add widgets.Window and fix paint_frame offset

docs/changelog.txt

@@ -48,6 +48,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 ## Lua
 - ``gui.View``: ``visible`` and ``active`` can now be functions that return a boolean
 - ``widgets.Panel``: new attributes to control window dragging and resizing with mouse or keyboard
+- ``widgets.Window``: Panel subclass with attributes preset for top-level windows
 
 ## Internals
 

docs/dev/Lua API.rst

@@ -4247,6 +4247,12 @@ Has functions:
   commit the new window size or :kbd:`Esc` to cancel. If resizing is canceled,
   then the window size from before the resize operation is restored.
 
+Window class
+------------
+
+Subclass of Panel; sets Panel attributes to useful defaults for a top-level
+framed, draggable window.
+
 ResizingPanel class
 -------------------
 

library/lua/gui.lua

@@ -704,8 +704,9 @@ GREY_LINE_FRAME = {
     signature_pen = to_pen{ fg = COLOR_DARKGREY, bg = COLOR_BLACK },
 }
 
-function paint_frame(x1,y1,x2,y2,style,title)
+function paint_frame(dc,rect,style,title)
     local pen = style.frame_pen
+    local x1,y1,x2,y2 = dc.x1+rect.x1, dc.y1+rect.y1, dc.x1+rect.x2, dc.y1+rect.y2
     dscreen.paintTile(style.lt_frame_pen or pen, x1, y1)
     dscreen.paintTile(style.rt_frame_pen or pen, x2, y1)
     dscreen.paintTile(style.lb_frame_pen or pen, x1, y2)
@@ -750,16 +751,13 @@ function FramedScreen:computeFrame(parent_rect)
 end
 
 function FramedScreen:onRenderFrame(dc, rect)
-    local x1,y1,x2,y2 = rect.x1, rect.y1, rect.x2, rect.y2
-
     if rect.wgap <= 0 and rect.hgap <= 0 then
         dc:clear()
     else
         self:renderParent()
         dc:fill(rect, self.frame_background)
     end
-
-    paint_frame(x1,y1,x2,y2,self.frame_style,self.frame_title)
+    paint_frame(dc,rect,self.frame_style,self.frame_title)
 end
 
 return _ENV

library/lua/gui/widgets.lua

@@ -420,8 +420,7 @@ end
 function Panel:onRenderFrame(dc, rect)
     Panel.super.onRenderFrame(self, dc, rect)
     if not self.frame_style then return end
-    local x1,y1,x2,y2 = rect.x1, rect.y1, rect.x2, rect.y2
-    gui.paint_frame(x1, y1, x2, y2, self.frame_style, self.frame_title)
+    gui.paint_frame(dc, rect, self.frame_style, self.frame_title)
     if self.kbd_get_pos then
         local pos = self.kbd_get_pos()
         local pen = dfhack.pen.parse{fg=COLOR_GREEN, bg=COLOR_BLACK}
@@ -433,6 +432,19 @@ function Panel:onRenderFrame(dc, rect)
     end
 end
 
+------------
+-- Window --
+------------
+
+Window = defclass(Window, Panel)
+
+Window.ATTRS {
+    frame_style = gui.GREY_LINE_FRAME,
+    frame_background = gui.CLEAR_PEN,
+    frame_inset = 1,
+    draggable = true,
+}
+
 -------------------
 -- ResizingPanel --
 -------------------