Package com.gonzales.mark.n_puzzle

Package containing all the Kotlin classes, resources, and Gradle files for configuring and running the application.

About the Project

8-Puzzle is a sliding puzzle game that features a walkthrough of the optimal solution and allows users to customize the tiles using photos selected from their Gallery. In finding the optimal path from the current puzzle state to the goal state, the system employs the informed search algorithm A* and uses Manhattan distance as an admissible and consistent heuristic to estimate the cost.

Inspired by an exercise in our Mobile Development class, I started creating this app during our university break, after finishing my second year of undergraduate studies. As one of my first personal projects, working on this was an opportunity to synthesize concepts and practices that I learned from our sophomore courses, such as:

Exploration of language features (Advanced Programming and Theory of Programming Languages)
Program optimization (Algorithms and Complexity)
Artificial intelligence and search algorithms (Introduction to Intelligent Systems)
Quality assurance and unit testing (Introduction to Software Engineering)

This project also utilizes a continuous integration/continuous delivery (CI/CD) pipeline — which is the focus of our third-year class Advanced Software Engineering.

Types

AnimationUtil

class AnimationUtil

Utility class providing constants related to timing the animations in the app.

FlingDetector

class FlingDetector

Class providing the constants and methods for identifying the direction of a fling gesture.

FlingDirection

enum FlingDirection : Enum<FlingDirection>

Enumeration class containing the directions of the fling gestures registered by the app (namely, the four cardinal directions) and an INVALID entry for unrecognized directions.

GridViewGesture

class GridViewGesture : GridView

Class extending GridView to register fling gestures.

ImageUtil

class ImageUtil

Utility class providing constants and methods for manipulating the puzzle image.

Key

enum Key : Enum<Key>

Enumeration class containing the keys used in handling bundles and shared preferences.

MoveUtil

class MoveUtil

Utility class providing methods for moving the tiles in the puzzle grid.

Node

data class Node(puzzleStatePair: StatePair, parent: Node?, g: Int, h: Int)

Data class corresponding to a node.

NodeByF

class NodeByF : Comparator<Node>

Comparator for nodes based on their f-values (in reference to the A* algorithm).

NPuzzleActivity

class NPuzzleActivity : AppCompatActivity

Class handling the core functionalities of this 8-puzzle app, including the actual gameplay.

OnFlingListener

interface OnFlingListener

Interface for responding to detected fling gestures.

PuzzleImage

enum PuzzleImage(drawableId: Int) : Enum<PuzzleImage>

Enumeration class containing the puzzle images that come with the app.

PuzzleUtil

class PuzzleUtil

Utility class providing methods related to the puzzle state.

RequestCode

enum RequestCode : Enum<RequestCode>

Class containing the codes used in requesting permissions related to launching activities related to the Gallery of the device.

ShuffleRunnable

class ShuffleRunnable(handler: Handler, tilePosition: Int, numTiles: Int) : Runnable

Runnable class related to shuffling the puzzle tiles.

ShuffleUtil

class ShuffleUtil

Utility class providing methods for shuffling the puzzle tiles.

SolveStatus

enum SolveStatus(successMessageId: Int) : Enum<SolveStatus>

Enumeration class containing the possible game statuses depending on whether user solves the puzzle or opts to play the solution walkthrough instead.

SolveUtil

class SolveUtil

Utility class providing constants and methods related to solving an 8-puzzle.

SpinnerAdapter

class SpinnerAdapter(context: Context?, textViewResourceId: Int, objects: Array<String?>?) : ArrayAdapter<String?>

Adapter for the spinner that handles the selection of the puzzle image.

SplashScreenActivity

class SplashScreenActivity : AppCompatActivity

Class handling the display of the splash screen and the loading of initial resources needed during app startup.

StatePair

data class StatePair(puzzleState: ArrayList<Int>, blankTilePos: Int)

Pair representing a puzzle state (flattened into one dimension, following row-major order) alongside the position of the blank tile in the puzzle grid (zero-based, following row-major order).

TileAdapter

class TileAdapter(tileImages: ArrayList<ImageButton>, tileWidth: Int, tileHeight: Int) : BaseAdapter

Adapter for GridViewGesture that handles the tiles in the puzzle grid.

TimeUtil

class TimeUtil

Utility class providing constants and methods related to the app's timer.

UploadUtil

class UploadUtil

Utility class providing methods for choosing a photo from the Gallery as the custom puzzle image.