#!/usr/bin/python 
# -*- coding: utf-8 -*- 
 
 
import sys, random 
from PyQt4 import QtCore, QtGui 
 
 
class Tetris(QtGui.QMainWindow): 
  #Tetris的构造函数，由于是QMainWindow的子类，所以要先调用父类的构造函数 
  def __init__(self): 
    super(Tetris, self).__init__() 
    #QtGui.QMainWindow.__init__(self) 
    self.initUI() 
     
     
  def initUI(self):   
 
    self.tboard = Board(self)  #创建一个Board类的实例 
    self.setCentralWidget(self.tboard) #将游戏窗口放到屏幕的中间 
 
    self.statusbar = self.statusBar()  #创建状态栏    
    self.tboard.msg2Statusbar[str].connect(self.statusbar.showMessage) #3种可能的信息：1.score 2.game over 3.pause 
     
    self.tboard.start() #开始初始化程序 
     
    self.resize(180, 380)  #游戏窗口的大小 
    #self.resize(480, 380)  #游戏窗口的大小 
    self.center() 
    self.setWindowTitle('Tetris')  #窗口的名字     
    self.show() #这句一定不能忘了，显示窗口 
     
 
  def center(self): 
    #将游戏窗口放到屏幕的中间 
    screen = QtGui.QDesktopWidget().screenGeometry() 
    size = self.geometry() 
    self.move((screen.width()-size.width())/2,  
      (screen.height()-size.height())/2) 
     
 
class Board(QtGui.QFrame): 
   
  msg2Statusbar = QtCore.pyqtSignal(str) 
   
  #游戏窗口的宽和高（单位为块） 
  BoardWidth = 10   #宽度为10块 
  BoardHeight = 22  #高度为22块 
  Speed = 300 #游戏的速度 
 
  def __init__(self, parent): 
    super(Board, self).__init__(parent) 
     
    self.initBoard() 
     
     
  def initBoard(self):    
    ''''' 
    初始化一些关键的变量 
    ''' 
    self.timer = QtCore.QBasicTimer()  #创建一个定时器 
    self.isWaitingAfterLine = False 
     
    self.curX = 0 
    self.curY = 0 
    self.numLinesRemoved = 0 
    #a list of numbers from 0-7. 
    #It represents the position of various shapes and remains of the shapes on the board. 
    self.board = []  
     
 
    self.setFocusPolicy(QtCore.Qt.StrongFocus) 
    self.isStarted = False 
    self.isPaused = False 
    self.clearBoard() 
     
  #determine the type of a shape at a given block.   
  #返回(x,y)坐标处对应的点的类型 
  def shapeAt(self, x, y): 
    return self.board[(y * Board.BoardWidth) + x] 
 
  #设置(x,y)坐标处对应的点的类型 
  def setShapeAt(self, x, y, shape): 
    self.board[(y * Board.BoardWidth) + x] = shape 
     
  #calculate the width of the single square in pixels and return it 
  #The Board.BoardWidth is the size of the board in blocks 
  def squareWidth(self): 
    return self.contentsRect().width() / Board.BoardWidth 
     
 
  def squareHeight(self): 
    return self.contentsRect().height() / Board.BoardHeight 
     
 
  def start(self): 
     
    if self.isPaused:  #如果暂停，直接返回 
      return 
 
    self.isStarted = True 
    self.isWaitingAfterLine = False 
    self.numLinesRemoved = 0 
    self.clearBoard() 
 
    self.msg2Statusbar.emit(str(self.numLinesRemoved)) 
 
    self.newPiece() 
    self.timer.start(Board.Speed, self) 
 
     
  def pause(self): 
     
    if not self.isStarted: 
      return 
 
    self.isPaused = not self.isPaused 
     
    if self.isPaused: 
      self.timer.stop() 
      self.msg2Statusbar.emit("paused") 
       
    else: 
      self.timer.start(Board.Speed, self) 
      self.msg2Statusbar.emit(str(self.numLinesRemoved)) 
 
    self.update() 
 
     
  def paintEvent(self, event): 
     
    painter = QtGui.QPainter(self) 
    rect = self.contentsRect() 
 
    boardTop = rect.bottom() - Board.BoardHeight * self.squareHeight() 
 
    for i in range(Board.BoardHeight): 
      for j in range(Board.BoardWidth): 
        shape = self.shapeAt(j, Board.BoardHeight - i - 1) 
         
        if shape != Tetrominoe.NoShape: 
          self.drawSquare(painter, 
            rect.left() + j * self.squareWidth(), 
            boardTop + i * self.squareHeight(), shape) 
 
    if self.curPiece.shape() != Tetrominoe.NoShape: 
       
      for i in range(4): 
         
        x = self.curX + self.curPiece.x(i) 
        y = self.curY - self.curPiece.y(i) 
        self.drawSquare(painter, rect.left() + x * self.squareWidth(), 
          boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(), 
          self.curPiece.shape()) 
 
  #按键相应函数 
  def keyPressEvent(self, event): 
    #如果游戏没有开始（暂停）或者curPiece为空（游戏结束），响应父窗口的按键事件，返回 
    if not self.isStarted or self.curPiece.shape() == Tetrominoe.NoShape: 
      super(Board, self).keyPressEvent(event) 
      return 
     
    key = event.key()  #捕获按键 
     
    if key == QtCore.Qt.Key_P: #如果按键为P，暂停或者重新继续 
      self.pause() 
      return 
       
    if self.isPaused:  #暂停时不响应按键 
      return 
         
    elif key == QtCore.Qt.Key_Left:   #如果按下了左箭头会尝试向左移动（也有可能移动不了） 
      self.tryMove(self.curPiece, self.curX - 1, self.curY) 
       
    elif key == QtCore.Qt.Key_Right: 
      self.tryMove(self.curPiece, self.curX + 1, self.curY) 
       
    elif key == QtCore.Qt.Key_Down:   #按下下箭头，向右旋转 
      self.tryMove(self.curPiece.rotateRight(), self.curX, self.curY) 
       
    elif key == QtCore.Qt.Key_Up:    #按下上箭头，向左旋转 
      self.tryMove(self.curPiece.rotateLeft(), self.curX, self.curY) 
       
    elif key == QtCore.Qt.Key_Space:  #按下空格键，直接掉到底部 
      self.dropDown() 
       
    elif key == QtCore.Qt.Key_D: 
      self.oneLineDown() 
       
    else: 
      super(Board, self).keyPressEvent(event) 
         
 
  def timerEvent(self, event): 
    ''''' 
    we either create a new piece, after the previous one was dropped to the bottom, 
    or we move a falling piece one line down. 
    ''' 
    if event.timerId() == self.timer.timerId(): 
       
      if self.isWaitingAfterLine: 
        self.isWaitingAfterLine = False 
        self.newPiece() 
      else: 
        self.oneLineDown() 
         
    else: 
      super(Board, self).timerEvent(event) 
 
       
  def clearBoard(self): 
    #  清除board，全部设置为NoShape 
    for i in range(Board.BoardHeight * Board.BoardWidth): 
      self.board.append(Tetrominoe.NoShape) 
 
     
  def dropDown(self): 
     
    newY = self.curY 
     
    while newY > 0: 
      #使curPiece一直沿着y减小的方向移动，直到不能移动或者到达底部为止 
      if not self.tryMove(self.curPiece, self.curX, newY - 1): 
        break        
      newY -= 1  #自减1 
 
    self.pieceDropped() 
     
 
  def oneLineDown(self): 
     
    if not self.tryMove(self.curPiece, self.curX, self.curY - 1): 
      self.pieceDropped() 
       
  #到达底部的时候 
  def pieceDropped(self): 
     
    for i in range(4): 
       
      x = self.curX + self.curPiece.x(i) 
      y = self.curY - self.curPiece.y(i) 
      self.setShapeAt(x, y, self.curPiece.shape()) 
     
    self.removeFullLines() #清除排满的行 
 
    if not self.isWaitingAfterLine: #如果不是在暂停，开始新的块 
      self.newPiece() 
       
 
  def removeFullLines(self): 
    ''''' 
    If the piece hits the bottom, we call the removeFullLines() method. 
    We find out all full lines and remove them. 
    We do it by moving all lines above the current full line to be removed one line down. 
    Notice that we reverse the order of the lines to be removed. 
    Otherwise, it would not work correctly. 
    In our case we use a naive gravity. This means, that the pieces may be floating above empty gaps. 
    ''' 
    numFullLines = 0 
    rowsToRemove = [] 
 
    for i in range(Board.BoardHeight): 
       
      n = 0  #n记录每行shape的个数 
      for j in range(Board.BoardWidth): 
        if not self.shapeAt(j, i) == Tetrominoe.NoShape: 
          n = n + 1 
      #如果n等于10，将行号加入要删除的队列 
      if n == 10: 
        rowsToRemove.append(i) 
 
    rowsToRemove.reverse() #行号队列反置 
     
 
    for m in rowsToRemove: 
      #从m行以上的shape均下移一行 
      for k in range(m, Board.BoardHeight): 
        for l in range(Board.BoardWidth): 
            self.setShapeAt(l, k, self.shapeAt(l, k + 1)) 
 
    numFullLines = numFullLines + len(rowsToRemove) #统计消除的行数 
 
    if numFullLines > 0: 
       
      self.numLinesRemoved = self.numLinesRemoved + numFullLines 
      self.msg2Statusbar.emit(str(self.numLinesRemoved)) 
         
      self.isWaitingAfterLine = True 
      self.curPiece.setShape(Tetrominoe.NoShape) 
      self.update() 
       
 
  def newPiece(self): 
    ''''' 
    The newPiece() method creates randomly a new tetris piece. 
    If the piece cannot go into its initial position, the game is over. 
    随机地创建一个方块。如果方块不能在它起始的位置，游戏结束。 
    ''' 
    self.curPiece = Shape()   #当前块 
    self.curPiece.setRandomShape() #随机设置 
    self.curX = Board.BoardWidth / 2 + 1    #current X位置在中心 
    self.curY = Board.BoardHeight - 1 + self.curPiece.minY() 
     
 
    #将self.curPiece移动到当前的坐标处，如果不能移动，游戏结束。 
    #curPiece置为空，timer停止，显示消息'game over' 
    if not self.tryMove(self.curPiece, self.curX, self.curY): 
        
      self.curPiece.setShape(Tetrominoe.NoShape) 
      self.timer.stop() 
      self.isStarted = False 
      self.msg2Statusbar.emit("Game over") 
 
 
 
  def tryMove(self, newPiece, newX, newY): 
    ''''' 
    如果the shape is at the edge of the board 或者 is adjacent to some other piece, 返回False 
    否则的话，变动位置并返回True 
    ''' 
    for i in range(4): 
       
      x = newX + newPiece.x(i) 
      y = newY - newPiece.y(i) 
      ''''' 
      如果x<0说明已经到了左边缘;如果x>=Board.BoardWidth,说明已经到了右边缘 
      如果y<0说明已经到了底部;如果x>=Board.BoardHeight,说明已经到了最顶部 
      以上情况均不能移动，返回False 
      ''' 
      if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight: 
        return False 
      #如果当前的位置不为空，返回False 
      if self.shapeAt(x, y) != Tetrominoe.NoShape: 
        return False 
 
    self.curPiece = newPiece 
    self.curX = newX  #现在的坐标变为新坐标 
    self.curY = newY 
    self.update()  #frame更新 
     
    return True 
     
 
  def drawSquare(self, painter, x, y, shape): 
     
    colorTable = [0x000000, 0xCC6666, 0x66CC66, 0x6666CC, 
           0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00] 
 
    color = QtGui.QColor(colorTable[shape]) 
    painter.fillRect(x + 1, y + 1, self.squareWidth() - 2,  
      self.squareHeight() - 2, color) 
 
    painter.setPen(color.light()) 
    painter.drawLine(x, y + self.squareHeight() - 1, x, y) 
    painter.drawLine(x, y, x + self.squareWidth() - 1, y) 
 
    painter.setPen(color.dark()) 
    painter.drawLine(x + 1, y + self.squareHeight() - 1, 
      x + self.squareWidth() - 1, y + self.squareHeight() - 1) 
    painter.drawLine(x + self.squareWidth() - 1,  
      y + self.squareHeight() - 1, x + self.squareWidth() - 1, y + 1) 
 
 
class Tetrominoe(object): 
  ''''' 
  定义游戏中出现的形状，共有8种，分别用0-7表示。 
  其中0表示没有形状，1-7表示可能出现的形状：Z,S,Line,T,Square,L,MirroredL。 
   
  相当于C++中的枚举类型，用有意义的字符串名代替数字 
  ''' 
  NoShape = 0 
  ZShape = 1 
  SShape = 2 
  LineShape = 3 
  TShape = 4 
  SquareShape = 5 
  LShape = 6 
  MirroredLShape = 7 
 
 
class Shape(object): 
  ''''' 
  Shape类保存每种方块的信息 
  ''' 
  #coordsTable tuple holds all possible coordinate values of our Tetris pieces. 0-7 
  coordsTable = ( 
    ((0, 0),   (0, 0),   (0, 0),   (0, 0)), 
    ((0, -1),  (0, 0),   (-1, 0),  (-1, 1)), 
    ((0, -1),  (0, 0),   (1, 0),   (1, 1)), 
    ((0, -1),  (0, 0),   (0, 1),   (0, 2)), 
    ((-1, 0),  (0, 0),   (1, 0),   (0, 1)), 
    ((0, 0),   (1, 0),   (0, 1),   (1, 1)), 
    ((-1, -1),  (0, -1),  (0, 0),   (0, 1)), 
    ((1, -1),  (0, -1),  (0, 0),   (0, 1)) 
  ) 
 
  def __init__(self): 
     
    self.coords = [[0,0] for i in range(4)]   #[[0, 0], [0, 0], [0, 0], [0, 0]] 
    self.pieceShape = Tetrominoe.NoShape 
 
    self.setShape(Tetrominoe.NoShape) 
     
  #返回当前shape类型 
  def shape(self): 
    return self.pieceShape 
     
 
  def setShape(self, shape): 
     
    table = Shape.coordsTable[shape]  #table是对应的tuple元组 
    #将对应的table赋给self.coords 
    for i in range(4): 
      for j in range(2): 
        self.coords[i][j] = table[i][j] 
 
    self.pieceShape = shape 
     
  #随机获取一个块形状（从1，2，3，4，5，6，7中随机选1个） 
  def setRandomShape(self): 
    self.setShape(random.randint(1, 7)) 
 
  #返回index的x坐标,index是从0-3，分别表示方块对应的4个点 
  def x(self, index): 
    return self.coords[index][0] 
 
  #返回index的y坐标  
  def y(self, index): 
    return self.coords[index][1] 
 
  #设置当前index的x坐标 
  def setX(self, index, x): 
    self.coords[index][0] = x 
 
  #设置当前index的y坐标 
  def setY(self, index, y): 
    self.coords[index][1] = y 
 
  #返回当前块的最小x坐标 
  def minX(self):  
    m = self.coords[0][0]   
    for i in range(4): 
      m = min(m, self.coords[i][0]) 
    return m 
 
  #返回当前块的最大x坐标   
  def maxX(self): 
    m = self.coords[0][0] 
    for i in range(4): 
      m = max(m, self.coords[i][0]) 
    return m 
 
  #返回当前块的最小y坐标   
  def minY(self):    
    m = self.coords[0][1] 
    for i in range(4): 
      m = min(m, self.coords[i][1]) 
    return m 
 
  #返回当前块的最大y坐标  
  def maxY(self):    
    m = self.coords[0][1] 
    for i in range(4): 
      m = max(m, self.coords[i][1]) 
    return m 
 
     
  def rotateLeft(self):  #rotate a piece to the left 
    #如果块是方块的话，直接返回当前块，不做任何处理 
    if self.pieceShape == Tetrominoe.SquareShape: 
      return self 
 
    result = Shape() 
    result.pieceShape = self.pieceShape    
    for i in range(4):     
      #将i点的x坐标换为y坐标 
      result.setX(i, self.y(i)) 
      #将i点的y坐标换为-x坐标 
      result.setY(i, -self.x(i)) 
    #返回新的左旋后的方块 
    return result 
 
     
  def rotateRight(self): 
    #如果块是方块的话，直接返回当前块，不做任何处理 
    if self.pieceShape == Tetrominoe.SquareShape: 
      return self 
 
    result = Shape() 
    result.pieceShape = self.pieceShape   
    for i in range(4): 
      #将i点的x坐标换为-y坐标 
      result.setX(i, -self.y(i)) 
      #将i点的y坐标换为x坐标 
      result.setY(i, self.x(i)) 
    #返回新的右旋后的方块 
    return result 
 
 
''''' 
The game is simplified a bit so that it is easier to understand. 
The game starts immediately after it is launched. 
We can pause the game by pressing the p key. 
The space key will drop the Tetris piece instantly to the bottom. 
The game goes at constant speed, no acceleration is implemented. 
The score is the number of lines that we have removed. 
 
''' 
def main(): 
  #创建一个界面app 
  app = QtGui.QApplication([]) 
  #创建一个俄罗斯方块类 
  tetris = Tetris()   
  #进入主循环 
  app.exec_() 
 
 
if __name__ == '__main__': 
  main()