[wxPython-users] Re: Bitmap in a wxScrolledWindow

[Gavana, Andrea]

Hello Andrew,

> Is it possible that you could post the source code of your 
> working solution? 

Well, at the moment these are the relevant pieces of code I am using in InfinImage (thanks to Will McGugan, Peter Damoc and Simon Clay):


Class declaration and __init__:

class ScrolledImage(wx.ScrolledWindow):

    def __init__(self, parent, id=-1, pos=wx.DefaultPosition, size=wx.DefaultSize):

        wx.ScrolledWindow.__init__(self, parent, id, pos, size)        

        self.size = wx.Size(0, 0)
        self.SetExtraStyle(0)

        self.Bind(wx.EVT_SIZE, self.OnSize)
        self.Bind(wx.EVT_PAINT, self.OnPaint)
        self.Bind(wx.EVT_ERASE_BACKGROUND, self.OnEraseBackground)


Image Loading:

    def ShowImage(self, image):

        PIL_bitmap = Image.open(image)
        bmp = PilToBitmap(PIL_bitmap)

        self.SetScrollbars(1, 1, PIL_bitmap.size[0], PIL_bitmap.size[1], 0, 0)

        size = self.GetSize()

        xmin = (size.x - PIL_bitmap.size[0])/2
        ymin = (size.y - PIL_bitmap.size[1])/2
        
        self.currentbmp = bmp
        self.size = wx.Size(self.currentbmp.GetSize().width, self.currentbmp.GetSize().height)
        
        self.Refresh()


OnPaint:

    def OnPaint(self, event):

        dc = wx.PaintDC(self)
        dc.Clear()            
        self.DoPaint(dc)


    def DoPaint(self, dc=None):

        if dc is None:
            dc = wx.ClientDC(self)

        self.PrepareDC(dc)

        iw, ih = self.size

        xmin = (self.windowsize.x - iw)/2
        ymin = (self.windowsize.y - ih)/2

        bm_dc = wx.MemoryDC()        
        bm_dc.SelectObject(self.currentbmp)

        if xmin < 0:
            xmin = 0
        if ymin < 0:
            ymin = 0

        dc.Blit(xmin, ymin, iw, ih, bm_dc, 0, 0, wx.COPY, True)
        bm_dc.SelectObject(wx.NullBitmap)


OnSize:

    def OnSize(self, event):

        iw, ih = self.size.width, self.size.height
        w, h = event.GetSize()

        scroll_x = w < iw
        scroll_y = h < ih

        scroll = scroll_x | scroll_y

        x, y = self.GetViewStart()

        self.SetScrollbars(scroll,scroll,iw,ih,x,y)
        self.windowsize = wx.Size(w, h)


OnEraseBackground:

    def OnEraseBackground(self, event):
        
        pass


I don't have at the moment a runnable piece of code, it's been a while since I worked last time on InfinImage. Well, I promised to my girlfriend to finish that image viewer, so I have to force myself to continue in some way. But there are only 24 hours in a day :-D
For the zooming part, at the moment I am using the mouse wheel event to handle it. It still needs some work to be done, but it's almost finished. I'll send some code when it will be ready.

Andrea.

_________________________________________
Andrea Gavana (gavana at kpo.kz)
Reservoir Engineer
KPDL
4, Millbank
SW1P 3JA London
 
Direct Tel: +44 (0) 20 717 08936
Mobile Tel: +44 (0) 77 487 70534
Fax: +44 (0) 20 717 08900
Web: http://xoomer.virgilio.it/infinity77
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