Question
Please Help!! Text Editor using Linked Lists in C++
This program comes in the Book of Data Structures and Algorithms in C ++, 4th edition by adam Drozdek, Chapter 3 Section 3.11, Programming assigment please if you have the solution manual in the book comes out, but not have the solutions manual.
Started functions here has the required functions only add code..
linkedlist.h
Here:
https://www.dropbox.com/sh/jwxq2ow6ou8v7y5/AACRuBrsg7nRlTsUsv4MAJJka?dl=0
In this project, you should write a simple line editor. Keep the entire text on a linked list, one line in a separate node. Start the program with entering EDIT file, after which a prompt appears along with the line number. If the letter I is entered with a number n following it, then insert the text to be followed before line n. If I is not followed by a number, then insert the text before the current line. If D is entered with two numbers n and m. one n. or no number following it, then delete lines n through m. line n, or the current line. Do the same with the command L, which stands for listing lines. If A is entered, then append the text to the existing lines. Entry E signifies exit and saving the text in a file. Here is an Example:
Explanation / Answer
/* FUNCTIONS: (i) CURSOR MOVEMENT (ii) CHARACTER INSERTION/DELETION AT ANY POINT (iii) VERTICAL SCROLLING (iv) PAGE_UP, PAGE_DOWN, HOME, END, DELETE, INSERT (v) READING AND MODIFYING AN EXISTING FILE (vi) WRITING A GIVEN FILE AS ANOTHER FILE THIS PROGRAM USES ARRAY TO STORE A LINE. VARIOUS LINES ARE LINKED USING A DOUBLY LINKED LIST (DLL). ********THIS PROGRAM RUNS IN TURBO C++ IDE.********** WHILE EDITING A FILE: (i) 'tab' CHARACTER DOES NOT WORK (ii) THE DOUBLE QUOTATION MARKS ("..") AREN'T VISIBLE (iii) THE MAX. NO OF CHARACTERS ALLOWED IN A LINE IS 100 (NO LINE WRAP) (iv) AT A TIME EDITOR WINDOW SHOWS MAXIMUM 36 LINE ONLY *************************************************************************** */ #include //HEADER FILES #include //FOR BGI GRAPHICS #include //FOR exit() #include //FOR atoi(),itoa() #include //FOR getch() #include //FOR FILE HANDLING #include //FOR STRING OPERATIONS #include //FOR CHARACTER FUNCTIONS #include //FOR delay() struct line //STRUCTURE DEFINITION FOR DLL { unsigned char string[101]; //TO STORE A LINE int len,x,y; //LENGTN OF LINE,CURRENT x-position OF CURSOR struct line * down,*up; //POINTERS TO LINK UPPER AND LOWER LINE }*temp,*head=NULL,*current,*last=NULL; //GLOBAL VARIABLES int xmax,ymax,i=-1,curri=0,currx=20,ins=0,top=0,save=1,iter=1; // xmax = MAX VALUE OF PIXELS IN HORIZONTAL DIRECTION // ymax = MAX VALUE OF PIXELS IN VERTICAL DIRECTION // i STORES 1 LESS THAN NO. OF NODES IN DLL // curri STORES THE SERIAL NO. OF CURRENT WORKING NODE // currx STORES THE CURRENT VALUE OF x IN PIXELS // ins KEEPS TRACK OF WHWTHER 'insert' BUTTON IS PRESSED // top STORES THE SERIAL NO. OF TOPMOST LINE ON EDITOR WINDOW // save KEEPS TRACK WHETHER THE CURRENTLY EDITED FILE IS SAVED OR NOT // iter IS INCREMENTED IF 'OPEN' FUNCTION IS USED char file[20]; //TO STORE FILE NAME ifstream fin; //FILE INPUT STREAM ofstream fout; //FILE OUTPUT SRTEAM /* THIS FUNCTION CALCULATES CURRENT CURSOR POS^N IN PIXELS THIS HAS TO BE DONE BCOZ CHARACTER WIDTH IS DIFFERENT IN WINDOWS */ void calcx() { currx=20; //INITIALIZE calcx for(int j=0;jx;j++) { if(current->string[j]=='>' || current->string[j]==':'||current->string[j]==';'||current->string[j]=='f'||current->string[j]=='i'||current->string[j]=='l'||current->string[j]=='t') currx+=5; else if(current->string[j]=='!') currx+=2; else if(current->string[j]=='%') currx+=7; else if(current->string[j]=='.') currx+=4; else if(current->string[j]=='"'||current->string[j]=='('||current->string[j]==')'||current->string[j]=='['||current->string[j]==']') currx+=5; else currx+=6; } } /* THIS FUNCTION DISPLAYS CURSOR AT REQUIRED POSITION*/ void cursor() { setcolor(RED); outtextxy(currx,(curri-top)*12+23,"_"); outtextxy(currx,(curri-top)*12+24,"_"); } /* THIS FUNCTION IS TO DISPLAY THE STATUS BAR AT RIGHTMOST EDGE OF EDITOR SCREEN */ void statusbar() { setfillstyle(1,7); bar(xmax-9,ymax/28,xmax-1,27*ymax/28); //DRAW DARKGRAY BAR float percent,bartop,barbot; if(i=27*ymax/28) barbot=27*ymax/28-1; setfillstyle(1,8); bar(xmax-7,(int)bartop,xmax-3,(int)barbot); //DRAW LIGHTGRAY BAR } /* THIS FUNCTION DISPLAYS THE CURRENT STATUS OF FILE BEING EDITED*/ void position() { char row[10],column[10]; int rowframe[]={xmax-90,27*ymax/28+1,xmax-69,27*ymax/28+1,xmax-69,ymax-1,xmax-90,ymax-1,xmax-90,27*ymax/28}; int colframe[]={xmax-20,27*ymax/28+1,xmax-1,27*ymax/28+1,xmax-1,ymax-1,xmax-20,ymax-1,xmax-20,27*ymax/28}; setcolor(7); setfillstyle(1,7); fillpoly(5,rowframe); // TO CLEAR PREVIOUSLY WRITTEN DATA fillpoly(5,colframe); // -- DO -- setcolor(8); itoa(curri+1,row,10); // CONVERT FORM INTEGER TO ARRAY itoa(current->x+1,column,10); // -- DO -- outtextxy(xmax-120,ymax-15,"Line: "); outtextxy(xmax-65,ymax-15,"Column: "); setcolor(RED); outtextxy(xmax-90,ymax-15,row); // PRINT CURRENT ROW outtextxy(xmax-20,ymax-15,column); // PRINT CURRENT COLUMN if(ins) setcolor(RED); else setcolor(7); outtextxy(xmax-70,3,"insert"); //PRINT insert IF INSERT IS ON bar(250,1,340,ymax/28-1); if(save==1) { setcolor(8); outtextxy(250,3,"Ready to edit"); //IF FILE IS SAVED PRINT THIS } else { setcolor(RED); outtextxy(250,3," Not saved"); //ELSE PRINT NOT SAVED } statusbar(); //DISPLAY STATUS BAR } /* THIS FUNCTION DRAWS THE BASIC EDITOR SCREEN*/ void disp_editscr() { xmax=getmaxx(); ymax=getmaxy(); int editwin[]={1,ymax/28,xmax-1,ymax/28,xmax-1,27*ymax/28,1,27*ymax/28,1,ymax/28}; cleardevice(); // TO CLEAR THE GRAPHICS SCREEN setcolor(7); setbkcolor(8); setfillstyle(1,7); bar(1,1,xmax-1,ymax/28); //NAME FRAME bar(1,27*ymax/28,xmax-1,ymax-1); //POSITION FRAME drawpoly(5,editwin); settextstyle(2,0,4); setcolor(8); outtextxy(3,3,"File :"); //DISPLAY VARIOUS MESSAGES outtextxy(15,ymax-15," Save"); // - DO - outtextxy(78,ymax-15," Save as"); // - DO - outtextxy(158,ymax-15," Open"); // - DO - outtextxy(215,ymax-15," Quit"); // - DO - setcolor(RED); outtextxy(40,3,file); outtextxy(3,ymax-15,"F1"); // - DO - outtextxy(66,ymax-15,"F2"); // - DO - outtextxy(146,ymax-15,"F3"); // - DO - outtextxy(203,ymax-15,"F4"); // - DO - } /* REFRESH THE FULL EDITOR SCREEN*/ void disp_full() { int j=curri; setcolor(8); setfillstyle(1,8); bar(2,ymax/28,xmax-2,27*ymax/28); //DRAW THE BACKGROUND struct line *temp1; temp1=current; while(j>top) //START DISPLAYING FROM SERIAL NO. TOP { temp1=temp1->up; j--; } int ycor=20; setcolor(7); settextstyle(2,0,4); while(temp1!=NULL&&jstring); ycor+=12; temp1=temp1->down; j++; } calcx(); cursor(); //DISPLAY CURSOR AT NEW POSITION position(); //DISPLAY UPDATED FILE STATUS } /* REFRESH THE LOWER PART ONLY*/ void disp_rem() { setcolor(8); setfillstyle(1,8); bar(2,(curri-top)*12+21,xmax-2,27*ymax/28); //REMAINING WINDOW setcolor(7); temp=current; int ycor=(curri-top)*12+20; int j=curri; while(temp!=NULL&&jstring); ycor+=12; temp=temp->down; j++; } calcx(); cursor(); //DISPLAY CURSOR AT NEW POSITION position(); //DISPLAY UPDATED FILE STATUS } /* TO REFRESH ONLY THREE LINES : THE CURRENT ONE, UPPER ONE AND LOWER ONE*/ void disp_three() { int subeditwin[]={2,(curri-top)*12+22,xmax-2,(curri-top)*12+22,xmax-2,(curri-top)*12+46,2,(curri-top)*12+46,2,(curri-top)*12+22}; setcolor(8); setfillstyle(1,8); fillpoly(5,subeditwin); setcolor(7); outtextxy(20,(curri-top)*12+20,current->string); //DISPLAY THE LINES outtextxy(20,(curri-top)*12+32,current->down->string); // - DO - calcx(); cursor(); //DISPLAY CURSOR AT NEW POSITION position(); //DISPLAY UPDATED FILE STATUS } /* TO COPY AN EXISTING FILE INTO LINKED LIST ON OPENING THE FILE*/ void copy() { do { temp=new (struct line); //MAKE A NEW NODE fin. get(temp->string,101); //READ LINE FROM FILE temp->x=0; // CALCULATE VARIOUS PARAMETERS temp->len=strlen(temp->string); // " temp->string[temp->len]=''; // " temp->y=i++; // " if(head==NULL) // MAKE THE LIST { temp->up=NULL; head=temp; } else { last->down=temp; temp->up=last; } temp->down=NULL; last=temp; current=temp; if(fin.get()==EOF) //CLOSE THE FILE { fin.close(); break; } }while(1); } /* TO HANDLE THE UP ARROW OPERATION */ void uparrow() { int subeditwin[]={2,(curri-top)*12+34,xmax-2,(curri-top)*12+34,xmax-2,(curri-top)*12+46,2,(curri-top)*12+46,2,(curri-top)*12+34}; setcolor(8); setfillstyle(1,8); fillpoly(5,subeditwin); setcolor(7); outtextxy(20,(curri-top)*12+32,current->down->string); calcx(); cursor(); position(); } /* TO HANDLE THE DOWN ARROW OPERATION */ void downarrow() { int subeditwin[]={2,(curri-top)*12+10,xmax-2,(curri-top)*12+10,xmax-2,(curri-top)*12+22,2,(curri-top)*12+22,2,(curri-top)*12+10}; setcolor(8); setfillstyle(1,8); fillpoly(5,subeditwin); setcolor(7); outtextxy(20,(curri-top)*12+8,current->up->string); calcx(); cursor(); position(); } /* TO HANDLE THE SIDE ARROW OPERATION */ void sidearrow() { int subeditwin[]={2,(curri-top)*12+22,xmax-2,(curri-top)*12+22,xmax-2,(curri-top)*12+34,2,(curri-top)*12+34,2,(curri-top)*12+22}; setcolor(8); setfillstyle(1,8); fillpoly(5,subeditwin); setcolor(7); outtextxy(20,(curri-top)*12+20,current->string); calcx(); cursor(); position(); } /* TO HANDLE THE ENTER KEY OPERATION */ void newline() { int j; temp=new (struct line); //MAKE NEW NODE temp->up=current; // FILL APPROPRIATE DATA temp->down=current->down; if(current->down!=NULL) current->down->up=temp; else last=temp; current->down=temp; for(j=current->x;jlen;j++) temp->string[j-current->x]=current->string[j]; current->string[current->x]=''; temp->len=current->len-current->x; current->len=current->x; sidearrow(); current=temp; current->x=0; current->y=curri++; //UPDATE GLOBAL VARIABLES i++; if(curri==top+36) { top++; disp_full(); } else disp_rem(); } void home() /* TO HANDLE THE 'HOME' OPERATION */ { current->x=0; sidearrow(); } void end() /* TO HANDLE THE 'END' OPERATION */ { current->x=current->len; sidearrow(); } void del() /* TO HANDLE THE DELETE OPERATION */ { int j; if(curri!=i&¤t->x==current->len) { temp=current; if(current->len+current->down->lendown->up=current->up; current->up->down=current->down; } else { current->down->up=NULL; head=head->down; } current=current->down; current->x=temp->len; current->len+=temp->len; strcat(temp->string,current->string); strcpy(current->string,temp->string); i--; delete(temp); } else { setcolor(4); outtextxy(xmax/2+100,3,"Next line is too long"); } disp_rem(); } else if(current->xlen) { for(j=current->x;jlen;j++) current->string[j]=current->string[j+1]; current->len--; sidearrow(); } else { setcolor(4); outtextxy(xmax/2+100,3,"Nothing to delete"); } } void validchar(char typed) //TO INSERT A VALID CHARACTER IN LINE { if(current->lenlen-1;j>=current->x;j--) current->string[j+1]=current->string[j]; if((int)typed==34) current->string[current->x]='"'; else current->string[current->x]=typed; current->x++; current->len++; current->string[current->len]=''; sidearrow(); } else { setcolor(4); outtextxy(xmax/2+100,3,"Maximum limit reached"); } } void insert(char typed) //THIS FUNCTION IS USED WHEN INSERT KEY IS ON { if((int)typed==34) current->string[current->x]='"'; else current->string[current->x]=typed; if(current->xlen) current->x++; else { current->x++; current->len++; current->string[current->len]=''; } sidearrow(); } void bkspace() /* TO HANDLE THE BKSPACE OPERATION */ { if(curri!=0&¤t->x==0) { temp=current; if(current->len+current->up->lendown!=NULL) { current->down->up=current->up; current->up->down=current->down; } else { current->up->down=NULL; last=current->up; } current=current->up; current->x=current->len; strcat(current->string,temp->string); current->len=strlen(current->string); curri--; i--; delete(temp); } else { setcolor(4); outtextxy(xmax/2+100,3,"Preceeding line is too long"); } if(curri==top-1) { top--; disp_full(); } else disp_rem(); } else if(current->x!=0) { for(int j=current->x-1;jlen;j++) current->string[j]=current->string[j+1]; current->x--; current->len--; sidearrow(); } else if(current->x==0) { setcolor(4); outtextxy(xmax/2+100,3,"Nowhere to go"); } } void pageup() /* TO HANDLE THE PAGE UP OPERATION */ { if(top>35) { top-=36; curri-=36; for(int j=0;jup; } else { top=0; curri=0; current=head; } disp_full(); calcx(); position(); cursor(); } void pagedown() /* TO HANDLE THE PAGE DOWN OPERATION */ { if(top+35string,temp->len); if(temp->down!=NULL) fout. put(' '); temp=temp->down; } fout.close(); save=1; calcx(); position(); } void save_as() // TO HANDLE SAVE_AS FUNCTION { char file_as[15]; getfile(file_as,0); temp=head; fout.open(file_as,ios::out); while(temp!=NULL) { fout. write(temp->string,temp->len); if(temp->down!=NULL) fout. put(' '); temp=temp->down; } fout.close(); delay(500); disp_full(); } void quit() ///* TO HANDLE THE QUIT OPERATION */ { char ch; if(save==0) { setfillstyle(1,7); setcolor(7); bar(40,90,600,140); setcolor(RED); settextstyle(1,0,3); outtextxy(50,100,"WANT TO SAVE CHANGES (Y/N):"); ch=getch(); if(tolower(ch)=='y') savefile(); } do // FREE ALL THE ALLOCATED MEMORY { temp=head; head=head->down; delete(temp); }while(temp!=NULL); } void newfile(); /* THIS FUNCTION IS THE MAIN DRIVER OF TEH PROGRAM. IT USES VARIOUS FUNCTIONS DEFINED ABOVE TO EXECUTE THE TASK */ void editor() { getfile(file,iter); //GET FILENAME TO BE OPENED int j,tp,bm,lt,rt; char typed; fin.open(file,ios::in|ios::nocreate); //OPEN THE FILE IN READ MODE if(!fin) // IF CAN'T OPEN { // THEN CREAYE NEW FILE setcolor(BLUE); settextstyle(3,0,2); outtextxy(150,250,"CREATING NEW FILE "); outtextxy(350,250,file); settextstyle(2,0,6); outtextxy(350,400,"PRESS ANY KEY TO CONTINUE..."); getch(); current=new (struct line); //MAKE A NODE FOR WORKING current->up=NULL; //ASSIGN VARIOUS PARAMETERS current->down=NULL; i++; current->x=0; current->y=0; current->len=0; current->string[0]=''; head=current; } else // IF FILE OPENS { copy(); //COPY ITS CONTENT TO DLL fin.close(); current=head; } calcx(); disp_editscr(); //DRAW EDITOR SCREEN disp_full(); // DISPLAY TEXT ON SCREEN int check; do // NOW DO THE FOLLOWING FOR ANY KEY PRESSED BY USER { check=getch(); if((check>=32&&check0) // UP ARROW PRESSED { current=current->up; curri--; if(curri==top-1) { top--; disp_full(); } else uparrow(); } else { setcolor(4); outtextxy(xmax/2+100,3,"Already at the top"); } break; case 80:if(curridown; curri++; if(curri==top+36) { top++; disp_full(); } else downarrow(); } else { setcolor(4); outtextxy(xmax/2+100,3,"Already at the bottom"); } break; case 75:if(current->x!=0) //LEFT ARROW PRESSED { current->x-=1; sidearrow(); } else { setcolor(4); outtextxy(xmax/2+100,3,"Already at left margin"); } break; case 77:if(current->xlen) //RIGHT ARROW PRESSED { current->x+=1; sidearrow(); } else { setcolor(4); outtextxy(xmax/2+100,3,"Already at right margin"); } break; case 83:save=0; //DELETE KEY PRESSED del(); break; case 82:if(!ins) //INSERT KEY PRESSED ins=1; else ins=0; position(); break; case 71:home(); //HOME KEY PRESSED break; case 79:end(); //END KEY PRESSED break; case 73:pageup(); //PAGE_UP KEY PRESSED break; case 81:pagedown(); //PAGE_DOWN KEY PRESSED break; case 59:savefile(); //F1 PRESSED break; case 60:save_as(); //F2 PRESSED break; case 61:newfile(); //F3 PRESSED break; case 62:quit(); //F4 PRESSED closegraph(); exit(0); break; } break; case -1:save=0; //INSERT THE VALID CHARACTER IN THE CURRENT LINE if(!ins) validchar(typed); else insert(typed); break; case 8 :save=0; //BACK_SPACE PRESSED bkspace(); break; } }while(1); } /* TO OPEN A NEW FILE WHILE EDITING*/ void newfile() { quit(); //QUIT FROM CURRENT FILE head=NULL; //RESET ALL GLOBAL VARIABLES last=NULL; i=-1; curri=0; currx=20; ins=0; top=0; save=1; iter++; cleardevice(); //START FROM BEGINING FOR NEW FILE setbkcolor(8); delay(500); editor(); } /* THE MAIN FUNCTION */ void main() { int gd=DETECT,gm; initgraph(&gd,&gm,""); editor(); // CALLING THE MAIN DRIVER FUNCTION }