- Qt 5.5
- Qt Quick
- Qt Quick Demo - Same Game
- samegame.js Example File
- Qt 5.5.1 Reference Documentation

# samegame.js Example File

demos/samegame/content/samegame.js

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
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    **
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    ** modification, are permitted provided that the following conditions are
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    /* This script file handles the game logic */
    .pragma library
    .import QtQuick.LocalStorage 2.0 as Sql

    var maxColumn = 10;
    var maxRow = 13;
    var types = 3;
    var maxIndex = maxColumn*maxRow;
    var board = new Array(maxIndex);
    var blockSrc = "Block.qml";
    var gameDuration;
    var component = Qt.createComponent(blockSrc);
    var gameCanvas;
    var betweenTurns = false;

    var puzzleLevel = null;
    var puzzlePath = "";

    var gameMode = "arcade"; //Set in new game, then tweaks behaviour of other functions
    var gameOver = false;

    function changeBlock(src)
    {
        blockSrc = src;
        component = Qt.createComponent(blockSrc);
    }

    // Index function used instead of a 2D array
    function index(column, row)
    {
        return column + row * maxColumn;
    }

    function timeStr(msecs)
    {
        var secs = Math.floor(msecs/1000);
        var m = Math.floor(secs/60);
        var ret = "" + m + "m " + (secs%60) + "s";
        return ret;
    }

    function cleanUp()
    {
        if (gameCanvas == undefined)
            return;
        // Delete blocks from previous game
        for (var i = 0; i < maxIndex; i++) {
            if (board[i] != null)
                board[i].destroy();
            board[i] = null;
        }
        if (puzzleLevel != null){
            puzzleLevel.destroy();
            puzzleLevel = null;
        }
        gameCanvas.mode = ""
    }

    function startNewGame(gc, mode, map)
    {
        gameCanvas = gc;
        if (mode == undefined)
            gameMode = "arcade";
        else
            gameMode = mode;
        gameOver = false;

        cleanUp();

        gc.gameOver = false;
        gc.mode = gameMode;
        // Calculate board size
        maxColumn = Math.floor(gameCanvas.width/gameCanvas.blockSize);
        maxRow = Math.floor(gameCanvas.height/gameCanvas.blockSize);
        maxIndex = maxRow * maxColumn;
        if (gameMode == "arcade") //Needs to be after board sizing
            getHighScore();

        // Initialize Board
        board = new Array(maxIndex);
        gameCanvas.score = 0;
        gameCanvas.score2 = 0;
        gameCanvas.moves = 0;
        gameCanvas.curTurn = 1;
        if (gameMode == "puzzle")
            loadMap(map);
        else//Note that we load them in reverse order for correct visual stacking
            for (var column = maxColumn - 1; column >= 0; column--)
                for (var row = maxRow - 1; row >= 0; row--)
                    createBlock(column, row);
        if (gameMode == "puzzle")
            getLevelHistory();//Needs to be after map load
        gameDuration = new Date();
    }

    var fillFound;  // Set after a floodFill call to the number of blocks found
    var floodBoard; // Set to 1 if the floodFill reaches off that node

    // NOTE: Be careful with vars named x,y, as the calling object's x,y are still in scope
    function handleClick(x,y)
    {
        if (betweenTurns || gameOver || gameCanvas == undefined)
            return;
        var column = Math.floor(x/gameCanvas.blockSize);
        var row = Math.floor(y/gameCanvas.blockSize);
        if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)
            return;
        if (board[index(column, row)] == null)
            return;
        // If it's a valid block, remove it and all connected (does nothing if it's not connected)
        floodFill(column,row, -1);
        if (fillFound <= 0)
            return;
        if (gameMode == "multiplayer" && gameCanvas.curTurn == 2)
            gameCanvas.score2 += (fillFound - 1) * (fillFound - 1);
        else
            gameCanvas.score += (fillFound - 1) * (fillFound - 1);
        if (gameMode == "multiplayer" && gameCanvas.curTurn == 2)
            shuffleUp();
        else
            shuffleDown();
        gameCanvas.moves += 1;
        if (gameMode == "endless")
            refill();
        else if (gameMode != "multiplayer")
            victoryCheck();
        if (gameMode == "multiplayer" && !gc.gameOver){
            betweenTurns = true;
            gameCanvas.swapPlayers();//signal, animate and call turnChange() when ready
        }
    }

    function floodFill(column,row,type)
    {
        if (board[index(column, row)] == null)
            return;
        var first = false;
        if (type == -1) {
            first = true;
            type = board[index(column,row)].type;

            // Flood fill initialization
            fillFound = 0;
            floodBoard = new Array(maxIndex);
        }
        if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)
            return;
        if (floodBoard[index(column, row)] == 1 || (!first && type != board[index(column, row)].type))
            return;
        floodBoard[index(column, row)] = 1;
        floodFill(column + 1, row, type);
        floodFill(column - 1, row, type);
        floodFill(column, row + 1, type);
        floodFill(column, row - 1, type);
        if (first == true && fillFound == 0)
            return; // Can't remove single blocks
        board[index(column, row)].dying = true;
        board[index(column, row)] = null;
        fillFound += 1;
    }

    function shuffleDown()
    {
        // Fall down
        for (var column = 0; column < maxColumn; column++) {
            var fallDist = 0;
            for (var row = maxRow - 1; row >= 0; row--) {
                if (board[index(column,row)] == null) {
                    fallDist += 1;
                } else {
                    if (fallDist > 0) {
                        var obj = board[index(column, row)];
                        obj.y = (row + fallDist) * gameCanvas.blockSize;
                        board[index(column, row + fallDist)] = obj;
                        board[index(column, row)] = null;
                    }
                }
            }
        }
        // Fall to the left
        fallDist = 0;
        for (column = 0; column < maxColumn; column++) {
            if (board[index(column, maxRow - 1)] == null) {
                fallDist += 1;
            } else {
                if (fallDist > 0) {
                    for (row = 0; row < maxRow; row++) {
                        obj = board[index(column, row)];
                        if (obj == null)
                            continue;
                        obj.x = (column - fallDist) * gameCanvas.blockSize;
                        board[index(column - fallDist,row)] = obj;
                        board[index(column, row)] = null;
                    }
                }
            }
        }
    }

    function shuffleUp()
    {
        // Fall up
        for (var column = 0; column < maxColumn; column++) {
            var fallDist = 0;
            for (var row = 0; row < maxRow; row++) {
                if (board[index(column,row)] == null) {
                    fallDist += 1;
                } else {
                    if (fallDist > 0) {
                        var obj = board[index(column, row)];
                        obj.y = (row - fallDist) * gameCanvas.blockSize;
                        board[index(column, row - fallDist)] = obj;
                        board[index(column, row)] = null;
                    }
                }
            }
        }
        // Fall to the left (or should it be right, so as to be left for P2?)
        fallDist = 0;
        for (column = 0; column < maxColumn; column++) {
            if (board[index(column, 0)] == null) {
                fallDist += 1;
            } else {
                if (fallDist > 0) {
                    for (row = 0; row < maxRow; row++) {
                        obj = board[index(column, row)];
                        if (obj == null)
                            continue;
                        obj.x = (column - fallDist) * gameCanvas.blockSize;
                        board[index(column - fallDist,row)] = obj;
                        board[index(column, row)] = null;
                    }
                }
            }
        }
    }

    function turnChange()//called by ui outside
    {
        betweenTurns = false;
        if (gameCanvas.curTurn == 1){
            shuffleUp();
            gameCanvas.curTurn = 2;
            victoryCheck();
        }else{
            shuffleDown();
            gameCanvas.curTurn = 1;
            victoryCheck();
        }
    }

    function refill()
    {
        for (var column = 0; column < maxColumn; column++) {
            for (var row = 0; row < maxRow; row++) {
                if (board[index(column, row)] == null)
                    createBlock(column, row);
            }
        }
    }

    function victoryCheck()
    {
        // Awards bonuses for no blocks left
        var deservesBonus = true;
        if (board[index(0,maxRow - 1)] != null || board[index(0,0)] != null)
            deservesBonus = false;
        // Checks for game over
        if (deservesBonus){
            if (gameCanvas.curTurn = 1)
                gameCanvas.score += 1000;
            else
                gameCanvas.score2 += 1000;
        }
        gameOver = deservesBonus;
        if (gameCanvas.curTurn == 1){
            if (!(floodMoveCheck(0, maxRow - 1, -1)))
                gameOver = true;
        }else{
            if (!(floodMoveCheck(0, 0, -1, true)))
                gameOver = true;
        }
        if (gameMode == "puzzle"){
            puzzleVictoryCheck(deservesBonus);//Takes it from here
            return;
        }
        if (gameOver) {
            var winnerScore = Math.max(gameCanvas.score, gameCanvas.score2);
            if (gameMode == "multiplayer"){
                gameCanvas.score = winnerScore;
                saveHighScore(gameCanvas.score2);
            }
            saveHighScore(gameCanvas.score);
            gameDuration = new Date() - gameDuration;
            gameCanvas.gameOver = true;
        }
    }

    // Only floods up and right, to see if it can find adjacent same-typed blocks
    function floodMoveCheck(column, row, type, goDownInstead)
    {
        if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)
            return false;
        if (board[index(column, row)] == null)
            return false;
        var myType = board[index(column, row)].type;
        if (type == myType)
            return true;
        if (goDownInstead)
            return floodMoveCheck(column + 1, row, myType, goDownInstead) ||
                   floodMoveCheck(column, row + 1, myType, goDownInstead);
        else
            return floodMoveCheck(column + 1, row, myType) ||
                   floodMoveCheck(column, row - 1, myType);
    }

    function createBlock(column,row,type)
    {
        // Note that we don't wait for the component to become ready. This will
        // only work if the block QML is a local file. Otherwise the component will
        // not be ready immediately. There is a statusChanged signal on the
        // component you could use if you want to wait to load remote files.
        if (component.status == 1){
            if (type == undefined)
                type = Math.floor(Math.random() * types);
            if (type < 0 || type > 4) {
                console.log("Invalid type requested");//TODO: Is this triggered by custom levels much?
                return;
            }
            var dynamicObject = component.createObject(gameCanvas,
                    {"type": type,
                    "x": column*gameCanvas.blockSize,
                    "y": -1*gameCanvas.blockSize,
                    "width": gameCanvas.blockSize,
                    "height": gameCanvas.blockSize,
                    "particleSystem": gameCanvas.ps});
            if (dynamicObject == null){
                console.log("error creating block");
                console.log(component.errorString());
                return false;
            }
            dynamicObject.y = row*gameCanvas.blockSize;
            dynamicObject.spawned = true;

            board[index(column,row)] = dynamicObject;
        }else{
            console.log("error loading block component");
            console.log(component.errorString());
            return false;
        }
        return true;
    }

    function showPuzzleError(str)
    {
        //TODO: Nice user visible UI?
        console.log(str);
    }

    function loadMap(map)
    {
        puzzlePath = map;
        var levelComp = Qt.createComponent(puzzlePath);
        if (levelComp.status != 1){
            console.log("Error loading level");
            showPuzzleError(levelComp.errorString());
            return;
        }
        puzzleLevel = levelComp.createObject();
        if (puzzleLevel == null || !puzzleLevel.startingGrid instanceof Array) {
            showPuzzleError("Bugger!");
            return;
        }
        gameCanvas.showPuzzleGoal(puzzleLevel.goalText);
        //showPuzzleGoal should call finishLoadingMap as the next thing it does, before handling more events
    }

    function finishLoadingMap()
    {
        for (var i in puzzleLevel.startingGrid)
            if (! (puzzleLevel.startingGrid[i] >= 0 && puzzleLevel.startingGrid[i] <= 9) )
                puzzleLevel.startingGrid[i] = 0;
        //TODO: Don't allow loading larger levels, leads to cheating
        while (puzzleLevel.startingGrid.length > maxIndex) puzzleLevel.startingGrid.shift();
        while (puzzleLevel.startingGrid.length < maxIndex) puzzleLevel.startingGrid.unshift(0);
        for (var i in puzzleLevel.startingGrid)
            if (puzzleLevel.startingGrid[i] > 0)
                createBlock(i % maxColumn, Math.floor(i / maxColumn), puzzleLevel.startingGrid[i] - 1);

        //### Experimental feature - allow levels to contain arbitrary QML scenes as well!
        //while (puzzleLevel.children.length)
        //    puzzleLevel.children[0].parent = gameCanvas;
        gameDuration = new Date(); //Don't start until we finish loading
    }

    function puzzleVictoryCheck(clearedAll)//gameOver has also been set if no more moves
    {
        var won = true;
        var soFar = new Date() - gameDuration;
        if (puzzleLevel.scoreTarget != -1 && gameCanvas.score < puzzleLevel.scoreTarget){
            won = false;
        } if (puzzleLevel.scoreTarget != -1 && gameCanvas.score >= puzzleLevel.scoreTarget && !puzzleLevel.mustClear){
            gameOver = true;
        } if (puzzleLevel.timeTarget != -1 && soFar/1000.0 > puzzleLevel.timeTarget){
            gameOver = true;
        } if (puzzleLevel.moveTarget != -1 && gameCanvas.moves >= puzzleLevel.moveTarget){
            gameOver = true;
        } if (puzzleLevel.mustClear && gameOver && !clearedAll) {
            won = false;
        }

        if (gameOver) {
            gameCanvas.gameOver = true;
            gameCanvas.showPuzzleEnd(won);

            if (won) {
                // Store progress
                saveLevelHistory();
            }
        }
    }

    function getHighScore()
    {
        var db = Sql.LocalStorage.openDatabaseSync(
            "SameGame",
            "2.0",
            "SameGame Local Data",
            100
        );
        db.transaction(
            function(tx) {
                tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(game TEXT, score NUMBER, gridSize TEXT, time NUMBER)');
                // Only show results for the current grid size
                var rs = tx.executeSql('SELECT * FROM Scores WHERE gridSize = "'
                    + maxColumn + "x" + maxRow + '" AND game = "' + gameMode + '" ORDER BY score desc');
                if (rs.rows.length > 0)
                    gameCanvas.highScore = rs.rows.item(0).score;
                else
                    gameCanvas.highScore = 0;
            }
        );
    }

    function saveHighScore(score)
    {
        // Offline storage
        var db = Sql.LocalStorage.openDatabaseSync(
            "SameGame",
            "2.0",
            "SameGame Local Data",
            100
        );
        var dataStr = "INSERT INTO Scores VALUES(?, ?, ?, ?)";
        var data = [
            gameMode,
            score,
            maxColumn + "x" + maxRow,
            Math.floor(gameDuration / 1000)
        ];
        if (score >= gameCanvas.highScore)//Update UI field
            gameCanvas.highScore = score;

        db.transaction(
            function(tx) {
                tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(game TEXT, score NUMBER, gridSize TEXT, time NUMBER)');
                tx.executeSql(dataStr, data);
            }
        );
    }

    function getLevelHistory()
    {
        var db = Sql.LocalStorage.openDatabaseSync(
            "SameGame",
            "2.0",
            "SameGame Local Data",
            100
        );
        db.transaction(
            function(tx) {
                tx.executeSql('CREATE TABLE IF NOT EXISTS Puzzle(level TEXT, score NUMBER, moves NUMBER, time NUMBER)');
                var rs = tx.executeSql('SELECT * FROM Puzzle WHERE level = "' + puzzlePath + '" ORDER BY score desc');
                if (rs.rows.length > 0) {
                    gameCanvas.puzzleWon = true;
                    gameCanvas.highScore = rs.rows.item(0).score;
                } else {
                    gameCanvas.puzzleWon = false;
                    gameCanvas.highScore = 0;
                }
            }
        );
    }

    function saveLevelHistory()
    {
        var db = Sql.LocalStorage.openDatabaseSync(
            "SameGame",
            "2.0",
            "SameGame Local Data",
            100
        );
        var dataStr = "INSERT INTO Puzzle VALUES(?, ?, ?, ?)";
        var data = [
            puzzlePath,
            gameCanvas.score,
            gameCanvas.moves,
            Math.floor(gameDuration / 1000)
        ];
        gameCanvas.puzzleWon = true;

        db.transaction(
            function(tx) {
                tx.executeSql('CREATE TABLE IF NOT EXISTS Puzzle(level TEXT, score NUMBER, moves NUMBER, time NUMBER)');
                tx.executeSql(dataStr, data);
            }
        );
    }

    function nuke() //For "Debug mode"
    {
        for (var row = 1; row <= 5; row++) {
            for (var col = 0; col < 5; col++) {
                if (board[index(col, maxRow - row)] != null) {
                    board[index(col, maxRow - row)].dying = true;
                    board[index(col, maxRow - row)] = null;
                }
            }
        }
        if (gameMode == "multiplayer" && gameCanvas.curTurn == 2)
            shuffleUp();
        else
            shuffleDown();
        if (gameMode == "endless")
            refill();
        else
            victoryCheck();
    }