fix menu iteration when the last item returns EINVAL

Author: SludgePhD

examples/drain-read.rs

@@ -12,10 +12,7 @@ use std::{
 };
 
 use anyhow::anyhow;
-use linuxvideo::{
-    format::{PixFormat, PixelFormat},
-    Device,
-};
+use linuxvideo::{format::Format, BufType, Device};
 
 fn main() -> anyhow::Result<()> {
     env_logger::init();
@@ -33,8 +30,10 @@ fn main() -> anyhow::Result<()> {
         device.capabilities()?.device_capabilities()
     );
 
-    let mut capture =
-        device.video_capture(PixFormat::new(u32::MAX, u32::MAX, PixelFormat::YUYV))?;
+    let Format::VideoCapture(fmt) = device.format(BufType::VIDEO_CAPTURE)? else {
+        unreachable!()
+    };
+    let mut capture = device.video_capture(fmt)?;
     println!("negotiated format: {:?}", capture.format());
     let size = capture.format().size_image() as usize;
     let mut buf = vec![0; size];

examples/drain-stream.rs

@@ -12,10 +12,7 @@ use std::{
 };
 
 use anyhow::anyhow;
-use linuxvideo::{
-    format::{PixFormat, PixelFormat},
-    Device,
-};
+use linuxvideo::{format::Format, BufType, Device};
 
 fn main() -> anyhow::Result<()> {
     env_logger::init();
@@ -33,7 +30,10 @@ fn main() -> anyhow::Result<()> {
         device.capabilities()?.device_capabilities()
     );
 
-    let capture = device.video_capture(PixFormat::new(u32::MAX, u32::MAX, PixelFormat::YUYV))?;
+    let Format::VideoCapture(fmt) = device.format(BufType::VIDEO_CAPTURE)? else {
+        unreachable!()
+    };
+    let capture = device.video_capture(fmt)?;
     println!("negotiated format: {:?}", capture.format());
 
     let mut stream = capture.into_stream()?;

src/controls.rs

@@ -175,10 +175,10 @@ impl Iterator for TextMenuIter<'_> {
     type Item = io::Result<TextMenuItem>;
 
     fn next(&mut self) -> Option<Self::Item> {
-        if self.next_index > self.max_index {
-            None
-        } else {
-            loop {
+        loop {
+            if self.next_index > self.max_index {
+                return None;
+            } else {
                 unsafe {
                     let mut raw = raw::QueryMenu {
                         id: self.cid.0,