Qt Reference Documentation

# samegame.js Example File

demos/declarative/samegame/qml/samegame/SamegameCore/samegame.js

     /* This script file handles the game logic */

     var maxColumn = 10;
     var maxRow = 15;
     var maxIndex = maxColumn*maxRow;
     var board = new Array(maxIndex);
     var blockSrc = "SamegameCore/BoomBlock.qml";
     var scoresURL = "";
     var gameDuration;
     var component = Qt.createComponent(blockSrc);
     var highScoreBar = 0;

     // 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 startNewGame()
     {
         // Delete blocks from previous game
         for (var i = 0; i < maxIndex; i++) {
             if (board[i] != null)
                 board[i].destroy();
         }

         // Calculate board size
         maxColumn = Math.floor(gameCanvas.width/gameCanvas.blockSize);
         maxRow = Math.floor(gameCanvas.height/gameCanvas.blockSize);
         maxIndex = maxRow * maxColumn;

         // Close dialogs
         nameInputDialog.forceClose();
         dialog.forceClose();

         // Initialize Board
         board = new Array(maxIndex);
         gameCanvas.score = 0;
         for (var column = 0; column < maxColumn; column++) {
             for (var row = 0; row < maxRow; row++) {
                 board[index(column, row)] = null;
                 createBlock(column, row);
             }
         }
         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)
     {
         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;
         gameCanvas.score += (fillFound - 1) * (fillFound - 1);
         shuffleDown();
         victoryCheck();
     }

     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 victoryCheck()
     {
         // Awards bonuses for no blocks left
         var deservesBonus = true;
         for (var column = maxColumn - 1; column >= 0; column--)
             if (board[index(column, maxRow - 1)] != null)
                 deservesBonus = false;
         if (deservesBonus)
             gameCanvas.score += 500;
         // Checks for game over
         if (deservesBonus || !(floodMoveCheck(0, maxRow - 1, -1))) {
             gameDuration = new Date() - gameDuration;
             if(gameCanvas.score > highScoreBar){
                 nameInputDialog.show("You won! Please enter your name:                 ");
                 nameInputDialog.initialWidth = nameInputDialog.text.width + 20;
                 if (nameInputDialog.name == "")
                     nameInputDialog.width = nameInputDialog.initialWidth;
                 nameInputDialog.text.opacity = 0; // Just a spacer
             }else{
                 dialog.show("You won!");
             }
         }
     }

     // Only floods up and right, to see if it can find adjacent same-typed blocks
     function floodMoveCheck(column, row, type)
     {
         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;
         return floodMoveCheck(column + 1, row, myType) ||
                floodMoveCheck(column, row - 1, board[index(column, row)].type);
     }

     function createBlock(column,row)
     {
         // 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 == Component.Ready){
             var dynamicObject = component.createObject(gameCanvas,
                     {"type": Math.floor(Math.random() * 3),
                     "x": column*gameCanvas.blockSize,
                     "width": gameCanvas.blockSize,
                     "height": gameCanvas.blockSize});
             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 initHighScoreBar()
     {
         if(scoresURL != "")
             return true;//don't query remote scores
         var db = openDatabaseSync(
             "SameGameScores",
             "1.0",
             "Local SameGame High Scores",
             100
         );
         db.transaction(
             function(tx) {
                 tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(name 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 + '" ORDER BY score desc LIMIT 10');
                 if(rs.rows.length < 10)
                     highScoreBar = 0;
                 else
                     highScoreBar = rs.rows.item(rs.rows.length - 1).score;
             }
         );
     }

     function saveHighScore(name)
     {
         if (scoresURL != "")
             sendHighScore(name);
         // Offline storage
         var db = openDatabaseSync(
             "SameGameScores",
             "1.0",
             "Local SameGame High Scores",
             100
         );
         var dataStr = "INSERT INTO Scores VALUES(?, ?, ?, ?)";
         var data = [
             name,
             gameCanvas.score,
             maxColumn + "x" + maxRow,
             Math.floor(gameDuration / 1000)
         ];
         db.transaction(
             function(tx) {
                 tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(name TEXT, score NUMBER, gridSize TEXT, time NUMBER)');
                 tx.executeSql(dataStr, data);

                 // Only show results for the current grid size
                 var rs = tx.executeSql('SELECT * FROM Scores WHERE gridSize = "'
                     + maxColumn + "x" + maxRow + '" ORDER BY score desc LIMIT 10');
                 var r = "\nHIGH SCORES for this grid size\n\n"
                 for (var i = 0; i < rs.rows.length; i++) {
                     r += (i+1) + ". " + rs.rows.item(i).name + ' got '
                         + rs.rows.item(i).score + ' points in '
                         + rs.rows.item(i).time + ' seconds.\n';
                 }
                 if(rs.rows.length == 10)
                     highScoreBar = rs.rows.item(9).score;
                 dialog.show(r);
             }
         );
     }

     function sendHighScore(name)
     {
         var postman = new XMLHttpRequest()
         var postData = "name=" + name + "&score=" + gameCanvas.score
             + "&gridSize=" + maxColumn + "x" + maxRow
             + "&time=" + Math.floor(gameDuration / 1000);
         postman.open("POST", scoresURL, true);
         postman.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
         postman.onreadystatechange = function() {
             if (postman.readyState == postman.DONE) {
                 dialog.show("Your score has been uploaded.");
             }
         }
         postman.send(postData);
     }