summaryrefslogtreecommitdiff
path: root/apps/web/src/hooks/use-timeline-playhead.ts
blob: cd2fc76eed68fc06790ce95bb4926837785c6667 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
import { snapTimeToFrame } from "@/constants/timeline-constants";
import { useProjectStore } from "@/stores/project-store";
import { useState, useEffect, useCallback } from "react";

interface UseTimelinePlayheadProps {
	currentTime: number;
	duration: number;
	zoomLevel: number;
	seek: (time: number) => void;
	rulerRef: React.RefObject<HTMLDivElement>;
	rulerScrollRef: React.RefObject<HTMLDivElement>;
	tracksScrollRef: React.RefObject<HTMLDivElement>;
	playheadRef?: React.RefObject<HTMLDivElement>;
}

export function useTimelinePlayhead({
	currentTime,
	duration,
	zoomLevel,
	seek,
	rulerRef,
	rulerScrollRef,
	tracksScrollRef,
	playheadRef,
}: UseTimelinePlayheadProps) {
	// Playhead scrubbing state
	const [isScrubbing, setIsScrubbing] = useState(false);
	const [scrubTime, setScrubTime] = useState<number | null>(null);

	// Ruler drag detection state
	const [isDraggingRuler, setIsDraggingRuler] = useState(false);
	const [hasDraggedRuler, setHasDraggedRuler] = useState(false);

	const playheadPosition =
		isScrubbing && scrubTime !== null ? scrubTime : currentTime;

	// --- Playhead Scrubbing Handlers ---
	const handlePlayheadMouseDown = useCallback(
		(e: React.MouseEvent) => {
			e.preventDefault();
			e.stopPropagation(); // Prevent ruler drag from triggering
			setIsScrubbing(true);
			handleScrub(e);
		},
		[duration, zoomLevel],
	);

	// Ruler mouse down handler
	const handleRulerMouseDown = useCallback(
		(e: React.MouseEvent) => {
			// Only handle left mouse button
			if (e.button !== 0) return;

			// Don't interfere if clicking on the playhead itself
			if (playheadRef?.current?.contains(e.target as Node)) return;

			e.preventDefault();
			setIsDraggingRuler(true);
			setHasDraggedRuler(false);

			// Start scrubbing immediately
			setIsScrubbing(true);
			handleScrub(e);
		},
		[duration, zoomLevel],
	);

	const handleScrub = useCallback(
		(e: MouseEvent | React.MouseEvent) => {
			const ruler = rulerRef.current;
			if (!ruler) return;
			const rect = ruler.getBoundingClientRect();
			const x = e.clientX - rect.left;
			const rawTime = Math.max(0, Math.min(duration, x / (50 * zoomLevel)));
			// Use frame snapping for playhead scrubbing
			const projectStore = useProjectStore.getState();
			const projectFps = projectStore.activeProject?.fps || 30;
			const time = snapTimeToFrame(rawTime, projectFps);
			setScrubTime(time);
			seek(time); // update video preview in real time
		},
		[duration, zoomLevel, seek, rulerRef],
	);

	// Mouse move/up event handlers
	useEffect(() => {
		if (!isScrubbing) return;
		const onMouseMove = (e: MouseEvent) => {
			handleScrub(e);
			// Mark that we've dragged if ruler drag is active
			if (isDraggingRuler) {
				setHasDraggedRuler(true);
			}
		};
		const onMouseUp = (e: MouseEvent) => {
			setIsScrubbing(false);
			if (scrubTime !== null) seek(scrubTime); // finalize seek
			setScrubTime(null);

			// Handle ruler click vs drag
			if (isDraggingRuler) {
				setIsDraggingRuler(false);
				// If we didn't drag, treat it as a click-to-seek
				if (!hasDraggedRuler) {
					handleScrub(e);
				}
				setHasDraggedRuler(false);
			}
		};
		window.addEventListener("mousemove", onMouseMove);
		window.addEventListener("mouseup", onMouseUp);
		return () => {
			window.removeEventListener("mousemove", onMouseMove);
			window.removeEventListener("mouseup", onMouseUp);
		};
	}, [
		isScrubbing,
		scrubTime,
		seek,
		handleScrub,
		isDraggingRuler,
		hasDraggedRuler,
	]);

	// --- Playhead auto-scroll effect ---
	useEffect(() => {
		const rulerViewport = rulerScrollRef.current?.querySelector(
			"[data-radix-scroll-area-viewport]",
		) as HTMLElement;
		const tracksViewport = tracksScrollRef.current?.querySelector(
			"[data-radix-scroll-area-viewport]",
		) as HTMLElement;
		if (!rulerViewport || !tracksViewport) return;
		const playheadPx = playheadPosition * 50 * zoomLevel; // TIMELINE_CONSTANTS.PIXELS_PER_SECOND = 50
		const viewportWidth = rulerViewport.clientWidth;
		const scrollMin = 0;
		const scrollMax = rulerViewport.scrollWidth - viewportWidth;
		// Center the playhead if it's not visible (100px buffer)
		const desiredScroll = Math.max(
			scrollMin,
			Math.min(scrollMax, playheadPx - viewportWidth / 2),
		);
		if (
			playheadPx < rulerViewport.scrollLeft + 100 ||
			playheadPx > rulerViewport.scrollLeft + viewportWidth - 100
		) {
			rulerViewport.scrollLeft = tracksViewport.scrollLeft = desiredScroll;
		}
	}, [playheadPosition, duration, zoomLevel, rulerScrollRef, tracksScrollRef]);

	return {
		playheadPosition,
		handlePlayheadMouseDown,
		handleRulerMouseDown,
		isDraggingRuler,
	};
}