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2022-07-16 10:37:08 +08:00
import sys
from PySide6 import QtCore, QtGui, QtWidgets
"""
QPlainTextEdit 信号
纯文本编辑器提供了许多可用信号
.textChanged() 当文档的内容发生变化时发射此信号例如文本插入删除或应用格式等
.selectionChanged() 当选中改变时发射此信号
.blockCountChanged(new_block_count: int) 当文档中块的数量发生变化时发射此信号新的块数量作为参数传出
.cursorPositionChanged() 当光标位置改变时发射此信号
.copyAvailable(yes: bool) 当复制功能可用状态发生变化时发射此信号可用状态作为参数传出
.undoAvailable(available: bool) 当撤销功能可用状态发生变化时发射此信号可用状态作为参数传出
.redoAvailable(available: bool) 当重做功能可用状态发生变化时发射此信号可用状态作为参数传出
.updateRequest(rect: QRect, dy: int) 当文本文档需要更新指定的矩形时发射此信号详情见下一节的案例
.modificationChanged(changed: bool) 当文档的内容以影响修改状态的方式发生变化时发射此信号文档是否已被修改作为参数传出
"""
class MyWidget(QtWidgets.QWidget):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.setWindowTitle("QPlainTextEdit-信号")
self.resize(800, 600)
self.pte = QtWidgets.QPlainTextEdit()
self.info_label = QtWidgets.QLabel()
self.setup_ui()
self.signal_test()
def setup_ui(self) -> None:
"""设置界面"""
self.pte.resize(600, 450)
clear_button = QtWidgets.QPushButton("清空")
copy_button = QtWidgets.QPushButton("复制")
undo_button = QtWidgets.QPushButton("撤销")
redo_button = QtWidgets.QPushButton("重做")
undo_redo_enable_checkbox = QtWidgets.QCheckBox("允许撤销/重做")
undo_redo_enable_checkbox.setChecked(True)
@QtCore.Slot(bool)
def undo_redo_enable_test(enable: bool):
"""测试禁用撤销/重做功能"""
self.pte.setUndoRedoEnabled(enable)
print(f"pte.isUndoRedoEnabled({self.pte.isUndoRedoEnabled()})")
undo_redo_enable_checkbox.toggled.connect(undo_redo_enable_test) # type: ignore
clear_button.clicked.connect(self.pte.clear) # type: ignore
copy_button.clicked.connect(self.pte.copy) # type: ignore
undo_button.clicked.connect(self.pte.undo) # type: ignore
redo_button.clicked.connect(self.pte.redo) # type: ignore
# 将按钮通过布局管理器放在组框中,首次学习可忽略本段代码
button_groupbox = QtWidgets.QGroupBox()
layout = QtWidgets.QVBoxLayout(button_groupbox)
layout.addWidget(clear_button)
layout.addWidget(copy_button)
layout.addWidget(undo_redo_enable_checkbox)
layout.addWidget(undo_button)
layout.addWidget(redo_button)
layout.addWidget(self.info_label)
button_groupbox.setLayout(layout)
main_layout = QtWidgets.QHBoxLayout(self)
main_layout.addWidget(self.pte)
main_layout.addWidget(button_groupbox)
self.setLayout(main_layout)
def signal_test(self) -> None:
# 测试信号时为避免干扰,每次只测试一个,注释掉其他
self.pte.textChanged.connect(lambda: self.info_label.setText("文本改变了!")) # type: ignore
# self.pte.selectionChanged.connect(lambda: self.info_label.setText("选中内容改变了!")) # type: ignore
# self.pte.blockCountChanged.connect(
# lambda new_block_count: self.info_label.setText(f"块数量变成了{new_block_count}")
# ) # type: ignore
# self.pte.cursorPositionChanged.connect(lambda: self.info_label.setText("光标位置改变了!")) # type: ignore
# self.pte.copyAvailable.connect(lambda yes: self.info_label.setText(f"复制可用状态变为了{yes}")) # type: ignore
# self.pte.undoAvailable.connect(lambda yes: self.info_label.setText(f"撤销可用状态变为了{yes}")) # type: ignore
# self.pte.redoAvailable.connect(lambda yes: self.info_label.setText(f"重做可用状态变为了{yes}")) # type: ignore
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
window = MyWidget()
window.show()
sys.exit(app.exec())