♻️ Refactor TextCursor and TextPositionWithAffinity

render-wasm/src/render/text_editor.rs

@@ -111,7 +111,7 @@ fn calculate_cursor_rect(
     let mut y_offset = vertical_align_offset(shape, &layout_paragraphs);
     for (idx, laid_out_para) in layout_paragraphs.iter().enumerate() {
         if idx == cursor.paragraph {
-            let char_pos = cursor.char_offset;
+            let char_pos = cursor.offset;
             // For cursor, we get a zero-width range at the position
             // We need to handle edge cases:
             // - At start of paragraph: use position 0
@@ -209,13 +209,13 @@ fn calculate_selection_rects(
             .sum();
 
         let range_start = if para_idx == start.paragraph {
-            start.char_offset
+            start.offset
         } else {
             0
         };
 
         let range_end = if para_idx == end.paragraph {
-            end.char_offset
+            end.offset
         } else {
             para_char_count
         };

render-wasm/src/shapes/text.rs

@@ -11,6 +11,7 @@ use skia_safe::textlayout::{RectHeightStyle, RectWidthStyle};
 use skia_safe::{
     self as skia,
     paint::{self, Paint},
+    textlayout::Affinity,
     textlayout::ParagraphBuilder,
     textlayout::ParagraphStyle,
     textlayout::PositionWithAffinity,
@@ -112,31 +113,51 @@ impl TextContentSize {
     }
 }
 
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Clone, Copy, Default)]
 pub struct TextPositionWithAffinity {
     #[allow(dead_code)]
     pub position_with_affinity: PositionWithAffinity,
-    pub paragraph: i32,
+    pub paragraph: usize,
-    #[allow(dead_code)]
+    pub offset: usize,
-    pub span: i32,
+}
-    #[allow(dead_code)]
+
-    pub span_relative_offset: i32,
+impl PartialEq for TextPositionWithAffinity {
-    pub offset: i32,
+    fn eq(&self, other: &Self) -> bool {
+        self.paragraph == other.paragraph && self.offset == other.offset
+    }
 }
 
 impl TextPositionWithAffinity {
     pub fn new(
         position_with_affinity: PositionWithAffinity,
-        paragraph: i32,
+        paragraph: usize,
-        span: i32,
+        offset: usize,
-        span_relative_offset: i32,
-        offset: i32,
     ) -> Self {
         Self {
             position_with_affinity,
             paragraph,
-            span,
+            offset,
-            span_relative_offset,
+        }
+    }
+
+    pub fn empty() -> Self {
+        Self {
+            position_with_affinity: PositionWithAffinity {
+                position: 0,
+                affinity: Affinity::Downstream,
+            },
+            paragraph: 0,
+            offset: 0,
+        }
+    }
+
+    pub fn new_without_affinity(paragraph: usize, offset: usize) -> Self {
+        Self {
+            position_with_affinity: PositionWithAffinity {
+                position: offset as i32,
+                affinity: Affinity::Downstream,
+            },
+            paragraph,
             offset,
         }
     }
@@ -433,10 +454,11 @@ impl TextContent {
         let mut offset_y = 0.0;
         let layout_paragraphs = self.layout.paragraphs.iter().flatten();
 
-        let mut paragraph_index: i32 = -1;
+        // IMPORTANT! I'm keeping this because I think it should be better to have the span index
-        let mut span_index: i32 = -1;
+        // cached the same way we keep the paragraph index.
-        for layout_paragraph in layout_paragraphs {
+        #[allow(dead_code)]
-            paragraph_index += 1;
+        let mut _span_index: usize = 0;
+        for (paragraph_index, layout_paragraph) in layout_paragraphs.enumerate() {
             let start_y = offset_y;
             let end_y = offset_y + layout_paragraph.height();
 
@@ -453,20 +475,22 @@ impl TextContent {
             if matches {
                 let position_with_affinity =
                     layout_paragraph.get_glyph_position_at_coordinate(*point);
-                if let Some(paragraph) = self.paragraphs().get(paragraph_index as usize) {
+                if let Some(paragraph) = self.paragraphs().get(paragraph_index) {
                     // Computed position keeps the current position in terms
                     // of number of characters of text. This is used to know
                     // in which span we are.
-                    let mut computed_position = 0;
+                    let mut computed_position: usize = 0;
-                    let mut span_offset = 0;
+
+                    // This could be useful in the future as part of the TextPositionWithAffinity.
+                    #[allow(dead_code)]
+                    let mut _span_offset: usize = 0;
 
                     // If paragraph has no spans, default to span 0, offset 0
                     if paragraph.children().is_empty() {
-                        span_index = 0;
+                        _span_index = 0;
-                        span_offset = 0;
+                        _span_offset = 0;
                     } else {
                         for span in paragraph.children() {
-                            span_index += 1;
                             let length = span.text.chars().count();
                             let start_position = computed_position;
                             let end_position = computed_position + length;
@@ -475,27 +499,26 @@ impl TextContent {
                             // Handle empty spans: if the span is empty and current position
                             // matches the start, this is the right span
                             if length == 0 && current_position == start_position {
-                                span_offset = 0;
+                                _span_offset = 0;
                                 break;
                             }
 
                             if start_position <= current_position
                                 && end_position >= current_position
                             {
-                                span_offset =
+                                _span_offset =
-                                    position_with_affinity.position - start_position as i32;
+                                    position_with_affinity.position as usize - start_position;
                                 break;
                             }
                             computed_position += length;
+                            _span_index += 1;
                         }
                     }
 
                     return Some(TextPositionWithAffinity::new(
                         position_with_affinity,
                         paragraph_index,
-                        span_index,
+                        position_with_affinity.position as usize,
-                        span_offset,
-                        position_with_affinity.position,
                     ));
                 }
             }
@@ -516,9 +539,7 @@ impl TextContent {
             return Some(TextPositionWithAffinity::new(
                 default_position,
                 0, // paragraph 0
-                0, // span 0
                 0, // offset 0
-                0,
             ));
         }
 

render-wasm/src/state/text_editor.rs

@@ -7,34 +7,10 @@ use skia_safe::{
     Color,
 };
 
-/// Cursor position within text content.
-/// Uses character offsets for precise positioning.
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Default)]
-pub struct TextCursor {
-    pub paragraph: usize,
-    pub char_offset: usize,
-}
-
-impl TextCursor {
-    pub fn new(paragraph: usize, char_offset: usize) -> Self {
-        Self {
-            paragraph,
-            char_offset,
-        }
-    }
-
-    pub fn zero() -> Self {
-        Self {
-            paragraph: 0,
-            char_offset: 0,
-        }
-    }
-}
-
 #[derive(Debug, Clone, Copy, Default)]
 pub struct TextSelection {
-    pub anchor: TextCursor,
+    pub anchor: TextPositionWithAffinity,
-    pub focus: TextCursor,
+    pub focus: TextPositionWithAffinity,
 }
 
 impl TextSelection {
@@ -42,10 +18,10 @@ impl TextSelection {
         Self::default()
     }
 
-    pub fn from_cursor(cursor: TextCursor) -> Self {
+    pub fn from_position_with_affinity(position: TextPositionWithAffinity) -> Self {
         Self {
-            anchor: cursor,
+            anchor: position,
-            focus: cursor,
+            focus: position,
         }
     }
 
@@ -57,12 +33,12 @@ impl TextSelection {
         !self.is_collapsed()
     }
 
-    pub fn set_caret(&mut self, cursor: TextCursor) {
+    pub fn set_caret(&mut self, cursor: TextPositionWithAffinity) {
         self.anchor = cursor;
         self.focus = cursor;
     }
 
-    pub fn extend_to(&mut self, cursor: TextCursor) {
+    pub fn extend_to(&mut self, cursor: TextPositionWithAffinity) {
         self.focus = cursor;
     }
 
@@ -74,24 +50,24 @@ impl TextSelection {
         self.focus = self.anchor;
     }
 
-    pub fn start(&self) -> TextCursor {
+    pub fn start(&self) -> TextPositionWithAffinity {
         if self.anchor.paragraph < self.focus.paragraph {
             self.anchor
         } else if self.anchor.paragraph > self.focus.paragraph {
             self.focus
-        } else if self.anchor.char_offset <= self.focus.char_offset {
+        } else if self.anchor.offset <= self.focus.offset {
             self.anchor
         } else {
             self.focus
         }
     }
 
-    pub fn end(&self) -> TextCursor {
+    pub fn end(&self) -> TextPositionWithAffinity {
         if self.anchor.paragraph > self.focus.paragraph {
             self.anchor
         } else if self.anchor.paragraph < self.focus.paragraph {
             self.focus
-        } else if self.anchor.char_offset >= self.focus.char_offset {
+        } else if self.anchor.offset >= self.focus.offset {
             self.anchor
         } else {
             self.focus
@@ -102,7 +78,7 @@ impl TextSelection {
 /// Events that the text editor can emit for frontend synchronization
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(u8)]
-pub enum EditorEvent {
+pub enum TextEditorEvent {
     None = 0,
     ContentChanged = 1,
     SelectionChanged = 2,
@@ -131,7 +107,7 @@ pub struct TextEditorState {
     pub active_shape_id: Option<Uuid>,
     pub cursor_visible: bool,
     pub last_blink_time: f64,
-    pending_events: Vec<EditorEvent>,
+    pending_events: Vec<TextEditorEvent>,
 }
 
 impl TextEditorState {
@@ -189,56 +165,44 @@ impl TextEditorState {
 
     pub fn select_all(&mut self, content: &TextContent) -> bool {
         self.is_pointer_selection_active = false;
-        self.set_caret_from_position(TextPositionWithAffinity::new(
+        self.set_caret_from_position(&TextPositionWithAffinity::empty());
-            PositionWithAffinity {
+        let num_paragraphs = content.paragraphs().len() - 1;
-                position: 0,
-                affinity: Affinity::Downstream,
-            },
-            0,
-            0,
-            0,
-            0,
-        ));
-        let num_paragraphs = (content.paragraphs().len() - 1) as i32;
         let Some(last_paragraph) = content.paragraphs().last() else {
             return false;
         };
-        let num_spans = (last_paragraph.children().len() - 1) as i32;
+        #[allow(dead_code)]
-        let Some(last_text_span) = last_paragraph.children().last() else {
+        let _num_spans = last_paragraph.children().len() - 1;
+        let Some(_last_text_span) = last_paragraph.children().last() else {
             return false;
         };
         let mut offset = 0;
         for span in last_paragraph.children() {
             offset += span.text.len();
         }
-        self.extend_selection_from_position(TextPositionWithAffinity::new(
+        self.extend_selection_from_position(&TextPositionWithAffinity::new(
             PositionWithAffinity {
                 position: offset as i32,
                 affinity: Affinity::Upstream,
             },
             num_paragraphs,
-            num_spans,
+            offset,
-            last_text_span.text.len() as i32,
-            offset as i32,
         ));
         self.reset_blink();
-        self.push_event(crate::state::EditorEvent::SelectionChanged);
+        self.push_event(crate::state::TextEditorEvent::SelectionChanged);
 
         true
     }
 
-    pub fn set_caret_from_position(&mut self, position: TextPositionWithAffinity) {
+    pub fn set_caret_from_position(&mut self, position: &TextPositionWithAffinity) {
-        let cursor = TextCursor::new(position.paragraph as usize, position.offset as usize);
+        self.selection.set_caret(*position);
-        self.selection.set_caret(cursor);
         self.reset_blink();
-        self.push_event(EditorEvent::SelectionChanged);
+        self.push_event(TextEditorEvent::SelectionChanged);
     }
 
-    pub fn extend_selection_from_position(&mut self, position: TextPositionWithAffinity) {
+    pub fn extend_selection_from_position(&mut self, position: &TextPositionWithAffinity) {
-        let cursor = TextCursor::new(position.paragraph as usize, position.offset as usize);
+        self.selection.extend_to(*position);
-        self.selection.extend_to(cursor);
         self.reset_blink();
-        self.push_event(EditorEvent::SelectionChanged);
+        self.push_event(TextEditorEvent::SelectionChanged);
     }
 
     pub fn update_blink(&mut self, timestamp_ms: f64) {
@@ -264,41 +228,17 @@ impl TextEditorState {
         self.last_blink_time = 0.0;
     }
 
-    pub fn push_event(&mut self, event: EditorEvent) {
+    pub fn push_event(&mut self, event: TextEditorEvent) {
         if self.pending_events.last() != Some(&event) {
             self.pending_events.push(event);
         }
     }
 
-    pub fn poll_event(&mut self) -> EditorEvent {
+    pub fn poll_event(&mut self) -> TextEditorEvent {
-        self.pending_events.pop().unwrap_or(EditorEvent::None)
+        self.pending_events.pop().unwrap_or(TextEditorEvent::None)
     }
 
     pub fn has_pending_events(&self) -> bool {
         !self.pending_events.is_empty()
     }
-
-    pub fn set_caret_position_from(
-        &mut self,
-        text_position_with_affinity: TextPositionWithAffinity,
-    ) {
-        self.set_caret_from_position(text_position_with_affinity);
-    }
-}
-
-/// TODO: Remove legacy code
-#[derive(Debug, PartialEq, Clone, Copy)]
-pub struct TextNodePosition {
-    pub paragraph: i32,
-    pub span: i32,
-}
-
-impl TextNodePosition {
-    pub fn new(paragraph: i32, span: i32) -> Self {
-        Self { paragraph, span }
-    }
-
-    pub fn is_invalid(&self) -> bool {
-        self.paragraph < 0 || self.span < 0
-    }
 }

render-wasm/src/wasm/text_editor.rs

@@ -1,7 +1,7 @@
 use crate::math::{Matrix, Point, Rect};
 use crate::mem;
-use crate::shapes::{Paragraph, Shape, TextContent, Type, VerticalAlign};
+use crate::shapes::{Paragraph, Shape, TextContent, TextPositionWithAffinity, Type, VerticalAlign};
-use crate::state::{TextCursor, TextSelection};
+use crate::state::TextSelection;
 use crate::utils::uuid_from_u32_quartet;
 use crate::utils::uuid_to_u32_quartet;
 use crate::{with_state, with_state_mut, STATE};
@@ -132,7 +132,7 @@ pub extern "C" fn text_editor_pointer_down(x: f32, y: f32) {
         if let Some(position) =
             text_content.get_caret_position_from_screen_coords(&point, &view_matrix, &shape_matrix)
         {
-            state.text_editor_state.set_caret_from_position(position);
+            state.text_editor_state.set_caret_from_position(&position);
         }
     });
 }
@@ -168,7 +168,7 @@ pub extern "C" fn text_editor_pointer_move(x: f32, y: f32) {
         {
             state
                 .text_editor_state
-                .extend_selection_from_position(position);
+                .extend_selection_from_position(&position);
         }
     });
 }
@@ -203,7 +203,7 @@ pub extern "C" fn text_editor_pointer_up(x: f32, y: f32) {
         {
             state
                 .text_editor_state
-                .extend_selection_from_position(position);
+                .extend_selection_from_position(&position);
         }
         state.text_editor_state.stop_pointer_selection();
     });
@@ -231,7 +231,7 @@ pub extern "C" fn text_editor_set_cursor_from_point(x: f32, y: f32) {
         if let Some(position) =
             text_content.get_caret_position_from_screen_coords(&point, &view_matrix, &shape_matrix)
         {
-            state.text_editor_state.set_caret_from_position(position);
+            state.text_editor_state.set_caret_from_position(&position);
         }
     });
 }
@@ -276,7 +276,8 @@ pub extern "C" fn text_editor_insert_text() {
         let cursor = state.text_editor_state.selection.focus;
 
         if let Some(new_offset) = insert_text_at_cursor(text_content, &cursor, &text) {
-            let new_cursor = TextCursor::new(cursor.paragraph, new_offset);
+            let new_cursor =
+                TextPositionWithAffinity::new_without_affinity(cursor.paragraph, new_offset);
             state.text_editor_state.selection.set_caret(new_cursor);
         }
 
@@ -286,10 +287,10 @@ pub extern "C" fn text_editor_insert_text() {
         state.text_editor_state.reset_blink();
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::ContentChanged);
+            .push_event(crate::state::TextEditorEvent::ContentChanged);
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::NeedsLayout);
+            .push_event(crate::state::TextEditorEvent::NeedsLayout);
 
         state.render_state.mark_touched(shape_id);
     });
@@ -336,10 +337,10 @@ pub extern "C" fn text_editor_delete_backward() {
         state.text_editor_state.reset_blink();
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::ContentChanged);
+            .push_event(crate::state::TextEditorEvent::ContentChanged);
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::NeedsLayout);
+            .push_event(crate::state::TextEditorEvent::NeedsLayout);
 
         state.render_state.mark_touched(shape_id);
     });
@@ -384,10 +385,10 @@ pub extern "C" fn text_editor_delete_forward() {
         state.text_editor_state.reset_blink();
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::ContentChanged);
+            .push_event(crate::state::TextEditorEvent::ContentChanged);
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::NeedsLayout);
+            .push_event(crate::state::TextEditorEvent::NeedsLayout);
 
         state.render_state.mark_touched(shape_id);
     });
@@ -423,7 +424,8 @@ pub extern "C" fn text_editor_insert_paragraph() {
         let cursor = state.text_editor_state.selection.focus;
 
         if split_paragraph_at_cursor(text_content, &cursor) {
-            let new_cursor = TextCursor::new(cursor.paragraph + 1, 0);
+            let new_cursor =
+                TextPositionWithAffinity::new_without_affinity(cursor.paragraph + 1, 0);
             state.text_editor_state.selection.set_caret(new_cursor);
         }
 
@@ -433,10 +435,10 @@ pub extern "C" fn text_editor_insert_paragraph() {
         state.text_editor_state.reset_blink();
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::ContentChanged);
+            .push_event(crate::state::TextEditorEvent::ContentChanged);
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::NeedsLayout);
+            .push_event(crate::state::TextEditorEvent::NeedsLayout);
 
         state.render_state.mark_touched(shape_id);
     });
@@ -494,7 +496,7 @@ pub extern "C" fn text_editor_move_cursor(direction: CursorDirection, extend_sel
         state.text_editor_state.reset_blink();
         state
             .text_editor_state
-            .push_event(crate::state::EditorEvent::SelectionChanged);
+            .push_event(crate::state::TextEditorEvent::SelectionChanged);
     });
 }
 
@@ -711,12 +713,12 @@ pub extern "C" fn text_editor_export_selection() -> *mut u8 {
                 .map(|span| span.text.chars().count())
                 .sum();
             let range_start = if para_idx == start.paragraph {
-                start.char_offset
+                start.offset
             } else {
                 0
             };
             let range_end = if para_idx == end.paragraph {
-                end.char_offset
+                end.offset
             } else {
                 para_char_count
             };
@@ -764,9 +766,9 @@ pub extern "C" fn text_editor_get_selection(buffer_ptr: *mut u32) -> u32 {
         let sel = &state.text_editor_state.selection;
         unsafe {
             *buffer_ptr = sel.anchor.paragraph as u32;
-            *buffer_ptr.add(1) = sel.anchor.char_offset as u32;
+            *buffer_ptr.add(1) = sel.anchor.offset as u32;
             *buffer_ptr.add(2) = sel.focus.paragraph as u32;
-            *buffer_ptr.add(3) = sel.focus.char_offset as u32;
+            *buffer_ptr.add(3) = sel.focus.offset as u32;
         }
         1
     })
@@ -776,7 +778,11 @@ pub extern "C" fn text_editor_get_selection(buffer_ptr: *mut u32) -> u32 {
 // HELPERS: Cursor & Selection
 // ============================================================================
 
-fn get_cursor_rect(text_content: &TextContent, cursor: &TextCursor, shape: &Shape) -> Option<Rect> {
+fn get_cursor_rect(
+    text_content: &TextContent,
+    cursor: &TextPositionWithAffinity,
+    shape: &Shape,
+) -> Option<Rect> {
     let paragraphs = text_content.paragraphs();
     if cursor.paragraph >= paragraphs.len() {
         return None;
@@ -794,7 +800,7 @@ fn get_cursor_rect(text_content: &TextContent, cursor: &TextCursor, shape: &Shap
     let mut y_offset = valign_offset;
     for (idx, laid_out_para) in layout_paragraphs.iter().enumerate() {
         if idx == cursor.paragraph {
-            let char_pos = cursor.char_offset;
+            let char_pos = cursor.offset;
 
             use skia_safe::textlayout::{RectHeightStyle, RectWidthStyle};
             let rects = laid_out_para.get_rects_for_range(
@@ -869,13 +875,13 @@ fn get_selection_rects(
             .map(|span| span.text.chars().count())
             .sum();
         let range_start = if para_idx == start.paragraph {
-            start.char_offset
+            start.offset
         } else {
             0
         };
 
         let range_end = if para_idx == end.paragraph {
-            end.char_offset
+            end.offset
         } else {
             para_char_count
         };
@@ -914,40 +920,49 @@ fn paragraph_char_count(para: &Paragraph) -> usize {
 }
 
 /// Clamp a cursor position to valid bounds within the text content.
-fn clamp_cursor(cursor: TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
+fn clamp_cursor(
+    position: TextPositionWithAffinity,
+    paragraphs: &[Paragraph],
+) -> TextPositionWithAffinity {
     if paragraphs.is_empty() {
-        return TextCursor::new(0, 0);
+        return TextPositionWithAffinity::new_without_affinity(0, 0);
     }
 
-    let para_idx = cursor.paragraph.min(paragraphs.len() - 1);
+    let para_idx = position.paragraph.min(paragraphs.len() - 1);
     let para_len = paragraph_char_count(&paragraphs[para_idx]);
-    let char_offset = cursor.char_offset.min(para_len);
+    let char_offset = position.offset.min(para_len);
 
-    TextCursor::new(para_idx, char_offset)
+    TextPositionWithAffinity::new_without_affinity(para_idx, char_offset)
 }
 
 /// Move cursor left by one character.
-fn move_cursor_backward(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
+fn move_cursor_backward(
-    if cursor.char_offset > 0 {
+    cursor: &TextPositionWithAffinity,
-        TextCursor::new(cursor.paragraph, cursor.char_offset - 1)
+    paragraphs: &[Paragraph],
+) -> TextPositionWithAffinity {
+    if cursor.offset > 0 {
+        TextPositionWithAffinity::new_without_affinity(cursor.paragraph, cursor.offset - 1)
     } else if cursor.paragraph > 0 {
         let prev_para = cursor.paragraph - 1;
         let char_count = paragraph_char_count(&paragraphs[prev_para]);
-        TextCursor::new(prev_para, char_count)
+        TextPositionWithAffinity::new_without_affinity(prev_para, char_count)
     } else {
         *cursor
     }
 }
 
 /// Move cursor right by one character.
-fn move_cursor_forward(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
+fn move_cursor_forward(
+    cursor: &TextPositionWithAffinity,
+    paragraphs: &[Paragraph],
+) -> TextPositionWithAffinity {
     let para = &paragraphs[cursor.paragraph];
     let char_count = paragraph_char_count(para);
 
-    if cursor.char_offset < char_count {
+    if cursor.offset < char_count {
-        TextCursor::new(cursor.paragraph, cursor.char_offset + 1)
+        TextPositionWithAffinity::new_without_affinity(cursor.paragraph, cursor.offset + 1)
     } else if cursor.paragraph < paragraphs.len() - 1 {
-        TextCursor::new(cursor.paragraph + 1, 0)
+        TextPositionWithAffinity::new_without_affinity(cursor.paragraph + 1, 0)
     } else {
         *cursor
     }
@@ -955,52 +970,58 @@ fn move_cursor_forward(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCur
 
 /// Move cursor up by one line.
 fn move_cursor_up(
-    cursor: &TextCursor,
+    cursor: &TextPositionWithAffinity,
     paragraphs: &[Paragraph],
     _text_content: &TextContent,
     _shape: &Shape,
-) -> TextCursor {
+) -> TextPositionWithAffinity {
     // TODO: Implement proper line-based navigation using line metrics
     if cursor.paragraph > 0 {
         let prev_para = cursor.paragraph - 1;
         let char_count = paragraph_char_count(&paragraphs[prev_para]);
-        let new_offset = cursor.char_offset.min(char_count);
+        let new_offset = cursor.offset.min(char_count);
-        TextCursor::new(prev_para, new_offset)
+        TextPositionWithAffinity::new_without_affinity(prev_para, new_offset)
     } else {
-        TextCursor::new(cursor.paragraph, 0)
+        TextPositionWithAffinity::new_without_affinity(cursor.paragraph, 0)
     }
 }
 
 /// Move cursor down by one line.
 fn move_cursor_down(
-    cursor: &TextCursor,
+    cursor: &TextPositionWithAffinity,
     paragraphs: &[Paragraph],
     _text_content: &TextContent,
     _shape: &Shape,
-) -> TextCursor {
+) -> TextPositionWithAffinity {
     // TODO: Implement proper line-based navigation using line metrics
     if cursor.paragraph < paragraphs.len() - 1 {
         let next_para = cursor.paragraph + 1;
         let char_count = paragraph_char_count(&paragraphs[next_para]);
-        let new_offset = cursor.char_offset.min(char_count);
+        let new_offset = cursor.offset.min(char_count);
-        TextCursor::new(next_para, new_offset)
+        TextPositionWithAffinity::new_without_affinity(next_para, new_offset)
     } else {
         let char_count = paragraph_char_count(&paragraphs[cursor.paragraph]);
-        TextCursor::new(cursor.paragraph, char_count)
+        TextPositionWithAffinity::new_without_affinity(cursor.paragraph, char_count)
     }
 }
 
 /// Move cursor to start of current line.
-fn move_cursor_line_start(cursor: &TextCursor, _paragraphs: &[Paragraph]) -> TextCursor {
+fn move_cursor_line_start(
+    cursor: &TextPositionWithAffinity,
+    _paragraphs: &[Paragraph],
+) -> TextPositionWithAffinity {
     // TODO: Implement proper line-start using line metrics
-    TextCursor::new(cursor.paragraph, 0)
+    TextPositionWithAffinity::new_without_affinity(cursor.paragraph, 0)
 }
 
 /// Move cursor to end of current line.
-fn move_cursor_line_end(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
+fn move_cursor_line_end(
+    cursor: &TextPositionWithAffinity,
+    paragraphs: &[Paragraph],
+) -> TextPositionWithAffinity {
     // TODO: Implement proper line-end using line metrics
     let char_count = paragraph_char_count(&paragraphs[cursor.paragraph]);
-    TextCursor::new(cursor.paragraph, char_count)
+    TextPositionWithAffinity::new_without_affinity(cursor.paragraph, char_count)
 }
 
 // ============================================================================
@@ -1028,7 +1049,7 @@ fn find_span_at_offset(para: &Paragraph, char_offset: usize) -> Option<(usize, u
 /// Insert text at a cursor position. Returns the new character offset after insertion.
 fn insert_text_at_cursor(
     text_content: &mut TextContent,
-    cursor: &TextCursor,
+    cursor: &TextPositionWithAffinity,
     text: &str,
 ) -> Option<usize> {
     let paragraphs = text_content.paragraphs_mut();
@@ -1048,7 +1069,7 @@ fn insert_text_at_cursor(
         return Some(text.chars().count());
     }
 
-    let (span_idx, offset_in_span) = find_span_at_offset(para, cursor.char_offset)?;
+    let (span_idx, offset_in_span) = find_span_at_offset(para, cursor.offset)?;
 
     let children = para.children_mut();
     let span = &mut children[span_idx];
@@ -1063,7 +1084,7 @@ fn insert_text_at_cursor(
     new_text.insert_str(byte_offset, text);
     span.set_text(new_text);
 
-    Some(cursor.char_offset + text.chars().count())
+    Some(cursor.offset + text.chars().count())
 }
 
 /// Delete a range of text specified by a selection.
@@ -1077,20 +1098,16 @@ fn delete_selection_range(text_content: &mut TextContent, selection: &TextSelect
     }
 
     if start.paragraph == end.paragraph {
-        delete_range_in_paragraph(
+        delete_range_in_paragraph(&mut paragraphs[start.paragraph], start.offset, end.offset);
-            &mut paragraphs[start.paragraph],
-            start.char_offset,
-            end.char_offset,
-        );
     } else {
         let start_para_len = paragraph_char_count(&paragraphs[start.paragraph]);
         delete_range_in_paragraph(
             &mut paragraphs[start.paragraph],
-            start.char_offset,
+            start.offset,
             start_para_len,
         );
 
-        delete_range_in_paragraph(&mut paragraphs[end.paragraph], 0, end.char_offset);
+        delete_range_in_paragraph(&mut paragraphs[end.paragraph], 0, end.offset);
 
         if end.paragraph < paragraphs.len() {
             let end_para_children: Vec<_> =
@@ -1189,13 +1206,19 @@ fn delete_range_in_paragraph(para: &mut Paragraph, start_offset: usize, end_offs
 }
 
 /// Delete the character before the cursor. Returns the new cursor position.
-fn delete_char_before(text_content: &mut TextContent, cursor: &TextCursor) -> Option<TextCursor> {
+fn delete_char_before(
-    if cursor.char_offset > 0 {
+    text_content: &mut TextContent,
+    cursor: &TextPositionWithAffinity,
+) -> Option<TextPositionWithAffinity> {
+    if cursor.offset > 0 {
         let paragraphs = text_content.paragraphs_mut();
         let para = &mut paragraphs[cursor.paragraph];
-        let delete_pos = cursor.char_offset - 1;
+        let delete_pos = cursor.offset - 1;
-        delete_range_in_paragraph(para, delete_pos, cursor.char_offset);
+        delete_range_in_paragraph(para, delete_pos, cursor.offset);
-        Some(TextCursor::new(cursor.paragraph, delete_pos))
+        Some(TextPositionWithAffinity::new_without_affinity(
+            cursor.paragraph,
+            delete_pos,
+        ))
     } else if cursor.paragraph > 0 {
         let prev_para_idx = cursor.paragraph - 1;
         let paragraphs = text_content.paragraphs_mut();
@@ -1211,14 +1234,17 @@ fn delete_char_before(text_content: &mut TextContent, cursor: &TextCursor) -> Op
 
         paragraphs.remove(cursor.paragraph);
 
-        Some(TextCursor::new(prev_para_idx, prev_para_len))
+        Some(TextPositionWithAffinity::new_without_affinity(
+            prev_para_idx,
+            prev_para_len,
+        ))
     } else {
         None
     }
 }
 
 /// Delete the character after the cursor.
-fn delete_char_after(text_content: &mut TextContent, cursor: &TextCursor) {
+fn delete_char_after(text_content: &mut TextContent, cursor: &TextPositionWithAffinity) {
     let paragraphs = text_content.paragraphs_mut();
     if cursor.paragraph >= paragraphs.len() {
         return;
@@ -1226,9 +1252,9 @@ fn delete_char_after(text_content: &mut TextContent, cursor: &TextCursor) {
 
     let para_len = paragraph_char_count(&paragraphs[cursor.paragraph]);
 
-    if cursor.char_offset < para_len {
+    if cursor.offset < para_len {
         let para = &mut paragraphs[cursor.paragraph];
-        delete_range_in_paragraph(para, cursor.char_offset, cursor.char_offset + 1);
+        delete_range_in_paragraph(para, cursor.offset, cursor.offset + 1);
     } else if cursor.paragraph < paragraphs.len() - 1 {
         let next_para_idx = cursor.paragraph + 1;
         let next_children: Vec<_> = paragraphs[next_para_idx].children_mut().drain(..).collect();
@@ -1241,7 +1267,10 @@ fn delete_char_after(text_content: &mut TextContent, cursor: &TextCursor) {
 }
 
 /// Split a paragraph at the cursor position. Returns true if split was successful.
-fn split_paragraph_at_cursor(text_content: &mut TextContent, cursor: &TextCursor) -> bool {
+fn split_paragraph_at_cursor(
+    text_content: &mut TextContent,
+    cursor: &TextPositionWithAffinity,
+) -> bool {
     let paragraphs = text_content.paragraphs_mut();
     if cursor.paragraph >= paragraphs.len() {
         return false;
@@ -1249,7 +1278,7 @@ fn split_paragraph_at_cursor(text_content: &mut TextContent, cursor: &TextCursor
 
     let para = &paragraphs[cursor.paragraph];
 
-    let Some((span_idx, offset_in_span)) = find_span_at_offset(para, cursor.char_offset) else {
+    let Some((span_idx, offset_in_span)) = find_span_at_offset(para, cursor.offset) else {
         return false;
     };