From c1b9efe48204f35fc0b8865877e6253aa755f844 Mon Sep 17 00:00:00 2001
From: pblundell <pblundell@roku.com>
Date: Fri, 27 Feb 2026 00:01:04 +0000
Subject: [PATCH] Update minimum SDK to API 21 (Android 5.0 Lollipop)

This commit migrates the entire LeakCanary project from minimum SDK API 14
to API 21, enabling modern Android features and simplifying the codebase.

API 21 corresponds to Android 5.0 (Lollipop), released in 2014, providing
over a decade of Android compatibility while enabling Material Design and
modern development practices.

Changes included:

## Build Configuration
- Update androidMinSdk from "14" to "21" in version catalog
- Standardize all modules to use libs.versions.androidMinSdk reference
- Update hardcoded minSdk values in sample and library modules to use TOML

## GitHub Actions / CI
- Remove API 16 and API 19 from test matrix
- Streamline CI to test only API 21+ (21, 23, 26, 31, 33, 34)
- Improve CI efficiency with fewer test combinations

## Test Infrastructure
- Upgrade androidx.test:orchestrator from 1.4.2 to 1.5.0
- Modernize test assertions to use direct assertThat(Throwable) calls
- Remove API 16 workaround comments and code

## Code Modernization
- Remove obsolete SDK version checks (9 lint issues resolved)
- Simplify file provider methods for API 21+ only
- Update notification builder usage for modern APIs
- Remove legacy view tree observer workarounds
- Modernize layout and rendering code

## Resources & UI
- Migrate drawable resources from selectors to Material ripple effects
- Update themes from Holo to Material Design (API 21+ requirement)
- Merge and remove obsolete -v21 resource folders
- Modernize button and touch feedback using ripples

## Benefits
- Access to Material Design components and APIs
- Simplified codebase with removed legacy compatibility code
- Enhanced test infrastructure with latest orchestrator
- Improved user experience with modern UI patterns
- Faster CI builds with fewer test matrix combinations

## Compatibility
All modules now consistently require Android 5.0 (API 21, 2014) or higher.
This affects minSdk but does not change the public API surface.

Co-Authored-By: Claude <noreply@anthropic.com>
---
 .github/workflows/main.yml                    |  9 ------
 gradle/libs.versions.toml                     |  4 +--
 .../internal/LeakCanaryFileProvider.kt        | 15 ++--------
 .../java/leakcanary/internal/Notifications.kt |  8 +-----
 .../internal/SquigglySpanRenderer.kt          |  3 +-
 .../internal/activity/db/Cursors.kt           |  2 +-
 .../activity/screen/RenderHeapDumpScreen.kt   |  8 +-----
 .../internal/navigation/NavigatingActivity.kt | 11 +++-----
 .../drawable-v21/leak_canary_gray_fill.xml    | 16 -----------
 .../leak_canary_list_selector.xml             |  9 ------
 .../leak_canary_primary_button.xml            | 17 -----------
 .../leak_canary_secondary_button.xml          | 17 -----------
 .../leak_canary_tab_background.xml            |  4 ---
 .../res/drawable/leak_canary_gray_fill.xml    |  9 +++---
 .../drawable/leak_canary_list_selector.xml    |  2 +-
 .../drawable/leak_canary_primary_button.xml   | 11 ++------
 .../drawable/leak_canary_secondary_button.xml | 11 ++------
 .../drawable/leak_canary_tab_background.xml   |  8 +++---
 .../leak_canary_tab_selector_ripple.xml       |  2 +-
 .../res/values-v21/leak_canary_themes.xml     | 28 -------------------
 .../main/res/values/leak_canary_themes.xml    |  6 ++--
 .../leakcanary/TestDescriptionHolderTest.kt   |  9 ++----
 .../build.gradle.kts                          |  2 +-
 .../src/main/java/leakcanary/ProcessInfo.kt   | 14 ++--------
 .../build.gradle.kts                          |  2 +-
 .../build.gradle.kts                          |  2 +-
 26 files changed, 41 insertions(+), 188 deletions(-)
 delete mode 100644 leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_gray_fill.xml
 delete mode 100644 leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_list_selector.xml
 delete mode 100644 leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_primary_button.xml
 delete mode 100644 leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_secondary_button.xml
 delete mode 100644 leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_background.xml
 rename leakcanary/leakcanary-android-core/src/main/res/{drawable-v21 => drawable}/leak_canary_tab_selector_ripple.xml (95%)
 delete mode 100644 leakcanary/leakcanary-android-core/src/main/res/values-v21/leak_canary_themes.xml

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 2cca2460f..207086403 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -42,15 +42,6 @@ jobs:
           - 31
           - 33
           - 34
-        include:
-          - arch: x86
-            api-level: 16
-            target: google_apis
-            channel: stable
-          - arch: x86
-            api-level: 19
-            target: google_apis
-            channel: stable
     steps:
       - name: Enable KVM group perms
         run: |
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 5409363a7..fead10726 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -23,7 +23,7 @@ androidXJunit = "1.1.5"
 workManager = "2.7.0"
 detekt = "1.23.8"
 hilt = "2.53"
-androidMinSdk = "14"
+androidMinSdk = "21"
 androidCompileSdk = "35"
 
 [libraries]
@@ -60,7 +60,7 @@ androidX-test-monitor = { module = "androidx.test:monitor", version = "1.6.1" }
 androidX-test-rules = { module = "androidx.test:rules", version.ref = "androidXTest" }
 # Exposed transitively, avoid increasing
 androidX-test-runner = { module = "androidx.test:runner", version = "1.5.2" }
-androidX-test-orchestrator = { module = "androidx.test:orchestrator", version = "1.4.2" } # 1.5.0+ requires API 21+, keeping at 1.4.2 for API 16 compatibility
+androidX-test-orchestrator = { module = "androidx.test:orchestrator", version = "1.5.0" }
 androidX-test-espresso = { module = "androidx.test.espresso:espresso-core", version = "3.5.1" }
 androidX-test-junit = { module = "androidx.test.ext:junit", version.ref = "androidXJunit" }
 androidX-test-junitKtx = { module = "androidx.test.ext:junit-ktx", version.ref = "androidXJunit" }
diff --git a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/LeakCanaryFileProvider.kt b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/LeakCanaryFileProvider.kt
index c5f6ae13a..00156837a 100644
--- a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/LeakCanaryFileProvider.kt
+++ b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/LeakCanaryFileProvider.kt
@@ -24,7 +24,6 @@ import android.content.pm.ProviderInfo
 import android.database.Cursor
 import android.database.MatrixCursor
 import android.net.Uri
-import android.os.Build
 import android.os.Environment
 import android.os.ParcelFileDescriptor
 import android.os.StrictMode
@@ -499,7 +498,7 @@ internal class LeakCanaryFileProvider : ContentProvider() {
             if (externalCacheDirs.isNotEmpty()) {
               target = externalCacheDirs[0]
             }
-          } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && TAG_EXTERNAL_MEDIA == tag) {
+          } else if (TAG_EXTERNAL_MEDIA == tag) {
             val externalMediaDirs = context.externalMediaDirs
             if (externalMediaDirs.isNotEmpty()) {
               target = externalMediaDirs[0]
@@ -519,19 +518,11 @@ internal class LeakCanaryFileProvider : ContentProvider() {
       context: Context,
       type: String?
     ): Array<File> {
-      return if (Build.VERSION.SDK_INT >= 19) {
-        context.getExternalFilesDirs(type)
-      } else {
-        arrayOf(context.getExternalFilesDir(type)!!)
-      }
+      return context.getExternalFilesDirs(type)
     }
 
     private fun getExternalCacheDirs(context: Context): Array<File> {
-      return if (Build.VERSION.SDK_INT >= 19) {
-        context.externalCacheDirs
-      } else {
-        arrayOf(context.externalCacheDir!!)
-      }
+      return context.externalCacheDirs
     }
 
     /**
diff --git a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/Notifications.kt b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/Notifications.kt
index 5a41a4181..ac18e5aa1 100644
--- a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/Notifications.kt
+++ b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/Notifications.kt
@@ -22,7 +22,6 @@ import android.app.NotificationManager
 import android.app.PendingIntent
 import android.content.Context
 import android.os.Build.VERSION.SDK_INT
-import android.os.Build.VERSION_CODES.JELLY_BEAN
 import android.os.Build.VERSION_CODES.O
 import com.squareup.leakcanary.core.R
 import leakcanary.LeakCanary
@@ -130,11 +129,6 @@ internal object Notifications {
       builder.setGroup(type.name)
     }
 
-    return if (SDK_INT < JELLY_BEAN) {
-      @Suppress("DEPRECATION")
-      builder.notification
-    } else {
-      builder.build()
-    }
+    return builder.build()
   }
 }
diff --git a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/SquigglySpanRenderer.kt b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/SquigglySpanRenderer.kt
index 36229b28d..ef17ee376 100644
--- a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/SquigglySpanRenderer.kt
+++ b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/SquigglySpanRenderer.kt
@@ -4,7 +4,6 @@ import android.content.Context
 import android.graphics.Canvas
 import android.graphics.Paint
 import android.graphics.Path
-import android.os.Build
 import android.text.Layout
 import com.squareup.leakcanary.core.R
 import kotlin.math.max
@@ -107,7 +106,7 @@ internal abstract class SquigglySpanRenderer(context: Context) {
 
     private fun Layout.getLineBottomWithoutSpacing(line: Int): Int {
       val lineBottom = getLineBottom(line)
-      val lastLineSpacingNotAdded = Build.VERSION.SDK_INT >= 19
+      val lastLineSpacingNotAdded = true
       val isLastLine = line == lineCount - 1
 
       val lineBottomWithoutSpacing: Int
diff --git a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Cursors.kt b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Cursors.kt
index 6cb1e2741..8e9277520 100644
--- a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Cursors.kt
+++ b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Cursors.kt
@@ -6,7 +6,7 @@ import kotlin.concurrent.getOrSet
 
 /**
  * Similar to the more generic use() for Closable.
- * Cursor started implementing Closable in API 16.
+ * Cursor implements Closable on all supported API levels (21+).
  */
 internal inline fun <R> Cursor.use(block: (Cursor) -> R): R {
   var exception: Throwable? = null
diff --git a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/screen/RenderHeapDumpScreen.kt b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/screen/RenderHeapDumpScreen.kt
index 09a62d5ee..32d68d372 100644
--- a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/screen/RenderHeapDumpScreen.kt
+++ b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/activity/screen/RenderHeapDumpScreen.kt
@@ -2,8 +2,6 @@ package leakcanary.internal.activity.screen
 
 import android.content.Intent
 import android.graphics.Bitmap
-import android.os.Build.VERSION
-import android.os.Build.VERSION_CODES
 import android.os.Environment
 import android.os.Environment.DIRECTORY_DOWNLOADS
 import android.view.View
@@ -60,11 +58,7 @@ internal class RenderHeapDumpScreen(
               imageView.visibility = View.VISIBLE
             }
           }
-          if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN) {
-            viewTreeObserver.removeOnGlobalLayoutListener(this)
-          } else {
-            viewTreeObserver.removeGlobalOnLayoutListener(this)
-          }
+          viewTreeObserver.removeOnGlobalLayoutListener(this)
         }
       })
 
diff --git a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/navigation/NavigatingActivity.kt b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/navigation/NavigatingActivity.kt
index 31e25c5d5..d376d93e6 100644
--- a/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/navigation/NavigatingActivity.kt
+++ b/leakcanary/leakcanary-android-core/src/main/java/leakcanary/internal/navigation/NavigatingActivity.kt
@@ -2,7 +2,6 @@ package leakcanary.internal.navigation
 
 import android.app.Activity
 import android.content.Intent
-import android.os.Build.VERSION.SDK_INT
 import android.os.Bundle
 import android.os.Parcelable
 import android.view.Menu
@@ -155,12 +154,10 @@ internal abstract class NavigatingActivity : Activity() {
 
   private fun screenUpdated() {
     invalidateOptionsMenu()
-    if (SDK_INT >= 18) {
-      actionBar?.run {
-        val goBack = backstack.size > 0
-        val indicator = if (goBack) 0 else android.R.drawable.ic_menu_close_clear_cancel
-        setHomeAsUpIndicator(indicator)
-      }
+    actionBar?.run {
+      val goBack = backstack.size > 0
+      val indicator = if (goBack) 0 else android.R.drawable.ic_menu_close_clear_cancel
+      setHomeAsUpIndicator(indicator)
     }
     onNewScreen(currentScreen)
   }
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_gray_fill.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_gray_fill.xml
deleted file mode 100644
index 00d67ea3a..000000000
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_gray_fill.xml
+++ /dev/null
@@ -1,16 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ripple xmlns:android="http://schemas.android.com/apk/res/android"
-    android:color="?android:attr/colorControlHighlight">
-    <item android:id="@android:id/mask">
-        <shape>
-            <solid android:color="@color/leak_canary_gray" />
-            <corners android:radius="20dp" />
-        </shape>
-    </item>
-    <item>
-        <shape>
-            <solid android:color="@color/leak_canary_gray" />
-            <corners android:radius="20dp" />
-        </shape>
-    </item>
-</ripple>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_list_selector.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_list_selector.xml
deleted file mode 100644
index 4bbb9c540..000000000
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_list_selector.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:state_focused="true" android:state_pressed="false">
-        <color android:color="?android:attr/colorControlHighlight" />
-    </item>
-    <item>
-        <color android:color="@android:color/transparent" />
-    </item>
-</selector>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_primary_button.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_primary_button.xml
deleted file mode 100644
index 67b9d2c63..000000000
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_primary_button.xml
+++ /dev/null
@@ -1,17 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ripple xmlns:android="http://schemas.android.com/apk/res/android"
-    android:color="@color/leak_canary_yellow_button_pressed">
-  <item>
-    <shape>
-      <solid android:color="@color/leak_canary_yellow_button" />
-      <corners android:radius="12dp" />
-    </shape>
-  </item>
-  <item android:id="@android:id/mask">
-    <shape>
-      <solid android:color="@color/leak_canary_yellow_button" />
-      <corners android:radius="12dp" />
-    </shape>
-  </item>
-</ripple>
-
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_secondary_button.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_secondary_button.xml
deleted file mode 100644
index 97cc859a0..000000000
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_secondary_button.xml
+++ /dev/null
@@ -1,17 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ripple xmlns:android="http://schemas.android.com/apk/res/android"
-    android:color="@color/leak_canary_gray_6f">
-  <item>
-    <shape>
-      <solid android:color="@color/leak_canary_gray_3f" />
-      <corners android:radius="12dp" />
-    </shape>
-  </item>
-  <item android:id="@android:id/mask">
-    <shape>
-      <solid android:color="@color/leak_canary_gray_3f" />
-      <corners android:radius="12dp" />
-    </shape>
-  </item>
-</ripple>
-
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_background.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_background.xml
deleted file mode 100644
index 2418076a5..000000000
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_background.xml
+++ /dev/null
@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-  <item android:drawable="@drawable/leak_canary_tab_selector_ripple" />
-</selector>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_gray_fill.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_gray_fill.xml
index 0685b99ef..00d67ea3a 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_gray_fill.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_gray_fill.xml
@@ -1,8 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:state_pressed="true">
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="?android:attr/colorControlHighlight">
+    <item android:id="@android:id/mask">
         <shape>
-            <solid android:color="@color/leak_canary_gray_3f" />
+            <solid android:color="@color/leak_canary_gray" />
             <corners android:radius="20dp" />
         </shape>
     </item>
@@ -12,4 +13,4 @@
             <corners android:radius="20dp" />
         </shape>
     </item>
-</selector>
+</ripple>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_list_selector.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_list_selector.xml
index 3f6a244ac..4bbb9c540 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_list_selector.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_list_selector.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <selector xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:state_focused="true" android:state_pressed="false">
-        <color android:color="@color/leak_canary_gray_3f" />
+        <color android:color="?android:attr/colorControlHighlight" />
     </item>
     <item>
         <color android:color="@android:color/transparent" />
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_primary_button.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_primary_button.xml
index 5fe33eade..8682faf1c 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_primary_button.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_primary_button.xml
@@ -1,16 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-  <item android:state_pressed="true">
-    <shape>
-      <solid android:color="@color/leak_canary_yellow_button_pressed" />
-      <corners android:radius="12dp" />
-    </shape>
-  </item>
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="@color/leak_canary_yellow_button_pressed">
   <item>
     <shape>
       <solid android:color="@color/leak_canary_yellow_button" />
       <corners android:radius="12dp" />
     </shape>
   </item>
-</selector>
+</ripple>
 
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_secondary_button.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_secondary_button.xml
index 8987d5f63..1329d0ff8 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_secondary_button.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_secondary_button.xml
@@ -1,15 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-<item android:state_pressed="true">
-    <shape>
-        <solid android:color="@color/leak_canary_gray_6f" />
-        <corners android:radius="12dp" />
-    </shape>
-</item>
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="@color/leak_canary_gray_6f">
 <item>
     <shape>
         <solid android:color="@color/leak_canary_gray_3f" />
         <corners android:radius="12dp" />
     </shape>
 </item>
-</selector>
+</ripple>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_background.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_background.xml
index 9d1173d49..015470a65 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_background.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_background.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-  <item android:state_pressed="false" android:drawable="@android:color/transparent" />
-  <item android:drawable="@color/leak_canary_gray_darkest_25p" />
-</selector>
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="@color/leak_canary_gray_darkest_25p">
+  <item android:drawable="@android:color/transparent" />
+</ripple>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_selector_ripple.xml b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_selector_ripple.xml
similarity index 95%
rename from leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_selector_ripple.xml
rename to leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_selector_ripple.xml
index a924d4e04..3c8726948 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/drawable-v21/leak_canary_tab_selector_ripple.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/drawable/leak_canary_tab_selector_ripple.xml
@@ -2,4 +2,4 @@
 <ripple
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:color="@color/leak_canary_gray_darkest_25p"
-    />
+    />
\ No newline at end of file
diff --git a/leakcanary/leakcanary-android-core/src/main/res/values-v21/leak_canary_themes.xml b/leakcanary/leakcanary-android-core/src/main/res/values-v21/leak_canary_themes.xml
deleted file mode 100644
index c18b95185..000000000
--- a/leakcanary/leakcanary-android-core/src/main/res/values-v21/leak_canary_themes.xml
+++ /dev/null
@@ -1,28 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-  ~ Copyright (C) 2015 Square, Inc.
-  ~
-  ~ Licensed under the Apache License, Version 2.0 (the "License");
-  ~ you may not use this file except in compliance with the License.
-  ~ You may obtain a copy of the License at
-  ~
-  ~      http://www.apache.org/licenses/LICENSE-2.0
-  ~
-  ~ Unless required by applicable law or agreed to in writing, software
-  ~ distributed under the License is distributed on an "AS IS" BASIS,
-  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
-  ~ limitations under the License.
-  -->
-<resources>
-  <style name="leak_canary_LeakCanary.Base" parent="android:Theme.Material">
-    <item name="android:windowBackground">@color/leak_canary_background_color</item>
-    <item name="android:actionBarStyle">@style/leak_canary_Widget.ActionBar</item>
-  </style>
-
-  <style name="leak_canary_Widget.ActionBar" parent="android:Widget.Material.ActionBar">
-    <item name="android:background">@color/leak_canary_background_color</item>
-    <item name="android:elevation">0dp</item>
-  </style>
-
-</resources>
diff --git a/leakcanary/leakcanary-android-core/src/main/res/values/leak_canary_themes.xml b/leakcanary/leakcanary-android-core/src/main/res/values/leak_canary_themes.xml
index bd8ddb82c..bfcdc4e3e 100644
--- a/leakcanary/leakcanary-android-core/src/main/res/values/leak_canary_themes.xml
+++ b/leakcanary/leakcanary-android-core/src/main/res/values/leak_canary_themes.xml
@@ -15,14 +15,14 @@
   ~ limitations under the License.
   -->
 <resources>
-  <style name="leak_canary_LeakCanary.Base" parent="android:Theme.Holo">
+  <style name="leak_canary_LeakCanary.Base" parent="android:Theme.Material">
     <item name="android:windowBackground">@color/leak_canary_background_color</item>
     <item name="android:actionBarStyle">@style/leak_canary_Widget.ActionBar</item>
   </style>
 
-  <style name="leak_canary_Widget.ActionBar" parent="android:Widget.Holo.ActionBar">
+  <style name="leak_canary_Widget.ActionBar" parent="android:Widget.Material.ActionBar">
     <item name="android:background">@color/leak_canary_background_color</item>
-    <item name="android:windowContentOverlay">@null</item>
+    <item name="android:elevation">0dp</item>
   </style>
 
   <style name="leak_canary_Theme.Transparent" parent="android:Theme">
diff --git a/leakcanary/leakcanary-android-instrumentation/src/androidTest/java/leakcanary/TestDescriptionHolderTest.kt b/leakcanary/leakcanary-android-instrumentation/src/androidTest/java/leakcanary/TestDescriptionHolderTest.kt
index 8f51e9443..19c079c18 100644
--- a/leakcanary/leakcanary-android-instrumentation/src/androidTest/java/leakcanary/TestDescriptionHolderTest.kt
+++ b/leakcanary/leakcanary-android-instrumentation/src/androidTest/java/leakcanary/TestDescriptionHolderTest.kt
@@ -64,19 +64,16 @@ class TestDescriptionHolderTest {
 
   @Test
   fun testDescriptionThrowsBeforeClass() {
-    // On API 16, assertThat(Throwable) causes a TypeComparators class init failure.
-    assertThat(beforeClassThrowable == null).isFalse()
+    assertThat(beforeClassThrowable).isNotNull()
   }
 
   @Test
   fun testDescriptionThrowsBeforeOuterEvaluate() {
-    // On API 16, assertThat(Throwable) causes a TypeComparators class init failure.
-    assertThat(outerRule.beforeEvaluateThrowable == null).isFalse()
+    assertThat(outerRule.beforeEvaluateThrowable).isNotNull()
   }
 
   @Test
   fun testDescriptionDoesNotThrowBeforeInnerEvaluate() {
-    // On API 16, assertThat(Throwable) causes a TypeComparators class init failure.
-    assertThat(innerRule.beforeEvaluateThrowable == null).isTrue()
+    assertThat(innerRule.beforeEvaluateThrowable).isNull()
   }
 }
diff --git a/leakcanary/leakcanary-android-release/build.gradle.kts b/leakcanary/leakcanary-android-release/build.gradle.kts
index 6f9ce35d2..c0be7e2c3 100644
--- a/leakcanary/leakcanary-android-release/build.gradle.kts
+++ b/leakcanary/leakcanary-android-release/build.gradle.kts
@@ -23,7 +23,7 @@ android {
   resourcePrefix = "leak_canary_"
   compileSdk = libs.versions.androidCompileSdk.get().toInt()
   defaultConfig {
-    minSdk = 16
+    minSdk = libs.versions.androidMinSdk.get().toInt()
     buildConfigField("String", "LIBRARY_VERSION", "\"${rootProject.property("VERSION_NAME")}\"")
     buildConfigField("String", "GIT_SHA", "\"${gitSha()}\"")
     consumerProguardFiles("consumer-proguard-rules.pro")
diff --git a/leakcanary/leakcanary-android-release/src/main/java/leakcanary/ProcessInfo.kt b/leakcanary/leakcanary-android-release/src/main/java/leakcanary/ProcessInfo.kt
index 5f1eba7a7..ab91756d4 100644
--- a/leakcanary/leakcanary-android-release/src/main/java/leakcanary/ProcessInfo.kt
+++ b/leakcanary/leakcanary-android-release/src/main/java/leakcanary/ProcessInfo.kt
@@ -64,7 +64,7 @@ interface ProcessInfo {
     override fun availableRam(context: Context): AvailableRam {
       val activityManager = context.getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager
 
-      if (SDK_INT >= 19 && activityManager.isLowRamDevice) {
+      if (activityManager.isLowRamDevice) {
         return LowRamDevice
       } else {
         activityManager.getMemoryInfo(memoryInfo)
@@ -91,17 +91,7 @@ interface ProcessInfo {
       val myPid = Process.myPid()
       val ticksAtProcessStart = readProcessStartTicks(myPid)
 
-      val ticksPerSecond = if (SDK_INT >= 21) {
-        Os.sysconf(OsConstants._SC_CLK_TCK)
-      } else {
-        val tckConstant = try {
-          Class.forName("android.system.OsConstants").getField("_SC_CLK_TCK").getInt(null)
-        } catch (e: ClassNotFoundException) {
-          Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null)
-        }
-        val os = Class.forName("libcore.io.Libcore").getField("os").get(null)!!
-        os::class.java.getMethod("sysconf", Integer.TYPE).invoke(os, tckConstant) as Long
-      }
+      val ticksPerSecond = Os.sysconf(OsConstants._SC_CLK_TCK)
       return ticksAtProcessStart * 1000 / ticksPerSecond
     }
 
diff --git a/leakcanary/leakcanary-android-uiautomator/build.gradle.kts b/leakcanary/leakcanary-android-uiautomator/build.gradle.kts
index ebf73980b..12c8cf84c 100644
--- a/leakcanary/leakcanary-android-uiautomator/build.gradle.kts
+++ b/leakcanary/leakcanary-android-uiautomator/build.gradle.kts
@@ -17,7 +17,7 @@ android {
   compileSdk = libs.versions.androidCompileSdk.get().toInt()
   defaultConfig {
     targetSdk = libs.versions.androidCompileSdk.get().toInt()
-    minSdk = 18
+    minSdk = libs.versions.androidMinSdk.get().toInt()
   }
   buildFeatures.buildConfig = false
   namespace = "com.squareup.leakcanary.android.uiautomator"
diff --git a/samples/leakcanary-android-sample/build.gradle.kts b/samples/leakcanary-android-sample/build.gradle.kts
index de935969b..d81861e5e 100644
--- a/samples/leakcanary-android-sample/build.gradle.kts
+++ b/samples/leakcanary-android-sample/build.gradle.kts
@@ -49,7 +49,7 @@ android {
 
   defaultConfig {
     applicationId = "com.example.leakcanary"
-    minSdk = 16
+    minSdk = libs.versions.androidMinSdk.get().toInt()
     targetSdk = libs.versions.androidCompileSdk.get().toInt()
 
     versionCode = 1