Article Outline
Python pyqt (gui) example 'itemcircleanimation'
Modules used in program:
import randomimport math
itemcircleanimation
Python pyqt example: itemcircleanimation
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## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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import math
import random
from PyQt5.QtCore import QLineF, QPointF, QRectF, Qt, QTime
from colors import Colors
from demoitem import DemoItem
from demoitemanimation import DemoItemAnimation
from guidecircle import GuideCircle
from guideline import GuideLine
from letteritem import LetterItem
class TickerPostEffect(object):
def tick(self, adjust):
pass
def transform(self, item, pos):
pass
class PostRotateXY(TickerPostEffect):
def __init__(self, speedx, speedy, curvx, curvy):
super(PostRotateXY, self).__init__()
self.currRotX = 0.0
self.currRotY = 0.0
self.speedx = speedx
self.speedy = speedy
self.curvx = curvx
self.curvy = curvy
def tick(self, adjust):
self.currRotX += self.speedx * adjust
self.currRotY += self.speedy * adjust
def transform(self, item, pos):
parent = item.parentItem()
center = parent.boundingRect().center()
pos.setX(center.x() + (pos.x() - center.x()) * math.cos(self.currRotX + pos.x() * self.curvx))
pos.setY(center.y() + (pos.y() - center.y()) * math.cos(self.currRotY + pos.y() * self.curvy))
class PostRotateXYTwist(PostRotateXY):
def transform(self, item, pos):
parent = item.parentItem()
center = parent.boundingRect().center()
pos.setX(center.x() + (pos.x() - center.x()) * math.cos(self.currRotX + pos.y() * self.curvx))
pos.setY(center.y() + (pos.y() - center.y()) * math.cos(self.currRotY + pos.x() * self.curvy))
class TickerEffect(object):
Normal, Intro, Outro = range(3)
def __init__(self, letters):
self.postEffect = TickerPostEffect()
self.status = TickerEffect.Intro
self.letters = letters
self.morphSpeed = self.normalMorphSpeed = Colors.tickerMorphSpeed
self.moveSpeed = self.normalMoveSpeed = Colors.tickerMoveSpeed
self.useSheepDog = True
self.morphBetweenModels = not Colors.noTickerMorph
def setPostEffect(self, effect):
self.postEffect = effect
def slowDownAfterIntro(self, adjust):
if self.morphBetweenModels:
if self.status == TickerEffect.Intro:
dec = 0.1 * adjust
self.moveSpeed -= dec
if self.moveSpeed < Colors.tickerMoveSpeed:
self.moveSpeed = self.normalMoveSpeed
self.morphSpeed = self.normalMorphSpeed
self.status = TickerEffect.Normal
def moveLetters(self, adjust):
adaptedMoveSpeed = self.moveSpeed * adjust
adaptedMorphSpeed = self.morphSpeed * adjust
self.postEffect.tick(adjust)
if self.morphBetweenModels:
move_speed = adaptedMoveSpeed
morph_speed = adaptedMorphSpeed
else:
move_speed = Colors.tickerMoveSpeed
morph_speed = -1
for letter in self.letters:
letter.guideAdvance(move_speed)
letter.guideMove(morph_speed)
pos = letter.getGuidedPos()
self.postEffect.transform(letter, pos)
if self.useSheepDog:
letter.setPosUsingSheepDog(pos, QRectF(0, 0, 800, 600))
else:
letter.setPos(pos)
def tick(self, adjust):
self.slowDownAfterIntro(adjust)
self.moveLetters(adjust)
class EffectWhirlWind(TickerEffect):
def __init__(self, letters):
super(EffectWhirlWind, self).__init__(letters)
self.moveSpeed = 50
for letter in self.letters:
letter.setGuidedPos(QPointF(0, 100))
class EffectSnake(TickerEffect):
def __init__(self, letters):
super(EffectSnake, self).__init__(letters)
self.moveSpeed = 40
for i, letter in enumerate(self.letters):
letter.setGuidedPos(QPointF(0, -250 - (i * 5)))
class EffectScan(TickerEffect):
def __init__(self, letters):
super(EffectScan, self).__init__(letters)
for letter in self.letters:
letter.setGuidedPos(QPointF(100, -300))
class EffectRaindrops(TickerEffect):
def __init__(self, letters):
super(EffectRaindrops, self).__init__(letters)
for letter in self.letters:
letter.setGuidedPos(QPointF(random.randint(-100, 100),
random.randint(-200, 1100)))
class EffectLine(TickerEffect):
def __init__(self, letters):
super(EffectLine, self).__init__(letters)
for i, letter in enumerate(self.letters):
letter.setGuidedPos(QPointF(100, 500 + i * 20))
class ItemCircleAnimation(DemoItem):
def __init__(self, parent=None):
super(ItemCircleAnimation, self).__init__(parent)
self.letterList = []
self.letterCount = Colors.tickerLetterCount
self.scale = 1.0
self.showCount = -1
self.tickOnPaint = False
self.paused = False
self.doIntroTransitions = True
self.setAcceptHoverEvents(True)
self.setCursor(Qt.OpenHandCursor)
self.setupGuides()
self.setupLetters()
self.useGuideQt()
self.effect = None
self.mouseMoveLastPosition = QPointF()
self.tickTimer = QTime()
def createLetter(self, c):
letter = LetterItem(c, self)
self.letterList.append(letter)
def setupLetters(self):
self.letterList = []
s = Colors.tickerText
tlen = len(s)
room = self.letterCount
while room >= tlen:
for c in s:
self.createLetter(c)
room -= tlen
# Fill in with blanks.
while room > 0:
self.createLetter(' ')
room -= 1
def setupGuides(self):
x = 0
y = 20
self.qtGuide1 = GuideCircle(QRectF(x, y, 260, 260), -36, 342)
GuideLine(QPointF(x + 240, y + 268), self.qtGuide1)
GuideLine(QPointF(x + 265, y + 246), self.qtGuide1)
GuideLine(QPointF(x + 158, y + 134), self.qtGuide1)
GuideLine(QPointF(x + 184, y + 109), self.qtGuide1)
GuideLine(QPointF(x + 160, y + 82), self.qtGuide1)
GuideLine(QPointF(x + 77, y + 163), self.qtGuide1)
GuideLine(QPointF(x + 100, y + 190), self.qtGuide1)
GuideLine(QPointF(x + 132, y + 159), self.qtGuide1)
GuideLine(QPointF(x + 188, y + 211), self.qtGuide1)
GuideCircle(QRectF(x + 30, y + 30, 200, 200), -30, 336, GuideCircle.CW, self.qtGuide1)
GuideLine(QPointF(x + 238, y + 201), self.qtGuide1)
y = 30
self.qtGuide2 = GuideCircle(QRectF(x + 30, y + 30, 200, 200), 135, 270, GuideCircle.CCW)
GuideLine(QPointF(x + 222, y + 38), self.qtGuide2)
GuideCircle(QRectF(x, y, 260, 260), 135, 270, GuideCircle.CW, self.qtGuide2)
GuideLine(QPointF(x + 59, y + 59), self.qtGuide2)
x = 115
y = 10
self.qtGuide3 = GuideLine(QLineF(x, y, x + 30, y))
GuideLine(QPointF(x + 30, y + 170), self.qtGuide3)
GuideLine(QPointF(x, y + 170), self.qtGuide3)
GuideLine(QPointF(x, y), self.qtGuide3)
self.qtGuide1.setFence(QRectF(0, 0, 800, 600))
self.qtGuide2.setFence(QRectF(0, 0, 800, 600))
self.qtGuide3.setFence(QRectF(0, 0, 800, 600))
def useGuide(self, guide, firstLetter, lastLetter):
padding = guide.lengthAll() / float(lastLetter - firstLetter)
for i, letter in enumerate(self.letterList[firstLetter:lastLetter]):
letter.useGuide(guide, i * padding)
def useGuideQt(self):
if self.currGuide is not self.qtGuide1:
self.useGuide(self.qtGuide1, 0, self.letterCount)
self.currGuide = self.qtGuide1
def useGuideTt(self):
if self.currGuide is not self.qtGuide2:
split = int(self.letterCount * 5.0 / 7.0)
self.useGuide(self.qtGuide2, 0, split)
self.useGuide(self.qtGuide3, split, self.letterCount)
self.currGuide = self.qtGuide2
def boundingRect(self):
return QRectF(0, 0, 300, 320)
def prepare(self):
pass
def switchToNextEffect(self):
self.showCount += 1
if self.showCount == 1:
self.effect = EffectSnake(self.letterList)
elif self.showCount == 2:
self.effect = EffectLine(self.letterList)
self.effect.setPostEffect(PostRotateXYTwist(0.01, 0.0, 0.003, 0.0))
elif self.showCount == 3:
self.effect = EffectRaindrops(self.letterList)
self.effect.setPostEffect(PostRotateXYTwist(0.01, 0.005, 0.003, 0.003))
elif self.showCount == 4:
self.effect = EffectScan(self.letterList)
self.effect.normalMoveSpeed = 0
self.effect.setPostEffect(PostRotateXY(0.008, 0.0, 0.005, 0.0))
else:
self.showCount = 0
self.effect = EffectWhirlWind(self.letterList)
def animationStarted(self, id):
if id == DemoItemAnimation.ANIM_IN:
if self.doIntroTransitions:
# Make all letters disappear.
for letter in self.letterList:
letter.setPos(1000, 0)
self.switchToNextEffect()
self.useGuideQt()
self.scale = 1.0
# The first time we run, we have a rather large delay to
# perform benchmark before the ticker shows. But now, since we
# are showing, use a more appropriate value.
self.currentAnimation.setStartDelay(1500)
elif self.effect is not None:
self.effect.useSheepDog = False
self.tickTimer = QTime.currentTime()
def swapModel(self):
if self.currGuide is self.qtGuide2:
self.useGuideQt()
else:
self.useGuideTt()
def hoverEnterEvent(self, event):
# Skip swap here to enhance ticker dragging.
pass
def hoverLeaveEvent(self, event):
self.swapModel()
def setTickerScale(self, s):
self.scale = s
self.qtGuide1.setScale(self.scale, self.scale)
self.qtGuide2.setScale(self.scale, self.scale)
self.qtGuide3.setScale(self.scale, self.scale)
def mousePressEvent(self, event):
self.mouseMoveLastPosition = event.scenePos();
if event.button() == Qt.LeftButton:
self.setCursor(Qt.ClosedHandCursor)
else:
self.switchToNextEffect()
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
self.setCursor(Qt.OpenHandCursor)
def mouseMoveEvent(self, event):
newPosition = event.scenePos()
self.setPosUsingSheepDog(self.pos() + newPosition - self.mouseMoveLastPosition, QRectF(-260, -280, 1350, 1160))
self.mouseMoveLastPosition = newPosition
def wheelEvent(self, event):
if event.angleDelta().y() > 0:
self.effect.moveSpeed -= 0.20
else:
self.effect.moveSpeed += 0.20
if self.effect.moveSpeed < 0:
self.effect.moveSpeed = 0.0
def pause(self, on):
self.paused = on
self.tickTimer = QTime.currentTime()
def tick(self):
if self.paused or not self.effect:
return
t = self.tickTimer.msecsTo(QTime.currentTime())
self.tickTimer = QTime.currentTime()
self.effect.tick(t / 10.0)
def paint(self, painter, opt, widget):
if self.tickOnPaint:
self.tick()
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/