tetrixboard.js Example File
script/tetrix/tetrixboard.js

 function TetrixBoard(ui)
 {
     this.ui = ui;

     this.isStarted = false;
     this.isPaused = false;

     this._board = new Array(TetrixBoard.BoardWidth * TetrixBoard.BoardHeight);
     this.clearBoard();

     this.curPiece = new TetrixPiece();
     this.nextPiece = new TetrixPiece();
     this.nextPiece.setRandomShape();

     ui.timer.timeout.connect(this, this.onTimer);
     ui.keyPressed.connect(this, this.onKeyPress);
     ui.paintRequested.connect(this, this.onPaint);
     ui.paintNextPieceRequested.connect(this, this.onPaintNextPiece);
 }

 TetrixBoard.BoardWidth = 10;
 TetrixBoard.BoardHeight = 22;

 TetrixBoard.prototype.start = function() {
     if (this.isPaused)
         return;

     this.isStarted = true;
     this.isWaitingAfterLine = false;
     this.numLinesRemoved = 0;
     this.numPiecesDropped = 0;
     this.score = 0;
     this.level = 1;
     this.clearBoard();

     this.ui.linesRemovedChanged(this.numLinesRemoved);
     this.ui.scoreChanged(this.score);
     this.ui.levelChanged(this.level);

     this.newPiece();
     this.ui.timer.start(this.timeoutTime());
 }

 TetrixBoard.prototype.pause = function() {
     if (!this.isStarted)
         return;

     this.isPaused = !this.isPaused;
     if (this.isPaused) {
         this.ui.timer.stop();
     } else {
         this.ui.timer.start(this.timeoutTime());
     }
     this.ui.update();
 }

 TetrixBoard.prototype.getShapeAt = function(x, y) {
     return this._board[(y * TetrixBoard.BoardWidth) + x];
 }

 TetrixBoard.prototype.setShapeAt = function(x, y, newShape) {
     this._board[(y * TetrixBoard.BoardWidth) + x] = newShape;
 }

 TetrixBoard.prototype.clearBoard = function() {
     for (var i = 0; i < TetrixBoard.BoardHeight * TetrixBoard.BoardWidth; ++i)
         this._board[i] = TetrixShape.NoShape;
 }

 TetrixBoard.prototype.dropDown = function() {
     var dropHeight = 0;
     var newY = this.curY;
     while (newY > 0) {
         if (!this.tryMove(this.curPiece, this.curX, newY - 1))
             break;
         --newY;
         ++dropHeight;
     }
     this.pieceDropped(dropHeight);
 }

 TetrixBoard.prototype.oneLineDown = function() {
     if (!this.tryMove(this.curPiece, this.curX, this.curY - 1))
         this.pieceDropped(0);
 }

 TetrixBoard.prototype.pieceDropped = function(dropHeight) {
     for (var i = 0; i < 4; ++i) {
         var x = this.curX + this.curPiece.getX(i);
         var y = this.curY - this.curPiece.getY(i);
         this.setShapeAt(x, y, this.curPiece.shape);
     }

     ++this.numPiecesDropped;
     if ((this.numPiecesDropped % 25) == 0) {
         ++this.level;
         this.ui.timer.start(this.timeoutTime());
         this.ui.levelChanged(this.level);
     }

     this.score += dropHeight + 7;
     this.ui.scoreChanged(this.score);
     this.removeFullLines();

     if (!this.isWaitingAfterLine)
         this.newPiece();
 }

 TetrixBoard.prototype.removeFullLines = function() {
     var numFullLines = 0;

     for (var i = TetrixBoard.BoardHeight - 1; i >= 0; --i) {
         var lineIsFull = true;

         for (var j = 0; j < TetrixBoard.BoardWidth; ++j) {
             if (this.getShapeAt(j, i) == TetrixShape.NoShape) {
                 lineIsFull = false;
                 break;
             }
         }

         if (lineIsFull) {
             ++numFullLines;
             for (var k = i; k < TetrixBoard.BoardHeight - 1; ++k) {
                 for (var j = 0; j < TetrixBoard.BoardWidth; ++j)
                     this.setShapeAt(j, k, this.getShapeAt(j, k + 1));
             }
             for (var j = 0; j < TetrixBoard.BoardWidth; ++j)
                 this.setShapeAt(j, TetrixBoard.BoardHeight - 1, TetrixShape.NoShape);
         }
     }

     if (numFullLines > 0) {
         this.numLinesRemoved += numFullLines;
         this.score += 10 * numFullLines;
         this.ui.linesRemovedChanged(this.numLinesRemoved);
         this.ui.scoreChanged(this.score);

         this.ui.timer.start(500);
         this.isWaitingAfterLine = true;
         this.curPiece.shape = TetrixShape.NoShape;
         this.ui.update();
     }
 }

 TetrixBoard.prototype.newPiece = function() {
     this.curPiece = this.nextPiece;
     this.nextPiece = new TetrixPiece();
     this.nextPiece.setRandomShape();
     this.ui.showNextPiece(this.nextPiece.maxX - this.nextPiece.minX + 1,
                           this.nextPiece.maxY - this.nextPiece.minY + 1);
     this.curX = TetrixBoard.BoardWidth / 2 + 1;
     this.curY = TetrixBoard.BoardHeight - 1 + this.curPiece.minY;

     if (!this.tryMove(this.curPiece, this.curX, this.curY)) {
         this.curPiece.shape = TetrixShape.NoShape;
         this.ui.timer.stop();
         this.isStarted = false;
     }
 }

 TetrixBoard.prototype.tryMove = function(newPiece, newX, newY) {
     for (var i = 0; i < 4; ++i) {
         var x = newX + newPiece.getX(i);
         var y = newY - newPiece.getY(i);
         if ((x < 0) || (x >= TetrixBoard.BoardWidth) || (y < 0) || (y >= TetrixBoard.BoardHeight))
             return false;
         if (this.getShapeAt(x, y) != TetrixShape.NoShape)
             return false;
     }

     this.curPiece = newPiece;
     this.curX = newX;
     this.curY = newY;
     this.ui.update();
     return true;
 }

 TetrixBoard.prototype.onPaint = function(painter) {
     if (this.isPaused) {
         this.ui.drawPauseScreen(painter);
         return;
     }

     for (var i = 0; i < TetrixBoard.BoardHeight; ++i) {
         for (var j = 0; j < TetrixBoard.BoardWidth; ++j) {
             var shape = this.getShapeAt(j, TetrixBoard.BoardHeight - i - 1);
             if (shape != TetrixShape.NoShape)
                 this.ui.drawSquare(painter, j, i, shape);
         }
     }

     if (this.curPiece.shape != TetrixShape.NoShape) {
         for (var i = 0; i < 4; ++i) {
             var x = this.curX + this.curPiece.getX(i);
             var y = this.curY - this.curPiece.getY(i);
             this.ui.drawSquare(painter, x, TetrixBoard.BoardHeight - y - 1,
                                this.curPiece.shape);
         }
     }
 }

 TetrixBoard.prototype.onPaintNextPiece = function(painter) {
     for (var i = 0; i < 4; ++i) {
         var x = this.nextPiece.getX(i) - this.nextPiece.minX;
         var y = this.nextPiece.getY(i) - this.nextPiece.minY;
         this.ui.drawSquare(painter, x, y, this.nextPiece.shape);
     }
 }

 TetrixBoard.prototype.onKeyPress = function(key) {
     if (!this.isStarted || this.isPaused || (this.curPiece.shape == TetrixShape.NoShape))
         return;

     switch (key) {
         case Qt.Key_Left:
             this.tryMove(this.curPiece, this.curX - 1, this.curY);
             break;
         case Qt.Key_Right:
             this.tryMove(this.curPiece, this.curX + 1, this.curY);
             break;
         case Qt.Key_Down:
             this.tryMove(this.curPiece.rotatedRight(), this.curX, this.curY);
             break;
         case Qt.Key_Up:
             this.tryMove(this.curPiece.rotatedLeft(), this.curX, this.curY);
             break;
         case Qt.Key_Space:
             this.dropDown();
             break;
         case Qt.Key_D:
             this.oneLineDown();
             break;
     }
 }

 TetrixBoard.prototype.onTimer = function() {
     if (this.isWaitingAfterLine) {
         this.isWaitingAfterLine = false;
         this.newPiece();
         this.ui.timer.start(this.timeoutTime());
     } else {
         this.oneLineDown();
     }
 }

 TetrixBoard.prototype.timeoutTime = function() {
     return 1000 / (1 + this.level);
 }