The wx.SashWindow is a powerful feature of the wxPython library that allows you to create resizable windows with adjustable sashes, similar to the sash windows commonly found in GUI applications. This sash window allows the user to dynamically adjust the size of different sections within the window by dragging the sashes.

In this blog post, we will explore how to use the wx.SashWindow class in wxPython to create resizable windows in Python.

Getting Started

Before we dive into the code examples, make sure you have wxPython installed. You can install it using pip:

pip install wxPython

Creating a Basic SashWindow

To get started, let’s create a basic wxPython application with a wx.SashWindow.

import wx

class MySashWindow(wx.SashWindow):
    def __init__(self, parent):
        wx.SashWindow.__init__(self, parent, id=wx.ID_ANY, style=wx.SW_3D | wx.SASH_BORDER)

        # Add content to the sash window
        self.panel = wx.Panel(self)
        self.panel.SetBackgroundColour(wx.WHITE)

        # Set initial sash position and size
        self.SetSashSize(10)
        self.SetSashVisible(wx.SASH_RIGHT, True)
        self.SetDefaultSize(wx.Size(200, 200))

        # Bind the sash events
        self.Bind(wx.EVT_SASH_DRAGGED_RANGE, self.OnSashDrag)

    def OnSashDrag(self, event):
        # Handle sash drag event here
        pass

class MyFrame(wx.Frame):
    def __init__(self, parent):
        wx.Frame.__init__(self, parent, title="Resizable Window Example")

        # Create a sash window
        self.sashWindow = MySashWindow(self)

        # Set the sash window as the main window
        self.SetSize(wx.Size(500, 500))
        self.Centre()

if __name__ == "__main__":
    app = wx.App()
    frame = MyFrame(None)
    frame.Show()
    app.MainLoop()

In the above code, we create a new class MySashWindow, which inherits from wx.SashWindow. We add content to the sash window by creating a panel and setting its background color to white. We then set the initial sash position and size using SetSashSize and SetSashVisible methods. Finally, we bind the EVT_SASH_DRAGGED_RANGE event to a handler function OnSashDrag, which will be called when the sash is dragged.

We also create a basic MyFrame class that inherits from wx.Frame and contains the sash window. We set the size of the frame and center it on the screen.

Handling Sash Drag Events

To handle sash drag events, we need to implement the OnSashDrag method. This method will be called whenever the user drags the sash. You can then update the window layout or perform any other action based on the sash position.

def OnSashDrag(self, event):
    # Get the sash position
    sashPosition = event.GetEdgePosition(wx.SASH_RIGHT)

    # Update the layout based on the sash position
    self.panel.SetSize(wx.Size(sashPosition, self.GetSize().height))

    # Refresh the layout
    self.Layout()

In the above example, we get the sash position using GetEdgePosition and update the size of the panel based on the sash position. We then call Layout to refresh the layout of the sash window.

Conclusion

In this blog post, we explored how to use the wx.SashWindow class in wxPython to create resizable windows in Python. We learned how to create a basic sash window, handle sash drag events, and update the window layout based on the sash position.

The wx.SashWindow provides a flexible and intuitive way to create resizable windows in your wxPython applications, giving your users more control over the application’s layout. Experiment with different configurations and layouts to make your applications more user-friendly and customizable.

Happy coding with wxPython and wx.SashWindow!