Improvement/truncate

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## dz6 v0.7.0
+
+- Hex view:
+  - Replace mode:
+    - `t` now truncates the file (it was `T` before).
+    - `T` reverse truncates the file (deletes from offset 0 to current offset).
+    - Both commands above need confirmation from the user as they can't be undone.
+
 ## dz6 v0.6.0
 
 - Hex view:

src/editor.rs

@@ -23,9 +23,11 @@ pub enum UIState {
     DialogLog,
     DialogNames,
     DialogNamesRegex,
+    DialogReverseTruncate,
     DialogSearch,
     DialogStrings,
     DialogStringsRegex,
+    DialogTruncate,
     Error,
     HexEditing,
     HexSelection,

src/events.rs

@@ -48,6 +48,10 @@ pub fn handle_events(app: &mut App) -> Result<bool> {
                 UIState::DialogCalculator => {
                     global::calculator::dialog_calculator_events(app, &event)?
                 }
+                UIState::DialogTruncate => hex::truncate::dialog_truncate_events(app, &event)?,
+                UIState::DialogReverseTruncate => {
+                    hex::truncate::dialog_reverse_truncate_events(app, &event)?
+                }
             };
         }
         Event::Resize(width, _height) => {

src/global/status_bar.rs

@@ -57,7 +57,13 @@ pub fn status_bar_draw(app: &mut App, frame: &mut Frame, area: Rect) {
     frame.render_widget(status_bar_info_left, area);
 
     let selected = if app.state == UIState::HexSelection {
-        format!("{:X}", app.hex_view.selection.end.saturating_sub(app.hex_view.selection.start))
+        format!(
+            "{:X}",
+            app.hex_view
+                .selection
+                .end
+                .saturating_sub(app.hex_view.selection.start)
+        )
     } else {
         "".to_string()
     };

src/hex/edit.rs

@@ -111,12 +111,16 @@ pub fn edit_events(app: &mut App, key: KeyEvent) -> Result<bool> {
                         fill_with(app, b.wrapping_sub(1), false);
                     }
                 } else if c == 'T' {
-                    // truncate the file
-                    if let Some(f) = &app.file_info.file {
-                        f.set_len((app.hex_view.offset + 1) as u64)?;
-                        app.reload_file();
-                        app.state = UIState::Normal;
-                        app.hex_view.editing_hex = true;
+                    // set a new start (reverse truncate)
+                    if app.hex_view.offset > 0 {
+                        app.dialog_renderer = Some(super::truncate::dialog_reverse_truncate);
+                        app.state = UIState::DialogReverseTruncate;
+                    }
+                } else if c == 't' {
+                    // set a new end (truncate)
+                    if app.hex_view.offset < app.file_info.size.saturating_sub(1) {
+                        app.dialog_renderer = Some(super::truncate::dialog_truncate);
+                        app.state = UIState::DialogTruncate;
                     }
                 } else if c == '~' {
                     if let Some(b) = app.read_u8(app.hex_view.offset) {

src/hex/mod.rs

@@ -8,3 +8,4 @@ pub mod names;
 pub mod search;
 pub mod selection;
 pub mod strings;
+pub mod truncate;

src/hex/truncate.rs

@@ -0,0 +1,68 @@
+use crossterm::event::{Event, KeyCode};
+use ratatui::Frame;
+use std::io::{Result, Write};
+
+use crate::{
+    app::App,
+    editor::UIState,
+    widgets::{Message, MessageType},
+};
+
+pub fn dialog_truncate(app: &mut App, frame: &mut Frame) {
+    let mut dialog = Message::from(&format!(
+        "Permanently delete from offset {:X} to the end of file? (y/N)",
+        app.hex_view.offset.saturating_add(1)
+    ));
+    dialog.kind = MessageType::Error;
+    dialog.render(app, frame);
+}
+
+pub fn dialog_truncate_events(app: &mut App, event: &Event) -> Result<bool> {
+    if let Event::Key(key) = event {
+        match key.code {
+            KeyCode::Char('y') => {
+                if let Some(f) = &app.file_info.file {
+                    f.set_len((app.hex_view.offset + 1) as u64)?;
+                    app.reload_file();
+                }
+            }
+            _ => {}
+        }
+        app.dialog_renderer = None;
+        app.state = UIState::Normal;
+        app.hex_view.editing_hex = true;
+    }
+    Ok(false)
+}
+
+pub fn dialog_reverse_truncate(app: &mut App, frame: &mut Frame) {
+    let mut dialog = Message::from(&format!(
+        "Permanently delete from offset 0 to {:X}? (y/N)",
+        app.hex_view.offset.saturating_sub(1)
+    ));
+    dialog.kind = MessageType::Error;
+    dialog.render(app, frame);
+}
+
+pub fn dialog_reverse_truncate_events(app: &mut App, event: &Event) -> Result<bool> {
+    if let Event::Key(key) = event {
+        match key.code {
+            KeyCode::Char('y') => {
+                let buff = &mut app.file_info.get_buffer().to_vec();
+                let new_buff = buff.drain(app.hex_view.offset..);
+
+                if let Some(f) = &mut app.file_info.file {
+                    f.write_all(new_buff.as_slice())?;
+                    f.set_len(new_buff.len() as u64)?;
+                    app.reload_file();
+                    app.goto(0);
+                }
+            }
+            _ => {}
+        }
+        app.dialog_renderer = None;
+        app.state = UIState::Normal;
+        app.hex_view.editing_hex = true;
+    }
+    Ok(false)
+}