErr: Saved system.err present when loaded
systemOut: Saved system.out present when loaded

JevaESUI()

actionPerformed(ActionEvent): Start up window frame when applet button is pushed.
awaitResult(Container)
dontRedirectSystemOutAndErr(int)
getHerald()
init(): Applet startup: Starts a window at which users can type top level expressions.
main(String[]): Application Startup: Starts a window at which users can type top level expressions.
repl(): Read-Eval-Print-Loop: creates a new window in which user may type java expressions and statements, including return to return a value.
repl(int, String, Class, Class[], IEnv): Read-Eval-Print-Loop: creates a new window in which user may type java expressions and statements, including return to return a value.
replTop(): Top read-eval-print-loop: creates a new window in which user may type java expressions and statements.

out

 public static PrintWriter out

PrintWriter stream for printing to result pane.

err

 public static PrintWriter err

PrintWriter stream for printing errors to result pane.

systemOut

 public static PrintStream systemOut

Saved system.out present when loaded

systemErr

 public static PrintStream systemErr

Saved system.err present when loaded

results

 public static Vector results

Vector of result values from expressions typed at the window

DontRedirectSystemOutAndErr

 public static final int DontRedirectSystemOutAndErr

option bits fit into a 32 bit int. 0 is default for each option. For applets in security sandbox, use DontRedirectSystemOutAndErr

NoThrowDeclarations

 public static final Class NoThrowDeclarations[]

default empty array argument for repl(... throwClasses)

JevaESUI

 public JevaESUI()

main

 public static void main(String ignore[])

Application Startup: Starts a window at which users can type top level expressions.

init

 public void init()

Applet startup: Starts a window at which users can type top level expressions.

Overrides:: init in class Applet

actionPerformed

 public void actionPerformed(ActionEvent e)

Start up window frame when applet button is pushed.

dontRedirectSystemOutAndErr

 public static boolean dontRedirectSystemOutAndErr(int options)

replTop

 public static void replTop()

Top read-eval-print-loop: creates a new window in which user may type java expressions and statements. Returns when window is closed.

repl

 public static Object repl() throws Throwable, AWTException

Read-Eval-Print-Loop: creates a new window in which user may type java expressions and statements, including return to return a value.

Throws: Throwable: --- throws anything user throws.
Throws: AWTException: if window is closed.

repl

 public static Object repl(int options,
                           String initialMessage,
                           Class returnClass,
                           Class throwClasses[],
                           IEnv env) throws Throwable, AWTException

Read-Eval-Print-Loop: creates a new window in which user may type java expressions and statements, including return to return a value.

Parameters:: options - Option flag bits or'ed together; 0 is default. Applets: require DontRedirectSystemOutAndErr due to security sandbox.; initialMessage - Non-null text replaces herald; if called from a breakpoint, a good practice is to show user contents of env.; returnClass - user may only return a value of this class (like method return type); Object.class is default. Use void.class for void result. If null, never returns (like a top level loop).; throwClasses - user may only throw Throwables which are instances of these classes, or instances of Error or RuntimeException (like method throw declarations). If null, defaults to no delcarations.; env - initial environment created with JevaES.makeDefaultEnv, JevaES.extendEnv(), or JevaES.parseEval..Statement If null, defaults to JevaES.makeDefaultEnv() Applet sandbox requires JevaES.checkPackageNames==false .
Throws: Throwable: --- throws anything user throws compatibile with throwClasses
Throws: AWTException: if window is closed.

awaitResult

 public static Object awaitResult(Container container) throws Throwable, AWTException

getHerald

 public static String getHerald()

All Packages  Class Hierarchy  This Package  Previous  Next  Index