ctrl+v image + @file accepts images (#1695)

allow ctrl+v in TUI for images + @file that are images are appended as
raw files (and read by the model) rather than pasted as a path that
cannot be read by the model.

Re-used components and same interface we're using for copying pasted
content in
72504f1d9c.
@aibrahim-oai as you've implemented this, mind having a look at this
one?


https://github.com/user-attachments/assets/c6c1153b-6b32-4558-b9a2-f8c57d2be710

---------

Co-authored-by: easong-openai <easong@openai.com>
Co-authored-by: Daniel Edrisian <dedrisian@openai.com>
Co-authored-by: Michael Bolin <mbolin@openai.com>

codex-rs/tui/src/clipboard_paste.rs

@@ -0,0 +1,97 @@
+use std::path::PathBuf;
+use tempfile::Builder;
+
+#[derive(Debug)]
+pub enum PasteImageError {
+    ClipboardUnavailable(String),
+    NoImage(String),
+    EncodeFailed(String),
+    IoError(String),
+}
+
+impl std::fmt::Display for PasteImageError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            PasteImageError::ClipboardUnavailable(msg) => write!(f, "clipboard unavailable: {msg}"),
+            PasteImageError::NoImage(msg) => write!(f, "no image on clipboard: {msg}"),
+            PasteImageError::EncodeFailed(msg) => write!(f, "could not encode image: {msg}"),
+            PasteImageError::IoError(msg) => write!(f, "io error: {msg}"),
+        }
+    }
+}
+impl std::error::Error for PasteImageError {}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EncodedImageFormat {
+    Png,
+}
+
+impl EncodedImageFormat {
+    pub fn label(self) -> &'static str {
+        match self {
+            EncodedImageFormat::Png => "PNG",
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct PastedImageInfo {
+    pub width: u32,
+    pub height: u32,
+    pub encoded_format: EncodedImageFormat, // Always PNG for now.
+}
+
+/// Capture image from system clipboard, encode to PNG, and return bytes + info.
+pub fn paste_image_as_png() -> Result<(Vec<u8>, PastedImageInfo), PasteImageError> {
+    tracing::debug!("attempting clipboard image read");
+    let mut cb = arboard::Clipboard::new()
+        .map_err(|e| PasteImageError::ClipboardUnavailable(e.to_string()))?;
+    let img = cb
+        .get_image()
+        .map_err(|e| PasteImageError::NoImage(e.to_string()))?;
+    let w = img.width as u32;
+    let h = img.height as u32;
+
+    let mut png: Vec<u8> = Vec::new();
+    let Some(rgba_img) = image::RgbaImage::from_raw(w, h, img.bytes.into_owned()) else {
+        return Err(PasteImageError::EncodeFailed("invalid RGBA buffer".into()));
+    };
+    let dyn_img = image::DynamicImage::ImageRgba8(rgba_img);
+    tracing::debug!("clipboard image decoded RGBA {w}x{h}");
+    {
+        let mut cursor = std::io::Cursor::new(&mut png);
+        dyn_img
+            .write_to(&mut cursor, image::ImageFormat::Png)
+            .map_err(|e| PasteImageError::EncodeFailed(e.to_string()))?;
+    }
+
+    tracing::debug!(
+        "clipboard image encoded to PNG ({len} bytes)",
+        len = png.len()
+    );
+    Ok((
+        png,
+        PastedImageInfo {
+            width: w,
+            height: h,
+            encoded_format: EncodedImageFormat::Png,
+        },
+    ))
+}
+
+/// Convenience: write to a temp file and return its path + info.
+pub fn paste_image_to_temp_png() -> Result<(PathBuf, PastedImageInfo), PasteImageError> {
+    let (png, info) = paste_image_as_png()?;
+    // Create a unique temporary file with a .png suffix to avoid collisions.
+    let tmp = Builder::new()
+        .prefix("codex-clipboard-")
+        .suffix(".png")
+        .tempfile()
+        .map_err(|e| PasteImageError::IoError(e.to_string()))?;
+    std::fs::write(tmp.path(), &png).map_err(|e| PasteImageError::IoError(e.to_string()))?;
+    // Persist the file (so it remains after the handle is dropped) and return its PathBuf.
+    let (_file, path) = tmp
+        .keep()
+        .map_err(|e| PasteImageError::IoError(e.error.to_string()))?;
+    Ok((path, info))
+}