fluxbox resize window complete full

If you want to have the resize grip available in the complete bottom edge and not just the corners then edit the file
src/FbWinFrame.cc
change:

const int grip_width = 20; //TODO to const int grip_width = m_window.width()/2 ; //TODO

Now there will the resize grip on the complete bottom of the window.

To increase the borderwidth or edge do the following:
name@linux:~ > grep -i width .fluxbox/styles/kde4/theme.cfg
menu.bevelWidth: 0
menu.borderWidth: 1
window.bevelWidth: 0
window.borderWidth: 2
window.handleWidth: 1
toolbar.borderWidth: 1
toolbar.bevelWidth: 1
toolbar.clock.borderWidth: 1
toolbar.workspace.borderWidth: 0
toolbar.iconbar.borderWidth: 1


Dont do this
to increase the thickness of the grip (only to the lower bottom of the window)
Edit: src/FbWinFrameTheme.cc
*m_handle_width = FbTk::Util::clamp(*m_handle_width, 0, 200);

to

*m_handle_width = FbTk::Util::clamp(*m_handle_width, 4, 200);