Golang wxWidgets Wrapper

Please feel free to folk and make your changes. I'm still available through GitHub Issues for any questions.

For Golang 1.10.0 and 1.9.4, there is a "Invalid flag" issue which causes the build fails. Please check Here for workaround.

Currently wxGo can compile and run on Windows, Linux and Mac OS X on amd64 architecture.

• 64-bit Go
• GCC / MinGW ver > 5 for Linux / Windows
• > 5GB Memory space

Remarks

32-bit go will run out of memory due to ~5GB memory consumption when compiling and I have no idea on how to decline the memory usage. Any suggestion or discussion will help.

The precompiled wxWidgets is compiled with gcc > 5 ( 6.2.1 on Linux, 5.3.0 on Windows using tdm-gcc). So if you want to use the precompiled wxWidgets, your gcc version has also to be > 5, because GCC changed its ABI since GCC 5 release series.

go get github.com/dontpanic92/wxGo/wx

You can add -x option to print each command it executes.

This section will introduce how to customize wxGo.

wxGo needs a 2-phase compilation. The first is the SWIG phase, that is using SWIG to generate the wrapper code. And the second is the Go phase, which has been described above.

You can regenerate the wrapper code using SWIG. Compilation dependencies are:

• python 2 or 3
• sed
• make
• A customized SWIG

We use a customized SWIG to generate the wrapper code. Please clone https://github.com/dontpanic92/SWIG and simply ./configure && make && sudo make install. Then you can modify the source as you want, and run make in the build folder.

If you want to use other wxWidgets build rather than the precompiled one, what you have to do is quite simple.

• Compile wxWidgets
• Run go get -d github.com/dontpanic92/wxGo/wx to let the go-tool just download the source
• Open wx/setup_OS_ARCH.go, change the CPPFLAGS and LDFLAGS
• Run go install github.com/dontpanic92/wxGo/wx

Done!

After importing github.com/dontpanic92/wxGo/wx, the following code will create an empty dialog with a "Hello World" as its caption.

    wx.NewApp()
    f := wx.NewDialog(wx.NullWindow, -1, "Hello World")
    f.ShowModal()
    f.Destroy()

All the wx-Classes' objects can be created using wx.NewCLASS. Now let us add some controls on it :

    wx.NewApp()
    f := wx.NewDialog(wx.NullWindow, -1, "Hello World")

    bSizer := wx.NewBoxSizer(wx.VERTICAL)

    checkBox := wx.NewCheckBox(f, wx.ID_ANY, "Check Me!", wx.DefaultPosition, wx.DefaultSize, 0)
    bSizer.Add(checkBox, 0, wx.ALL|wx.EXPAND, 5)

    textCtrl := wx.NewTextCtrl(f, wx.ID_ANY, "", wx.DefaultPosition, wx.DefaultSize, 0)
    bSizer.Add(textCtrl, 0, wx.ALL|wx.EXPAND, 5)

    f.SetSizer(bSizer)
    f.Layout()
    f.ShowModal()
    f.Destroy()

And then we can bind an event on the checkbox :

func checkboxClicked(e wx.Event) {
    wx.MessageBox("Checkbox clicked!")
}

//....
    wx.Bind(f, wx.EVT_CHECKBOX, checkboxClicked, checkBox.GetId())
//....

Bravo!

Remarks : about the memory management

All wx.NewCLASS functions will allocate memory on C++ side (on heap), thus it will not be tracked by Go's garbage collector. However, in most cases we don't need to worry about it, because wxWidgets will handle it. Some common cases are listed below:

• √ When a wxWindow (or its subclasses) being deleted , it will automatically delete all of its children.

• √ When we click the close button of a wxFrame, by default the Destroy will be called and it will be deleted by itself (and also all children).

• × However when we close a wxDialog, the Destroy won't be called by default and we have to manually destroy it.

• × If an object isn't in the GUI hierarchy, we have to free the memory by calling DeleteCLASS.

In a word, p := wx.NewCLASS in Go acts the same as p = new wxCLASS() in C++. Where we need a delete p, then we need a wx.DeleteCLASS.

More Info:

• wxWidgets docs on window deletion

• SWIG docs on Go memory management

Examples are in the examples folder. Dapeton is a simple notepad, and controls is a dialog that contains several widgets.

wxGo is licensed under the wxWindows Library Licence.