Turn the app drawer into a one-column list with letter headers

PRD M2 (AD-1 to AD-3, AD-7, AD-8, HS-7). The drawer keeps Launcher3's adapter, sorting,
live updates, click, long-press menu and drag; only what differs from the grid is new.

- FlexeraDrawer (flexera/src): column count, row styling, and a letter-header adapter item
- flexera/res/layout/all_apps_icon.xml overrides Launcher3's grid cell with a horizontal
  row (46dp icon, name beside it, 64dp tall)
- AlphabeticalAppsList adds a header item at the start of each letter group and points
  the fast-scroll section at it; Private Space keeps its own framing
- BaseAllAppsAdapter creates and binds the header view type and styles rows
- DeviceProfileOverrides forces one drawer column
- DeviceProfile.getAllAppsIconStartMargin returns the row padding for a one-column
  drawer, which keeps the search bar full width
- Suggested apps row above the list is off by default

Tested on the Android 17 emulator: scrolling, tap to launch, long-press menu, drag to the
home screen, and live removal and return of an app all work. The right-edge fast
scroller did not respond to scripted drags and still needs a hand test.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

flexera/res/layout/all_apps_icon.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Flexera Launcher: an app row in the drawer list (PRD AD-2).
+  Overrides Launcher3's res/layout/all_apps_icon.xml, which is a grid cell with the icon above the
+  label. Here the icon sits at the start and the name beside it. It is still a BubbleTextView, so
+  click, long-press menu, drag and notification dots keep working unchanged.
+  Height, icon gap and text size are set in code by FlexeraDrawer.styleAppRow.
+-->
+<com.android.launcher3.BubbleTextView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:launcher="http://schemas.android.com/apk/res-auto"
+    style="@style/BaseIcon.AllApps"
+    android:id="@+id/icon"
+    android:ellipsize="end"
+    android:gravity="start|center_vertical"
+    android:paddingStart="@dimen/flexera_drawer_row_padding_start"
+    android:paddingEnd="@dimen/flexera_drawer_row_padding_end"
+    android:textAlignment="viewStart"
+    launcher:centerVertically="false"
+    launcher:iconDisplay="all_apps"
+    launcher:iconSizeOverride="@dimen/flexera_drawer_row_icon_size"
+    launcher:layoutHorizontal="true" />

flexera/res/layout/flexera_all_apps_section_header.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Flexera Launcher: a letter header that starts each group in the drawer list (PRD AD-3). -->
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="@dimen/flexera_drawer_header_height"
+    android:gravity="start|bottom"
+    android:importantForAccessibility="yes"
+    android:accessibilityHeading="true"
+    android:paddingStart="@dimen/flexera_drawer_row_padding_start"
+    android:paddingEnd="@dimen/flexera_drawer_row_padding_end"
+    android:paddingBottom="@dimen/flexera_drawer_header_padding_bottom"
+    android:textAlignment="viewStart"
+    android:textColor="?android:attr/textColorSecondary"
+    android:textSize="@dimen/flexera_drawer_header_text_size"
+    android:textStyle="bold" />

flexera/res/values/flexera_config.xml

@@ -14,4 +14,7 @@
 
     <!-- Lawnchair's own nightly updater does not apply to this app. -->
     <bool name="config_default_enable_nightly_auto_updater">false</bool>
+
+    <!-- The drawer is a plain alphabetical list (PRD AD-2), so no row of suggested apps above it. -->
+    <bool name="config_default_show_suggested_apps_at_drawer_top">false</bool>
 </resources>

flexera/res/values/flexera_dimens.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- Drawer list (PRD AD-2, AD-3). Rows are sized for thumb taps; 48dp is Android's minimum target. -->
+    <dimen name="flexera_drawer_row_height">64dp</dimen>
+    <!-- Smaller than a home-screen icon, so rows have air between them. -->
+    <dimen name="flexera_drawer_row_icon_size">46dp</dimen>
+    <dimen name="flexera_drawer_row_icon_gap">20dp</dimen>
+    <dimen name="flexera_drawer_row_text_size">17sp</dimen>
+    <dimen name="flexera_drawer_row_padding_start">24dp</dimen>
+    <!-- Leaves the screen edge free for the scroller now and the wave alphabet later (M3). -->
+    <dimen name="flexera_drawer_row_padding_end">56dp</dimen>
+
+    <dimen name="flexera_drawer_header_height">44dp</dimen>
+    <dimen name="flexera_drawer_header_padding_bottom">6dp</dimen>
+    <dimen name="flexera_drawer_header_text_size">14sp</dimen>
+</resources>

flexera/src/app/flexera/drawer/FlexeraDrawer.kt

@@ -0,0 +1,77 @@
+package app.flexera.drawer
+
+import android.content.Context
+import android.util.TypedValue
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+import com.android.launcher3.BubbleTextView
+import com.android.launcher3.R
+import com.android.launcher3.allapps.BaseAllAppsAdapter.AdapterItem
+
+/**
+ * Flexera Launcher's app drawer: a single-column alphabetical list with letter headers
+ * (PRD AD-2 and AD-3), built on Launcher3's all-apps adapter rather than replacing it.
+ *
+ * Launcher3 keeps doing the work it already does well: loading apps, sorting them, live updates,
+ * click, long-press menu and drag. This object supplies only what differs from the stock grid:
+ *  - the column count ([COLUMNS]),
+ *  - the look of a row ([styleAppRow]; the row layout itself is flexera/res/layout/all_apps_icon.xml,
+ *    which overrides Launcher3's layout of the same name), and
+ *  - a letter header row ([VIEW_TYPE_SECTION_HEADER] and the functions that create and bind it).
+ */
+object FlexeraDrawer {
+
+    /** The drawer is one column wide. */
+    const val COLUMNS = 1
+
+    /**
+     * Adapter view type of a letter header row. Launcher3 uses bits 1 to 10 and Lawnchair's search
+     * results use bits 10 to 22, so this stays clear of both.
+     */
+    const val VIEW_TYPE_SECTION_HEADER = 1 shl 24
+
+    /** Creates the adapter item for the header that starts the section named [sectionName]. */
+    @JvmStatic
+    fun sectionHeader(sectionName: String): AdapterItem = SectionHeaderItem(sectionName)
+
+    @JvmStatic
+    fun createSectionHeader(inflater: LayoutInflater, parent: ViewGroup): View =
+        inflater.inflate(R.layout.flexera_all_apps_section_header, parent, false)
+
+    @JvmStatic
+    fun bindSectionHeader(view: View, item: AdapterItem) {
+        (view as TextView).text = (item as? SectionHeaderItem)?.sectionName.orEmpty()
+    }
+
+    /**
+     * Finishes turning a freshly inflated all-apps icon into a list row. Launcher3 sizes the view
+     * as a grid cell (icon above a small label); a row needs its own height, a wider gap between
+     * icon and name, and a label large enough to read in a list.
+     */
+    @JvmStatic
+    fun styleAppRow(icon: BubbleTextView) {
+        val res = icon.resources
+        icon.layoutParams.height = res.getDimensionPixelSize(R.dimen.flexera_drawer_row_height)
+        icon.compoundDrawablePadding = res.getDimensionPixelSize(R.dimen.flexera_drawer_row_icon_gap)
+        icon.setTextSize(TypedValue.COMPLEX_UNIT_PX, res.getDimension(R.dimen.flexera_drawer_row_text_size))
+    }
+
+    /**
+     * How far a row's icon sits from the edge of the list. Launcher3 uses its grid version of
+     * this number to line the search bar up with the first icon, so the list supplies its own.
+     */
+    @JvmStatic
+    fun rowStartPadding(context: Context): Int =
+        context.resources.getDimensionPixelSize(R.dimen.flexera_drawer_row_padding_start)
+
+    /**
+     * A letter header. It carries its letter so that the adapter's diffing notices when the
+     * header at a position changes, for example after an app is installed or removed.
+     */
+    class SectionHeaderItem(val sectionName: String) : AdapterItem(VIEW_TYPE_SECTION_HEADER) {
+        override fun isContentSame(other: AdapterItem): Boolean =
+            other is SectionHeaderItem && other.sectionName == sectionName
+    }
+}

lawnchair/src/app/lawnchair/DeviceProfileOverrides.kt

@@ -158,8 +158,9 @@ class DeviceProfileOverrides @Inject constructor(
 
         fun applyUi(idp: InvariantDeviceProfile) {
             // apply grid size
-            idp.numAllAppsColumns = numAllAppsColumns
-            idp.numDatabaseAllAppsColumns = numAllAppsColumns
+            // Flexera Launcher: the drawer is a one-column list, whatever the column preference says.
+            idp.numAllAppsColumns = app.flexera.drawer.FlexeraDrawer.COLUMNS
+            idp.numDatabaseAllAppsColumns = app.flexera.drawer.FlexeraDrawer.COLUMNS
             idp.numFolderRows[INDEX_DEFAULT] = numFolderRows
             idp.numFolderColumns[INDEX_DEFAULT] = numFolderColumns
 

src/com/android/launcher3/DeviceProfile.java

@@ -1979,6 +1979,14 @@ public class DeviceProfile {
 
     /** The margin between the edge of all apps and the edge of the first icon. */
     public int getAllAppsIconStartMargin(Context context) {
+        // Flexera Launcher: in the one-column drawer list the first icon sits at the row's start
+        // padding. The grid maths below would instead centre it in a full-width cell, which
+        // squeezed the search bar down to a small pill.
+        if (numShownAllAppsColumns == app.flexera.drawer.FlexeraDrawer.COLUMNS) {
+            return (Utilities.isRtl(context.getResources()) ? allAppsPadding.right
+                    : allAppsPadding.left)
+                    + app.flexera.drawer.FlexeraDrawer.rowStartPadding(context);
+        }
         int allAppsSpacing;
         if (isVerticalBarLayout()) {
             // On phones, the landscape layout uses a different setup.

src/com/android/launcher3/allapps/AlphabeticalAppsList.java

@@ -491,6 +491,17 @@ public class AlphabeticalAppsList<T extends Context & ActivityContext> implement
         Log.d(TAG, "Adding apps with sections. HasPrivateApps: " + hasPrivateApps);
         for (int i = 0; i < appList.size(); i++) {
             AppInfo info = appList.get(i);
+            // Flexera Launcher: start each letter group with a header row (PRD AD-3). The header
+            // takes this position, so the fast-scroll section created below lands on the header.
+            // Private Space keeps Launcher3's own framing and gets no headers.
+            if (!hasPrivateApps && !info.sectionName.equals(lastSectionName)) {
+                mAdapterItems.add(app.flexera.drawer.FlexeraDrawer.sectionHeader(info.sectionName));
+                Log.d(TAG, "addAppsWithSections: adding sectionName: " + info.sectionName
+                        + " with header at position: " + position);
+                lastSectionName = info.sectionName;
+                mFastScrollerSections.add(new FastScrollSectionInfo(info.sectionName, position));
+                position++;
+            }
             // Apply decorator to private apps.
             if (hasPrivateApps) {
                 mAdapterItems.add(AdapterItem.asAppWithDecorationInfo(info,

src/com/android/launcher3/allapps/BaseAllAppsAdapter.java

@@ -243,7 +243,13 @@ public abstract class BaseAllAppsAdapter<T extends Context & ActivityContext> ex
                 // Ensure the all apps icon height matches the workspace icons in portrait mode.
                 icon.getLayoutParams().height =
                         mActivityContext.getDeviceProfile().getAllAppsProfile().getCellHeightPx();
+                // Flexera Launcher: the drawer is a list, so size and style this as a row.
+                app.flexera.drawer.FlexeraDrawer.styleAppRow(icon);
                 return new ViewHolder(icon);
+            case app.flexera.drawer.FlexeraDrawer.VIEW_TYPE_SECTION_HEADER:
+                // Flexera Launcher: letter header that starts each group in the drawer list.
+                return new ViewHolder(app.flexera.drawer.FlexeraDrawer.createSectionHeader(
+                        mLayoutInflater, parent));
             case VIEW_TYPE_EMPTY_SEARCH:
                 return new ViewHolder(mLayoutInflater.inflate(R.layout.all_apps_empty_search,
                         parent, false));
@@ -325,6 +331,11 @@ public abstract class BaseAllAppsAdapter<T extends Context & ActivityContext> ex
                 }
                 break;
             }
+            case app.flexera.drawer.FlexeraDrawer.VIEW_TYPE_SECTION_HEADER:
+                // Flexera Launcher: letter header in the drawer list.
+                app.flexera.drawer.FlexeraDrawer.bindSectionHeader(
+                        holder.itemView, mApps.getAdapterItems().get(position));
+                break;
             case VIEW_TYPE_EMPTY_SEARCH: {
                 AppInfo info = mApps.getAdapterItems().get(position).itemInfo;
                 if (info != null) {