'完善注释'

sqlcn · sqlcn · commit e521a90fafef · 2020-07-19T10:10:01.000+08:00
diff --git a/aniStack.py b/aniStack.py
@@ -2,33 +2,33 @@
 import time
 import math
 
-TubeX0 = 50
+# 以下为全局变量
+TubeX0 = 50         # 栈的左上角坐标位置
 TubeY0 = 150
-TubeDeep = 5
-BallRaius = 50
-
-QueueX0 = 200
-QueueY0 = 100
-
-MoveStep = 100
-Speed = 2
-
-TubeX1 = TubeX0+BallRaius
+TubeDeep = 5        # 栈的深度（能容纳5个球）
+BallRaius = 50      # 每个球的半径
+# 预先计算栈的其他坐标点
+TubeX1 = TubeX0+BallRaius                       # 栈底部小球的中心坐标
 TubeY1 = TubeY0+BallRaius*TubeDeep
-TubeTopX = TubeX0+BallRaius/2
+TubeTopX = TubeX0+BallRaius/2                   # 栈顶部出入口外的中心坐标
 TubeTopY = TubeY0 - BallRaius/2-BallRaius/4
 
+QueueX0 = 200       # 待进栈小球的坐标位置
+QueueY0 = 100
+
+# 运算动画时的相关坐标
 EvalX1 = TubeX1 + (BallRaius+2)*2
 EvalY = TubeY1-BallRaius/2
 EvalX2 = EvalX1 + (BallRaius+2)*2
 EvalXe = (EvalX1+EvalX2)/2
 
+Speed = 2  # 小球移动的速度
 
-class Ball:
-    def __init__(self, canvas, txt, pos):
+class Ball:     # window:TK窗口对象，canvas:画布对象，txt:小球的内容，txt:小球的坐标
+    def __init__(self, window, canvas, txt, pos):
+        self.window = window
         self.canvas = canvas
         self.txt = txt
-        # self.index = index
 
         self.ballId = self.canvas.create_oval(
             pos[0]-BallRaius/2, pos[1]-BallRaius /
@@ -41,35 +41,33 @@ def __init__(self, canvas, txt, pos):
     def getTxt(self):
         return self.txt
 
-    def getIndex(self):
-        return self.index
+    # def getIndex(self):
+    #     return self.index
 
     def getPos(self):
         pos = self.canvas.coords(self.ballId)
         return [(pos[0]+pos[2])/2, (pos[1]+pos[3])/2]
 
     def animate(self, poly):
-        for pos in poly:
-            startPos = self.getPos()
-            distance = self.distance(startPos, pos)
-            # dx = (pos[0]-startPos[0])/MoveStep
-            # dy = (pos[1]-startPos[1])/MoveStep
-            while not self.match(self.getPos(), pos):         # 测试是否到达终点
-                global window
+        for pos in poly:                                        # 遍历路径的每一个途经点
+            startPos = self.getPos()                            # 获得开始位置坐标
+            distance = self.distance(startPos, pos)             # 获得每一步需移动的x和y的步长（可能为负数）
+            while not self.match(self.getPos(), pos):  # 测试是否到途经点
+                # 根据x和y的步长，分别移动小球和小球里的数字（符号）
                 self.canvas.move(self.ballId, distance[0], distance[1])
                 self.canvas.move(self.numId, distance[0], distance[1])
-                window.update()
+                self.window.update()
                 time.sleep(0.01)
 
     def distance(self, pos1, pos2):
-        dx = pos2[0]-pos1[0]
+        dx = pos2[0]-pos1[0]                # 分别计算x坐标和y坐标的距离
         dy = pos2[1]-pos1[1]
-        dist = math.sqrt(dx*dx+dy*dy)      # 两点的距离
-        dtime = dist/Speed                 # 走完动画花的时间
-        return [dx/dtime, dy/dtime]
+        dist = math.sqrt(dx*dx+dy*dy)       # 利用勾股定理计算两点的距离
+        dtime = dist/Speed                  # 走完行程所用的时间
+        return [dx/dtime, dy/dtime]         # 返回每次移动的步长
 
-    def match(self, pos1, pos2, mat=1):
-        if abs(pos2[0]-pos1[0]) < mat and abs(pos2[1]-pos1[1]) < mat:
+    def match(self, pos1, pos2, mat=1):     # 判断两个坐标点pos1和pos2是否重合，mat为精度，即mat=1时，误差+-0.5都算重合
+        if abs(pos2[0]-pos1[0]) < mat and abs(pos2[1]-pos1[1]) < mat: #简单计算而不用勾股定理计算距离
             return True
         return False
 
@@ -78,10 +76,11 @@ def destory(self):
         self.canvas.delete(self.numId)
 
 
-class Stack:
+class Stack:    # canvas:画布对象
     def __init__(self, canvas):
         self.stack = []
         self.canvas = canvas
+        # 画出栈的外形
         self.canvas.create_line(TubeX0-2, TubeY0-2,
                                 TubeX0-2, TubeY1+2,
                                 TubeX1+2, TubeY1+2,
@@ -90,21 +89,19 @@ def __init__(self, canvas):
 
     def push(self, ball):
         index = len(self.stack)
-        # ball = Ball(self.canvas, number, [
-        #             TubeX0+BallRaius/2, TubeY1-(index*BallRaius)-BallRaius/2])
-        ball.animate(
-            [[TubeTopX, TubeTopY], [TubeTopX, TubeY1-(index*BallRaius)-BallRaius/2]])
+        # 小球移动的动画，参数是两个坐标点，先到栈口上部，然后落到栈里
+        ball.animate([[TubeTopX, TubeTopY], [TubeTopX, TubeY1-(index*BallRaius)-BallRaius/2]])
         self.stack.append(ball)
 
     def pop(self):
         index = len(self.stack)-1
         ball = self.stack.pop()
+        # 出栈动画，小球移动到栈口上方
         ball.animate([[TubeTopX, TubeTopY]])
         return ball
 
 
 def main():
-    global window
 
     strBuf = '65+1-5*'  # 需解析的字符串
     queue = []          # 等待处理的球的队列
@@ -121,7 +118,7 @@ def main():
     # 生成球的队列
     index = 0
     for char in strBuf:
-        ball = Ball(canvas, char, [QueueX0+BallRaius*index, QueueY0])
+        ball = Ball(window, canvas, char, [QueueX0+BallRaius*index, QueueY0])
         queue.append(ball)
         # print(ball.getPos())
         index += 1
@@ -131,6 +128,7 @@ def main():
         if c.isnumeric():               # 判断球内的字符是否数字
             stk.push(ball)              # 是数字，球就进栈
         elif c == '+' or c == '-' or c == '*' or c == '/':
+            #下面几个animate方法演示计算过程的动画
             ball.animate([[EvalXe, EvalY]])
 
             ball1 = stk.pop()
@@ -143,9 +141,9 @@ def main():
             a2 = ball2.getTxt()
             ball1.animate([[EvalXe, EvalY]])
             ball2.animate([[EvalXe, EvalY]])
-            
+
             result = eval(a1+c+a2)
-            newBall = Ball(canvas, str(result), ball.getPos())
+            newBall = Ball(window, canvas, str(result), ball.getPos())
 
             ball1.destory()
             ball2.destory()
