Port the tree reporter to textual

Now that we are using Textual for the live mode, we can port the tree
reporter to be a live Textual App. This has plenty of advantages over
the static version as it offers interactive exploration of the tree, as
well as the possibility of using different screens for showing detailed
information about allocations such as the source and metadata.

Signed-off-by: Pablo Galindo <[email protected]>

Author: pablogsal

docs/_static/images/tree_example.png

@@ -6,9 +6,9 @@ the tracked process at the time when its memory usage was at its peak.
 
 .. image:: _static/images/tree_example.png
 
-The tree reporter shows some statistics followed by a tree representation of
-the allocated memory. Several aspects are important when interpreting the tree
-representation:
+The tree reporter shows an interactive terminal applocation displaying a tree
+representation of the allocated memory. Several aspects are important when
+interpreting the tree representation:
 
 * Only the 10 source locations responsible for the most allocated bytes are
   displayed. This is configurable with the ``--biggest-allocs`` command line
@@ -17,17 +17,24 @@ representation:
   calculated based only on the allocations that are shown. Since any allocation
   not big enough to be shown will not be included there, the reported total
   memory of the root node is normally less than the process's peak memory size.
-* Call chains of one node are collapsed for better readability. This means that
-  branches in the tree where each node has only one child are collapsed and a
-  special node is shown to reflect this. The hidden frames **never** correspond
-  to frames that contained one of the source locations with the biggest
-  allocations. The hidden frames are always callers of functions where the reported
-  allocation happened.
 * The "📂" icon represents a frame that is a **caller** of a function where an
   allocation happened while the "📄" icon represents a frame that allocated
   memory.
 * Frames are colored based on their reported memory usage percentage, from red
   (most bytes allocated) to green (fewest).
+* You can interact with the application using the following keys:
+
+  * You can navigate the tree using the arrow keys. Pressing the up arrow key
+    will move up one level in the tree, while pressing the down arrow key will
+    move down one level. When a selected node is changed, the panel on the right
+    will be updated to show the source code of the selected frame and some metadata
+    about the allocations assigned to that frame.
+  * Pressing the 'e' key will expand nodes and their children recursively until a node with
+    more than one child is found. This can be used to quickly expand the tree.
+  * Pressing the 'i' key will hide all nodes that belong to the import system and their
+    children.
+  * Presing the 'u' key will show all nodes that are marked as "uninteresting".
+
 
 Basic Usage
 -----------

docs/tree.rst

@@ -0,0 +1 @@
+Port the tree reporter to be an interactive Textual App.

news/499.feature.rst

@@ -3,11 +3,8 @@
 from pathlib import Path
 from textwrap import dedent
 
-from rich import print as rprint
-
 from memray import FileReader
 from memray._errors import MemrayCommandError
-from memray._memray import size_fmt
 from memray.commands.common import warn_if_not_enough_symbols
 from memray.reporters.tree import TreeReporter
 
@@ -80,14 +77,4 @@ def run(self, args: argparse.Namespace, parser: argparse.ArgumentParser) -> None
                 f"Failed to parse allocation records in {result_path}\nReason: {e}",
                 exit_code=1,
             )
-        print()
-        header = "Allocation metadata"
-        rprint(f"{header}\n{'-'*len(header)}")
-        rprint(f"Command line arguments: '{reader.metadata.command_line}'")
-        rprint(f"Peak memory size: {size_fmt(reader.metadata.peak_memory)}")
-        rprint(f"Number of allocations: {reader.metadata.total_allocations}")
-        print()
-        header = f"Biggest {args.biggest_allocs} allocations:"
-        rprint(header)
-        rprint("-" * len(header))
         reporter.render()