From 770336d0cfe6a68befd594ea4d04b0e5bc581ac5 Mon Sep 17 00:00:00 2001
From: snowykte0426 <snowykte0426@naver.com>
Date: Tue, 18 Aug 2026 14:08:14 +0900
Subject: [PATCH] fix(recipient-completion): show which suggestion the keyboard
 has selected

Moving through the recipient completion list with a keyboard left no trace on
screen, so there was no way to tell which suggestion was about to be picked.

The list selector cannot do this reliably. `setListSelection()` reaches
`ListView.layoutChildren`, which positions the selector with
`positionSelector(INVALID_POSITION, sel)`; `AbsListView.positionSelector` then
computes `positionChanged = position != mSelectorPosition` and skips the block
that refreshes the selector's drawable state, because both sides are -1. The
selector is therefore painted with an empty state set on the first selection.
Its state is the list's own state as well, and `DropDownListView` reports
itself as focused for as long as the popup exists, so a stateful selector
cannot tell a selected row from a cleared one either.

The row does not have that problem: `ListView.setupChild` calls
`child.setSelected(selected && shouldShowSelector())`, which is correct from
the first selection onwards. So give the row a background that draws the
selection, and leave the list selector alone so touch feedback is unchanged.

`colorSecondaryContainer`, the Material token for a selected list item, is not
usable here: the rows take their text colour from
`textColorPrimaryRecipientDropdown`, which is `@android:color/primary_text_light`
and pinned to black in the light theme, and that only reaches 3.3:1 on
`lightSecondaryContainer`. `colorSurfaceContainerHighest` keeps the text at
16:1 but is itself only 1.22:1 against the popup background, so the selected
row also gets a `colorPrimary` outline: 7.7:1 in the light theme and 14.1:1 in
the dark one, which meets WCAG 1.4.11 for a state indicator.

This has no visible effect on its own. The completion list ignores the arrow
keys until something is selected, so #11413, which makes the tab key select the
first suggestion, is what reaches this code path.
---
 .../recipient_dropdown_item_background.xml    | 39 +++++++++++++++++++
 .../res/layout/recipient_dropdown_item.xml    |  1 +
 2 files changed, 40 insertions(+)
 create mode 100644 legacy/ui/legacy/src/main/res/drawable/recipient_dropdown_item_background.xml

diff --git a/legacy/ui/legacy/src/main/res/drawable/recipient_dropdown_item_background.xml b/legacy/ui/legacy/src/main/res/drawable/recipient_dropdown_item_background.xml
new file mode 100644
index 00000000000..2a4ce37bc0d
--- /dev/null
+++ b/legacy/ui/legacy/src/main/res/drawable/recipient_dropdown_item_background.xml
@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Marks the recipient completion suggestion that the keyboard has selected.
+
+    The selection has to be drawn by the row rather than by the list selector. ListView.setupChild() calls
+    child.setSelected() on the row, which is correct from the first selection onwards, whereas the selector's
+    drawable state is the list's own state (AbsListView.getDrawableStateForSelector) and DropDownListView
+    reports itself as focused for as long as the popup exists, so a stateful selector cannot tell a selected
+    row from a cleared one. The list selector is deliberately left alone, so touch feedback is unchanged.
+
+    The fill on its own is only 1.22:1 against the popup background in the light theme, so the outline carries
+    the contrast: colorPrimary is 7.7:1 there and 14.1:1 in the dark theme. colorSecondaryContainer, the
+    Material token for a selected list item, is not usable here because the rows take their text colour from
+    textColorPrimaryRecipientDropdown, which is pinned to black in the light theme and reaches only 3.3:1 on it.
+
+    Note that state_selected also propagates to the row's TextViews. It does not change their colour today
+    because @android:color/primary_text_* matches its state_window_focused="false" entry first, and this popup
+    is never focusable, but making the popup focusable would turn the selected row's text black on black.
+-->
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <item android:state_selected="true">
+        <inset android:inset="2dp">
+            <shape android:shape="rectangle">
+                <solid android:color="?attr/colorSurfaceContainerHighest" />
+                <stroke
+                    android:width="2dp"
+                    android:color="?attr/colorPrimary"
+                    />
+                <corners android:radius="4dp" />
+            </shape>
+        </inset>
+    </item>
+
+    <item>
+        <color android:color="@android:color/transparent" />
+    </item>
+
+</selector>
diff --git a/legacy/ui/legacy/src/main/res/layout/recipient_dropdown_item.xml b/legacy/ui/legacy/src/main/res/layout/recipient_dropdown_item.xml
index 9a0f00442d8..3e42f23f1e6 100644
--- a/legacy/ui/legacy/src/main/res/layout/recipient_dropdown_item.xml
+++ b/legacy/ui/legacy/src/main/res/layout/recipient_dropdown_item.xml
@@ -8,6 +8,7 @@
     android:minHeight="?android:listPreferredItemHeight"
     android:gravity="center"
     android:orientation="horizontal"
+    android:background="@drawable/recipient_dropdown_item_background"
     >
 
     <de.hdodenhof.circleimageview.CircleImageView