From bef0dd14ae255240a71615c4d1152400eb9ef1c6 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 08:08:43 +0000
Subject: [PATCH 01/22] :sparkles: Add an API call for downloading the source
 of a PEP

---
 src/peplum/peps/api.py | 71 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 61 insertions(+), 10 deletions(-)

diff --git a/src/peplum/peps/api.py b/src/peplum/peps/api.py
index 3f74066..e9f34bb 100644
--- a/src/peplum/peps/api.py
+++ b/src/peplum/peps/api.py
@@ -7,7 +7,7 @@
 
 ##############################################################################
 # HTTPX imports.
-from httpx import AsyncClient, HTTPStatusError, RequestError
+from httpx import AsyncClient, HTTPStatusError, RequestError, Response
 
 
 ##############################################################################
@@ -38,19 +38,20 @@ def _client(self) -> AsyncClient:
             self._client_ = AsyncClient()
         return self._client_
 
-    async def get_peps(self) -> dict[int, dict[str, Any]]:
-        """Download a fresh list of all known PEPs.
+    async def _get(self, url: str) -> Response:
+        """Make a GET request.
+
+        Args:
+            url: The URL to make the request of.
 
         Returns:
-            The PEP JSON data.
+            The response.
 
         Raises:
-            RequestError: If there was a problem getting the PEPS.
+            RequestError: If there was some sort of error.
         """
         try:
-            response = await self._client.get(
-                self._URL, headers={"user-agent": self.AGENT}
-            )
+            response = await self._client.get(url, headers={"user-agent": self.AGENT})
         except (RequestError, SSLCertVerificationError) as error:
             raise self.RequestError(str(error)) from None
 
@@ -59,10 +60,60 @@ async def get_peps(self) -> dict[int, dict[str, Any]]:
         except HTTPStatusError as error:
             raise self.RequestError(str(error)) from None
 
-        if isinstance(raw_data := response.json(), dict):
-            return raw_data
+        return response
+
+    async def get_peps(self) -> dict[int, dict[str, Any]]:
+        """Download a fresh list of all known PEPs.
+
+        Returns:
+            The PEP JSON data.
 
+        Raises:
+            RequestError: If there was a problem getting the PEPS.
+        """
+        if isinstance(
+            raw_data := (
+                await self._get("https://peps.python.org/api/peps.json")
+            ).json(),
+            dict,
+        ):
+            return raw_data
         raise RequestError("Unexpected data received from the PEP API")
 
+    @staticmethod
+    def pep_file(pep: int) -> str:
+        """Generate the name of the source file of a PEP.
+
+        Args:
+            pep: The number of the PEP.
+
+        Returns:
+            The name of the source file for that PEP.
+        """
+        return f"pep-{pep:04}.rst"
+
+    @classmethod
+    def pep_url(cls, pep: int) -> str:
+        """Generate the URL for the source of a PEP.
+
+        Args:
+            pep: The number of the PEP.
+
+        Returns:
+            The URL for the source of the PEP.
+        """
+        return f"https://raw.githubusercontent.com/python/peps/refs/heads/main/peps/{cls.pep_file(pep)}"
+
+    async def get_pep(self, pep: int) -> str:
+        """Download the text of a given PEP.
+
+        Args:
+            pep: The number of the PEP to download.
+
+        Returns:
+            The text for the PEP.
+        """
+        return (await self._get(self.pep_url(pep))).text
+
 
 ### api.py ends here

From cd68210749afa28b83091898e127a35360cdce98 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 08:43:36 +0000
Subject: [PATCH 02/22] :sparkles: Add the core framework of a PEP source
 viewer screen

See #2.
---
 src/peplum/app/commands/__init__.py  |   2 +
 src/peplum/app/commands/main.py      |   8 +++
 src/peplum/app/providers/main.py     |   2 +
 src/peplum/app/screens/main.py       |  14 ++++
 src/peplum/app/screens/pep_viewer.py | 101 +++++++++++++++++++++++++++
 5 files changed, 127 insertions(+)
 create mode 100644 src/peplum/app/screens/pep_viewer.py

diff --git a/src/peplum/app/commands/__init__.py b/src/peplum/app/commands/__init__.py
index 92073b8..d964eea 100644
--- a/src/peplum/app/commands/__init__.py
+++ b/src/peplum/app/commands/__init__.py
@@ -25,6 +25,7 @@
     Quit,
     RedownloadPEPs,
     TogglePEPDetails,
+    ViewPEP,
 )
 from .navigation_sorting import (
     ToggleAuthorsSortOrder,
@@ -59,6 +60,7 @@
     "TogglePythonVersionsSortOrder",
     "ToggleStatusesSortOrder",
     "ToggleTypesSortOrder",
+    "ViewPEP",
 ]
 
 ### __init__.py ends here
diff --git a/src/peplum/app/commands/main.py b/src/peplum/app/commands/main.py
index 5d121db..cdf007f 100644
--- a/src/peplum/app/commands/main.py
+++ b/src/peplum/app/commands/main.py
@@ -61,4 +61,12 @@ class TogglePEPDetails(Command):
     BINDING_KEY = "f3"
 
 
+##############################################################################
+class ViewPEP(Command):
+    """View the source of the currently-highlighted PEP"""
+
+    FOOTER_TEXT = "View"
+    BINDING_KEY = "f4"
+
+
 ### main.py ends here
diff --git a/src/peplum/app/providers/main.py b/src/peplum/app/providers/main.py
index fc88c25..1736c0a 100644
--- a/src/peplum/app/providers/main.py
+++ b/src/peplum/app/providers/main.py
@@ -24,6 +24,7 @@
     TogglePythonVersionsSortOrder,
     ToggleStatusesSortOrder,
     ToggleTypesSortOrder,
+    ViewPEP,
 )
 from .commands_provider import CommandHits, CommandsProvider
 
@@ -59,6 +60,7 @@ def commands(self) -> CommandHits:
         yield TogglePythonVersionsSortOrder()
         yield ToggleStatusesSortOrder()
         yield ToggleTypesSortOrder()
+        yield ViewPEP()
 
 
 ### main.py ends here
diff --git a/src/peplum/app/screens/main.py b/src/peplum/app/screens/main.py
index a3a6bf9..efdf61d 100644
--- a/src/peplum/app/screens/main.py
+++ b/src/peplum/app/screens/main.py
@@ -44,6 +44,7 @@
     TogglePythonVersionsSortOrder,
     ToggleStatusesSortOrder,
     ToggleTypesSortOrder,
+    ViewPEP,
 )
 from ..data import (
     PEP,
@@ -78,6 +79,7 @@
 from ..widgets import Navigation, PEPDetails, PEPsView
 from .help import HelpScreen
 from .notes_editor import NotesEditor
+from .pep_viewer import PEPViewer
 from .search_input import SearchInput
 
 
@@ -148,6 +150,7 @@ class Main(Screen[None]):
         Help,
         EditNotes,
         TogglePEPDetails,
+        ViewPEP,
         Quit,
         RedownloadPEPs,
         # Everything else.
@@ -529,5 +532,16 @@ async def action_edit_notes_command(self) -> None:
                 self.all_peps.patch_pep(self.selected_pep.annotate(notes=notes))
             )
 
+    @on(ViewPEP)
+    def action_view_pep_command(self) -> None:
+        """View the currently-highlighted PEP's source."""
+        if self.selected_pep is None:
+            self.notify("Highlight a PEP to view it.", severity="warning")
+            return
+        if self.selected_pep.number == 0:
+            self.notify("PEP0 has no source to view.", severity="warning")
+            return
+        self.app.push_screen(PEPViewer(self.selected_pep))
+
 
 ### main.py ends here
diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
new file mode 100644
index 0000000..fb9668c
--- /dev/null
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -0,0 +1,101 @@
+"""A dialog for viewing the text of a PEP."""
+
+##############################################################################
+# Textual imports.
+from textual import on, work
+from textual.app import ComposeResult
+from textual.containers import Horizontal, Vertical, VerticalScroll
+from textual.screen import ModalScreen
+from textual.widgets import Button, Static
+
+##############################################################################
+# Local imports.
+from ...peps import API
+from ..data import PEP
+
+
+##############################################################################
+class PEPViewer(ModalScreen[None]):
+    """A modal screen for viewing a PEP's source."""
+
+    CSS = """
+    PEPViewer {
+        align: center middle;
+
+        &> Vertical {
+            width: 80%;
+            height: 80%;
+            max-height: 80%;
+            background: $panel;
+            border: panel $border;
+        }
+
+        #viewer {
+            height: 1fr;
+        }
+
+        #text {
+            padding: 0 1;
+        }
+
+        #buttons {
+            height: auto;
+            margin-top: 1;
+            align-horizontal: right;
+        }
+
+        Button {
+            margin-right: 1;
+        }
+    }
+    """
+
+    BINDINGS = [("escape", "close")]
+
+    def __init__(self, pep: PEP) -> None:
+        """Initialise the dialog.
+
+        Args:
+            pep: The PEP to view.
+        """
+        super().__init__()
+        self._pep = pep
+        """The PEP to view."""
+
+    def compose(self) -> ComposeResult:
+        """Compose the dialog's content."""
+        with Vertical() as dialog:
+            dialog.border_title = f"PEP{self._pep.number}"
+            yield VerticalScroll(Static(id="text"), id="viewer")
+            with Horizontal(id="buttons"):
+                yield Button("Close [dim]\\[Esc][/]")
+
+    @work
+    async def _download_text(self) -> None:
+        """Download the text of the PEP."""
+        try:
+            self.query_one("#text", Static).update(
+                await API().get_pep(self._pep.number)
+            )
+        except API.RequestError as error:
+            self.query_one("#text", Static).update("[error]Error[/]")
+            self.notify(
+                str(error), title="Error downloading PEP source", severity="error"
+            )
+            return
+        finally:
+            self.query_one("#viewer").loading = False
+        self.set_focus(self.query_one("#viewer"))
+
+    def on_mount(self) -> None:
+        """Populate the dialog once the"""
+        self.query_one("#viewer").loading = True
+        self._download_text()
+
+    @on(Button.Pressed)
+    def action_close(self) -> None:
+        """Close the dialog."""
+        self.dismiss(None)
+
+
+### pep_viewer.py ends here

From 495f94b04bc5e522ff8f3f3f0e833cae6cfba4e0 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 09:23:45 +0000
Subject: [PATCH 03/22] :lipstick: Improve the look of the PEP viewer

---
 src/peplum/app/peplum.py             |  5 +++++
 src/peplum/app/screens/pep_viewer.py | 12 +++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/peplum/app/peplum.py b/src/peplum/app/peplum.py
index 131d49d..4a1a7ef 100644
--- a/src/peplum/app/peplum.py
+++ b/src/peplum/app/peplum.py
@@ -33,6 +33,11 @@ class Peplum(App[None]):
         }
     }
 
+    /* Make the LoadingIndicator look less like it was just slapped on. */
+    LoadingIndicator {
+        background: transparent;
+    }
+
     /* Remove cruft from the Header. */
     Header {
         /* The header icon is ugly and pointless. Remove it. */
diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index fb9668c..307a9c1 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -32,6 +32,15 @@ class PEPViewer(ModalScreen[None]):
 
         #viewer {
             height: 1fr;
+            scrollbar-background: $panel;
+            scrollbar-background-hover: $panel;
+            scrollbar-background-active: $panel;
+            Static {
+                color: $text-muted;
+            }
+            &:focus Static {
+                color: $text;
+            }
         }
 
         #text {
@@ -42,6 +51,7 @@ class PEPViewer(ModalScreen[None]):
             height: auto;
             margin-top: 1;
             align-horizontal: right;
+            border-top: round $border;
         }
 
         Button {
@@ -68,7 +78,7 @@ def compose(self) -> ComposeResult:
             dialog.border_title = f"PEP{self._pep.number}"
             yield VerticalScroll(Static(id="text"), id="viewer")
             with Horizontal(id="buttons"):
-                yield Button("Close [dim]\\[Esc][/]")
+                yield Button("Close [dim]\\[Esc][/]", variant="default")
 
     @work
     async def _download_text(self) -> None:

From dd2bcc3c849aa51b572d08a1a7eaba505c621884 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 11:13:13 +0000
Subject: [PATCH 04/22] :hammer: Have API.pep_file return a Path rather than a
 string

---
 src/peplum/peps/api.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/peplum/peps/api.py b/src/peplum/peps/api.py
index e9f34bb..5eb7fdd 100644
--- a/src/peplum/peps/api.py
+++ b/src/peplum/peps/api.py
@@ -2,6 +2,7 @@
 
 ##############################################################################
 # Python imports.
+from pathlib import Path
 from ssl import SSLCertVerificationError
 from typing import Any, Final
 
@@ -81,7 +82,7 @@ async def get_peps(self) -> dict[int, dict[str, Any]]:
         raise RequestError("Unexpected data received from the PEP API")
 
     @staticmethod
-    def pep_file(pep: int) -> str:
+    def pep_file(pep: int) -> Path:
         """Generate the name of the source file of a PEP.
 
         Args:
@@ -90,7 +91,7 @@ def pep_file(pep: int) -> str:
         Returns:
             The name of the source file for that PEP.
         """
-        return f"pep-{pep:04}.rst"
+        return Path(f"pep-{pep:04}.rst")
 
     @classmethod
     def pep_url(cls, pep: int) -> str:

From b204d51acbe91680f11e6bdfcccd182f4bc32b50 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 11:17:11 +0000
Subject: [PATCH 05/22] :hammer: Simplify the CSS for the PEP viewer

---
 src/peplum/app/screens/pep_viewer.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index 307a9c1..b304938 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -35,18 +35,15 @@ class PEPViewer(ModalScreen[None]):
             scrollbar-background: $panel;
             scrollbar-background-hover: $panel;
             scrollbar-background-active: $panel;
-            Static {
+            #text {
+                padding: 0 1;
                 color: $text-muted;
             }
-            &:focus Static {
+            &:focus #text {
                 color: $text;
             }
         }
 
-        #text {
-            padding: 0 1;
-        }
-
         #buttons {
             height: auto;
             margin-top: 1;

From 6611517487229e153ac7278e7bcbd17bb294f540 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 16:52:57 +0000
Subject: [PATCH 06/22] :sparkles: Add support for a cache location

---
 src/peplum/app/data/__init__.py  |  1 +
 src/peplum/app/data/locations.py | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/peplum/app/data/__init__.py b/src/peplum/app/data/__init__.py
index 333c1b9..a459d1a 100644
--- a/src/peplum/app/data/__init__.py
+++ b/src/peplum/app/data/__init__.py
@@ -8,6 +8,7 @@
     save_configuration,
     update_configuration,
 )
+from .locations import cache_dir
 from .notes import Notes
 from .pep import PEP, PEPStatus, PEPType, PostHistory
 from .peps import (
diff --git a/src/peplum/app/data/locations.py b/src/peplum/app/data/locations.py
index ae4c6cb..7d6deed 100644
--- a/src/peplum/app/data/locations.py
+++ b/src/peplum/app/data/locations.py
@@ -41,6 +41,21 @@ def data_dir() -> Path:
     return _app_dir(xdg_data_home())
 
 
+##############################################################################
+def cache_dir() -> Path:
+    """The path to the cache directory for the application.
+
+    Returns:
+        The path to the cache directory for the application.
+
+    Note:
+        If the directory doesn't exist, it will be created as a side-effect
+        of calling this function.
+    """
+    (cache := data_dir() / "cache").mkdir(parents=True, exist_ok=True)
+    return cache
+
+
 ##############################################################################
 def config_dir() -> Path:
     """The path to the configuration directory for the application.

From 1b8f02c10aeef6f12a1f8da6c02f8ef3720c0fb3 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 16:53:23 +0000
Subject: [PATCH 07/22] :art: Tidy the order of the exports

---
 src/peplum/app/data/__init__.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/peplum/app/data/__init__.py b/src/peplum/app/data/__init__.py
index a459d1a..e65a2c7 100644
--- a/src/peplum/app/data/__init__.py
+++ b/src/peplum/app/data/__init__.py
@@ -29,17 +29,18 @@
 ##############################################################################
 # Exports.
 __all__ = [
-    "pep_data",
     "AuthorCount",
+    "cache_dir",
     "Configuration",
     "Containing",
     "load_configuration",
     "Notes",
     "PEP",
-    "PEPStatus",
-    "PEPType",
+    "pep_data",
     "PEPCount",
     "PEPs",
+    "PEPStatus",
+    "PEPType",
     "PostHistory",
     "PythonVersionCount",
     "save_configuration",

From 073589a6ea98ae440a6472f1d15d06f74ff5caff Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 16:54:08 +0000
Subject: [PATCH 08/22] :sparkles: Add a cache facility to the PEP source
 viewer screen

---
 src/peplum/app/screens/pep_viewer.py | 71 +++++++++++++++++++++-------
 1 file changed, 54 insertions(+), 17 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index b304938..1e10985 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -1,5 +1,9 @@
 """A dialog for viewing the text of a PEP."""
 
+##############################################################################
+# Python imports.
+from pathlib import Path
+
 ##############################################################################
 # Textual imports.
 from textual import on, work
@@ -11,7 +15,7 @@
 ##############################################################################
 # Local imports.
 from ...peps import API
-from ..data import PEP
+from ..data import PEP, cache_dir
 
 
 ##############################################################################
@@ -57,7 +61,7 @@ class PEPViewer(ModalScreen[None]):
     }
     """
 
-    BINDINGS = [("escape", "close")]
+    BINDINGS = [("escape", "close"), ("ctrl+r", "refresh")]
 
     def __init__(self, pep: PEP) -> None:
         """Initialise the dialog.
@@ -75,23 +79,46 @@ def compose(self) -> ComposeResult:
             dialog.border_title = f"PEP{self._pep.number}"
             yield VerticalScroll(Static(id="text"), id="viewer")
             with Horizontal(id="buttons"):
-                yield Button("Close [dim]\\[Esc][/]", variant="default")
+                yield Button("Refresh [dim]\\[^r][/]", id="refresh")
+                yield Button("Close [dim]\\[Esc][/]", id="close")
+
+    @property
+    def _cache_name(self) -> Path:
+        """The name of the file that is the cached version of the PEP source."""
+        return cache_dir() / API.pep_file(self._pep.number)
 
     @work
     async def _download_text(self) -> None:
-        """Download the text of the PEP."""
-        try:
-            self.query_one("#text", Static).update(
-                await API().get_pep(self._pep.number)
-            )
-        except API.RequestError as error:
-            self.query_one("#text", Static).update("[error]Error[/]")
-            self.notify(
-                str(error), title="Error downloading PEP source", severity="error"
-            )
-            return
-        finally:
-            self.query_one("#viewer").loading = False
+        """Download the text of the PEP.
+
+        Notes:
+            Once downloaded a local copy will be saved. Subsequently, when
+            attempting to download the PEP, this local copy will be used
+            instead.
+        """
+        pep_source = ""
+        if self._cache_name.exists():
+            try:
+                pep_source = self._cache_name.read_text(encoding="utf-8")
+            except IOError:
+                pass
+
+        if not pep_source:
+            try:
+                self._cache_name.write_text(
+                    pep_source := await API().get_pep(self._pep.number),
+                    encoding="utf-8",
+                )
+            except IOError:
+                pass
+            except API.RequestError as error:
+                pep_source = "Error downloading PEP source"
+                self.notify(
+                    str(error), title="Error downloading PEP source", severity="error"
+                )
+
+        self.query_one("#text", Static).update(pep_source)
+        self.query_one("#viewer").loading = False
         self.set_focus(self.query_one("#viewer"))
 
     def on_mount(self) -> None:
@@ -99,10 +126,20 @@ def on_mount(self) -> None:
         self.query_one("#viewer").loading = True
         self._download_text()
 
-    @on(Button.Pressed)
+    @on(Button.Pressed, "#close")
     def action_close(self) -> None:
         """Close the dialog."""
         self.dismiss(None)
 
+    @on(Button.Pressed, "#refresh")
+    def action_refresh(self) -> None:
+        """Refresh the PEP source."""
+        try:
+            self._cache_name.unlink(missing_ok=True)
+        except IOError:
+            pass
+        self.query_one("#viewer").loading = True
+        self._download_text()
+
 
 ### pep_viewer.py ends here

From f32faa481cb983d727db95595ea393879952a580 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Jan 2025 17:08:08 +0000
Subject: [PATCH 09/22] :books: Add mention of the cache files to the "File
 locations" in README

---
 README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/README.md b/README.md
index 8d391fc..54761a1 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,7 @@ Expanding for the common locations, the files normally created are:
 
 - `~/.config/peplum/configuration.json` -- The configuration file.
 - `~/.local/share/peplum/*.json` -- The locally-held PEP data.
+- `~/.local/share/peplum/cache/*.rst` -- The locally-cached PEP source files.
 
 ## Getting help
 

From 29e963df0be6a68b34aff82f6c1afb708be55c78 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 07:12:42 +0000
Subject: [PATCH 10/22] :hammer: Only set loading in one place

---
 src/peplum/app/screens/pep_viewer.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index 1e10985..1e6b193 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -96,7 +96,9 @@ async def _download_text(self) -> None:
             attempting to download the PEP, this local copy will be used
             instead.
         """
+        self.query_one("#viewer").loading = True
         pep_source = ""
+
         if self._cache_name.exists():
             try:
                 pep_source = self._cache_name.read_text(encoding="utf-8")
@@ -123,7 +125,6 @@ async def _download_text(self) -> None:
 
     def on_mount(self) -> None:
         """Populate the dialog once the"""
-        self.query_one("#viewer").loading = True
         self._download_text()
 
     @on(Button.Pressed, "#close")
@@ -138,7 +139,6 @@ def action_refresh(self) -> None:
             self._cache_name.unlink(missing_ok=True)
         except IOError:
             pass
-        self.query_one("#viewer").loading = True
         self._download_text()
 
 

From 4f2fd6a5d89e24a0f7b6f20134705baf85230d7f Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 07:39:35 +0000
Subject: [PATCH 11/22] :hammer: Swap to using a ScrollableContainer

---
 src/peplum/app/screens/pep_viewer.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index 1e6b193..b90a5d5 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -8,7 +8,7 @@
 # Textual imports.
 from textual import on, work
 from textual.app import ComposeResult
-from textual.containers import Horizontal, Vertical, VerticalScroll
+from textual.containers import Horizontal, ScrollableContainer, Vertical
 from textual.screen import ModalScreen
 from textual.widgets import Button, Static
 
@@ -77,7 +77,7 @@ def compose(self) -> ComposeResult:
         """Compose the dialog's content."""
         with Vertical() as dialog:
             dialog.border_title = f"PEP{self._pep.number}"
-            yield VerticalScroll(Static(id="text"), id="viewer")
+            yield ScrollableContainer(Static(id="text"), id="viewer")
             with Horizontal(id="buttons"):
                 yield Button("Refresh [dim]\\[^r][/]", id="refresh")
                 yield Button("Close [dim]\\[Esc][/]", id="close")

From d533a82e1022b6498884378da29d1ffca7ff053b Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 07:47:35 +0000
Subject: [PATCH 12/22] :hammer: Swap to using a read-only TextArea to view the
 PEP source

---
 src/peplum/app/screens/pep_viewer.py | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index b90a5d5..a1fd115 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -8,9 +8,9 @@
 # Textual imports.
 from textual import on, work
 from textual.app import ComposeResult
-from textual.containers import Horizontal, ScrollableContainer, Vertical
+from textual.containers import Horizontal, Vertical
 from textual.screen import ModalScreen
-from textual.widgets import Button, Static
+from textual.widgets import Button, TextArea
 
 ##############################################################################
 # Local imports.
@@ -34,17 +34,17 @@ class PEPViewer(ModalScreen[None]):
             border: panel $border;
         }
 
-        #viewer {
+        #text {
+            color: $text-muted;
             height: 1fr;
+            background: transparent;
             scrollbar-background: $panel;
             scrollbar-background-hover: $panel;
             scrollbar-background-active: $panel;
-            #text {
-                padding: 0 1;
-                color: $text-muted;
-            }
-            &:focus #text {
+            border: none;
+            &:focus {
                 color: $text;
+                border: none;
             }
         }
 
@@ -77,7 +77,7 @@ def compose(self) -> ComposeResult:
         """Compose the dialog's content."""
         with Vertical() as dialog:
             dialog.border_title = f"PEP{self._pep.number}"
-            yield ScrollableContainer(Static(id="text"), id="viewer")
+            yield TextArea(id="text", read_only=True)
             with Horizontal(id="buttons"):
                 yield Button("Refresh [dim]\\[^r][/]", id="refresh")
                 yield Button("Close [dim]\\[Esc][/]", id="close")
@@ -96,7 +96,7 @@ async def _download_text(self) -> None:
             attempting to download the PEP, this local copy will be used
             instead.
         """
-        self.query_one("#viewer").loading = True
+        (text := self.query_one("#text", TextArea)).loading = True
         pep_source = ""
 
         if self._cache_name.exists():
@@ -119,9 +119,9 @@ async def _download_text(self) -> None:
                     str(error), title="Error downloading PEP source", severity="error"
                 )
 
-        self.query_one("#text", Static).update(pep_source)
-        self.query_one("#viewer").loading = False
-        self.set_focus(self.query_one("#viewer"))
+        text.text = pep_source
+        text.loading = False
+        self.set_focus(text)
 
     def on_mount(self) -> None:
         """Populate the dialog once the"""

From 94f1c7c89db63012cf922c333e2e5ceb6341ce11 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 08:10:24 +0000
Subject: [PATCH 13/22] :sparkles: Add a text viewing widget

---
 src/peplum/app/widgets/__init__.py    |  3 +-
 src/peplum/app/widgets/text_viewer.py | 59 +++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 src/peplum/app/widgets/text_viewer.py

diff --git a/src/peplum/app/widgets/__init__.py b/src/peplum/app/widgets/__init__.py
index 913221b..a0d2c6e 100644
--- a/src/peplum/app/widgets/__init__.py
+++ b/src/peplum/app/widgets/__init__.py
@@ -5,10 +5,11 @@
 from .navigation import Navigation
 from .pep_details import PEPDetails
 from .peps_view import PEPsView
+from .text_viewer import TextViewer
 
 ##############################################################################
 # Exports.
-__all__ = ["Navigation", "PEPDetails", "PEPsView"]
+__all__ = ["Navigation", "PEPDetails", "PEPsView", "TextViewer"]
 
 
 ### __init__.py ends here
diff --git a/src/peplum/app/widgets/text_viewer.py b/src/peplum/app/widgets/text_viewer.py
new file mode 100644
index 0000000..2fc48b4
--- /dev/null
+++ b/src/peplum/app/widgets/text_viewer.py
@@ -0,0 +1,59 @@
+"""A widget for viewing text."""
+
+##############################################################################
+# Textual imports.
+from textual.widgets import TextArea
+
+
+##############################################################################
+class TextViewer(TextArea):
+    """A widget for viewing text."""
+
+    DEFAULT_CSS = """
+    TextViewer {
+        background: transparent;
+        border: none;
+        &:focus {
+            border: none;
+        }
+    }
+    """
+
+    def __init__(
+        self,
+        text: str = "",
+        *,
+        name: str | None = None,
+        id: str | None = None,
+        classes: str | None = None,
+        disabled: bool = False,
+    ) -> None:
+        """Initialise the object.
+
+        Args:
+            text: The text to view.
+            name: The name of the TextViewer.
+            id: The ID of the TextViewer in the DOM.
+            classes: The CSS classes of the TextViewer.
+            disabled: Whether the TextViewer is disabled or not.
+        """
+        super().__init__(
+            text,
+            read_only=True,
+            name=name,
+            id=id,
+            classes=classes,
+            disabled=disabled,
+        )
+
+    def action_copy(self) -> None:
+        """Action for copying text to the clipboard."""
+        if for_clipboard := self.selected_text:
+            self.notify("Selected text copied to the clipboard.")
+        else:
+            for_clipboard = self.text
+            self.notify("All text copied to the clipboard.")
+        self.app.copy_to_clipboard(for_clipboard)
+
+
+### text_viewer.py ends here

From 801925832f5041ac86e218f3c2e2dd46903e1fa4 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 08:14:14 +0000
Subject: [PATCH 14/22] :sparkles: Swap the PEP source viewer over to the
 TextViewer widget

---
 src/peplum/app/screens/pep_viewer.py | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index a1fd115..6ebec8c 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -16,6 +16,7 @@
 # Local imports.
 from ...peps import API
 from ..data import PEP, cache_dir
+from ..widgets import TextViewer
 
 
 ##############################################################################
@@ -34,17 +35,14 @@ class PEPViewer(ModalScreen[None]):
             border: panel $border;
         }
 
-        #text {
+        TextViewer {
             color: $text-muted;
             height: 1fr;
-            background: transparent;
             scrollbar-background: $panel;
             scrollbar-background-hover: $panel;
             scrollbar-background-active: $panel;
-            border: none;
             &:focus {
                 color: $text;
-                border: none;
             }
         }
 
@@ -61,7 +59,7 @@ class PEPViewer(ModalScreen[None]):
     }
     """
 
-    BINDINGS = [("escape", "close"), ("ctrl+r", "refresh")]
+    BINDINGS = [("escape", "close"), ("ctrl+r", "refresh"), ("ctrl+c", "copy")]
 
     def __init__(self, pep: PEP) -> None:
         """Initialise the dialog.
@@ -77,8 +75,9 @@ def compose(self) -> ComposeResult:
         """Compose the dialog's content."""
         with Vertical() as dialog:
             dialog.border_title = f"PEP{self._pep.number}"
-            yield TextArea(id="text", read_only=True)
+            yield TextViewer()
             with Horizontal(id="buttons"):
+                yield Button("Copy [dim]\\[^c][/]", id="copy")
                 yield Button("Refresh [dim]\\[^r][/]", id="refresh")
                 yield Button("Close [dim]\\[Esc][/]", id="close")
 
@@ -96,7 +95,7 @@ async def _download_text(self) -> None:
             attempting to download the PEP, this local copy will be used
             instead.
         """
-        (text := self.query_one("#text", TextArea)).loading = True
+        (text := self.query_one(TextViewer)).loading = True
         pep_source = ""
 
         if self._cache_name.exists():
@@ -141,5 +140,10 @@ def action_refresh(self) -> None:
             pass
         self._download_text()
 
+    @on(Button.Pressed, "#copy")
+    async def action_copy(self) -> None:
+        """Copy PEP text to the clipboard."""
+        await self.query_one(TextArea).run_action("copy")
+
 
 ### pep_viewer.py ends here

From cc75e1bc3e10f30d3a98c1bc518e4cd1cccd25fb Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 08:20:51 +0000
Subject: [PATCH 15/22] :books: Update the ChangeLog

---
 ChangeLog.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index be635c1..2f31e92 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,12 @@
 # Peplum ChangeLog
 
+## Unreleased
+
+**Released: WiP**
+
+- Added the ability to view the source of a PEP.
+  ([#17](https://github.com/davep/peplum/pull/17))
+
 ## v0.2.0
 
 **Released: 2025-01-27**

From b816a143571635399607ad685a12c2cde646bbcf Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 08:54:07 +0000
Subject: [PATCH 16/22] :lipstick: Remove the line highlight from the
 TextViewer widget

---
 src/peplum/app/widgets/text_viewer.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/peplum/app/widgets/text_viewer.py b/src/peplum/app/widgets/text_viewer.py
index 2fc48b4..d450b88 100644
--- a/src/peplum/app/widgets/text_viewer.py
+++ b/src/peplum/app/widgets/text_viewer.py
@@ -16,6 +16,9 @@ class TextViewer(TextArea):
         &:focus {
             border: none;
         }
+        & > .text-area--cursor-line {
+           background: transparent;
+        }
     }
     """
 

From a5a96c9799736445d7efc3a8e58c36a040a59d45 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 09:12:35 +0000
Subject: [PATCH 17/22] :sparkles: Add some movement tweaks to the TextViewer

---
 src/peplum/app/widgets/text_viewer.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/peplum/app/widgets/text_viewer.py b/src/peplum/app/widgets/text_viewer.py
index d450b88..ea1f761 100644
--- a/src/peplum/app/widgets/text_viewer.py
+++ b/src/peplum/app/widgets/text_viewer.py
@@ -22,6 +22,11 @@ class TextViewer(TextArea):
     }
     """
 
+    BINDINGS = [
+        ("<", "cursor_line_start"),
+        (">", "cursor_line_end"),
+    ]
+
     def __init__(
         self,
         text: str = "",
@@ -58,5 +63,20 @@ def action_copy(self) -> None:
             self.notify("All text copied to the clipboard.")
         self.app.copy_to_clipboard(for_clipboard)
 
+    def action_cursor_line_start(self, select: bool = False) -> None:
+        """Add a slightly smarter use of going 'home'."""
+        if self.cursor_at_start_of_line:
+            self.move_cursor((0, 0), select=select)
+        else:
+            super().action_cursor_line_start(select)
+
+    def action_cursor_line_end(self, select: bool = False) -> None:
+        """Add a slightly smarter use of going 'end'."""
+        if self.cursor_at_end_of_line:
+            self.move_cursor((self.document.line_count, 0), select=select)
+            pass
+        else:
+            super().action_cursor_line_end(select)
+
 
 ### text_viewer.py ends here

From 94330a6dc13198e2b184518934f60c5eeb50a3c1 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 09:32:44 +0000
Subject: [PATCH 18/22] :sparkles: Add all the options for copying

---
 src/peplum/app/widgets/text_viewer.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/peplum/app/widgets/text_viewer.py b/src/peplum/app/widgets/text_viewer.py
index ea1f761..e6f026a 100644
--- a/src/peplum/app/widgets/text_viewer.py
+++ b/src/peplum/app/widgets/text_viewer.py
@@ -25,6 +25,7 @@ class TextViewer(TextArea):
     BINDINGS = [
         ("<", "cursor_line_start"),
         (">", "cursor_line_end"),
+        ("c, C", "copy"),
     ]
 
     def __init__(

From 19ef6790537931c1c9209984882977b6459d4cdb Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 09:36:00 +0000
Subject: [PATCH 19/22] :hammer: Correctly identify the start and end of the
 text to view

Also remove a rogue `pass` that got left in, from when I was writing the
code earlier.
---
 src/peplum/app/widgets/text_viewer.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/peplum/app/widgets/text_viewer.py b/src/peplum/app/widgets/text_viewer.py
index e6f026a..1bc3ff2 100644
--- a/src/peplum/app/widgets/text_viewer.py
+++ b/src/peplum/app/widgets/text_viewer.py
@@ -67,15 +67,14 @@ def action_copy(self) -> None:
     def action_cursor_line_start(self, select: bool = False) -> None:
         """Add a slightly smarter use of going 'home'."""
         if self.cursor_at_start_of_line:
-            self.move_cursor((0, 0), select=select)
+            self.move_cursor(self.document.start, select=select)
         else:
             super().action_cursor_line_start(select)
 
     def action_cursor_line_end(self, select: bool = False) -> None:
         """Add a slightly smarter use of going 'end'."""
         if self.cursor_at_end_of_line:
-            self.move_cursor((self.document.line_count, 0), select=select)
-            pass
+            self.move_cursor(self.document.end, select=select)
         else:
             super().action_cursor_line_end(select)
 

From 759b67d8d8ed5e2ed26dfceac2f29dc6933ef01c Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 10:43:45 +0000
Subject: [PATCH 20/22] :books: Fix a documentation typo

---
 src/peplum/app/screens/pep_viewer.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index 6ebec8c..5499e2e 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -123,7 +123,7 @@ async def _download_text(self) -> None:
         self.set_focus(text)
 
     def on_mount(self) -> None:
-        """Populate the dialog once the"""
+        """Populate the dialog once the DOM is ready."""
         self._download_text()
 
     @on(Button.Pressed, "#close")

From 03ea80a2ce9e1fd47e9813725be05c2af3d2a986 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 13:51:06 +0000
Subject: [PATCH 21/22] :lipstick: Improve the cosmetics of the PEP source
 viewer

---
 src/peplum/app/screens/pep_viewer.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index 5499e2e..097cab7 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -32,7 +32,7 @@ class PEPViewer(ModalScreen[None]):
             height: 80%;
             max-height: 80%;
             background: $panel;
-            border: panel $border;
+            border: solid $border;
         }
 
         TextViewer {
@@ -48,9 +48,8 @@ class PEPViewer(ModalScreen[None]):
 
         #buttons {
             height: auto;
-            margin-top: 1;
             align-horizontal: right;
-            border-top: round $border;
+            border-top: solid $border;
         }
 
         Button {

From 86414da3a934a5dab3cac9e743a44a3e143d497a Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Wed, 29 Jan 2025 13:55:12 +0000
Subject: [PATCH 22/22] :lipstick: Use the accent colour to highlight the keys
 in buttons

---
 src/peplum/app/screens/pep_viewer.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/peplum/app/screens/pep_viewer.py b/src/peplum/app/screens/pep_viewer.py
index 097cab7..3ef6930 100644
--- a/src/peplum/app/screens/pep_viewer.py
+++ b/src/peplum/app/screens/pep_viewer.py
@@ -72,13 +72,16 @@ def __init__(self, pep: PEP) -> None:
 
     def compose(self) -> ComposeResult:
         """Compose the dialog's content."""
+        key_colour = (
+            "dim" if self.app.current_theme is None else self.app.current_theme.accent
+        )
         with Vertical() as dialog:
             dialog.border_title = f"PEP{self._pep.number}"
             yield TextViewer()
             with Horizontal(id="buttons"):
-                yield Button("Copy [dim]\\[^c][/]", id="copy")
-                yield Button("Refresh [dim]\\[^r][/]", id="refresh")
-                yield Button("Close [dim]\\[Esc][/]", id="close")
+                yield Button(f"Copy [{key_colour}]\\[^c][/]", id="copy")
+                yield Button(f"Refresh [{key_colour}]\\[^r][/]", id="refresh")
+                yield Button(f"Close [{key_colour}]\\[Esc][/]", id="close")
 
     @property
     def _cache_name(self) -> Path: