import random from PySide2.QtCore import (QAbstractAnimation, Qt, QPropertyAnimation, Property) from PySide2.QtGui import QPen from PySide2.QtWidgets import QGraphicsObject, QLabel class AnimatedText(QGraphicsObject): def __init__(self, text, parent=None): super().__init__(parent=parent) self.parent = parent self.actual_text = text self.shown_text = '' self.delay = 3 # Set up pens for drawing self.default_pen = QPen() self.default_pen.setColor(Qt.white) self.shown_length = 0 # Set up the length to be animated self.anim = QPropertyAnimation(self, b'shown_length') self.anim.setDuration(len(self.actual_text) * 50) # Animation speed self.anim.setStartValue(0) for t in range(1, 10): self.anim.setKeyValueAt(t / 10, (len(self.actual_text) + self.delay) * t/10) self.anim.setEndValue(len(self.actual_text) + self.delay) self.visibleChanged.connect(self.show_text) def show_text(self): if self.isVisible(): self.toggle_anim(True) else: self.shown_length = 0 # Toggle the animation to be play forward or backward def toggle_anim(self, toggling): if toggling: self.anim.setDirection(QAbstractAnimation.Forward) else: self.anim.setDirection(QAbstractAnimation.Backward) self.anim.start() def boundingRect(self): return self.parent.boundingRect() def paint(self, painter, style, widget=None): painter.setPen(self.default_pen) painter.drawText(self.parent.boundingRect(), Qt.AlignCenter, self.shown_text) # Defining the length to be drawn as a Property @Property(int) def shown_length(self): return self._shown_length # Determine the length of the four lines to be drawn @shown_length.setter def shown_length(self, value): self._shown_length = value if value < self.delay: # All printed text should be garbage garbage = [chr(num) for num in [random.choice(range(33, 127)) for _ in range(value)]] self.shown_text = ''.join(garbage) else: # Printed text contain some actual text garbage = [chr(num) for num in [random.choice(range(33, 127)) for _ in range(min(len(self.actual_text) + self.delay - value, self.delay))]] self.shown_text = self.actual_text[:value - self.delay] + ''.join(garbage) self.update() class AnimatedLabel(QLabel): """ QLabel that a message, which is displayed through animation. """ def __init__(self, text, speed=75, delay=20, parent=None): """ Does some text processing, and set up the animation to display the text Parameters ---------- text: str Text to be displayed speed : int The period at which a new character is printed The total time is calculated as length of text * speed 0 means instant display, like a regular QLabel. delay : int The number of garbage to be printed before printing the actual text parent: QWidget Pass into QLabel init method """ super().__init__(text, parent) self.speed = speed self.setWordWrap(True) self.setContentsMargins(0, 0, 0, 0) # Text processing # Make sure the garbage does not exceed the length of actual text self.actual_text = text self.shown_text = '' if delay >= 0: self.delay = min(delay, len(self.actual_text)) else: self.delay = len(self.actual_text) # Find out where the new paragraphs are so that it is retained self.splitpoints = [] current_point = 0 line_splits = self.actual_text.split('\n') for line in line_splits: current_point += len(line) self.splitpoints.append(current_point) current_point += 1 # Set up the shown text length to be animated self.shown_length = 0 self.anim = QPropertyAnimation(self, b'shown_length') self.anim.setDuration(len(self.actual_text) * speed) self.anim.setStartValue(0) self.anim.setEndValue(len(self.actual_text) + self.delay) #self.setStyleSheet(""" # color: rgb(0, 255, 0); # """) self.toggle_anim(True) @Property(int) def shown_length(self): """ int : The value for the animation When the value is set, the text to be printed is generated accordingly. It determines whether actual text is to be printed, and retains the paragraphs when printing garbage. """ return self._shown_length @shown_length.setter def shown_length(self, value): self._shown_length = value if value < self.delay: # All printed text should be garbage garbage = [chr(num) for num in [random.choice(range(33, 127)) for _ in range(value)]] # Retain the paragraphs for num in self.splitpoints[:-1]: if num < value: garbage[num] = '\n' self.setText(''.join(garbage)) else: # Printed text contain some actual text garbage = [chr(num) for num in [random.choice(range(33, 127)) for _ in range(min(len(self.actual_text) + self.delay - value, self.delay))]] # Retain the paragraphs, but offset by the number of actual text non_garbage = value - self.delay for num in self.splitpoints[:-1]: if num - non_garbage > 0 and num < value: garbage[num - non_garbage] = '\n' self.setText(self.actual_text[:value - self.delay] + ''.join(garbage)) def toggle_anim(self, toggling): """ Toggle the animation to be play forward or backward Parameters ---------- toggling: bool True for forward, False for backward """ if toggling: self.anim.setDirection(QAbstractAnimation.Forward) else: self.anim.setDirection(QAbstractAnimation.Backward) self.anim.start() def replace_text(self, new_text): self.shown_length = 0 self.actual_text = new_text self.anim.setDuration(len(self.actual_text) * self.speed) self.anim.setEndValue(len(self.actual_text) + self.delay) self.toggle_anim(True)