give more control over the resizing dimensions of ResizingPanels

docs/dev/Lua API.rst

@@ -4416,6 +4416,13 @@ Subclass of Panel; automatically adjusts its own frame height and width to the
 minimum required to show its subviews. Pairs nicely with a parent Panel that has
 ``autoarrange_subviews`` enabled.
 
+It has the following attributes:
+
+:auto_height: Sets self.frame.h from the positions and height of its subviews
+              (default is ``true``).
+:auto_width: Sets self.frame.w from the positions and width of its subviews
+             (default is ``false``).
+
 Pages class
 -----------
 

library/lua/gui/widgets.lua

@@ -530,6 +530,11 @@ Window.ATTRS {
 
 ResizingPanel = defclass(ResizingPanel, Panel)
 
+ResizingPanel.ATTRS{
+    auto_height = true,
+    auto_width = false,
+}
+
 -- adjust our frame dimensions according to positions and sizes of our subviews
 function ResizingPanel:postUpdateLayout(frame_body)
     local w, h = 0, 0
@@ -550,6 +555,8 @@ function ResizingPanel:postUpdateLayout(frame_body)
     end
     if not self.frame then self.frame = {} end
     local oldw, oldh = self.frame.w, self.frame.h
+    if not self.auto_height then h = oldh end
+    if not self.auto_width then w = oldw end
     self.frame.w, self.frame.h = w, h
     if not self._updateLayoutGuard and (oldw ~= w or oldh ~= h) then
         self._updateLayoutGuard = true -- protect against infinite loops