Gantt Manager – Java Swing Application

A Java-based desktop application for loading, filtering, reporting, and visualising Gantt chart project data. Built as a group project for the academic year 2022‑23.

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Table of Contents

• Overview
• Features
• Architecture & Design
• Key Components
• Data Format
• How to Run
• Testing
• Results & Observations
• Future Improvements

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Overview

Gantt Manager is a three‑tier Java application that parses TSV (tab‑separated) files describing project tasks, computes derived properties for composite tasks, and provides:

• Console‑based execution via NaiveClient
• Swing GUI with file choosers, filter dialogs, tabular views, and a Gantt‑like raster visualisation (via AppStarter)
• Report generation in plain text, Markdown, and HTML

The project follows a clear separation of concerns: backend (core logic), dom2app (data transfer model), and app (orchestration + GUI).

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Features

Feature	Description
Load TSV files	Parse tab‑separated project files with columns: TaskId, TaskText, MamaId, Start, End, Cost
Auto‑compute composite tasks	Tasks with no explicit dates ("-") derive Start/End/Cost from their sub‑tasks
Topological sorting	Tasks are sorted so that top‑level tasks appear before their children, ordered by Start date
Filter by prefix	Search tasks whose description starts with a given text (case‑insensitive)
Filter by ID	Retrieve a single task by its numeric ID
Top‑level tasks	Extract only tasks with MamaId = 0
Raster (Gantt) view	Transform table data into a time‑ranged matrix suitable for Gantt‑chart visualisation
Export reports	Generate TXT, Markdown, and HTML reports of the sorted project
Swing GUI	Full desktop interface with menus, file choosers, and internal frames
JUnit tests	6 unit tests covering load, filters, and edge cases

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Architecture & Design

The application follows a three‑tier architecture: ┌──────────────────────────────────────────────┐ │ app (Orchestration + GUI) │ │ AppController, AppStarter, NaiveClient │ ├──────────────────────────────────────────────┤ │ backend (Business Logic) │ │ IMainController, MainController, ReportType │ ├──────────────────────────────────────────────┤ │ dom2app (Data Transfer) │ │ SimpleTableModel, SimpleRasterModel │ └──────────────────────────────────────────────┘

Design Patterns

• Factory Pattern – MainControllerFactory creates IMainController implementations
• Interface Segregation – IMainController defines the contract between front‑end and back‑end
• MVC‑like separation – SimpleTableModel / SimpleRasterModel extend AbstractTableModel (Swing's MVC)

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Key Components

Class	Package	Responsibility
IMainController	backend	Interface defining all core operations
MainController	backend	Implements load, filter, sort, and report generation logic
MainControllerFactory	backend	Factory for creating MainController instances
ReportType	backend	Enum: TEXT, MD, HTML
SimpleTableModel	dom2app	Extends AbstractTableModel; holds column names and row data
SimpleRasterModel	app	Extends AbstractTableModel; represents Gantt‑raster data
AppController	app	Orchestrator: delegates to backend and converts between models
AppStarter	app.gui	Entry point for Swing GUI
JFrameLevel00RootFrame	app.gui	Main Swing frame with menus and internal frames
JTableViewer	app.gui.jtableview	Renders AbstractTableModel in a JTable
NaiveClient	app.naive	Console‑based demo client

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Data Format

Input files are tab‑separated (TSV) with exactly 6 columns:

Column	Meaning	Example
TaskId	Unique integer ID	100
TaskText	Human‑readable description	Prepare Fry
MamaId	Parent task ID (0 = top‑level)	0
Start	Start day (integer)	1
End	End day (integer)	12
Cost	Numeric cost	60

Composite tasks have "-" for Start, End, and Cost. Their values are automatically computed as:

• Start = minimum Start of all sub‑tasks
• End = maximum End of all sub‑tasks
• Cost = sum of all sub‑task costs

Sample Data (EggsScrambled.tsv)

100 Prepare Fry 0 1 12 60 101 Turn on burner (low) 100 1 1 10 102 Break eggs and pour into fry 100 2 4 10 103 Steer mixture to avoid sticking 100 5 10 10 104 Throw yellow cheese into fry 100 6 12 10 105 Salt, pepper 100 5 5 10 106 Turn burner off 100 12 12 10 200 Prepare the bread 0 10 12 20 201 Heat bread in toaster 200 10 12 10 202 Little bit of salt, galric spice 200 12 12 10 300 Serve eggs 0 13 20 30 301 Put bread in plate 300 13 13 10 302 Put eggs on bread 300 14 14 10 303 Wash fry 300 15 20 10

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How to Run

Prerequisites

• Java Development Kit (JDK 8 or later)
• Eclipse IDE (project includes .classpath and .project files) or any IDE supporting Java

Option 1 – Using Eclipse

1. Clone the repository:

   git clone https://github.com/MikeMiaris/gantt-chart-java.git
   

2. In Eclipse: File → Import → Existing Projects into Workspace
3. Navigate to the gantt-chart-java/4633_4645_4735_GanttManager folder 4.Select the project and click Finish 5.Right-click src/main/java/app/gui/AppStarter.java → Run As → Java Application

Option 2 - Command Line (Console Demo)

cd 4633_4645_4735_GanttManager javac -d bin src/main/java/**/*.java java -cp bin app.naive.NaiveClient

Option 3 – Run Tests

java -cp bin:lib/junit-4.13.2.jar:lib/hamcrest-core-1.3.jar org.junit.runner.JUnitCore test.MainControllerTest

Testing

The project includes 6 JUnit tests in MainControllerTest.java:

Test Method	What It Verifies
testLoad()	TSV loading and expected row ordering after sorting
testGetTopLevelTasks()	Correct extraction of tasks with MamaId = 0
testGetTaskByPrefix()	Case‑insensitive prefix search (e.g., "put" → "Put eggs on bread", "Put bread in plate")
testGetTaskByPrefix2()	Graceful handling of non‑matching prefix ("cook" → error message row)
testGetTaskById()	Exact ID lookup
testGetTaskById2()	Graceful handling of non‑existent ID (120 → error message row)

All tests pass successfully against the EggsScrambled.tsv fixture.

Results & Observations

• Composite task computation works reliably: parent tasks dynamically derive their Start, End, and Cost from children.
• Sorting algorithm (manual bubble‑sort) correctly orders tasks hierarchically: top‑level tasks appear before their descendants, both sorted by Start date and then by TaskId for tie‑breaking.
• Filter functions include helpful error messages when no match is found, rather than returning empty results.
• Report generation automatically appends the correct file extension (.txt, .md, .html) if omitted by the user.
• The Gantt raster view successfully maps time‑based data onto a 2D matrix suitable for visual representation in a JTable.

Future Improvements

Repository & Structure

• Add .gitignore to exclude bin/, .class, and IDE files
• Declare a proper Java package (e.g., com.ganttmanager) instead of default‑ish packages
• Add Maven/Gradle build to manage dependencies (JUnit, etc.)

Code Quality

• Replace raw List types with generics (e.g., List<String[]> instead of List)
• Fix spelling: "galric" → "garlic", "Steer" → "Stir", "mamaId" → "parentId" or "mammaId"
• Replace manual bubble‑sort with Comparator + Collections.sort() for clarity
• Use try-with‑resources consistently for file I/O
• Add Javadoc to all public methods

Features

• Drag‑and‑drop task editing in the GUI
• Export to PNG/PDF of the Gantt chart
• Undo/redo support
• Direct editing of task properties within the table view