Make headers info display configurable

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 * The *rollback ratio* is now displayed in the "global" header (#385).
+* Let the display of header's sections be configurable.
 
 ### Changed
 

README.md

@@ -146,8 +146,13 @@ ex:
 read from `${XDG_CONFIG_HOME:~/.config}/pg_activity.conf` or
 `/etc/pg_activity.conf` in that order. Command-line options may override
 configuration file settings.
-This is used to control how columns in the processes table are rendered, e.g.:
+This is used to control how columns in the processes table are rendered or which
+items of the header should be displayed, e.g.:
 ```ini
+[header]
+system_info = yes
+worker_info = no
+
 [client]
 hidden = yes
 

pgactivity/cli.py

@@ -321,23 +321,23 @@ def get_parser() -> ArgumentParser:
         dest="header_instance_info",
         action="store_false",
         help="Hide instance information.",
-        default=True,
+        default=None,
     )
     # --no-sys-info
     group.add_argument(
         "--no-sys-info",
         dest="header_system_info",
         action="store_false",
         help="Hide system information.",
-        default=True,
+        default=None,
     )
     # --no-proc-info
     group.add_argument(
         "--no-proc-info",
         dest="header_worker_info",
         action="store_false",
         help="Hide workers process information.",
-        default=True,
+        default=None,
     )
 
     group = parser.add_argument_group("Other display options")

pgactivity/config.py

@@ -2,7 +2,7 @@
 import enum
 import os
 from pathlib import Path
-from typing import IO, Any, Dict, List, Optional, Type, TypeVar
+from typing import IO, Any, Dict, List, Optional, Type, TypeVar, Union
 
 import attr
 from attr import validators
@@ -160,20 +160,50 @@ def load(
         return flag
 
 
+class BaseSectionMixin:
+    @classmethod
+    def check_options(
+        cls: type[attr.AttrsInstance], section: configparser.SectionProxy
+    ) -> list[str]:
+        known_options = {f.name for f in attr.fields(cls)}
+        unknown_options = set(section) - set(known_options)
+        if unknown_options:
+            raise ValueError(f"invalid option(s): {', '.join(sorted(unknown_options))}")
+        return list(sorted(known_options))
+
+
 @attr.s(auto_attribs=True, frozen=True, slots=True)
-class UISection:
+class HeaderSection(BaseSectionMixin):
+    instance_info: bool = True
+    system_info: bool = True
+    worker_info: bool = True
+
+    _T = TypeVar("_T", bound="HeaderSection")
+
+    @classmethod
+    def from_config_section(cls: Type[_T], section: configparser.SectionProxy) -> _T:
+        values: Dict[str, bool] = {}
+        for optname in cls.check_options(section):
+            try:
+                value = section.getboolean(optname)
+            except configparser.NoOptionError:
+                continue
+            if value is not None:
+                values[optname] = value
+        return cls(**values)
+
+
+@attr.s(auto_attribs=True, frozen=True, slots=True)
+class UISection(BaseSectionMixin):
     hidden: bool = False
     width: Optional[int] = attr.ib(default=None, validator=validators.optional(gt(0)))
 
     _T = TypeVar("_T", bound="UISection")
 
     @classmethod
     def from_config_section(cls: Type[_T], section: configparser.SectionProxy) -> _T:
+        cls.check_options(section)
         values: Dict[str, Any] = {}
-        known_options = {f.name: f for f in attr.fields(cls)}
-        unknown_options = set(section) - set(known_options)
-        if unknown_options:
-            raise ValueError(f"invalid option(s): {', '.join(sorted(unknown_options))}")
         try:
             hidden = section.getboolean("hidden")
         except configparser.NoOptionError:
@@ -192,9 +222,12 @@ def from_config_section(cls: Type[_T], section: configparser.SectionProxy) -> _T
 ETC = Path("/etc")
 
 
-class Configuration(Dict[str, UISection]):
+class Configuration(Dict[str, Union[HeaderSection, UISection]]):
     _T = TypeVar("_T", bound="Configuration")
 
+    def header(self) -> Optional[HeaderSection]:
+        return self.get("header")  # type: ignore[return-value]
+
     @classmethod
     def parse(cls: Type[_T], f: IO[str], name: str) -> _T:
         r"""Parse configuration from 'f'.
@@ -250,6 +283,9 @@ def parse(cls: Type[_T], f: IO[str], name: str) -> _T:
                 if section:
                     raise InvalidSection(p.default_section, name)
                 continue
+            if sname == "header":
+                config[sname] = HeaderSection.from_config_section(section)
+                continue
             if sname not in known_sections:
                 raise InvalidSection(sname, name)
             try:

pgactivity/types.py

@@ -25,7 +25,7 @@
 from attr import validators
 
 from . import colors, compat, pg, utils
-from .config import Configuration, Flag
+from .config import Configuration, Flag, HeaderSection, UISection
 
 
 class Pct(float):
@@ -214,6 +214,19 @@ class UIHeader:
     system_info: bool = True
     worker_info: bool = True
 
+    @classmethod
+    def make(
+        cls, config: Optional[HeaderSection], **options: bool | None
+    ) -> "UIHeader":
+        """Build a UIHeader from configuration and command-line options, the latter
+        taking precedence over the former.
+        """
+        values = {}
+        if config is not None:
+            values.update(attr.asdict(config))
+        values.update({k: v for k, v in options.items() if v is not None})
+        return cls(**values)
+
     def toggle_system_info(self) -> None:
         """Toggle the 'system_info' attribute.
 
@@ -289,7 +302,7 @@ def make(
         **kwargs: Any,
     ) -> "UI":
         if header is None:
-            header = UIHeader()
+            header = UIHeader.make(config.header() if config else None)
 
         possible_columns: Dict[str, Column] = {}
 
@@ -300,6 +313,7 @@ def add_column(key: str, name: str, **kwargs: Any) -> None:
                 except KeyError:
                     pass
                 else:
+                    assert isinstance(cfg, UISection), cfg
                     if cfg.width is not None:
                         kwargs["min_width"] = kwargs["max_width"] = cfg.width
             assert key not in possible_columns, f"duplicated key {key}"

pgactivity/ui.py

@@ -38,7 +38,8 @@ def main(
 
     flag = Flag.load(config, is_local=is_local, **vars(options))
     ui = types.UI.make(
-        header=types.UIHeader(
+        header=types.UIHeader.make(
+            config.header() if config else None,
             instance_info=options.header_instance_info,
             system_info=options.header_system_info,
             worker_info=options.header_worker_info,

tests/test_config.py

@@ -81,6 +81,18 @@ def asdict(cfg: Configuration) -> Dict[str, Any]:
     cfg = Configuration.lookup(user_config_home=tmp_path)
     assert cfg is None
 
-    (tmp_path / "pg_activity.conf").write_text("\n".join(["[client]", "width=5"]))
+    (tmp_path / "pg_activity.conf").write_text(
+        "\n".join(
+            [
+                "[client]",
+                "width=5",
+                "[header]",
+                "instance_info=no",
+            ]
+        )
+    )
     cfg = Configuration.lookup(user_config_home=tmp_path)
-    assert cfg is not None and asdict(cfg) == {"client": {"hidden": False, "width": 5}}
+    assert cfg is not None and asdict(cfg) == {
+        "client": {"hidden": False, "width": 5},
+        "header": {"instance_info": False, "system_info": True, "worker_info": True},
+    }