PyQt 给Edit 添加行号

Edit添加行号实际上是一个控件重绘的过程。

需要在Edit中重绘一个矩形区域，然后把行号“画”在这个矩形区域上。

 

首先，需要定义一个行号栏类：

class NumberBar(QtGui.QWidget):
    def __init__(self, editor):
        QtGui.QWidget.__init__(self, editor)
        self.codeEditor = editor
    
    #get行号值
    def getWidth(self):
        digits = 1

        try:
            if ui.ui2isOpen:
                blockNumber = ui2.verticalScrollBar1.value()
            else:
                blockNumber = ui.verticalScrollBar1.value()
        except Exception, e:
            blockNumber = self.codeEditor.blockCount()

        Max = max(1, blockNumber)
        while (Max >= 10) :
            Max /= 10
            digits += 1
        
        space = 30 + self.codeEditor.fontMetrics().width('9') * digits
        return space
    
    #更新行号栏宽度
    def updateWidth(self):
        width = self.getWidth()
        self.codeEditor.setViewportMargins(width, 0, 0, 0)
    
    #根据 updateRequest 信号  调整行号栏
    def updateArea(self, rect, dy):
        if dy:
            self.scroll(0, dy)
        else:
            self.update(0, rect.y(), self.getWidth(), rect.height())

        if (rect.contains(self.codeEditor.viewport().rect())):
            width = self.getWidth()
            self.codeEditor.setViewportMargins(width, 0, 0, 0)
    
    #绘制行号栏
    def paintEvent(self, event):        
        painter = QtGui.QPainter(self)
        rect = event.rect()

        painter.fillRect(rect, QtGui.QColor(243,243,243))
        block = self.codeEditor.firstVisibleBlock()

        if ui.ui2isOpen:
            blockNumber = ui2.verticalScrollBar1.value()
        else:
            blockNumber = ui.verticalScrollBar1.value()

        top = int(self.codeEditor.blockBoundingGeometry(block).translated(self.codeEditor.contentOffset()).top())
        bottom = top + int(self.codeEditor.blockBoundingRect(block).height())
        while (block.isValid() and top <= rect.bottom()):
            if (block.isVisible() and bottom >= rect.top()):
                number = QtCore.QString.number(blockNumber + 1)
                painter.setPen(QtGui.QColor(59,153,181))
                painter.drawText(0, top, self.codeEditor.lineNumberArea.width(), \
                                 painter.fontMetrics().height(), \
                                 QtCore.Qt.AlignVCenter|QtCore.Qt.AlignRight, number + ' ')

            block = block.next()
            top = bottom
            bottom = top + int(self.codeEditor.blockBoundingRect(block).height())
            blockNumber += 1

 然后重写Edit类：

在Edit类的__init__()函数中：

1、定义一个行号栏类NumberBar类的对象self.lineNumberArea，并且为信号添加以下事件：

self.connect(self, QtCore.SIGNAL('blockCountChanged(int)'),\
                    self.lineNumberArea.updateWidth)
self.connect(self, QtCore.SIGNAL('updateRequest(const QRect &, int)'),\
                    self.lineNumberArea.updateArea)

 2、然后调用self.lineNumberArea的updateWidth()函数：

self.lineNumberArea.updateWidth()

 

效果：