MiniCalc

Table of content

• Description
• Project Structure
• How to run
• Keyboard Shortcuts
• Error Handling

Description

MiniCalc is a lightweight graphical calculator developed in C using the Xlib library. It provides a basic GUI interface and supports both mouse and keyboard interaction.The project implements the following functionalities:

• Basic arithmetic operations (+, -, *, /)
• Advanced operations (// - integer division, % - modulo)
• Handling of both integers and decimal numbers
• Full parentheses support ( and ) for complex expressions
• Change of sign operation (+/-)
• Memory operations (M+, MR, MC) for saving and recalling values
• Error handling (e.g., division by zero, unbalanced parentheses)
• Display of error messages inside the calculator screen
• Smooth redraw and interaction handling

Project Structure

MiniCalc/
|
├── include/       # Header files (gui.h, logic.h)
├── src/           # Source files (.c files: main.c, gui.c, logic.c)
├── Makefile       # Makefile for automated compilation
├── README.md      # Project documentation (this file)
├── bin/           # Folder containing the built executable
└── MiniCalc       # Final executable

How to Run

You can compile the project easily by running:

make run

This will:

• Compile all .c files
• Generate the MiniCalc executable inside the bin/ folder
• Run the executable (A running X server is required)

To clean the compiled files:

make clean

Keyboard Shortcuts

Key	Function
0-9	Insert digits
+ - * /	Arithmetic operators
.	Insert decimal point
( )	Insert parentheses
Enter	Calculate result (=)
Backspace	Delete last character (CE)
Delete	Clear the entire input (C)
m	M+ (store value in memory)
r	MR (recall value from memory)
c	MC (clear memory)
q or Escape	Exit the application

Error Handling

• Division by zero → displays "Division by zero is undefined"
• Unmatched parentheses → displays "Unmatched parentheses."
• Saving expressions to memory → displays "Cannot store expression in memory"
• Memory recall overflow → displays "Not enough space for memory value"
• Multiple decimal points prevention in one number