max / audiofiles

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1	//! Native OS drag-out: lets users drag samples from the file list to
2	//! Finder/Explorer, DAWs, or any drop target.
3	//!
4	//! Content-addressed files have hash-based names on disk, so we create
5	//! temporary links with friendly names before starting the drag.
6	//!
7	//! Platform backends:
8	//! - macOS: `NSDraggingSession` via objc2
9	//! - Windows: `DoDragDrop` + COM `IDataObject`/`IDropSource` with `CF_HDROP`
10
11	use std::path::{Path, PathBuf};
12	use std::sync::atomic::{AtomicBool, Ordering};
13
14	use tracing::warn;
15
16	/// Prevents re-entrant calls while a drag is pending or in progress.
17	static DRAG_ACTIVE: AtomicBool = AtomicBool::new(false);
18
19	#[cfg(target_os = "macos")]
20	mod macos;
21	#[cfg(target_os = "windows")]
22	mod windows;
23
24	/// A file to be dragged out of the application.
25	pub struct DragFile {
26	/// Display name the drop target will see (e.g. "My Kick.wav").
27	pub friendly_name: String,
28	/// Absolute path to the content-addressed file in the sample store.
29	pub store_path: PathBuf,
30	}
31
32	// ---------- Shared: temp file preparation ----------
33
34	/// Prepare a temp directory with friendly-named links to the store files.
35	/// Uses symlinks on Unix, hard links (with copy fallback) on Windows.
36	fn prepare_files(files: &[DragFile]) -> Vec<PathBuf> {
37	let dir = drag_dir();
38
39	// Clean previous drag artifacts.
40	let _ = std::fs::remove_dir_all(&dir);
41	if std::fs::create_dir_all(&dir).is_err() {
42	warn!("Failed to create drag temp dir");
43	return Vec::new();
44	}
45
46	let mut result = Vec::with_capacity(files.len());
47
48	for file in files {
49	// Sanitize friendly name: reject path separators and traversal sequences.
50	let safe_name = file.friendly_name.replace(['/', '\\'], "_");
51	let safe_name = safe_name.replace("..", "_");
52	let safe_name = safe_name.trim().to_string();
53	if safe_name.is_empty() {
54	warn!(name = %file.friendly_name, "Empty or invalid drag filename, skipping");
55	continue;
56	}
57	let mut target = dir.join(&safe_name);
58
59	// Handle name collisions with (1), (2), ... suffixes.
60	if target.exists() {
61	let stem = Path::new(&safe_name)
62	.file_stem()
63	.unwrap_or_default()
64	.to_string_lossy()
65	.into_owned();
66	let ext = Path::new(&safe_name)
67	.extension()
68	.map(\|e\| format!(".{}", e.to_string_lossy()))
69	.unwrap_or_default();
70	for n in 1..1000 {
71	target = dir.join(format!("{stem} ({n}){ext}"));
72	if !target.exists() {
73	break;
74	}
75	}
76	}
77
78	if create_link(&file.store_path, &target).is_err() {
79	warn!(name = %file.friendly_name, "Failed to create drag link");
80	continue;
81	}
82
83	result.push(target);
84	}
85
86	result
87	}
88
89	fn drag_dir() -> PathBuf {
90	std::env::temp_dir().join(format!("audiofiles-drag-{}", std::process::id()))
91	}
92
93	/// Create a filesystem link from `original` to `link`.
94	/// macOS: symlink. Windows: hard link, falling back to copy.
95	fn create_link(original: &Path, link: &Path) -> std::io::Result<()> {
96	#[cfg(unix)]
97	{
98	std::os::unix::fs::symlink(original, link)
99	}
100	#[cfg(windows)]
101	{
102	// Hard links avoid copying but require same volume.
103	// Fall back to copy if hard link fails.
104	std::fs::hard_link(original, link).or_else(\|_\| std::fs::copy(original, link).map(\|_\| ()))
105	}
106	}
107
108	// ---------- Public API ----------
109
110	/// Start a native OS drag session for the given files.
111	///
112	/// Returns `true` if the drag session was successfully initiated.
113	/// Returns `false` gracefully on any failure (no window, no event, link error).
114	#[tracing::instrument(skip_all, fields(count = files.len()))]
115	pub fn begin_drag(files: &[DragFile]) -> bool {
116	// Only one drag session at a time (macOS defers via dispatch_async,
117	// so this guard persists across the async boundary).
118	if DRAG_ACTIVE
119	.compare_exchange(false, true, Ordering::AcqRel, Ordering::Acquire)
120	.is_err()
121	{
122	return true; // already in progress
123	}
124
125	let paths = prepare_files(files);
126	if paths.is_empty() {
127	DRAG_ACTIVE.store(false, Ordering::Release);
128	return false;
129	}
130
131	#[cfg(target_os = "macos")]
132	{
133	macos::begin_drag_session(&paths)
134	}
135	#[cfg(target_os = "windows")]
136	{
137	let result = windows::begin_drag_session(&paths);
138	DRAG_ACTIVE.store(false, Ordering::Release);
139	result
140	}
141	#[cfg(not(any(target_os = "macos", target_os = "windows")))]
142	{
143	DRAG_ACTIVE.store(false, Ordering::Release);
144	false
145	}
146	}
147