Painting in your UI

All the controls that are visible on screen are created by being painted to DeviceContext. wxPython offers the EVT_PAINT event to allow user codes to paint their own custom displays on a canvas, such as a window, control, or panel. With this level of control on how the UI is painted, your imagination is the limit; however, in this recipe, we will start simple with just the basics of using EVT_PAINT and PaintDC. We will use these features to make a custom panel control that can use bitmaps as its background.

How to do it…

You need to perform the following steps:

1. First, let's start by defining the custom Panel class that will use a bitmap for the background, as follows:

   class ImageBackground(wx.Panel):
       def __init__(self, parent, bitmap):
           super(ImageBackground, self).__init__(parent)
   
           self.bitmap = bitmap
           self.width = bitmap.Size.width
           self.height = bitmap.Size.height
   
           self.Bind(wx.EVT_PAINT, self.OnPaint)

2. Next, we will define the OnPaint...