From 5b946bd06e949e905603811199336a20d1300e46 Mon Sep 17 00:00:00 2001
From: Antoni Spaanderman <56turtle56@gmail.com>
Date: Sat, 15 Nov 2025 12:19:28 +0100
Subject: [PATCH] Deprecate `From` implementation of `SwapInterval` that could
 panic, add `TryFrom`-like inherent function.

---
 changelog.md      |  2 ++
 src/sdl2/video.rs | 36 ++++++++++++++++++++++++++++--------
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/changelog.md b/changelog.md
index 6fd043b790..e18fa94fd2 100644
--- a/changelog.md
+++ b/changelog.md
@@ -3,6 +3,8 @@ when upgrading from a version of rust-sdl2 to another.
 
 ### v0.39.0
 
+[PR #1413](https://github.com/Rust-SDL2/rust-sdl2/pull/1413) Deprecate `From` implementation of `SwapInterval` that could panic, add `TryFrom`-like inherent function.
+
 [PR #1507](https://github.com/Rust-SDL2/rust-sdl2/pull/1507) **BREAKING CHANGE** Add binding for `SDL_ComposeCustomBlendMode`. This should only be a breaking change for users relying on internal details of `BlendMode` and `SDL_BlendMode`.
 
 [PR #1510](https://github.com/Rust-SDL2/rust-sdl2/pull/1510) Fix clippy warnings.
diff --git a/src/sdl2/video.rs b/src/sdl2/video.rs
index abb6321d6f..460354de4c 100644
--- a/src/sdl2/video.rs
+++ b/src/sdl2/video.rs
@@ -592,17 +592,37 @@ pub enum SwapInterval {
     LateSwapTearing = -1,
 }
 
-impl From<i32> for SwapInterval {
-    fn from(i: i32) -> Self {
-        match i {
+impl SwapInterval {
+    /// This function will be replaced with a [`TryFrom`] implementation later.
+    pub fn try_from(value: i32) -> Result<Self, SwapIntervalConversionError> {
+        Ok(match value {
             -1 => SwapInterval::LateSwapTearing,
             0 => SwapInterval::Immediate,
             1 => SwapInterval::VSync,
-            other => panic!(
-                "Invalid value for SwapInterval: {}; valid values are -1, 0, 1",
-                other
-            ),
-        }
+            _ => return Err(SwapIntervalConversionError(value)),
+        })
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct SwapIntervalConversionError(pub i32);
+
+impl fmt::Display for SwapIntervalConversionError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "Invalid value for SwapInterval: {}; valid values are -1, 0, 1",
+            self.0
+        )
+    }
+}
+
+impl Error for SwapIntervalConversionError {}
+
+impl From<i32> for SwapInterval {
+    /// This function is deprecated, use [`SwapInterval::try_from`] instead and handle the error.
+    fn from(i: i32) -> Self {
+        Self::try_from(i).unwrap()
     }
 }