calcobj.cpp

计算器程序

//****************************************************************
//This software may not be distributed further without permission from
// Sun Xueshi's Group
//      
//This software is distributed WITHOUT ANY WARRANTY. No claims are made
// as to its functionality or purpose.
// 
//Authors: 孙学诗
// Date: 12/4/03
// 
//****************************************************************


#include <iostream>
#include <fstream> 
#include <assert.h>
#include <label>
#include "calcobj.h"
#include <stdio.h>

using namespace std;

//Constructor for CalcObj
//SimpleWindow W1 is the Calc Window and W2 is the About Window
CalcObj::CalcObj(SimpleWindow &W1, SimpleWindow &W2) : 
	W(W1), AboutWin(W2) ,Btn(BtnVectorLength){
   // No body needed
}

// Initialize -- initialize the calculator object
void CalcObj::Initialize() {
      	assert(W.GetStatus() == WindowOpen);

	//load calculator bitmap
        Calc.SetWindow(W);
        Calc.Load("calc.bmp");
        assert(Calc.GetStatus() == BitMapOkay);
	Calc.SetPosition(Position(0, 0));
	Calc.Draw();
        //Insert all buttons
	InsertButton();
	Reset();
}

//MouseClick--if button is clicked corresponding events is triggered
int CalcObj:: MouseClick(const Position &MousePosn) {
	int s;
	if((s = Find(MousePosn)) >= 0) {
		CurrentButton = Btn[s];                  //find the current button that is clicked
		CurrentButton.SetStatus(Down);
		CurrentButton.Draw();	               //button is press down
		W.StartTimer(100);                         //start timer event to control button's jumping up
		switch(CurrentButton.ButtonValue) {
			case 'a':                                  //About button is clicked then show author information 
				About();
				break;
			case 'b':                                  //Backspace button is clicked then do Backspace
				Backspace();
				break;
			case 'c':
				Reset();                           //Cancel button is clicked then do Reset
				break;
			case 'n':                                   //Null-value button is clicked then do nothing
				break;
		        default:
		        	//"="and"%" can't be the in front of the expression
		        	if(index==0 && (CurrentButton.ButtonValue=='='||CurrentButton.ButtonValue=='%') ) {
		        		ValueText[0]='0';
		        		index--;
		        	}
                                //number of ")" should equals number of "("
		        	else if(CurrentButton.ButtonValue == ')' && Bracket == 0) {index--;}
		        	//if input make the expression incorrect then forbid the current input:
		        	//incorrent expression include like this: "3(", ")6",  ")(", "()", "+-" and so on
		        	else if(index>0 && (!Evaluate.IsOperator(ValueText[index-1]) && (CurrentButton.ButtonValue=='(')
		        	    ||ValueText[index-1]==')' && !Evaluate.IsOperator(CurrentButton.ButtonValue)
		        	    ||ValueText[index-1]=='(' && CurrentButton.ButtonValue==')'
		        	    ||ValueText[index-1]==')' && CurrentButton.ButtonValue=='('
		        	    ||ValueText[index-1]!='(' && ValueText[index-1]!=')'
		        	        && CurrentButton.ButtonValue!='(' && CurrentButton.ButtonValue!=')'
		        	        && Evaluate.IsOperator(ValueText[index-1]) && Evaluate.IsOperator(CurrentButton.ButtonValue)))
		        	{index--;}     //keep index unchanged
		        	else if(Bracket>0 && CurrentButton.ButtonValue=='=')  {index--;}
		        	else {
		        		cout << CurrentButton.ButtonValue;                     //output the current input on dos window
		        	        ValueText[index] = CurrentButton.ButtonValue;    // put corrent input into ValueText array
		        	        ValueText[index+1] = '\0';                                     
		        	        if(CurrentButton.ButtonValue == '(')                     //count left brackets
		        	        	Bracket++;
		        	        if(CurrentButton.ButtonValue == ')')                     //keep number of ")" the same as "("
		        	        	Bracket--;
		        	        if(CurrentButton.ButtonValue == '=') {
		        	        	for(int i=0; i<=index; i++)
		        	        		putc(ValueText[i], Stream);                    //put ValueText into a stream
		        		        Evaluate.Interface(Stream);                          //pass the stream to Evaluate object
		        		        Evaluate.Run();                                              //Do Evaluate
		        		        fclose(Stream);                                              //close stream file
		        		        Stream = fopen("DUMMY.FIL", "w+");            //Save stream in a virtual file "DUMMY.FIL"
		        	        }
		        	}
		        	index++;
		        	if(index>0)
		        		Display();                                
		}
	}
	return 1;
}

//JumpUpTimer -- automate the current object's status from down to up within an interval
void CalcObj::JumpUpTimer() {
        CurrentButton.Flip();
        if(CurrentButton.GetStatus() == Up) 
		W.StopTimer();
}       

// Find -- find the selected Button object
int CalcObj::Find(const Position &MousePosn) const{
	for (int p = 0; p < BtnVectorLength; p++)
		if (Btn[p].IsInside(MousePosn))
			return p;
        return -1;
}


void CalcObj::InsertButton() {
	//define some parameters need in function InsertButton
	int i = 0, j = 0, k = 0, p;
	const float X = InitialPosition.GetXDistance();
        const float Y = InitialPosition.GetYDistance();
        float X1, Y2, X3, Y3;
        X3 = X1 = X+1.3;
        Y3 = Y2 = Y+0.98;

        //get bitmap name of Up buttons from a file"buttonfile_up.nbr"
	vector<string> BitMapFile_up(BtnVectorLength);
	ifstream fin1("buttonfile_up.nbr");
	while (fin1 >> BitMapFile_up[i]) { i++; }

        //get bitmap name of Down buttons from a file"buttonfile_down.nbr"
	vector<string> BitMapFile_down(BtnVectorLength);
	ifstream fin2("buttonfile_down.nbr");
	while (fin2 >> BitMapFile_down[j]) { j++; }

        //get buttons' value  a file"buttondata.nbr"
	ifstream fin3("buttondate.nbr");
	while (fin3 >> Btn[k].ButtonValue) { k++;}

        //Initialize 27 buttons in proper positions
	for (p = 0; p < 3; p++) {
	        Btn[p].Initialize(W, BitMapFile_up[p], BitMapFile_down[p], Position(X1, Y));
	        X1 = X+1.3+(p+1)*(Btn[p].GetWidth()+0.08);
	 }
	for (p=3; p>=3&&p<7; p++) {
		Btn[p].Initialize(W, BitMapFile_up[p], BitMapFile_down[p], Position(X, Y2));
		Y2 = Y+0.98+(p-2)*(Btn[p].GetHeight()+0.08);
	}
	for (p=7; p<27; p++) {
		Btn[p].Initialize(W, BitMapFile_up[p], BitMapFile_down[p], Position(X3, Y3));
		X3 = X+1.3+((p-6)%5)*(Btn[p].GetWidth()+0.085);
		Y3 = Y+0.98+((p-6)/5)*(Btn[p].GetHeight()+0.08);
	}
}

//Display--display expression and result on calculator screen
void CalcObj::Display() {
	Erase();
	//display expression
	Label Display(W, Position(6.9, 0.87)-Position(0.12*index, 0), ValueText);
	Display.Draw();
	//display result
	if(CurrentButton.ButtonValue == '=') {
		Result = Evaluate.GetResult();
		Erase();
		Label Display(W, Position(6.9, 0.87)-Position(0.10*Result.size(), 0), Result);
		Display.Draw();
		ValueText[0] = '0';
		Result = "";
	        index = 0;
	}
}

//Reset-- reset all parameters to default value
void CalcObj::Reset() {
       Erase();
       Label Display0(W, Position(6.9, 0.87), "0.");
       Display0.Draw();
       Stream = fopen("DUMMY.FIL", "w+");
       index = 0;
       Bracket = 0;
       ValueText[0] = '\0';
       Result = "";
}

//Erase--display null to clear calculator screen
void CalcObj::Erase() {
	Label DisplayNull(W, Position(3.7, 0.87), "                                                            ");
	DisplayNull.Draw();
}

//About--Show information of authors
void CalcObj::About() {
         //open about window
	AboutWin.Open();                        
	assert(AboutWin.GetStatus() == WindowOpen);
	//load about bitmap
	AboutBmp.SetWindow(AboutWin);
        AboutBmp.Load("about.bmp");
        assert(AboutBmp.GetStatus() == BitMapOkay);
	AboutBmp.SetPosition(Position(0, 0));
	AboutBmp.Draw();
}

//Backspace--erase mistake input character
void CalcObj::Backspace() {
	if (index>0)
		index--;
	ValueText[index] = '\0';
	Display();
}