feat: media session source and media card

app/src/main/java/top/yeij/hearth/media/MediaInfo.kt

@@ -0,0 +1,15 @@
+package top.yeij.hearth.media
+
+// 媒体会话快照：标题/艺术家/专辑 + 播放状态/进度 + 来源包名
+// Media session snapshot: title/artist/album + playback state/progress + source package
+data class MediaInfo(
+    val title: String,
+    val artist: String,
+    val album: String,
+    val playing: Boolean,
+    val position: Long,
+    val duration: Long,
+    val packageName: String,
+) {
+    fun toJson(): String = com.google.gson.Gson().toJson(this)
+}

app/src/main/java/top/yeij/hearth/media/MediaSessionSource.kt

@@ -0,0 +1,41 @@
+package top.yeij.hearth.media
+
+import android.content.Context
+import android.media.MediaMetadata
+import android.media.session.MediaController
+import android.media.session.MediaSessionManager
+import android.media.session.PlaybackState
+import android.util.Log
+
+// 监听系统活跃媒体会话，取第一个 controller 的 metadata + playbackState 构造 MediaInfo 回调
+// Watch active media sessions; build MediaInfo from the first controller's metadata + playbackState
+class MediaSessionSource(context: Context) {
+    private val msm = context.getSystemService(Context.MEDIA_SESSION_SERVICE) as MediaSessionManager
+    private var listener: ((MediaInfo?) -> Unit)? = null
+
+    fun start(cb: (MediaInfo?) -> Unit) {
+        listener = cb
+        msm.addOnActiveSessionsChangedListener({ controllers ->
+            val c = controllers?.firstOrNull()
+            if (c == null) {
+                Log.d("HearthMedia", "no active media session")
+                cb(null)
+                return@addOnActiveSessionsChangedListener
+            }
+            val meta = c.metadata
+            val state = c.playbackState
+            cb(
+                MediaInfo(
+                    meta?.getString(MediaMetadata.METADATA_KEY_TITLE) ?: "",
+                    meta?.getString(MediaMetadata.METADATA_KEY_ARTIST) ?: "",
+                    meta?.getString(MediaMetadata.METADATA_KEY_ALBUM) ?: "",
+                    state?.state == PlaybackState.STATE_PLAYING,
+                    state?.position ?: 0L,
+                    meta?.getLong(MediaMetadata.METADATA_KEY_DURATION) ?: 0L,
+                    c.packageName,
+                )
+            )
+            Log.d("HearthMedia", "media: ${c.packageName}")
+        }, null)
+    }
+}

app/src/main/java/top/yeij/hearth/webview/JsBridge.kt

@@ -4,6 +4,7 @@ import android.util.Log
 import top.yeij.hearth.app.AppRepository
 import top.yeij.hearth.card.Card
 import top.yeij.hearth.card.CardRepository
+import top.yeij.hearth.media.MediaSessionSource
 import top.yeij.hearth.webapp.WebApp
 import top.yeij.hearth.webapp.WebAppRepository
 
@@ -55,4 +56,18 @@ class JsBridge(
         Log.d("HearthBridge", "fetchCards: ${cards.size} cards")
         return gson.toJson(cards)
     }
+
+    // 注册媒体会话监听，回调推送给 H5（info 为 null 时推 "null"）
+    // Register media session listener; push callbacks to H5 (push "null" when info is null)
+    fun setMediaListener(source: MediaSessionSource, webView: android.webkit.WebView) {
+        source.start { info ->
+            webView.post {
+                val json = info?.toJson() ?: "null"
+                webView.evaluateJavascript(
+                    "window.HearthEvents && window.HearthEvents.mediaSessionChanged($json);",
+                    null
+                )
+            }
+        }
+    }
 }