Add copying text in object preview

assets/keybindings.toml

@@ -72,6 +72,7 @@ download_as = ["shift-s"]
 encoding = ["e"]
 toggle_wrap = ["w"]
 toggle_number = ["n"]
+copy = ["c"]
 
 [help]
 close = ["?", "backspace"]

docs/src/features/object-preview.md

@@ -10,6 +10,7 @@
     - It must be enabled in the [config](../configurations/config-file-format.md#previewauto_detect_encoding)
 - Download object
   - Download a single selected object
+- Copy the text content to clipboard
 
 ![Object Preview](https://raw.githubusercontent.com/lusingander/stu/refs/heads/master/img/object-preview.png)
 ![Object Preview Image](https://raw.githubusercontent.com/lusingander/stu/refs/heads/master/img/object-preview-image.png)

src/keys.rs

@@ -68,6 +68,7 @@ pub enum UserEvent {
     ObjectPreviewEncoding,
     ObjectPreviewToggleWrap,
     ObjectPreviewToggleNumber,
+    ObjectPreviewCopy,
     HelpClose,
     InputDialogClose,
     InputDialogApply,
@@ -183,6 +184,7 @@ fn build_user_event_mapper(
     set_event_to_map(&mut map, &bindings, "object_preview", "encoding", UserEvent::ObjectPreviewEncoding)?;
     set_event_to_map(&mut map, &bindings, "object_preview", "toggle_wrap", UserEvent::ObjectPreviewToggleWrap)?;
     set_event_to_map(&mut map, &bindings, "object_preview", "toggle_number", UserEvent::ObjectPreviewToggleNumber)?;
+    set_event_to_map(&mut map, &bindings, "object_preview", "copy", UserEvent::ObjectPreviewCopy)?;
 
     set_event_to_map(&mut map, &bindings, "help", "close", UserEvent::HelpClose)?;
 

src/pages/object_preview.rs

@@ -141,6 +141,9 @@ impl ObjectPreviewPage {
                     UserEvent::ObjectPreviewEncoding => {
                         self.open_encoding_dialog();
                     }
+                    UserEvent::ObjectPreviewCopy => {
+                        self.copy_text_content();
+                    }
                     UserEvent::Help => {
                         self.tx.send(AppEventType::OpenHelp);
                     }
@@ -159,6 +162,9 @@ impl ObjectPreviewPage {
                         self.open_save_dialog();
                         self.disable_image_render();
                     }
+                    UserEvent::ObjectPreviewCopy => {
+                        self.tx.send(AppEventType::NotifyWarn("Cannot copy image content. Copy is only available for text files.".to_string()));
+                    }
                     UserEvent::Help => {
                         self.tx.send(AppEventType::OpenHelp);
                     }
@@ -264,6 +270,7 @@ impl ObjectPreviewPage {
                     BuildHelpsItem::new(UserEvent::ObjectPreviewDownload, "Download object"),
                     BuildHelpsItem::new(UserEvent::ObjectPreviewDownloadAs, "Download object as"),
                     BuildHelpsItem::new(UserEvent::ObjectPreviewEncoding, "Open encoding dialog"),
+                    BuildHelpsItem::new(UserEvent::ObjectPreviewCopy, "Copy content to clipboard"),
                 ]
             },
             (ViewState::Default, PreviewType::Image(_)) => {
@@ -304,6 +311,7 @@ impl ObjectPreviewPage {
                     BuildShortHelpsItem::group(vec![UserEvent::ObjectPreviewGoToTop, UserEvent::ObjectPreviewGoToBottom], "Top/End", 5),
                     BuildShortHelpsItem::group(vec![UserEvent::ObjectPreviewDownload, UserEvent::ObjectPreviewDownloadAs], "Download", 3),
                     BuildShortHelpsItem::single(UserEvent::ObjectPreviewEncoding, "Encoding", 4),
+                    BuildShortHelpsItem::single(UserEvent::ObjectPreviewCopy, "Copy", 6),
                     BuildShortHelpsItem::single(UserEvent::ObjectPreviewBack, "Close", 1),
                     BuildShortHelpsItem::single(UserEvent::Help, "Help", 0),
                 ]
@@ -342,6 +350,19 @@ impl ObjectPreviewPage {
         self.view_state = ViewState::SaveDialog(InputDialogState::new(name));
     }
 
+    fn copy_text_content(&mut self) {
+        if let PreviewType::Text(state) = &self.preview_type {
+            let encoding: &encoding_rs::Encoding = state.encoding.into();
+            let (content, _, _) = encoding.decode(&self.object.bytes);
+            let content_string = content.into_owned();
+
+            self.tx.send(AppEventType::CopyToClipboard(
+                self.file_detail.name.clone(),
+                content_string,
+            ));
+        }
+    }
+
     fn close_save_dialog(&mut self) {
         self.view_state = ViewState::Default;
     }
@@ -426,7 +447,13 @@ mod tests {
 
     use super::*;
     use chrono::{DateTime, Local, NaiveDateTime};
-    use ratatui::{backend::TestBackend, buffer::Buffer, style::Color, Terminal};
+    use ratatui::{
+        backend::TestBackend,
+        buffer::Buffer,
+        crossterm::event::{KeyCode, KeyModifiers},
+        style::Color,
+        Terminal,
+    };
 
     fn object(ss: &[&str]) -> RawObject {
         RawObject {
@@ -589,4 +616,96 @@ mod tests {
             object_url: "https://bucket-1.s3.ap-northeast-1.amazonaws.com/file.txt".to_string(),
         }
     }
+
+    #[tokio::test]
+    async fn test_copy_text_content() {
+        let ctx = Rc::default();
+        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
+        let tx = Sender::new(tx);
+
+        let file_detail = file_detail();
+        let preview = ["Hello, world!", "This is test content."];
+        let object = object(&preview);
+        let mut page = ObjectPreviewPage::new(file_detail, None, object, ctx, tx);
+
+        page.handle_key(
+            vec![UserEvent::ObjectPreviewCopy],
+            KeyEvent::new(KeyCode::Char('y'), KeyModifiers::empty()),
+        );
+
+        assert!(matches!(page.preview_type, PreviewType::Text(_)));
+    }
+
+    #[tokio::test]
+    async fn test_copy_image_content_shows_warning() {
+        use crate::event::AppEventType;
+
+        let ctx = Rc::default();
+        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();
+        let tx = Sender::new(tx);
+
+        let image_bytes = vec![
+            0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, // PNG signature
+            0x00, 0x00, 0x00, 0x0D, // IHDR chunk size
+            0x49, 0x48, 0x44, 0x52, // "IHDR"
+            0x00, 0x00, 0x00, 0x01, // width: 1
+            0x00, 0x00, 0x00, 0x01, // height: 1
+            0x08, 0x02, // bit depth: 8, color type: 2 (RGB)
+            0x00, 0x00, 0x00, // compression, filter, interlace
+        ];
+        let object = RawObject { bytes: image_bytes };
+
+        let mut file_detail = file_detail();
+        file_detail.name = "image.png".to_string();
+        file_detail.content_type = "image/png".to_string();
+
+        let mut page = ObjectPreviewPage::new(file_detail, None, object, ctx, tx);
+
+        assert!(matches!(page.preview_type, PreviewType::Image(_)));
+
+        // NOTE: Clear any initial warning messages (like "Image preview is disabled")
+        while rx.try_recv().is_ok() {
+            // Drain events
+        }
+
+        page.handle_key(
+            vec![UserEvent::ObjectPreviewCopy],
+            KeyEvent::new(KeyCode::Char('y'), KeyModifiers::empty()),
+        );
+
+        if let Ok(event) = rx.try_recv() {
+            match event {
+                AppEventType::NotifyWarn(msg) => {
+                    assert!(
+                        msg.contains("Cannot copy image content"),
+                        "Message was: {}",
+                        msg
+                    );
+                }
+                _ => panic!("Expected NotifyWarn event, got: {:?}", event),
+            }
+        } else {
+            panic!("Expected NotifyWarn event to be sent");
+        }
+    }
+
+    #[test]
+    fn test_copy_respects_encoding() {
+        let ctx = Rc::default();
+        let tx = sender();
+
+        let text = "Hello, 世界!";
+        let utf16_bytes: Vec<u8> = text.encode_utf16().flat_map(|c| c.to_be_bytes()).collect();
+
+        let object = RawObject { bytes: utf16_bytes };
+
+        let file_detail = file_detail();
+        let page = ObjectPreviewPage::new(file_detail, None, object, ctx, tx);
+
+        if let PreviewType::Text(ref state) = page.preview_type {
+            assert!(matches!(state.encoding, _));
+        } else {
+            panic!("Expected text preview type");
+        }
+    }
 }