Release0170 (#2165)

* blog post

* blog post

* options list

* snapshot

* words

* fix flicker

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
-## Unreleased
+## [0.17.0] - 2023-03-29
 
 ### Fixed
 
@@ -33,6 +33,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Screens with alpha in their background color will now blend with the background. https://github.com/Textualize/textual/pull/2139
 - Added "thick" border style. https://github.com/Textualize/textual/pull/2139
 - message_pump.app will now set the active app if it is not already set.
+- DataTable now has max height set to 100vh
 
 ### Added
 

docs/blog/posts/release0-17-0.md

@@ -0,0 +1,96 @@
+---
+draft: false
+date: 2023-03-29
+categories:
+  - Release
+title: "Textual 0.17.0 adds translucent screens and Option List"
+authors:
+  - willmcgugan
+---
+
+# Textual 0.17.0 adds translucent screens and Option List
+
+This is a surprisingly large release, given it has been just 7 days since the last version (and we were down a developer for most of that time).
+
+What's new in this release?
+
+<!-- more -->
+
+There are two new notable features I want to cover. The first is a compositor effect.
+
+## Translucent screens
+
+Textual has a concept of "screens" which you can think of as independent UI modes, each with their own user interface and logic.
+The App class keeps a stack of these screens so you can switch to a new screen and later return to the previous screen.
+
+!!! tip inline end "Screens"
+
+    See the [guide](../../guide/screens.md) to learn more about the screens API.
+
+    <a href="/guide/screens">
+    <div class="excalidraw">
+    --8<-- "docs/images/screens/pop_screen.excalidraw.svg"
+    </div>
+    </a>
+
+Screens can be used to build modal dialogs by *pushing* a screen with controls / buttons, and *popping* the screen when the user has finished with it.
+The problem with this approach is that there was nothing to indicate to the user that the original screen was still there, and could be returned to.
+
+In this release we have added alpha support to the Screen's background color which allows the screen underneath to show through, typically blended with a little color.
+Applying this to a screen makes it clear than the user can return to the previous screen when they have finished interacting with the modal.
+
+Here's how you can enable this effect with CSS:
+
+```sass hl_lines="3"
+DialogScreen {
+    align: center middle;
+    background: $primary 30%;
+}
+```
+
+Setting the background to `$primary` will make the background blue (with the default theme).
+The addition of `30%` sets the alpha so that it will be blended with the background.
+Here's the kind of effect this creates:
+
+<div>
+--8<-- "docs/blog/images/transparent_background.svg"
+</div>
+
+There are 4 screens in the above screenshot, one for the base screen and one for each of the three dialogs.
+Note how each screen modifies the color of the screen below, but leaves everything visible.
+
+See the [docs on screen opacity](../../guide/screens.md#screen-opacity) if you want to add this to your apps.
+
+## Option list
+
+Textual has had a [ListView](../../widgets/list_view.md) widget for a while, which is an excellent way of navigating a list of items (actually other widgets). In this release we've added an [OptionList](../../widgets/option_list.md) which is similar in appearance, but uses the [line api](../../guide/widgets.md#line-api) under the hood. The Line API makes it more efficient when you approach thousands of items.
+
+```{.textual path="docs/examples/widgets/option_list_strings.py"}
+```
+
+The Options List accepts [Rich](https://github.com/Textualize/rich/) *renderable*, which means that anything Rich can render may be displayed in a list. Here's an Option List of tables:
+
+```{.textual path="docs/examples/widgets/option_list_tables.py" columns="100" lines="32"}
+```
+
+We plan to build on the `OptionList` widget to implement drop-downs, menus, check lists, etc.
+But it is still very useful as it is, and you can add it to apps now.
+
+## What else?
+
+There are a number of fixes regarding refreshing in this release. If you had issues with parts of the screen not updating, the new version should resolve it.
+
+There's also a new logging handler, and a "thick" border type.
+
+See [release notes](https://github.com/Textualize/textual/releases/tag/v0.17.0) for the full details.
+
+
+## Next week
+
+Next week we plan to take a break from building Textual to *building apps* with Textual.
+We do this now and again to give us an opportunity to step back and understand things from the perspective of a developer using Textual.
+We will hopefully have something interesting to show from the exercise, and new Open Source apps to share.
+
+## Join us
+
+If you want to talk about this update or anything else Textual related, join us on our [Discord server](https://discord.gg/Enf6Z3qhVr).

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "textual"
-version = "0.16.0"
+version = "0.17.0"
 homepage = "https://github.com/Textualize/textual"
 description = "Modern Text User Interface framework"
 authors = ["Will McGugan <will@textualize.io>"]

src/textual/_compositor.py

@@ -849,6 +849,7 @@ class Compositor:
         """
         screen_region = self.size.region
         update_regions = self._dirty_regions.copy()
+        self._dirty_regions.clear()
         if update_regions:
             # Create a crop region that surrounds all updates.
             crop = Region.from_union(update_regions).intersection(screen_region)

src/textual/app.py

@@ -1599,6 +1599,7 @@ class App(Generic[ReturnType], DOMNode):
                     try:
                         await self._dispatch_message(events.Compose())
                         await self._dispatch_message(events.Mount())
+                        self.check_idle()
                     finally:
                         self._mounted_event.set()
 

src/textual/message_pump.py

@@ -437,6 +437,7 @@ class MessagePump(metaclass=MessagePumpMeta):
         try:
             await self._dispatch_message(events.Compose())
             await self._dispatch_message(events.Mount())
+            self.check_idle()
             self._post_mount()
         except Exception as error:
             self.app._handle_exception(error)

src/textual/screen.py

@@ -382,7 +382,6 @@ class Screen(Widget):
                         self._repaint_required = False
 
                     if self._dirty_widgets:
-                        self._on_timer_update()
                         self.update_timer.resume()
 
         # The Screen is idle - a good opportunity to invoke the scheduled callbacks

src/textual/widgets/_data_table.py

@@ -247,6 +247,7 @@ class DataTable(ScrollView, Generic[CellType], can_focus=True):
         background: $surface ;
         color: $text;
         height: auto;
+        max-height: 100vh
     }
     DataTable > .datatable--header {
         text-style: bold;

src/textual/widgets/_option_list.py

@@ -176,7 +176,7 @@ class OptionList(ScrollView, can_focus=True):
     }
 
     OptionList > .option-list--separator {
-        color: $text-muted;
+        color: $foreground 15%;
     }
 
     OptionList > .option-list--option-highlighted {