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Diffstat (limited to 'events-example3.py')
| -rwxr-xr-x | events-example3.py | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/events-example3.py b/events-example3.py new file mode 100755 index 0000000..d21877b --- /dev/null +++ b/events-example3.py @@ -0,0 +1,206 @@ +#!/usr/bin/python +# events-example3.py +# Demos timer, mouse, and keyboard events + +from tkinter import * +import math +import random + +class Vector(object): + """N-dimensional vector class.""" + def __init__(self, *components): + """Create a vector from its components.""" + self.components = components + + def __add__(self, other): + """Add two vectors.""" + return self.__class__( + *map(lambda xy: xy[0] + xy[1], zip(self.components, other.components)) + ) + + def __sub__(self, other): + """Subtract two vectors.""" + return self.__class__( + *map(lambda xy: xy[0] - xy[1], zip(self.components, other.components)) + ) + + def __mul__(self, other): + """Multiply a vector by a constant.""" + return self.__class__(*map(lambda x: x * other, self.components)) + + def __rmul__(self, other): + """Multiply a constant by a vector.""" + return self * other + + def __abs__(self): + """Return the 2-norm of the vector.""" + return math.sqrt(sum(map(lambda x: x * x, self.components))) + + def __truediv__(self, scalar): + """Return self * 1 / scalar.""" + return self * (1 / scalar) + + def __eq__(self, other): + return self.components == other.components + + +def init(data): + data.squareLeft = 50 + data.squareTop = 0 + data.squareFill = "red" + data.squareSize = 25 + data.circleCenters = [ ] + data.counter = 0 + data.headingRight = True + data.headingDown = True + data.isPaused = False + data.timerDelay = 50 + + data.speed = Vector(10, 0) + data.drag = -1 + + data.tailAcceleration = Vector(5, 0) + data.tailDuration = 2 + data.tailMoving = False + data.tailThreshold = 5 + data.tailMoveCount = 0 + +def mousePressed(event, data): + newCircleCenter = (event.x, event.y) + data.circleCenters.append(newCircleCenter) + +def keyPressed(event, data): + if (event.char == "d"): + if (len(data.circleCenters) > 0): + data.circleCenters.pop(0) + else: + print("No more circles to delete!") + elif (event.char == "p"): + data.isPaused = not data.isPaused + elif (event.char == "s"): + doStep(data) + if (event.keysym == "Left"): + moveLeft(data) + elif (event.keysym == "Right"): + moveRight(data) + +def moveLeft(data): + data.squareLeft -= 20 + +def moveRight(data): + data.squareLeft += 20 + +def moveUp(data): + data.squareTop -= 20 + +def moveDown(data): + data.squareTop += 20 + +def timerFired(data): + if (not data.isPaused): doStep(data) + +def fixDirection(data, theta=None): + if theta is None: + theta = random.random() * 2 * math.pi + costheta = math.cos(theta) + sintheta = math.sin(theta) + speedx = data.tailAcceleration.components[0] + speedy = data.tailAcceleration.components[1] + # From en.wikipedia.org/wiki/Rotation_matrix + data.tailAcceleration = Vector( + speedx * costheta - speedy * sintheta, + speedx * sintheta + speedy * costheta + ) + +def doStep(data): + data.counter += 1 + if random.random() < 1 / 50: + fixDirection(data) + #print(abs(data.tailAcceleration)) + data.speed += data.drag * data.speed / abs(data.speed) + if abs(data.speed) < data.tailThreshold: + data.tailMoving = True + if data.tailMoveCount > data.tailDuration: + data.tailMoveCount = 0 + data.tailMoving = False + if data.tailMoving: + data.speed += data.tailAcceleration + data.tailMoveCount += 1 + data.squareLeft += data.speed.components[0] + data.squareTop += data.speed.components[1] + if data.squareLeft + data.squareSize > data.width: + data.squareLeft = 0 + if data.squareLeft < 0: + data.squareLeft = data.width - data.squareSize + if data.squareTop < 0: + data.squareTop = data.height - data.squareSize + if data.squareTop + data.squareSize > data.height: + data.squareTop = 0 + +def redrawAll(canvas, data): + # draw the square + canvas.create_rectangle(data.squareLeft, + data.squareTop, + data.squareLeft + data.squareSize, + data.squareTop + data.squareSize, + fill=data.squareFill) + # draw the circles + for circleCenter in data.circleCenters: + (cx, cy) = circleCenter + r = 20 + canvas.create_oval(cx-r, cy-r, cx+r, cy+r, fill="cyan") + # draw the text + canvas.create_text(150,20,text="events-example3.py") + canvas.create_text(150,40,text="Mouse clicks create circles") + canvas.create_text(150,60,text="Pressing 'd' deletes circles") + canvas.create_text(150,80,text="Pressing 'p' pauses/unpauses timer") + canvas.create_text(150,100,text="Pressing 's' steps the timer once") + canvas.create_text(150,120,text="Left arrow moves square left") + canvas.create_text(150,140,text="Right arrow moves square right") + canvas.create_text(150,160,text="Timer changes color of square") + +#################################### +# use the run function as-is +#################################### + +def run(width=300, height=300): + def redrawAllWrapper(canvas, data): + canvas.delete(ALL) + redrawAll(canvas, data) + canvas.update() + + def mousePressedWrapper(event, canvas, data): + mousePressed(event, data) + redrawAllWrapper(canvas, data) + + def keyPressedWrapper(event, canvas, data): + keyPressed(event, data) + redrawAllWrapper(canvas, data) + + def timerFiredWrapper(canvas, data): + timerFired(data) + redrawAllWrapper(canvas, data) + # pause, then call timerFired again + canvas.after(data.timerDelay, timerFiredWrapper, canvas, data) + # Set up data and call init + class Struct(object): pass + data = Struct() + data.width = width + data.height = height + data.timerDelay = 100 # milliseconds + init(data) + # create the root and the canvas + root = Tk() + canvas = Canvas(root, width=data.width, height=data.height) + canvas.pack() + # set up events + root.bind("<Button-1>", lambda event: + mousePressedWrapper(event, canvas, data)) + root.bind("<Key>", lambda event: + keyPressedWrapper(event, canvas, data)) + timerFiredWrapper(canvas, data) + # and launch the app + root.mainloop() # blocks until window is closed + print("bye!") + +run(600, 1000) |