Support containers in LaTeX output.

Support containers in the LaTeX writer by outputting the start and end
of a LaTeX group, wrapping the beginning and end of a LaTeX
environment. The class name(s) are passed as an argument to the
environment.

sphinx/texinputs/sphinx.sty

@@ -270,6 +270,11 @@
 \input{sphinxlatexshadowbox.sty}
 
 
+%% CONTAINERS
+%
+\input{sphinxlatexcontainers.sty}
+
+
 %% PYGMENTS
 % stylesheet for highlighting with pygments
 \RequirePackage{sphinxhighlight}

sphinx/texinputs/sphinxlatexcontainers.sty

@@ -0,0 +1,12 @@
+%% CONTAINER DIRECTIVES
+%
+% change this info string if making any custom modification
+\ProvidesFile{sphinxlatexcontainers.sty}[2021/05/03 containers]
+
+% The purpose of this file is to provide a dummy environment sphinxcontainer
+% which will be inserted for every container directive the container class
+% name will be passed as the argument to the environment. User-defined
+% formatting of directives can be achieved by renewing the definition of 
+% this environment, and branching on the value of the argument.
+
+\newenvironment{sphinxcontainer}[1]{}{}

sphinx/writers/latex.py

@@ -1975,10 +1975,12 @@ class LaTeXTranslator(SphinxTranslator):
         pass
 
     def visit_container(self, node: Element) -> None:
-        pass
+        classes = node.get('classes', [])
+        self.body.append(
+            '\n\\bgroup\\begin{sphinxcontainer}{%s}' % ' '.join(classes))
 
     def depart_container(self, node: Element) -> None:
-        pass
+        self.body.append('\n\\end{sphinxcontainer}\\egroup')
 
     def visit_decoration(self, node: Element) -> None:
         pass