Initial commit

2026-07-14 11:11:36 +08:00
commit 656499cf94
604 changed files with 119518 additions and 0 deletions
@@ -0,0 +1,186 @@
+import 'package:canvas_danmaku/canvas_danmaku.dart';
+import 'package:flutter/foundation.dart' show debugPrint;
+import 'package:flutter/material.dart' show Colors;
+
+import '../../../../core/contracts/danmaku.dart';
+import '../../../../core/media/danmaku_comment_pipeline.dart';
+
+
+const double _kBackwardSeekThreshold = -1.0;
+const double _kForwardSeekThreshold = 5.0;
+
+
+const int _kMaxFeedPerTick = 10;
+
+
+const double _kMaxFeedLagSec = 1.0;
+
+enum DanmakuPlaybackState { detached, disabled, playing, frozen, seeking }
+
+class DanmakuFeeder {
+  DanmakuController? _canvas;
+  List<DanmakuComment> _comments = const [];
+  DanmakuPanelSettings _settings = const DanmakuPanelSettings();
+  int _feedIndex = 0;
+  double _lastPosSec = -1;
+  DanmakuPlaybackState _state = DanmakuPlaybackState.detached;
+  double? _frozenPosSec;
+
+  void attach(DanmakuController controller) {
+    _canvas = controller;
+    _state = _settings.enabled
+        ? DanmakuPlaybackState.frozen
+        : DanmakuPlaybackState.disabled;
+  }
+
+  void detach() {
+    _canvas = null;
+    _state = DanmakuPlaybackState.detached;
+  }
+
+
+  void setComments(List<DanmakuComment> commentsSortedByTime) {
+    _comments = commentsSortedByTime;
+    _canvas?.clear();
+    _feedIndex = 0;
+    _lastPosSec = -1;
+    _frozenPosSec = null;
+  }
+
+  void setPanelSettings(
+    DanmakuPanelSettings settings, {
+    DanmakuOption? option,
+  }) {
+    _settings = settings;
+    if (!_settings.enabled) {
+      _state = DanmakuPlaybackState.disabled;
+    } else if (_state == DanmakuPlaybackState.disabled) {
+      _state = _canvas == null
+          ? DanmakuPlaybackState.detached
+          : DanmakuPlaybackState.frozen;
+    }
+    if (option != null) {
+      try {
+        _canvas?.updateOption(option);
+      } catch (e) {
+        debugPrint('[DanmakuFeeder] updateOption failed: $e; detaching canvas');
+        _canvas = null;
+        _state = DanmakuPlaybackState.detached;
+      }
+    }
+  }
+
+
+  void onPosition(double posSec) {
+    final canvas = _canvas;
+    if (canvas == null ||
+        _comments.isEmpty ||
+        !_settings.enabled ||
+        _state != DanmakuPlaybackState.playing) {
+      return;
+    }
+    final effectivePos = posSec - _settings.offset;
+    final last = _lastPosSec;
+    if (last >= 0 && _isTimelineJump(posSec - last)) {
+      canvas.clear();
+      _feedIndex = lowerBoundByTime(_comments, effectivePos);
+    }
+    _lastPosSec = posSec;
+
+    var fedThisTick = 0;
+    while (_feedIndex < _comments.length && fedThisTick < _kMaxFeedPerTick) {
+      final comment = _comments[_feedIndex];
+      if (comment.time > effectivePos) break;
+      _feedIndex++;
+      if (effectivePos - comment.time > _kMaxFeedLagSec) continue;
+      canvas.addDanmaku(_toContentItem(comment));
+      fedThisTick++;
+    }
+  }
+
+  void freezeAt(double posSec) {
+    final canvas = _canvas;
+    if (canvas == null) {
+      _state = DanmakuPlaybackState.detached;
+      return;
+    }
+    if (!_settings.enabled) {
+      _state = DanmakuPlaybackState.disabled;
+      return;
+    }
+    _state = DanmakuPlaybackState.frozen;
+    _frozenPosSec = posSec;
+    _lastPosSec = posSec;
+    if (canvas.running) {
+      canvas.pause();
+    }
+  }
+
+  void playFrom(double posSec) {
+    final canvas = _canvas;
+    if (canvas == null) {
+      _state = DanmakuPlaybackState.detached;
+      return;
+    }
+    if (!_settings.enabled) {
+      _state = DanmakuPlaybackState.disabled;
+      return;
+    }
+    final frozenPos = _frozenPosSec;
+    if (_state == DanmakuPlaybackState.frozen &&
+        frozenPos != null &&
+        posSec > frozenPos) {
+      final targetIndex = lowerBoundByTime(
+        _comments,
+        posSec - _settings.offset,
+      );
+      if (targetIndex > _feedIndex) {
+        _feedIndex = targetIndex;
+      }
+    }
+    _lastPosSec = posSec;
+    _frozenPosSec = null;
+    _state = DanmakuPlaybackState.playing;
+    if (!canvas.running) {
+      canvas.resume();
+    }
+  }
+
+  void seekTo(double posSec, {bool clear = true}) {
+    if (clear) _canvas?.clear();
+    _feedIndex = lowerBoundByTime(_comments, posSec - _settings.offset);
+    _lastPosSec = posSec;
+    _frozenPosSec = null;
+    if (_canvas == null) {
+      _state = DanmakuPlaybackState.detached;
+    } else {
+      _state = _settings.enabled
+          ? DanmakuPlaybackState.seeking
+          : DanmakuPlaybackState.disabled;
+    }
+  }
+
+  bool _isTimelineJump(double deltaSec) {
+    return deltaSec < _kBackwardSeekThreshold ||
+        deltaSec > _kForwardSeekThreshold;
+  }
+
+  DanmakuContentItem _toContentItem(DanmakuComment c) {
+    final baseColor = _settings.colored ? c.color : Colors.white;
+
+
+    final opacity = _settings.opacity.clamp(0.0, 1.0);
+    final color = opacity >= 1.0
+        ? baseColor
+        : baseColor.withValues(alpha: opacity);
+    return DanmakuContentItem(
+      c.text,
+      color: color,
+      type: switch (c.type) {
+        4 when !_settings.fixedToScroll => DanmakuItemType.bottom,
+        5 when !_settings.fixedToScroll => DanmakuItemType.top,
+        _ => DanmakuItemType.scroll,
+      },
+    );
+  }
+}