#!/usr/bin/env ruby

require "qte"
require "qpe"
include Qte
include Qpe

require 'bigdecimal'
#require 'bigdecimal/math'
#include BigMath


class SampleWindow < QMainWindow

	MAX_DIGIT = 20  # LCD表示桁数

	def initialize()
		super()
		setCaption(tr("電卓"))
		@f = QFrame.new(self, 'frame')
		setCentralWidget(@f)

		# 部品配置用グリッド 6x4
		@v = QGridLayout.new(@f, 6, 4, 10, 10, 'grid')
#		@v.setRowStretch(0, 1)
#		@v.setRowStretch(1, 3)
#		@v.setRowStretch(2, 3)
#		@v.setRowStretch(3, 3)
#		@v.setRowStretch(4, 3)
#		@v.setRowStretch(5, 3)

		# LCD表示部分
		@lcd = QLCDNumber.new(MAX_DIGIT, @f)
		@lcd.setSegmentStyle( QLCDNumber::Flat )
		@lcd.setSmallDecimalPoint( true )
		# グリッド1行目(0,0)-(0,3)に配置
		@v.addMultiCellWidget(@lcd, 0,0,0,3)

		# ボタン用フォント
		@fnt_pb = QFont.new("helvetica",24, QFont::Bold)

		# ボタン定義
		@pb_ac = QPushButton.new('AC', @f)
		@pb_ac.setFont(@fnt_pb)
		@v.addWidget(@pb_ac, 1, 3)

		@pb_7 = QPushButton.new('7', @f)
		@pb_7.setFont(@fnt_pb)
		@v.addWidget(@pb_7, 2, 0)
		@pb_8 = QPushButton.new('8', @f)
		@pb_8.setFont(@fnt_pb)
		@v.addWidget(@pb_8, 2, 1)
		@pb_9 = QPushButton.new('9', @f)
		@pb_9.setFont(@fnt_pb)
		@v.addWidget(@pb_9, 2, 2)
		@pb_div = QPushButton.new('/', @f)
		@pb_div.setFont(@fnt_pb)
		@v.addWidget(@pb_div, 2, 3)

		@pb_4 = QPushButton.new('4', @f)
		@pb_4.setFont(@fnt_pb)
		@v.addWidget(@pb_4, 3, 0)
		@pb_5 = QPushButton.new('5', @f)
		@pb_5.setFont(@fnt_pb)
		@v.addWidget(@pb_5, 3, 1)
		@pb_6 = QPushButton.new('6', @f)
		@pb_6.setFont(@fnt_pb)
		@v.addWidget(@pb_6, 3, 2)
		@pb_mul = QPushButton.new('X', @f)
		@pb_mul.setFont(@fnt_pb)
		@v.addWidget(@pb_mul, 3, 3)

		@pb_1 = QPushButton.new('1', @f)
		@pb_1.setFont(@fnt_pb)
		@v.addWidget(@pb_1, 4, 0)
		@pb_2 = QPushButton.new('2', @f)
		@pb_2.setFont(@fnt_pb)
		@v.addWidget(@pb_2, 4, 1)
		@pb_3 = QPushButton.new('3', @f)
		@pb_3.setFont(@fnt_pb)
		@v.addWidget(@pb_3, 4, 2)
		@pb_sub = QPushButton.new('-', @f)
		@pb_sub.setFont(@fnt_pb)
		@v.addWidget(@pb_sub, 4, 3)

		@pb_0 = QPushButton.new('0', @f)
		@pb_0.setFont(@fnt_pb)
		@v.addWidget(@pb_0, 5, 0)
		@pb_point = QPushButton.new('.', @f)
		@pb_point.setFont(@fnt_pb)
		@v.addWidget(@pb_point, 5, 1)
		@pb_equal = QPushButton.new('=', @f)
		@pb_equal.setFont(@fnt_pb)
		@v.addWidget(@pb_equal, 5, 2)
		@pb_add = QPushButton.new('+', @f)
		@pb_add.setFont(@fnt_pb)
		@v.addWidget(@pb_add, 5, 3)

		connect(@pb_ac,    QSIGNAL("clicked()"), self, 'push_ac')
		connect(@pb_9,     QSIGNAL("clicked()"), self, 'push_9')
		connect(@pb_8,     QSIGNAL("clicked()"), self, 'push_8')
		connect(@pb_7,     QSIGNAL("clicked()"), self, 'push_7')
		connect(@pb_6,     QSIGNAL("clicked()"), self, 'push_6')
		connect(@pb_5,     QSIGNAL("clicked()"), self, 'push_5')
		connect(@pb_4,     QSIGNAL("clicked()"), self, 'push_4')
		connect(@pb_3,     QSIGNAL("clicked()"), self, 'push_3')
		connect(@pb_2,     QSIGNAL("clicked()"), self, 'push_2')
		connect(@pb_1,     QSIGNAL("clicked()"), self, 'push_1')
		connect(@pb_0,     QSIGNAL("clicked()"), self, 'push_0')
		connect(@pb_point, QSIGNAL("clicked()"), self, 'push_point')
		connect(@pb_equal, QSIGNAL("clicked()"), self, 'push_equal')
		connect(@pb_div,   QSIGNAL("clicked()"), self, 'push_div')
		connect(@pb_mul,   QSIGNAL("clicked()"), self, 'push_mul')
		connect(@pb_sub,   QSIGNAL("clicked()"), self, 'push_sub')
		connect(@pb_add,   QSIGNAL("clicked()"), self, 'push_add')

		@max = MAX_DIGIT + 2
		push_ac
	end

	# 文字列をLCDに表示
	def display(str) # str = String
		s = str
		s = str.split(/\./)[0] if str =~ /\./
		if s.size > MAX_DIGIT || str == 'Infinity'
			@lcd.display('Error')
			return nil
		end
		if str =~ /\./
			nstring = str[0, 21]
		else
			nstring = str[0, 20]
		end
		@lcd.display(nstring)
		true
	end

	# All Clear
	def push_ac
		clr_input
		@ope   = nil
		@stack = nil
		display(@input)
	end
	def clr_input
		@input = '0'
		@point = false
	end

	# 数字キー入力
	def push_num(str) # str= String
		@stack = nil if !@ope && @stack
		return if @input.size > MAX_DIGIT
		case str
		when '.'
			if !@point
				@input << str
				@point = true
			end
		when '0'
			@input << str if @input != '0'
		else
			if @input == '0'
				@input = str
			else
				@input << str
			end
		end
		display(@input)
	end

	# 演算子キー入力
	def push_ope(str) # str = String
		if !@stack
			@stack = BigDecimal(@input, @max)
		else @ope
			calc(@ope)
			display(@stack.to_s('F'))
		end
		@ope = str
		clr_input
	end
	# イコールキー入力
	def push_equal
		if @ope
			calc(@ope)
		else
			@stack = BigDecimal(@input, @max)
		end
		@ope   = nil
		clr_input
		display(@stack.to_s('F'))
	end

	# @inputと@stackで計算し結果を@stackへ
	def calc(str) # str = String
		case str
		when '/'
			@stack = @stack / BigDecimal(@input)
		when '*'
			@stack = @stack * BigDecimal(@input)
		when '-'
			@stack = @stack - BigDecimal(@input)
		when '+'
			@stack = @stack + BigDecimal(@input)
		end
	end



	def push_9
		push_num('9')
	end
	def push_8
		push_num('8')
	end
	def push_7
		push_num('7')
	end
	def push_6
		push_num('6')
	end
	def push_5
		push_num('5')
	end
	def push_4
		push_num('4')
	end
	def push_3
		push_num('3')
	end
	def push_2
		push_num('2')
	end
	def push_1
		push_num('1')
	end
	def push_0
		push_num('0')
	end
	def push_point
		push_num('.')
	end
	def push_div
		push_ope('/')
	end
	def push_mul
		push_ope('*')
	end
	def push_sub
		push_ope('-')
	end
	def push_add
		push_ope('+')
	end

end

$defaultCodec = QTextCodec.codecForName("utf8")
app = QPEApplication.new([$0]+ARGV)
app.setDefaultCodec($defaultCodec)
QApplication.setFont(QFont.new("lcfont",18))
app.showMainWidget(SampleWindow.new)
app.exec