feat(podcasts): translatable show description + synthetic playback waveform

- The show description on the podcast screen now renders through TranslatableRichTextViewer (rich text + translation), matching how a profile's About is shown, instead of a plain Text. PodcastHeader takes a nav for the rich content's links. - Audio playback now shows a decorative per-episode waveform when the source has none, instead of a flat strip — same behaviour as music tracks. Extracted MusicTrack's private syntheticWaveformFor into a shared wavefront/SyntheticWaveform.kt used by both music and podcast players; the podcast player still prefers a real IMeta waveform when one is present.
2026-08-11 00:37:41 +00:00 · 2026-05-29 21:21:54 +00:00
parent 07855c2240
commit 063ebbebce
5 changed files with 112 additions and 77 deletions
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.playback.composable.wavefront
+
+import com.vitorpamplona.amethyst.service.playback.composable.WaveformData
+import kotlin.math.sin
+import kotlin.random.Random
+
+private const val SYNTHETIC_WAVEFORM_SAMPLES = 96
+private const val TWO_PI = (Math.PI * 2).toFloat()
+
+/**
+ * Builds a stable, decorative waveform from a [seed] (usually an event id). ExoPlayer drives
+ * actual playback progress — these bars only exist so an audio player has the familiar
+ * "audio silhouette" shape rather than a flat strip when the source carries no `waveform` tag.
+ * Shared by every audio renderer whose spec omits waveforms (music tracks, podcast episodes, …).
+ *
+ * Every shape parameter (phase offset, carrier frequency, baseline, envelope skew, jitter
+ * envelope) is drawn from the seeded RNG before the per-bar loop, so two different seeds
+ * produce visibly different waveforms — earlier versions used a fixed envelope + carrier that
+ * only varied by per-bar noise, which made every track look like the same slow-fade sine with
+ * minor wiggle.
+ */
+fun syntheticWaveformFor(seed: String): WaveformData {
+    // Fold the seed's 32-bit hash into a Long so two ids whose hashCode happens to collide
+    // (rare for hex addresses but cheap to defend against) still differ via the bit shuffle.
+    val rng = Random((seed.hashCode().toLong() * 0x9E3779B97F4A7C15uL.toLong()) xor seed.length.toLong())
+
+    // Shape parameters drawn once per seed — these are what makes seed A look different
+    // from seed B at a glance.
+    val phaseOffset = rng.nextFloat() * TWO_PI
+    val carrierCycles = 2.5f + rng.nextFloat() * 5.5f // 2.5–8 full cycles across the strip
+    val carrierWeight = 0.18f + rng.nextFloat() * 0.18f // 0.18–0.36
+    val baseline = 0.28f + rng.nextFloat() * 0.22f // 0.28–0.50
+    val envelopeStrength = rng.nextFloat() * 0.45f // 0.0–0.45; some fade in/out, others don't
+    val noiseStrength = 0.18f + rng.nextFloat() * 0.22f // 0.18–0.40
+
+    val bars =
+        List(SYNTHETIC_WAVEFORM_SAMPLES) { index ->
+            val phase = index.toFloat() / SYNTHETIC_WAVEFORM_SAMPLES
+            // Optional gentle fade so some taper at the ends, others stay even.
+            val envelope = 1f - envelopeStrength * (1f - sin(phase * Math.PI).toFloat())
+            val carrier = sin(phase * TWO_PI * carrierCycles + phaseOffset) * carrierWeight
+            val noise = (rng.nextFloat() - 0.5f) * 2f * noiseStrength
+            ((baseline + carrier + noise) * envelope).coerceIn(0.05f, 1.0f)
+        }
+    return WaveformData(bars)
+}
@@ -62,8 +62,8 @@ import com.vitorpamplona.amethyst.service.playback.composable.GetVideoController
 import com.vitorpamplona.amethyst.service.playback.composable.LoadThumbAndThenVideoView
 import com.vitorpamplona.amethyst.service.playback.composable.PauseControllerWhenInBackground
 import com.vitorpamplona.amethyst.service.playback.composable.VideoView
-import com.vitorpamplona.amethyst.service.playback.composable.WaveformData
 import com.vitorpamplona.amethyst.service.playback.composable.mediaitem.GetMediaItem
+import com.vitorpamplona.amethyst.service.playback.composable.wavefront.syntheticWaveformFor
 import com.vitorpamplona.amethyst.ui.components.LoadNote
 import com.vitorpamplona.amethyst.ui.components.MyAsyncImage
 import com.vitorpamplona.amethyst.ui.components.TranslatableRichTextViewer
@@ -438,46 +438,6 @@ private fun TopicChip(
    )
 }

-private const val SYNTHETIC_WAVEFORM_SAMPLES = 96
-private const val TWO_PI = (Math.PI * 2).toFloat()
-
-/**
- * Builds a stable, decorative waveform from the track id. ExoPlayer drives actual playback
- * progress — these bars only exist so the audio player has the familiar "music silhouette"
- * shape rather than a flat strip when the spec has no `waveform` tag.
- *
- * Every shape parameter (phase offset, carrier frequency, baseline, envelope skew, jitter
- * envelope) is drawn from the seeded RNG before the per-bar loop, so two different track ids
- * produce visibly different waveforms — earlier versions used a fixed envelope + carrier that
- * only varied by per-bar noise, which made every track look like the same slow-fade sine with
- * minor wiggle.
- */
-private fun syntheticWaveformFor(seed: String): WaveformData {
-    // Fold the seed's 32-bit hash into a Long so two ids whose hashCode happens to collide
-    // (rare for hex addresses but cheap to defend against) still differ via the bit shuffle.
-    val rng = kotlin.random.Random((seed.hashCode().toLong() * 0x9E3779B97F4A7C15uL.toLong()) xor seed.length.toLong())
-
-    // Shape parameters drawn once per track — these are what makes track A look different
-    // from track B at a glance.
-    val phaseOffset = rng.nextFloat() * TWO_PI
-    val carrierCycles = 2.5f + rng.nextFloat() * 5.5f // 2.5–8 full cycles across the strip
-    val carrierWeight = 0.18f + rng.nextFloat() * 0.18f // 0.18–0.36
-    val baseline = 0.28f + rng.nextFloat() * 0.22f // 0.28–0.50
-    val envelopeStrength = rng.nextFloat() * 0.45f // 0.0–0.45; some tracks fade in/out, others don't
-    val noiseStrength = 0.18f + rng.nextFloat() * 0.22f // 0.18–0.40
-
-    val bars =
-        List(SYNTHETIC_WAVEFORM_SAMPLES) { index ->
-            val phase = index.toFloat() / SYNTHETIC_WAVEFORM_SAMPLES
-            // Optional gentle fade so some tracks taper at the ends, others stay even.
-            val envelope = 1f - envelopeStrength * (1f - kotlin.math.sin(phase * Math.PI).toFloat())
-            val carrier = kotlin.math.sin(phase * TWO_PI * carrierCycles + phaseOffset) * carrierWeight
-            val noise = (rng.nextFloat() - 0.5f) * 2f * noiseStrength
-            ((baseline + carrier + noise) * envelope).coerceIn(0.05f, 1.0f)
-        }
-    return WaveformData(bars)
-}
-
 // ---------------------------------------------------------------------------
 // @Preview composables. These wire a constructed MusicTrackEvent through
 // LocalCache so the renderer pulls the real Note path it would in production.
@@ -33,15 +33,10 @@ import com.vitorpamplona.amethyst.service.playback.composable.GetVideoController
 import com.vitorpamplona.amethyst.service.playback.composable.PauseControllerWhenInBackground
 import com.vitorpamplona.amethyst.service.playback.composable.WaveformData
 import com.vitorpamplona.amethyst.service.playback.composable.mediaitem.GetMediaItem
+import com.vitorpamplona.amethyst.service.playback.composable.wavefront.syntheticWaveformFor
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.quartz.nipF4Podcasts.episode.tags.AudioTag

-// NIP-F4 episodes carry no waveform tag, so every episode renders with the same flat baseline.
-// Hoisted to a top-level constant so we share one List<Float> + WaveformData across the whole
-// feed instead of allocating a fresh 96-element list per visible card.
-private const val WAVEFORM_SAMPLES = 96
-private val FLAT_WAVEFORM = WaveformData(List(WAVEFORM_SAMPLES) { 0.4f })
-
 // The voice player's internal controls are laid out for 100.dp; 80.dp is the tightest height
 // that still fits the play button without clipping it. Shared so the feed card and the
 // per-podcast list row stay pixel-identical.
@@ -62,6 +57,17 @@ fun PodcastEpisodeAudioPlayer(
    accountViewModel: AccountViewModel,
 ) {
    val callbackUri = remember(note) { note.toNostrUri() }
+    // Use a real waveform when the episode ships one in its IMeta; NIP-F4 usually doesn't, so
+    // fall back to a decorative waveform seeded by the note id — same approach as music tracks,
+    // a per-episode silhouette instead of a flat strip.
+    val waveform =
+        remember(note) {
+            note.event
+                ?.getAudioMetaWithWaveform()
+                ?.waveform
+                ?.let { WaveformData(it) }
+                ?: syntheticWaveformFor(note.idHex)
+        }

    Row(
        PLAYER_HEIGHT_MODIFIER,
@@ -77,7 +83,7 @@ fun PodcastEpisodeAudioPlayer(
            aspectRatio = null,
            proxyPort = accountViewModel.httpClientBuilder.proxyPortForVideo(audio.url),
            keepPlaying = false,
-            waveformData = FLAT_WAVEFORM,
+            waveformData = waveform,
        ) { mediaItem ->
            GetVideoController(
                mediaItem = mediaItem,
@@ -87,7 +93,7 @@ fun PodcastEpisodeAudioPlayer(
                RenderVoicePlayer(
                    mediaItem = mediaItem,
                    controllerState = controller,
-                    waveform = FLAT_WAVEFORM,
+                    waveform = waveform,
                    borderModifier = borderModifier,
                    accountViewModel = accountViewModel,
                )
@@ -20,7 +20,6 @@
 */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.podcasts

-import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.ExperimentalLayoutApi
@@ -31,17 +30,20 @@ import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.EmptyTagList
+import com.vitorpamplona.amethyst.commons.model.toImmutableListOfLists
 import com.vitorpamplona.amethyst.model.Note
+import com.vitorpamplona.amethyst.ui.components.TranslatableRichTextViewer
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.note.types.PodcastCoverCard
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.theme.DividerThickness
@@ -50,9 +52,9 @@ import com.vitorpamplona.amethyst.ui.theme.grayText
 import com.vitorpamplona.quartz.nipF4Podcasts.metadata.PodcastMetadataEvent

 /**
- * Hero header for a single podcast screen: large cover art, title, websites and a tappable
- * (collapse/expand) description, followed by the "Episodes (N)" section divider that the
- * episode rows hang under.
+ * Hero header for a single podcast screen: large cover art, title, websites and the show
+ * description (rich text + translation, same as a profile's About), followed by the
+ * "Episodes (N)" section divider that the episode rows hang under.
 */
@OptIn(ExperimentalLayoutApi::class)
@Composable
@@ -61,11 +63,13 @@ fun PodcastHeader(
    metadataEvent: PodcastMetadataEvent?,
    episodeCount: Int?,
    accountViewModel: AccountViewModel,
+    nav: INav,
 ) {
    val title = remember(metadataEvent) { metadataEvent?.title() }
    val image = remember(metadataEvent) { metadataEvent?.image() }
    val description = remember(metadataEvent) { metadataEvent?.description() }
    val websites = remember(metadataEvent) { metadataEvent?.websites() ?: emptyList() }
+    val tags = remember(metadataEvent) { metadataEvent?.tags?.toImmutableListOfLists() ?: EmptyTagList }

    Column(Modifier.fillMaxWidth()) {
        PodcastCoverCard(image, metadataNote, accountViewModel)
@@ -103,7 +107,21 @@ fun PodcastHeader(
                }
            }

-            description?.let { ExpandableDescription(it) }
+            description?.let {
+                val background = remember { mutableStateOf(Color.Transparent) }
+
+                TranslatableRichTextViewer(
+                    content = it,
+                    canPreview = false,
+                    quotesLeft = 1,
+                    modifier = Modifier.fillMaxWidth(),
+                    tags = tags,
+                    backgroundColor = background,
+                    id = metadataNote.idHex,
+                    accountViewModel = accountViewModel,
+                    nav = nav,
+                )
+            }
        }

        // Only render once episodes have actually loaded — avoids flashing "0 episodes"
@@ -123,19 +141,3 @@ fun PodcastHeader(
        }
    }
 }
-
-@Composable
-private fun ExpandableDescription(description: String) {
-    var expanded by remember(description) { mutableStateOf(false) }
-
-    Text(
-        text = description,
-        style = MaterialTheme.typography.bodyMedium,
-        maxLines = if (expanded) Int.MAX_VALUE else 4,
-        overflow = TextOverflow.Ellipsis,
-        modifier =
-            Modifier
-                .fillMaxWidth()
-                .clickable { expanded = !expanded },
-    )
-}
@@ -147,17 +147,17 @@ private fun PodcastScreenBody(
            PodcastEpisodesList(metadataNote, metadataEvent, state, listState, accountViewModel, nav)

        is FeedState.Empty ->
-            PodcastHeaderWithStatus(metadataNote, metadataEvent, listState, accountViewModel) {
+            PodcastHeaderWithStatus(metadataNote, metadataEvent, listState, accountViewModel, nav) {
                StatusText(stringRes(R.string.podcast_no_episodes))
            }

        is FeedState.FeedError ->
-            PodcastHeaderWithStatus(metadataNote, metadataEvent, listState, accountViewModel) {
+            PodcastHeaderWithStatus(metadataNote, metadataEvent, listState, accountViewModel, nav) {
                FeedError(state.errorMessage) { feedViewModel.invalidateData() }
            }

        is FeedState.Loading ->
-            PodcastHeaderWithStatus(metadataNote, metadataEvent, listState, accountViewModel) {
+            PodcastHeaderWithStatus(metadataNote, metadataEvent, listState, accountViewModel, nav) {
                Box(Modifier.fillMaxWidth().padding(32.dp), contentAlignment = Alignment.Center) {
                    CircularProgressIndicator()
                }
@@ -181,7 +181,7 @@ private fun PodcastEpisodesList(
        contentPadding = rememberFeedContentPadding(FeedPadding),
    ) {
        item("header") {
-            PodcastHeader(metadataNote, metadataEvent, items.list.size, accountViewModel)
+            PodcastHeader(metadataNote, metadataEvent, items.list.size, accountViewModel, nav)
        }

        itemsIndexed(
@@ -204,6 +204,7 @@ private fun PodcastHeaderWithStatus(
    metadataEvent: PodcastMetadataEvent?,
    listState: LazyListState,
    accountViewModel: AccountViewModel,
+    nav: INav,
    status: @Composable () -> Unit,
 ) {
    LazyColumn(
@@ -211,7 +212,7 @@ private fun PodcastHeaderWithStatus(
        contentPadding = rememberFeedContentPadding(FeedPadding),
    ) {
        item("header") {
-            PodcastHeader(metadataNote, metadataEvent, null, accountViewModel)
+            PodcastHeader(metadataNote, metadataEvent, null, accountViewModel, nav)
        }
        item("status") { status() }
    }