Notepad_Application

Windows console notepad for a Data Structures assignment. The document is a 2-D linked grid (Node with left / right / up / down), not a char[][] buffer. File menu: new, load, save, exit. Visual Studio project id i222327_Assignment02.

Sources: Header.h, Source.cpp
Solution: Project1.sln · i222327_Assignment02.vcxproj
Author: Mohammad Rohaan (22I-2327) · rohaan2802

rohaan.txt in this repo restates the brief: do not use arrays for the document; use linked lists; map keys for save / next line; insertion and deletion must work before undo/redo would be marked.

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Table of contents

1. What this program does
2. Architecture
3. Data structure
4. File-by-file
5. Console geometry and chrome
6. Menus and persistence
7. Keyboard input (Source.cpp)
8. Load-file editor (load_file)
9. Data files
10. Build and run
11. Limitations
12. Author

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What this program does

1. Maximize the console (maximizeConsole / ShowWindow(..., SW_MAXIMIZE)).
2. Show a numbered file menu (show_menu).
3. Draw a framed writing area (display_fun).
4. Accept letters, arrows, Enter, Backspace, and F1 (back to menu).
5. Store each typed character in a linked_list of Node cells and, on insert, append to a .txt file via insert_character.

This is a custom text editor, not Microsoft Notepad. Digits, punctuation, and Unicode are not part of the insert path in main.

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Architecture

main()                    Header.h globals + menu
  maximizeConsole()
  show_menu()             1 New / 2 Load / 3 Save / 4 Exit
  display_fun()           frame + SEARCH / WORD SUGGESTIONS chrome
  ReadConsoleInput loop   arrows, letters, Enter, Backspace, F1
        │
        ├── list.insert_at_end / list.delete_at_end / list.fun1
        ├── insert_character  → ofstream append to file_
        └── F1 → show_menu()

Header.h is not a pure header: it defines Node, linked_list, show_menu, create_file, load_file, insert_character, save_file, and Win32 helpers. Source.cpp includes it and runs the live editor loop.

Two list objects exist:

Object	Where	Used by
list1	Header.h	load_file
list	Source.cpp	main key loop

They do not share nodes. Loading a file fills list1; typing in the main loop fills list.

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Data structure

class Node
  char data
  Node* left, *right, *up, *down
  Node(char value)  // all links nullptr

class linked_list
  Node* head
  insert_at_end(char value, int &x, int &y)
  delete_at_end(int x, int y)
  fun1(int x)              // reprint one row at gotoxy(1, x)
  delete_from_file()       // rewrite file_ from the grid

insert_at_end walks down x times (creating \0 row sentinels if needed), then right y times (creating \0 column sentinels), then splices a new character node and wires up/down to the previous row.

delete_at_end walks to (x, y), copies the next node’s data leftward (or writes '\0'), then calls delete_from_file().

The assignment point is that links are the document. Cursor motion uses integer x,y plus gotoxy, not a stored “current node” pointer.

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File-by-file

File	Role
Header.h	Constants, globals, Node / linked_list, menu, file I/O, Win32 UI
Source.cpp	main: maximize, menu, ReadConsoleInput editor
Project1.sln	Visual Studio solution
i222327_Assignment02.vcxproj	MSBuild project (assignment id)
i222327_Assignment02.vcxproj.filters	Solution Explorer filters
er.txt	Sample / scratch text (may be empty)
rohaan.txt	Assignment notes plus leftover typed text
.gitattributes / .gitignore	Git metadata

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Console geometry and chrome

From Header.h:

Constant	Value	Meaning
left_	1	Left of writing area
top_	0	Top row
right_	143	Right bound
bottom_	31	Bottom row

gotoxy uses SetConsoleCursorPosition. clear_fun overwrites 30 rows with spaces. Hitting y == bottom_ && x == right_ - 1 sets isFull and calls warning_msg() (MessageBox: “Writing space is full.”).

display_fun prints a pipe-bordered banner that includes the word SEARCH on the first line and WORD SUGGESTIONS under the frame. Those labels are layout only; there is no search or dictionary function.

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Menus and persistence

show_menu (invalid choice recurses; Save uses goto label):

Choice	Action
1 New File	create_file()
2 Load File	load_file(x, y, isFull)
3 Save File	If safe_flag, saved_msg(); else “CREATE FILE FIRST OR LOAD FILE”
4 Exit	If safe_flag, confrim_msg(); IDYES → saved_msg() then exit(0)

create_file / load_file read up to 12 name characters, then append .txt into file_[20]. create_file opens the file and sets safe_flag = true.

Declared helpers:

• insert_character(char ch) — ios::app one character to file_
• save_file() — list1.delete_from_file() (rewrites from list1, not Source.cpp’s list)
• confrim_msg() — “Do you want to save the file before exiting?” (MB_YESNO)
• saved_msg() — “File saved successfully!”

Menu cases 3 and 4 never call save_file(). Typing in main persists only through insert_character appends. Backspace in main rewrites via list.delete_from_file().

Globals: ofstream obj1, ifstream obj_2, flag, safe_flag, isFull, file_.

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Keyboard input (Source.cpp)

main uses GetNumberOfConsoleInputEvents / ReadConsoleInput on INPUT_RECORD (up to 200 events). First key clears the frame via clear_fun.

Key	Handler
VK_UP / VK_DOWN	Move y within top_…bottom_
VK_LEFT	Decrement x if x > left_
VK_RIGHT	If x < right_ - 1, insert_character(' ') and increment x
VK_RETURN	Next row, x = left_, insert_character('\n')
VK_BACK	list.delete_at_end(y, x) then list.fun1(y) to redraw the row
VK_F1	cls + show_menu()
Default / letters	After the switch, AsciiChar in A–Z / a–z → list.insert_at_end + echo + insert_character

The while (Running) loop never sets Running = false; exit is exit(0) from menu option 4. Space is not inserted in this loop (only letters). VK_RIGHT appends spaces to the file without inserting a Node.

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Load-file editor (load_file)

If file_ opens:

1. display_fun(), then read characters with obj_2.get.
2. Keep letters, space, and '\n' (skip other bytes).
3. Insert into list1 with insert_at_end(file_char, y, x) (note argument order vs main, which passes y, x as well).
4. Wrap at right_; full-buffer → warning_msg.
5. If not full, a nested _getch() loop until Esc (27): letters, Backspace, Enter (\r), space. Then show_menu().

If the file is missing, it creates file_ (ios::out), sets safe_flag, and returns without entering the nested editor.

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Data files

File	Contents
er.txt	Present in the tree; may be empty
rohaan.txt	Assignment constraints (no arrays for the document; key mappings; undo/redo not marked unless insert/delete work) plus leftover editor text

Working directory should be the folder that contains these .txt files so create_file / load_file resolve names.

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Build and run

Windows only: Windows.h, conio.h, HWND, MessageBoxW (L"..." strings), ReadConsoleInput.

1. Open Project1.sln in Visual Studio (Console subsystem).
2. Build and run, or cl Source.cpp with the Windows SDK (the .cpp includes Header.h).
3. Choose 1 or 2, then type in the frame. F1 returns to the menu. Esc leaves the load-file nested editor.

There is no CMake/g++ portable path: MessageBox and console APIs are Win32.

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Limitations

• SEARCH and WORD SUGGESTIONS are printed labels only.
• No undo/redo (mentioned in rohaan.txt; not implemented).
• save_file() is unused by the menu; Save/Exit dialogs do not rewrite the grid.
• Dual lists (list vs list1) desynchronize load vs type-in-main.
• Insert in main is letters only; load path also allows space/newline.
• file_[20] and other C arrays exist for names/UI; the document is the linked grid.
• show_menu uses goto and recursion on invalid input.
• Implementations live in Header.h (slower incremental builds, ODR risk if included twice).

Extend (only if you add it): one shared list; call save_file from menu 3/4; wire search; digits/punctuation; real undo stack.

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Author

Mohammad Rohaan — 22I-2327
https://github.com/rohaan2802