multiple cursors with primary separate

src/buffer/mod.rs

@@ -1,3 +1,4 @@
+use core::slice::GetDisjointMutIndex;
 use std::{fs::File, io::Read, path::PathBuf};
 use crossterm::event::KeyEvent;
 use ratatui::{style::Color, text::Span};
@@ -12,7 +13,8 @@ pub struct Buffer {
 	pub contents: Vec<u8>,
 	
 	pub scroll_position: usize,
-	pub cursor: Cursor,
+	pub primary_cursor: Cursor,
+	pub cursors: Vec<Cursor>,
 	
 	pub mode: Mode,
 	pub partial_action: Option<PartialAction>,
@@ -79,7 +81,8 @@ impl Buffer {
 			contents,
 			
 			scroll_position: 0,
-			cursor: Cursor::default(),
+			primary_cursor: Cursor::default(),
+			cursors: Vec::new(),
 			
 			mode: Mode::Normal,
 			partial_action: None,
@@ -110,8 +113,13 @@ impl Buffer {
 				if let Some(partial_replace) = self.partial_replace.take() {
 					self.execute_and_add(
 						EditAction::Replace {
-							cursor: self.cursor,
-							old_data: self.contents[self.cursor.range()].into(),
+							primary_cursor: self.primary_cursor,
+							cursors: self.cursors.clone(),
+							primary_old_data: self.contents[self.primary_cursor.range()].to_vec(),
+							old_data: self.cursors
+								.iter()
+								.map(|cursor| self.contents[cursor.range()].to_vec())
+								.collect(),
 							new_byte: partial_replace << 4 | nybble
 						}
 					);
@@ -161,6 +169,32 @@ impl Buffer {
 	pub const fn max_contents_index(&self) -> usize {
 		self.contents.len().saturating_sub(1)
 	}
+	
+	pub fn combine_cursors_if_overlapping(&mut self) {
+		if self.cursors.is_empty() { return; }
+		
+		let mut index = 0;
+		
+		while index < self.cursors.len() - 1 {
+			while index < self.cursors.len() - 1 &&
+				self.cursors[index].range().is_overlapping(
+					&self.cursors[index + 1].range())
+			{
+				let next_cursor = self.cursors[index + 1];
+				self.cursors[index].combine_with(next_cursor);
+				self.cursors.remove(index + 1);
+			}
+			
+			if self.primary_cursor.range()
+				.is_overlapping(&self.cursors[index].range())
+			{
+				self.primary_cursor.combine_with(self.cursors[index]);
+				self.cursors.remove(index);
+			}
+			
+			index += 1;
+		}
+	}
 }
 
 fn nybble_from_hex(hex: char) -> Option<u8> {

src/buffer/widget.rs

@@ -82,7 +82,7 @@ mod address {
 }
 
 mod hex {
-	use std::{borrow::Cow, mem};
+	use std::{borrow::Cow, iter, mem};
 	use itertools::{Itertools, repeat_n};
 	use ratatui::{style::{Color, Style, Stylize}, text::Span};
 	
@@ -199,7 +199,9 @@ mod hex {
 			byte: u8
 		) -> Span<'static> {
 			if self.partial_action == Some(PartialAction::Replace) &&
-			   self.cursor.contains(address).is_some()
+			   iter::once(&self.primary_cursor)
+				.chain(&self.cursors)
+				.any(|cursor| cursor.contains(address).is_some())
 			{
 				let replaced_byte = self.partial_replace.unwrap_or(0) << 4;
 				
@@ -224,7 +226,10 @@ mod hex {
 				_ => Color::Gray
 			};
 			
-			match self.cursor.contains(address) {
+			match iter::once(&self.primary_cursor)
+				.chain(&self.cursors)
+				.find_map(|cursor| cursor.contains(address))
+			{
 				Some(InCursor::Head) => span.bg(head_color),
 				Some(InCursor::Rest) => span.bg(Color::select_grey()),
 				None => span,
@@ -232,7 +237,10 @@ mod hex {
 		}
 		
 		fn render_large_space_before(&self, address: usize) -> Span<'static> {
-			if self.cursor.contains_space_before(address) {
+			if iter::once(&self.primary_cursor)
+				.chain(&self.cursors)
+				.any(|cursor| cursor.contains_space_before(address))
+			{
 				Span {
 					style: Style::new().bg(Color::select_grey()),
 					content: "  ".into()
@@ -243,7 +251,10 @@ mod hex {
 		}
 		
 		fn render_space_before(&self, address: usize) -> Span<'static> {
-			if self.cursor.contains_space_before(address) {
+			if iter::once(&self.primary_cursor)
+				.chain(&self.cursors)
+				.any(|cursor| cursor.contains_space_before(address))
+			{
 				Span {
 					style: Style::new().bg(Color::select_grey()),
 					content: " ".into()
@@ -306,7 +317,7 @@ mod hex {
 }
 
 mod character_panel {
-	use std::{borrow::Cow, mem};
+	use std::{borrow::Cow, iter, mem};
 	use ratatui::{style::{Color, Style, Stylize}, text::Span};
 	use crate::{buffer::Buffer, cardinality::HasCardinality, cursor::InCursor, custom_greys::CustomGreys, empty_span::empty_span};
 	
@@ -332,7 +343,10 @@ mod character_panel {
 			
 			let span = SPAN_FOR_BYTE[byte as usize].clone();
 			
-			match self.cursor.contains(address) {
+			match iter::once(&self.primary_cursor)
+				.chain(&self.cursors)
+				.find_map(|cursor| cursor.contains(address))
+			{
 				Some(InCursor::Head) => span.bg(Color::select_grey()),
 				Some(InCursor::Rest) => span.on_dark_gray(),
 				None => span,
@@ -434,7 +448,7 @@ mod extra_statuses {
 				format!("{partial_action} ").into()
 			} else {
 				#[allow(clippy::cast_precision_loss)]
-				let percentage = self.cursor.head as f64 / self.max_contents_index() as f64 * 100.0;
+				let percentage = self.primary_cursor.head as f64 / self.max_contents_index() as f64 * 100.0;
 				
 				format!("{partial_action} {percentage:.0}% ").into()
 			}