Delphi MVC

Samples of Delphi App with MVC Pattern, used for educational purposes.

Please note: The examples are simplified and not complete.

Examples:

Calculator

1. Calculator_VCL_Flat (no MVC)

A simple calculator without MVC pattern implementation.

2. Calculator_MVC (Enhanced - VCL & FMX)

A full-featured calculator application implementing the MVC pattern with both VCL and FireMonkey (FMX) support, demonstrating true cross-platform architecture.

Features:

• Standard Calculator: Basic arithmetic operations with a clean, modern interface
• Scientific Calculator: Extended with 6 scientific operations:
  • |x| - Absolute value
  • x³ - Cube
  • exp - Exponential (e^x)
  • x^y - Power (binary operation)
  • 10^x - Power of 10
  • log - Base-10 logarithm
• Theme Selector (VCL only): Runtime enumeration and selection of VCL styles
• Font Selector (VCL only): System font selection with live preview
• Navigation Menu:
  • VCL: TSplitView with TCategoryButtons for easy navigation
  • FMX: TMultiView (Drawer mode) with TListBox for mobile-friendly navigation
• Settings Persistence: Theme and window position saved to .ini file

Architecture:

• Model-View-Controller Pattern: Clean separation of concerns
  • Model: Pure business logic and mathematical operations (shared between VCL and FMX)
  • View: Reusable frames implementing ICalculatorView interface
  • Controller: Mediates between Model and View (shared between VCL and FMX)
• Frame-Based UI: Modular, reusable components for both VCL and FMX
• Shared Business Logic: Model and Controller units work with both UI frameworks
• Platform-Specific Views: Separate frame implementations for VCL and FMX
• Full Keyboard Support: Complete keyboard input for both calculators (VCL)
• Error Handling: Robust validation (division by zero, invalid logarithms, etc.)
• Unicode Symbols: Mathematical symbols for better visualization

Technical Highlights:

Common (VCL & FMX):

• Frame switching with dynamic Controller management
• Separate Controllers for Standard and Scientific calculators
• GridPanel/GridLayout for responsive button grids
• Comprehensive XML documentation for educational purposes

VCL-Specific:

• TSplitView with overlay mode for slide-in menu
• TCategoryButtons with two categories (Calculator, Settings)
• VCL Actions for operation handling
• Intelligent keyboard input forwarding to active frame

FMX-Specific:

• TMultiView in Drawer mode for mobile-friendly navigation
• TListBox with custom styled items for menu
• Cross-platform compatibility (Windows, macOS, iOS, Android)
• Touch-friendly interface with larger buttons
• Responsive layouts using TGridLayout

Project Structure:

Calculator_MVC/
├── Sources/
│   ├── Calculator.Types.pas          (Shared - VCL & FMX)
│   ├── Calculator.Model.pas          (Shared - VCL & FMX)
│   ├── Calculator.Controller.pas     (Shared - VCL & FMX)
│   ├── Calculator.Resources.pas/dfm  (Shared - VCL & FMX)
│   │
│   ├── Calculator.MainForm.pas/dfm            (VCL Main Form)
│   ├── Calculator.CalculatorFrame.pas/dfm     (VCL Standard Frame)
│   ├── Calculator.ScientificFrame.pas/dfm     (VCL Scientific Frame)
│   ├── Calculator.ThemeFrame.pas/dfm          (VCL Theme Selector)
│   ├── Calculator.FontFrame.pas/dfm           (VCL Font Selector)
│   │
│   ├── Calculator.MainForm.FMX.pas/fmx        (FMX Main Form)
│   ├── Calculator.CalculatorFrame.FMX.pas/fmx (FMX Standard Frame)
│   └── Calculator.ScientificFrame.FMX.pas/fmx (FMX Scientific Frame)
│
└── Projects/
    ├── Calculator.VCL.MVC.Project.dpr  (VCL Windows Application)
    └── Calculator.FMX.MVC.Project.dpr  (FMX Cross-Platform Application)

Code Reusability:

• ~60% shared code: Model, Controller, and Types units work identically in both frameworks
• ~40% platform-specific: UI frames and main forms adapted for VCL/FMX
• Demonstrates best practices for maximizing code reuse in multi-platform Delphi applications

Orders/Customers

1. MVC_Simple_Orders
2. MVC_Orders_Customers
3. MVC_Orders_Customers_IO

Delphi Day 2025

Demos and exercises for Delphi Day Seminar - Piacenza 16 June 2025

Licensing

Copyright (c) 2025 (Ethea S.r.l.)

Author: Carlo Barazzetta

Contributors: Claude Code

Licensed under the Apache License, Version 2.0 (the "License");