allow dragging by frame edge for non-resizable windows

docs/changelog.txt

@@ -59,6 +59,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 - `gui/blueprint`: recording of stockpile layouts and categories is now supported. note that detailed stockpile configurations will *not* be saved (yet)
 - Core: For debugging purposes, you can now pass ``--disable-dfhack`` on the Dwarf Fortress commandline or specify ``DFHACK_DISABLE=1`` in the environment to disable DFHack for the current session.
 - `overlay`: added links to the quickstart guide and the control panel on the DF title screen
+- Window behavior: non-resizable windows now allow dragging by their frame edges by default
 - `gui/autodump`: fort-mode keybinding: Ctrl-H
 
 ## Documentation

docs/dev/Lua API.rst

@@ -4503,7 +4503,7 @@ Has attributes:
   Called from ``postComputeFrame``.
 
 * ``draggable = bool`` (default: ``false``)
-* ``drag_anchors = {}`` (default: ``{title=true, frame=false, body=false}``)
+* ``drag_anchors = {}`` (default: ``{title=true, frame=false/true, body=true}``)
 * ``drag_bound = 'frame' or 'body'`` (default: ``'frame'``)
 * ``on_drag_begin = function()`` (default: ``nil``)
 * ``on_drag_end = function(bool)`` (default: ``nil``)
@@ -4511,7 +4511,7 @@ Has attributes:
   If ``draggable`` is set to ``true``, then the above attributes come into play
   when the panel is dragged around the screen, either with the mouse or the
   keyboard. ``drag_anchors`` sets which parts of the panel can be clicked on
-  with the left mouse button to start dragging. ``drag_bound`` configures
+  with the left mouse button to start dragging. The frame is a drag anchor by default only if ``resizable`` (below) is ``false``. ``drag_bound`` configures
   whether the frame of the panel (if any) can be dragged outside the containing
   parent's boundary. The body will never be draggable outside of the parent,
   but you can allow the frame to cross the boundary by setting ``drag_bound`` to

library/lua/gui/widgets.lua

@@ -87,7 +87,7 @@ Panel.ATTRS {
 
 function Panel:init(args)
     if not self.drag_anchors then
-        self.drag_anchors = {title=true, frame=false, body=true}
+        self.drag_anchors = {title=true, frame=not self.resizable, body=true}
     end
     if not self.resize_anchors then
         self.resize_anchors = {t=false, l=true, r=true, b=true}