在PyQt中使用行号创建文本区域（textEdit）

在PyQt中使用行号创建文本区域（textEdit）

这是您在寻找基于C ++ http://doc.qt.io/qt-5/qtwidgets-widgets-preeditor-
example.html的
pyqt中的CodeEditor示例的原因

将其放在一起用于python3（我使用PyQt4而不是5，但我想它是相似的）（并且使用QPlainTextEdit而不是QTextEdit参见QTextEditvs QPlainTextEdit）：

import sysfrom PyQt4.QtGui import *from PyQt4.QtCore import *import numpy as npclass LineNumberArea(QWidget):    def __init__(self, editor):        super().__init__(editor)        self.myeditor = editor    def sizeHint(self):        return Qsize(self.editor.lineNumberAreaWidth(), 0)    def paintEvent(self, event):        self.myeditor.lineNumberAreaPaintEvent(event)class CodeEditor(QPlainTextEdit):    def __init__(self):        super().__init__()        self.lineNumberArea = LineNumberArea(self)        self.connect(self, SIGNAL('blockCountChanged(int)'), self.updateLineNumberAreaWidth)        self.connect(self, SIGNAL('updateRequest(QRect,int)'), self.updateLineNumberArea)        self.connect(self, SIGNAL('cursorPositionChanged()'), self.highlightCurrentLine)        self.updateLineNumberAreaWidth(0)    def lineNumberAreaWidth(self):        digits = 1        count = max(1, self.blockCount())        while count >= 10: count /= 10 digits += 1        space = 3 + self.fontMetrics().width('9') * digits        return space    def updateLineNumberAreaWidth(self, _):        self.setViewportMargins(self.lineNumberAreaWidth(), 0, 0, 0)    def updateLineNumberArea(self, rect, dy):        if dy: self.lineNumberArea.scroll(0, dy)        else: self.lineNumberArea.update(0, rect.y(), self.lineNumberArea.width(), rect.height())        if rect.contains(self.viewport().rect()): self.updateLineNumberAreaWidth(0)    def resizeEvent(self, event):        super().resizeEvent(event)        cr = self.contentsRect();        self.lineNumberArea.setGeometry(QRect(cr.left(), cr.top(),         self.lineNumberAreaWidth(), cr.height()))    def lineNumberAreaPaintEvent(self, event):        mypainter = QPainter(self.lineNumberArea)        mypainter.fillRect(event.rect(), Qt.lightGray)        block = self.firstVisibleBlock()        blockNumber = block.blockNumber()        top = self.blockBoundingGeometry(block).translated(self.contentOffset()).top()        bottom = top + self.blockBoundingRect(block).height()        # Just to make sure I use the right font        height = self.fontMetrics().height()        while block.isValid() and (top <= event.rect().bottom()): if block.isVisible() and (bottom >= event.rect().top()):     number = str(blockNumber + 1)     mypainter.setPen(Qt.black)     mypainter.drawText(0, top, self.lineNumberArea.width(), height,      Qt.AlignRight, number) block = block.next() top = bottom bottom = top + self.blockBoundingRect(block).height() blockNumber += 1    def highlightCurrentLine(self):        extraSelections = []        if not self.isReadonly(): selection = QTextEdit.ExtraSelection() lineColor = QColor(Qt.yellow).lighter(160) selection.format.setBackground(lineColor) selection.format.setProperty(QTextFormat.FullWidthSelection, True) selection.cursor = self.textCursor() selection.cursor.clearSelection() extraSelections.append(selection)        self.setExtraSelections(extraSelections)if __name__ == "__main__":    app = QApplication(sys.argv)    txt = CodeEditor()    txt.show()    sys.exit(app.exec_())