Initial work on adding a LayerData renderer type

volatility3/framework/interfaces/renderers.py

@@ -9,8 +9,10 @@ renderer interface which can interact with a TreeGrid to produce
 suitable output.
 """
 
+from dataclasses import dataclass
 import datetime
-from abc import abstractmethod, ABCMeta
+from volatility3.framework import interfaces
+from abc import ABCMeta, abstractmethod
 from collections import abc
 from typing import (
     Any,
@@ -20,9 +22,9 @@ from typing import (
     List,
     NamedTuple,
     Optional,
-    TypeVar,
-    Type,
     Tuple,
+    Type,
+    TypeVar,
     Union,
 )
 
@@ -124,6 +126,13 @@ class Disassembly:
         self.offset = offset
 
 
+@dataclass
+class LayerData(object):
+    layer_name: str
+    offset: int
+    length: int
+
+
 # We don't class these off a shared base, because the BaseTypes must only
 # contain the types that the validator will accept (which would not include the base)
 
@@ -136,6 +145,7 @@ BaseTypes = Union[
     Type[datetime.datetime],
     Type[BaseAbsentValue],
     Type[Disassembly],
+    Type[LayerData],
 ]
 ColumnsType = List[Tuple[str, BaseTypes]]
 VisitorSignature = Callable[[TreeNode, _Type], _Type]
@@ -163,7 +173,12 @@ class TreeGrid(metaclass=ABCMeta):
         Disassembly,
     )
 
-    def __init__(self, columns: ColumnsType, generator: Generator) -> None:
+    def __init__(
+        self,
+        columns: ColumnsType,
+        generator: Generator,
+        context: Optional[interfaces.context.ContextInterface] = None,
+    ) -> None:
         """Constructs a TreeGrid object using a specific set of columns.
 
         The TreeGrid itself is a root element, that can have children but no values.
@@ -174,6 +189,15 @@ class TreeGrid(metaclass=ABCMeta):
             columns: A list of column tuples made up of (name, type).
             generator: An iterable containing row for a tree grid, each row contains a indent level followed by the values for each column in order.
         """
+        self._context = context
+
+    @property
+    def context(self) -> Optional[interfaces.context.ContextInterface]:
+        """Returns the context value for the tree grid (to retrieve data items)
+
+        This is a property to ensure the renderers don't try changing the context for any reason
+        """
+        return self._context
 
     @staticmethod
     @abstractmethod