--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2013 Alexis Laferrière <alexis.laf@xymus.net>
+#
+# 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.
+
+import gtk
+
+class CalculatorContext
+ var result : nullable Float = null
+
+ var last_op : nullable Char = null
+
+ var current : nullable Float = null
+ var after_point : nullable Int = null
+
+ fun push_op( op : Char )
+ do
+ apply_last_op_if_any
+ last_op = op # store for next push_op
+
+ # prepare next current
+ after_point = null
+ current = null
+ end
+
+ fun push_digit( digit : Int )
+ do
+ var current = current
+ if current == null then current = 0.0
+
+ var after_point = after_point
+ if after_point == null then
+ current = current * 10.0 + digit.to_f
+ else
+ current = current + digit.to_f * 10.0.pow(after_point.to_f)
+ after_point -= 1
+ end
+
+ self.current = current
+ end
+
+ fun switch_to_decimals
+ do
+ if after_point != null then return
+
+ after_point = -1
+ end
+
+ fun apply_last_op_if_any
+ do
+ var op = last_op
+
+ var result = result
+ if result == null then result = 0.0
+
+ var current = current
+ if current == null then current = 0.0
+
+ if op == null then
+ result = current
+ else if op == '+' then
+ result = result + current
+ else if op == '-' then
+ result = result - current
+ else if op == '/' then
+ result = result / current
+ else if op == '*' then
+ result = result * current
+ end
+ self.result = result
+ self.current = null
+ end
+end
+
+class CalculatorGui
+ super GtkCallable
+
+ var win : GtkWindow
+ var container : GtkGrid
+
+ var lbl_disp : GtkLabel
+ var but_eq : GtkButton
+
+ var context = new CalculatorContext
+
+ redef fun signal( sender, user_data )
+ do
+ if user_data isa Char then # is an operation
+ var c = user_data
+ if c == '.' then
+ context.switch_to_decimals
+ else
+ context.push_op( c )
+ lbl_disp.text = context.result.to_s
+ end
+ else if user_data isa Int then # is a number
+ var n = user_data
+ context.push_digit( n )
+ lbl_disp.text = context.current.to_s
+ end
+ end
+
+ init
+ do
+ init_gtk
+
+ win = new GtkWindow( 0 )
+
+ container = new GtkGrid(2,1,true)
+ win.add( container )
+
+ lbl_disp = new GtkLabel( "_" )
+ container.attach( lbl_disp, 0, 0, 5, 1 )
+
+ # digits
+ for n in [0..9] do
+ var but = new GtkButton.with_label( n.to_s )
+ but.set_size_request( 64, 64 )
+ but.signal_connect( "clicked", self, n )
+ if n == 0 then
+ container.attach( but, 0, 4, 1, 1 )
+ else container.attach( but, (n-1)%3, 3-(n-1)/3, 1, 1 )
+ end
+
+ # operators
+ var r = 1
+ for op in ['+', '-', '*', '/' ] do
+ var but = new GtkButton.with_label( op.to_s )
+ but.set_size_request( 64, 64 )
+ but.signal_connect( "clicked", self, op )
+ container.attach( but, 4, r, 1, 1 )
+ r+=1
+ end
+
+ # =
+ but_eq = new GtkButton.with_label( "=" )
+ but_eq.set_size_request( 64, 64 )
+ but_eq.signal_connect( "clicked", self, '=' )
+ container.attach( but_eq, 5, 3, 1, 2 )
+
+ # .
+ var but_dot = new GtkButton.with_label( "." )
+ but_dot.set_size_request( 64, 64 )
+ but_dot.signal_connect( "clicked", self, '.' )
+ container.attach( but_dot, 1, 4, 1, 1 )
+
+ win.show_all
+ end
+end
+
+# context tests
+var context = new CalculatorContext
+context.push_digit( 1 )
+context.push_digit( 2 )
+context.push_op( '+' )
+context.push_digit( 3 )
+context.push_op( '*' )
+context.push_digit( 2 )
+context.push_op( '=' )
+var r = context.result.to_precision( 2 )
+assert r == "30.00" else print r
+
+context = new CalculatorContext
+context.push_digit( 1 )
+context.push_digit( 4 )
+context.switch_to_decimals
+context.push_digit( 1 )
+context.push_op( '*' )
+context.push_digit( 3 )
+context.push_op( '=' )
+r = context.result.to_precision( 2 )
+assert r == "42.30" else print r
+
+context.push_op( '+' )
+context.push_digit( 1 )
+context.push_digit( 1 )
+context.push_op( '=' )
+r = context.result.to_precision( 2 )
+assert r == "53.30" else print r
+
+context = new CalculatorContext
+context.push_digit( 4 )
+context.push_digit( 2 )
+context.switch_to_decimals
+context.push_digit( 3 )
+context.push_op( '/' )
+context.push_digit( 3 )
+context.push_op( '=' )
+r = context.result.to_precision( 2 )
+assert r == "14.10" else print r
+
+# graphical application
+
+if "NIT_TESTING".environ != "true" then
+ var app = new CalculatorGui
+ run_gtk
+end
nitlanguage / nit.git / commitdiff