samples/bsh/calculator.rex

/* A silly little calculator implemented in Object Rexx using
   Java components for the UI. ("bsf\samples\bsh\calculator.js" served as an example)

   ooRexx (FOSS):   <http://www.ooRexx.org>
   BSF4Rexx (FOSS): <http://wi.wu-wien.ac.at/rgf/rexx/bsf4rexx/current/> or
                    eventually at <https://sourceforge.net/projects/bsf4rexx>

   license:

    ------------------------ Apache Version 2.0 license -------------------------
       Copyright (C) 2001-2006 Rony G. Flatscher

       Licensed under the Apache License, Version 2.0 (the "License");
       you may not use this file except in compliance with the License.
       You may obtain a copy of the License at

           http://www.apache.org/licenses/LICENSE-2.0

       Unless required by applicable law or agreed to in writing, software
       distributed under the License is distributed on an "AS IS" BASIS,
       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       See the License for the specific language governing permissions and
       limitations under the License.
    -----------------------------------------------------------------------------
*/

if      BsfInvokedBy()=1 then say "This Rexx program was invoked by Java!"
else if BsfInvokedBy()=2 then say "This Rexx program was invoked by Rexx, JVM loaded by Rexx!"
else                          say "No JVM present, we got troubles ..."

.bsf~bsf.import("java.awt.TextField", "awtTextField")
.bsf~bsf.import("java.awt.Label"    , "awtLabel"    )

f = .bsf~new("java.awt.Frame", "BSH Calculator (ooRexx)")
f~bsf.addEventListener("window", "windowClosing", "call bsf 'exit'")

f1 = .awtTextField~newStrict("int", 20)   -- "newStrict" to force the constructor with the "int" argument
f1~bsf.addEventListener("action", "", "call doMath /* action event */")

f2 = .awtTextField~newStrict("int", 20)
f2~bsf.addEventListener("text", "", "call doMath /* text event */")

p = .bsf~new( "java.awt.Panel") ~~setLayout(.bsf~new("java.awt.GridLayout", 2, 2))
p ~~add(.awtLabel~new("Enter operand")) ~~add(f1)
p ~~add(.awtLabel~new("Enter operand")) ~~add(f2)

f ~~add("North", p) ~~add("Center", .awtLabel~new("Results:"))

p =  .bsf~new("java.awt.Panel") ~~setLayout(.bsf~new("java.awt.GridLayout", 4, 2))

sum= .awtTextField~newStrict("int", 20)
p ~~add(.awtLabel~new("Sum")) ~~add(sum)

diff= .awtTextField~newStrict("int", 20)
p ~~add(.awtLabel~new("Difference")) ~~add(diff)

prod= .awtTextField~newStrict("int", 20)
p ~~add(.awtLabel~new("Product")) ~~add(prod)

quo = .awtTextField~newStrict("int", 20)
p ~~add(.awtLabel~new("Quotient")) ~~add(quo)

f ~~add("South", p) ~~pack ~~show ~~toFront

do forever
   interpret .bsf~bsf.pollEventText -- retrieve eventText and interpret it
end
exit

getField: procedure
   use arg f
   t=f~getText
   if t="" then return 0
   return t

doMath:
   n1 = getField(f1); if n1="-" then n1=-1;else if n1="+" then n1=1
   n2 = getField(f2); if n2="-" then n2=-1;else if n2="+" then n2=1
   sum ~setText(n1+n2)
   diff~setText(n1-n2)
   prod~setText(n1*n2)
   if n2=0 then quo~setText("DIVISION by 0 !!!")
           else quo~setText(n1/n2)
   return

::requires BSF.CLS    -- get Object Rexx wrapper support