plot.py 文件源码

def OnPrintPage(self, page):
        dc = self.GetDC()  # allows using floats for certain functions
        # Note PPIScreen does not give the correct number
        # Calulate everything for printer and then scale for preview
        PPIPrinter = self.GetPPIPrinter()        # printer dots/inch (w,h)
        # PPIScreen= self.GetPPIScreen()          # screen dots/inch (w,h)
        dcSize = dc.GetSize()                    # DC size
        if self.graph._antiAliasingEnabled and not isinstance(dc, wx.GCDC):
            try:
                dc = wx.GCDC(dc)
            except Exception:
                pass
            else:
                if self.graph._hiResEnabled:
                    # high precision - each logical unit is 1/20 of a point
                    dc.SetMapMode(wx.MM_TWIPS)
        pageSize = self.GetPageSizePixels()  # page size in terms of pixcels
        clientDcSize = self.graph.GetClientSize()
        # find what the margins are (mm)
        margLeftSize, margTopSize = self.graph.pageSetupData.GetMarginTopLeft()
        margRightSize, margBottomSize = self.graph.pageSetupData.GetMarginBottomRight()
        # calculate offset and scale for dc
        pixLeft = margLeftSize * PPIPrinter[0] / 25.4  # mm*(dots/in)/(mm/in)
        pixRight = margRightSize * PPIPrinter[0] / 25.4
        pixTop = margTopSize * PPIPrinter[1] / 25.4
        pixBottom = margBottomSize * PPIPrinter[1] / 25.4
        plotAreaW = pageSize[0] - (pixLeft + pixRight)
        plotAreaH = pageSize[1] - (pixTop + pixBottom)
        # ratio offset and scale to screen size if preview
        if self.IsPreview():
            ratioW = float(dcSize[0]) / pageSize[0]
            ratioH = float(dcSize[1]) / pageSize[1]
            pixLeft *= ratioW
            pixTop *= ratioH
            plotAreaW *= ratioW
            plotAreaH *= ratioH
        # rescale plot to page or preview plot area
        self.graph._setSize(plotAreaW, plotAreaH)
        # Set offset and scale
        dc.SetDeviceOrigin(pixLeft, pixTop)
        # Thicken up pens and increase marker size for printing
        ratioW = float(plotAreaW) / clientDcSize[0]
        ratioH = float(plotAreaH) / clientDcSize[1]
        aveScale = (ratioW + ratioH) / 2
        if self.graph._antiAliasingEnabled and not self.IsPreview():
            scale = dc.GetUserScale()
            dc.SetUserScale(
                scale[0] / self.graph._pointSize[0], scale[1] / self.graph._pointSize[1])
        self.graph._setPrinterScale(aveScale)  # tickens up pens for printing
        self.graph._printDraw(dc)
        # rescale back to original
        self.graph._setSize()
        self.graph._setPrinterScale(1)
        self.graph.Redraw()  # to get point label scale and shift correct
        return True
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