Plexamp Lite 1.14: Android 4.1 build with ExoPlayer, lyrics, home-screen widget

- One build per Android level, as in Tenda: build/PlexampLite.apk (Android 2.2+, versionCode 1508) and
  build/PlexampLite-api16.apk (Android 4.1+, 1516), from shared src/ plus platform/api8 or platform/api16.
- Android 4.1 build: ExoPlayer 2.18.7 behind a small Engine interface (gapless hand-over to read-ahead and
  downloaded files, a longer buffer, MediaPlayer fallback for tracks it can't decode), a notification and
  lock screen with art and buttons, a resizable widget, Holo, a menu button without a Menu key, metered networks.
  R8 shrinks ExoPlayer and Guava (tools/fetch_exoplayer.sh, tools/r8-rules.pro).
- Both builds: lyrics in Now Playing as in the Mac app (timed lyrics follow and seek), a home-screen widget,
  media play/pause keys, the moon icon drawn without clipPath.
- PlexampLite-noreport on the SD card stops play reports, for tests against a real server.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/fetch_exoplayer.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+# Fetches what the Android 4.1 build needs beyond tools/setup_toolchain.sh: ExoPlayer 2.18.7 (Google's Maven) and
+# Guava (Maven Central), checked against these SHA-256s, into $TOOLS/exoplayer-2.18.7 (TOOLS default ~/android-toolchain).
+# 2.18.7 because it's the newest that needs only Guava (2.19 adds AndroidX Core); every 2.x runs on Android 4.1.
+set -euo pipefail
+T=${TOOLS:-$HOME/android-toolchain}
+D=$T/exoplayer-2.18.7
+G=https://dl.google.com/dl/android/maven2/com/google/android/exoplayer
+M=https://repo1.maven.org/maven2/com/google/guava
+mkdir -p "$D"
+tmp=$(mktemp -d)
+trap 'rm -rf "$tmp"' EXIT
+get() {   # url sha256 file
+  if [ -f "$D/$3" ] && [ "$(shasum -a 256 "$D/$3" | cut -d' ' -f1)" = "$2" ]; then return; fi
+  curl -fsSL -o "$tmp/$3" "$1"
+  [ "$(shasum -a 256 "$tmp/$3" | cut -d' ' -f1)" = "$2" ] || { echo "$3: checksum mismatch"; exit 1; }
+  mv "$tmp/$3" "$D/$3"
+}
+for m in core:2b51c5f07aa25f89e4adb7a833073e1a4adc5b87a388bd0045ebc3429b1bf42f \
+         common:adfef7d3cbd69dd8fcc4ce05642a886c9fbc2764826bc39a6075ba6a0c62d003 \
+         datasource:cbe67ad9eaf94be7b35d1a625252a79ed5c18601d19f7b4d787acfbcea009208 \
+         decoder:598c0b444db71770f9b89b4e444e34cb03d5ed2eb5c12fb062afb2f9b05b9a1e \
+         extractor:c3e34c7b07ecd3c78a75bb7185671030bea4371ac88d854000a856fc05f7eeff \
+         database:31f0929246fb81296345be8414e7fa080a82deb8d382eb5d875974649030619d; do
+  a=${m%%:*}; sum=${m#*:}
+  get "$G/exoplayer-$a/2.18.7/exoplayer-$a-2.18.7.aar" "$sum" "exoplayer-$a.aar"
+  # an AAR is a zip: the code is classes.jar, the keep rules for apps that shrink it are proguard.txt
+  unzip -o -q -d "$tmp/$a" "$D/exoplayer-$a.aar"
+  cp "$tmp/$a/classes.jar" "$D/exoplayer-$a.jar"
+  if [ -f "$tmp/$a/proguard.txt" ]; then cp "$tmp/$a/proguard.txt" "$D/exoplayer-$a.pro"; fi
+  rm "$D/exoplayer-$a.aar"
+done
+get "$M/guava/31.0.1-android/guava-31.0.1-android.jar" 9425a423a4cb9d9db0356300722d9bd8e634cf539f29d97bb84f457cccd16eb8 guava.jar
+get "$M/failureaccess/1.0.1/failureaccess-1.0.1.jar" a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26 failureaccess.jar
+ls "$D"

tools/r8-rules.pro

@@ -0,0 +1,17 @@
+# R8 for the Android 4.1 build (build.sh): shrinks ExoPlayer and Guava to what the app uses and turns their Java 8
+# code into what Android 4.1 runs. The app (and its Bouncy Castle copy) stays whole and readable in crash reports.
+-keep class com.minamp.** { *; }
+-dontobfuscate
+# referenced only by annotations, or by code for newer Androids that ExoPlayer guards by version
+# (build.sh gives R8 the Android 4.1 API, so anything newer is "missing")
+-dontwarn android.**
+-dontwarn androidx.annotation.**
+-dontwarn org.checkerframework.**
+-dontwarn com.google.errorprone.annotations.**
+-dontwarn com.google.j2objc.annotations.**
+-dontwarn javax.annotation.**
+-dontwarn kotlin.**
+-dontwarn org.codehaus.mojo.animal_sniffer.**
+-dontwarn sun.misc.Unsafe
+-dontwarn java.lang.ClassValue
+-dontwarn javax.lang.model.element.Modifier

tools/strings.py

@@ -256,6 +256,18 @@ S = {
     "set_delete_downloads": ("Delete all downloads (%1$s)", "Borrar todas as descargas (%1$s)"),
     "downloaded": ("Downloaded", "Descargada"),
     "quit_app": ("Close Plexamp Lite", "Pechar Plexamp Lite"),
+
+    # lyrics (as in the Mac app)
+    "lyrics": ("Lyrics", "Letra"),
+    "loading_lyrics": ("Loading lyrics…", "Cargando a letra…"),
+    "no_lyrics": ("No lyrics for this track", "Esta pista non ten letra"),
+    "lyrics_failed": ("Couldn't load the lyrics", "Non se puido cargar a letra"),
+
+    # home-screen widget, notification and lock-screen buttons
+    "widget_name": ("Plexamp Lite player", "Reprodutor de Plexamp Lite"),
+    "previous": ("Previous", "Anterior"),
+    "next": ("Next", "Seguinte"),
+    "play_pause": ("Play or pause", "Reproducir ou pausar"),
     "stalled": ("Playback got stuck: the network isn't keeping up.", "A reprodución quedou parada: a rede non dá abasto."),
     "quality_bt_title": ("Quality over Bluetooth", "Calidade por Bluetooth"),
     "set_quality_bt": ("Quality over Bluetooth: %1$s", "Calidade por Bluetooth: %1$s"),