Files
penpot/render-wasm/src/wasm/text_editor.rs
2026-02-12 09:34:20 +01:00

1330 lines
42 KiB
Rust

use crate::math::{Matrix, Point, Rect};
use crate::mem;
use crate::shapes::{Paragraph, Shape, TextContent, Type, VerticalAlign};
use crate::state::{TextCursor, TextSelection};
use crate::utils::uuid_from_u32_quartet;
use crate::utils::uuid_to_u32_quartet;
use crate::{with_state, with_state_mut, STATE};
// ============================================================================
// STATE MANAGEMENT
// ============================================================================
#[no_mangle]
pub extern "C" fn text_editor_start(a: u32, b: u32, c: u32, d: u32) -> bool {
with_state_mut!(state, {
let shape_id = uuid_from_u32_quartet(a, b, c, d);
let Some(shape) = state.shapes.get(&shape_id) else {
return false;
};
if !matches!(shape.shape_type, Type::Text(_)) {
return false;
}
state.text_editor_state.start(shape_id);
true
})
}
#[no_mangle]
pub extern "C" fn text_editor_stop() {
with_state_mut!(state, {
state.text_editor_state.stop();
});
}
#[no_mangle]
pub extern "C" fn text_editor_is_active() -> bool {
with_state!(state, { state.text_editor_state.is_active })
}
#[no_mangle]
pub extern "C" fn text_editor_get_active_shape_id(buffer_ptr: *mut u32) {
with_state!(state, {
if let Some(shape_id) = state.text_editor_state.active_shape_id {
let (a, b, c, d) = uuid_to_u32_quartet(&shape_id);
unsafe {
*buffer_ptr = a;
*buffer_ptr.add(1) = b;
*buffer_ptr.add(2) = c;
*buffer_ptr.add(3) = d;
}
}
})
}
#[no_mangle]
pub extern "C" fn text_editor_select_all() {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let Some(shape) = state.shapes.get(&shape_id) else {
return;
};
let Type::Text(text_content) = &shape.shape_type else {
return;
};
let paragraphs = text_content.paragraphs();
if paragraphs.is_empty() {
return;
}
let last_para_idx = paragraphs.len() - 1;
let last_para = &paragraphs[last_para_idx];
let total_chars: usize = last_para
.children()
.iter()
.map(|span| span.text.chars().count())
.sum();
use crate::state::TextCursor;
state.text_editor_state.selection.anchor = TextCursor::new(0, 0);
state.text_editor_state.selection.focus = TextCursor::new(last_para_idx, total_chars);
state.text_editor_state.reset_blink();
state
.text_editor_state
.push_event(crate::state::EditorEvent::SelectionChanged);
});
}
#[no_mangle]
pub extern "C" fn text_editor_poll_event() -> u8 {
with_state_mut!(state, { state.text_editor_state.poll_event() as u8 })
}
// ============================================================================
// SELECTION MANAGEMENT
// ============================================================================
#[no_mangle]
pub extern "C" fn text_editor_set_cursor_from_point(x: f32, y: f32) {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let (shape_matrix, view_matrix, selrect, vertical_align) = {
let Some(shape) = state.shapes.get(&shape_id) else {
return;
};
(
shape.get_concatenated_matrix(&state.shapes),
state.render_state.viewbox.get_matrix(),
shape.selrect(),
shape.vertical_align(),
)
};
let Some(inv_view_matrix) = view_matrix.invert() else {
return;
};
let Some(inv_shape_matrix) = shape_matrix.invert() else {
return;
};
let mut matrix = Matrix::new_identity();
matrix.post_concat(&inv_view_matrix);
matrix.post_concat(&inv_shape_matrix);
let mapped_point = matrix.map_point(Point::new(x, y));
let Some(shape) = state.shapes.get_mut(&shape_id) else {
return;
};
let Type::Text(text_content) = &mut shape.shape_type else {
return;
};
if text_content.layout.paragraphs.is_empty() && !text_content.paragraphs().is_empty() {
let bounds = text_content.bounds;
text_content.update_layout(bounds);
}
// Calculate vertical alignment offset (same as in render/text_editor.rs)
let layout_paragraphs: Vec<_> = text_content.layout.paragraphs.iter().flatten().collect();
let total_height: f32 = layout_paragraphs.iter().map(|p| p.height()).sum();
let vertical_offset = match vertical_align {
crate::shapes::VerticalAlign::Center => (selrect.height() - total_height) / 2.0,
crate::shapes::VerticalAlign::Bottom => selrect.height() - total_height,
_ => 0.0,
};
// Adjust point: subtract selrect offset and vertical alignment
// The text layout expects coordinates where (0, 0) is the top-left of the text content
let adjusted_point = Point::new(
mapped_point.x - selrect.x(),
mapped_point.y - selrect.y() - vertical_offset,
);
if let Some(position) = text_content.get_caret_position_at(&adjusted_point) {
state.text_editor_state.set_caret_from_position(position);
}
});
}
#[no_mangle]
pub extern "C" fn text_editor_extend_selection_to_point(x: f32, y: f32) {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let (shape_matrix, view_matrix, selrect, vertical_align) = {
let Some(shape) = state.shapes.get(&shape_id) else {
return;
};
(
shape.get_concatenated_matrix(&state.shapes),
state.render_state.viewbox.get_matrix(),
shape.selrect(),
shape.vertical_align(),
)
};
let Some(inv_view_matrix) = view_matrix.invert() else {
return;
};
let Some(inv_shape_matrix) = shape_matrix.invert() else {
return;
};
let mut matrix = Matrix::new_identity();
matrix.post_concat(&inv_view_matrix);
matrix.post_concat(&inv_shape_matrix);
let mapped_point = matrix.map_point(Point::new(x, y));
let Some(shape) = state.shapes.get_mut(&shape_id) else {
return;
};
let Type::Text(text_content) = &mut shape.shape_type else {
return;
};
if text_content.layout.paragraphs.is_empty() && !text_content.paragraphs().is_empty() {
let bounds = text_content.bounds;
text_content.update_layout(bounds);
}
// Calculate vertical alignment offset (same as in render/text_editor.rs)
let layout_paragraphs: Vec<_> = text_content.layout.paragraphs.iter().flatten().collect();
let total_height: f32 = layout_paragraphs.iter().map(|p| p.height()).sum();
let vertical_offset = match vertical_align {
crate::shapes::VerticalAlign::Center => (selrect.height() - total_height) / 2.0,
crate::shapes::VerticalAlign::Bottom => selrect.height() - total_height,
_ => 0.0,
};
// Adjust point: subtract selrect offset and vertical alignment
let adjusted_point = Point::new(
mapped_point.x - selrect.x(),
mapped_point.y - selrect.y() - vertical_offset,
);
if let Some(position) = text_content.get_caret_position_at(&adjusted_point) {
state
.text_editor_state
.extend_selection_from_position(position);
}
});
}
// ============================================================================
// TEXT OPERATIONS
// ============================================================================
#[no_mangle]
pub extern "C" fn text_editor_insert_text() {
let bytes = crate::mem::bytes();
let text = match String::from_utf8(bytes) {
Ok(s) => s,
Err(_) => return,
};
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let Some(shape) = state.shapes.get_mut(&shape_id) else {
return;
};
let Type::Text(text_content) = &mut shape.shape_type else {
return;
};
let selection = state.text_editor_state.selection;
if selection.is_selection() {
delete_selection_range(text_content, &selection);
let start = selection.start();
state.text_editor_state.selection.set_caret(start);
}
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);
state.text_editor_state.selection.set_caret(new_cursor);
}
text_content.layout.paragraphs.clear();
text_content.layout.paragraph_builders.clear();
state.text_editor_state.reset_blink();
state
.text_editor_state
.push_event(crate::state::EditorEvent::ContentChanged);
state
.text_editor_state
.push_event(crate::state::EditorEvent::NeedsLayout);
state.render_state.mark_touched(shape_id);
});
crate::mem::free_bytes();
}
#[no_mangle]
pub extern "C" fn text_editor_delete_backward() {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let Some(shape) = state.shapes.get_mut(&shape_id) else {
return;
};
let Type::Text(text_content) = &mut shape.shape_type else {
return;
};
let selection = state.text_editor_state.selection;
if selection.is_selection() {
delete_selection_range(text_content, &selection);
let start = selection.start();
let clamped = clamp_cursor(start, text_content.paragraphs());
state.text_editor_state.selection.set_caret(clamped);
} else {
let cursor = selection.focus;
if let Some(new_cursor) = delete_char_before(text_content, &cursor) {
state.text_editor_state.selection.set_caret(new_cursor);
}
}
text_content.layout.paragraphs.clear();
text_content.layout.paragraph_builders.clear();
state.text_editor_state.reset_blink();
state
.text_editor_state
.push_event(crate::state::EditorEvent::ContentChanged);
state
.text_editor_state
.push_event(crate::state::EditorEvent::NeedsLayout);
state.render_state.mark_touched(shape_id);
});
}
#[no_mangle]
pub extern "C" fn text_editor_delete_forward() {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let Some(shape) = state.shapes.get_mut(&shape_id) else {
return;
};
let Type::Text(text_content) = &mut shape.shape_type else {
return;
};
let selection = state.text_editor_state.selection;
if selection.is_selection() {
delete_selection_range(text_content, &selection);
let start = selection.start();
let clamped = clamp_cursor(start, text_content.paragraphs());
state.text_editor_state.selection.set_caret(clamped);
} else {
let cursor = selection.focus;
delete_char_after(text_content, &cursor);
let clamped = clamp_cursor(cursor, text_content.paragraphs());
state.text_editor_state.selection.set_caret(clamped);
}
text_content.layout.paragraphs.clear();
text_content.layout.paragraph_builders.clear();
state.text_editor_state.reset_blink();
state
.text_editor_state
.push_event(crate::state::EditorEvent::ContentChanged);
state
.text_editor_state
.push_event(crate::state::EditorEvent::NeedsLayout);
state.render_state.mark_touched(shape_id);
});
}
#[no_mangle]
pub extern "C" fn text_editor_insert_paragraph() {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let Some(shape) = state.shapes.get_mut(&shape_id) else {
return;
};
let Type::Text(text_content) = &mut shape.shape_type else {
return;
};
let selection = state.text_editor_state.selection;
if selection.is_selection() {
delete_selection_range(text_content, &selection);
let start = selection.start();
state.text_editor_state.selection.set_caret(start);
}
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);
state.text_editor_state.selection.set_caret(new_cursor);
}
text_content.layout.paragraphs.clear();
text_content.layout.paragraph_builders.clear();
state.text_editor_state.reset_blink();
state
.text_editor_state
.push_event(crate::state::EditorEvent::ContentChanged);
state
.text_editor_state
.push_event(crate::state::EditorEvent::NeedsLayout);
state.render_state.mark_touched(shape_id);
});
}
// ============================================================================
// NAVIGATION
// ============================================================================
#[no_mangle]
pub extern "C" fn text_editor_move_cursor(direction: u8, extend_selection: bool) {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
let Some(shape) = state.shapes.get(&shape_id) else {
return;
};
let Type::Text(text_content) = &shape.shape_type else {
return;
};
let paragraphs = text_content.paragraphs();
if paragraphs.is_empty() {
return;
}
let current = state.text_editor_state.selection.focus;
let new_cursor = match direction {
0 => move_cursor_left(&current, paragraphs),
1 => move_cursor_right(&current, paragraphs),
2 => move_cursor_up(&current, paragraphs, text_content, shape),
3 => move_cursor_down(&current, paragraphs, text_content, shape),
4 => move_cursor_line_start(&current, paragraphs),
5 => move_cursor_line_end(&current, paragraphs),
_ => current,
};
if extend_selection {
state.text_editor_state.selection.extend_to(new_cursor);
} else {
state.text_editor_state.selection.set_caret(new_cursor);
}
state.text_editor_state.reset_blink();
if direction == 0 || direction == 1 || direction == 4 || direction == 5 {
state.text_editor_state.clear_x_affinity();
}
state
.text_editor_state
.push_event(crate::state::EditorEvent::SelectionChanged);
});
}
// ============================================================================
// RENDERING & EXPORT
// ============================================================================
#[no_mangle]
pub extern "C" fn text_editor_get_cursor_rect() -> *mut u8 {
with_state_mut!(state, {
if !state.text_editor_state.is_active || !state.text_editor_state.cursor_visible {
return std::ptr::null_mut();
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return std::ptr::null_mut();
};
let Some(shape) = state.shapes.get(&shape_id) else {
return std::ptr::null_mut();
};
let Type::Text(text_content) = &shape.shape_type else {
return std::ptr::null_mut();
};
let cursor = &state.text_editor_state.selection.focus;
if let Some(rect) = get_cursor_rect(text_content, cursor, shape) {
let mut bytes = vec![0u8; 16];
bytes[0..4].copy_from_slice(&rect.left().to_le_bytes());
bytes[4..8].copy_from_slice(&rect.top().to_le_bytes());
bytes[8..12].copy_from_slice(&rect.width().to_le_bytes());
bytes[12..16].copy_from_slice(&rect.height().to_le_bytes());
return mem::write_bytes(bytes);
}
std::ptr::null_mut()
})
}
#[no_mangle]
pub extern "C" fn text_editor_get_selection_rects() -> *mut u8 {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return std::ptr::null_mut();
}
if state.text_editor_state.selection.is_collapsed() {
return std::ptr::null_mut();
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return std::ptr::null_mut();
};
let Some(shape) = state.shapes.get(&shape_id) else {
return std::ptr::null_mut();
};
let Type::Text(text_content) = &shape.shape_type else {
return std::ptr::null_mut();
};
let selection = &state.text_editor_state.selection;
let rects = get_selection_rects(text_content, selection, shape);
if rects.is_empty() {
return std::ptr::null_mut();
}
let mut bytes = Vec::with_capacity(4 + rects.len() * 16);
bytes.extend_from_slice(&(rects.len() as u32).to_le_bytes());
for rect in rects {
bytes.extend_from_slice(&rect.left().to_le_bytes());
bytes.extend_from_slice(&rect.top().to_le_bytes());
bytes.extend_from_slice(&rect.width().to_le_bytes());
bytes.extend_from_slice(&rect.height().to_le_bytes());
}
mem::write_bytes(bytes)
})
}
#[no_mangle]
pub extern "C" fn text_editor_update_blink(timestamp_ms: f64) {
with_state_mut!(state, {
state.text_editor_state.update_blink(timestamp_ms);
});
}
#[no_mangle]
pub extern "C" fn text_editor_render_overlay() {
with_state_mut!(state, {
if !state.text_editor_state.is_active {
return;
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return;
};
if let Some(shape) = state.shapes.get(&shape_id) {
if let Type::Text(text_content) = &shape.shape_type {
if text_content.needs_update_layout() {
let selrect = shape.selrect();
if let Some(shape) = state.shapes.get_mut(&shape_id) {
if let Type::Text(text_content) = &mut shape.shape_type {
text_content.update_layout(selrect);
}
}
}
}
}
let Some(shape) = state.shapes.get(&shape_id) else {
return;
};
let transform = shape.get_concatenated_matrix(&state.shapes);
use crate::render::text_editor as te_render;
use crate::render::SurfaceId;
let canvas = state.render_state.surfaces.canvas(SurfaceId::Target);
canvas.save();
let viewbox = state.render_state.viewbox;
let zoom = viewbox.zoom * state.render_state.options.dpr();
canvas.scale((zoom, zoom));
canvas.translate((-viewbox.area.left, -viewbox.area.top));
te_render::render_overlay(canvas, &state.text_editor_state, shape, &transform);
canvas.restore();
state.render_state.flush_and_submit();
});
}
#[no_mangle]
pub extern "C" fn text_editor_export_content() -> *mut u8 {
with_state!(state, {
if !state.text_editor_state.is_active {
return std::ptr::null_mut();
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return std::ptr::null_mut();
};
let Some(shape) = state.shapes.get(&shape_id) else {
return std::ptr::null_mut();
};
let Type::Text(text_content) = &shape.shape_type else {
return std::ptr::null_mut();
};
let mut json_parts: Vec<String> = Vec::new();
for para in text_content.paragraphs() {
let mut span_parts: Vec<String> = Vec::new();
for span in para.children() {
let escaped_text = span
.text
.replace('\\', "\\\\")
.replace('"', "\\\"")
.replace('\n', "\\n")
.replace('\r', "\\r")
.replace('\t', "\\t");
span_parts.push(format!("\"{}\"", escaped_text));
}
json_parts.push(format!("[{}]", span_parts.join(",")));
}
let json = format!("[{}]", json_parts.join(","));
let mut bytes = json.into_bytes();
bytes.push(0);
crate::mem::write_bytes(bytes)
})
}
#[no_mangle]
pub extern "C" fn text_editor_export_selection() -> *mut u8 {
use std::ptr;
with_state!(state, {
if !state.text_editor_state.is_active {
return ptr::null_mut();
}
let Some(shape_id) = state.text_editor_state.active_shape_id else {
return ptr::null_mut();
};
let Some(shape) = state.shapes.get(&shape_id) else {
return ptr::null_mut();
};
let Type::Text(text_content) = &shape.shape_type else {
return ptr::null_mut();
};
let selection = &state.text_editor_state.selection;
let start = selection.start();
let end = selection.end();
let paragraphs = text_content.paragraphs();
let mut result = String::new();
let end_paragraph = end.paragraph.min(paragraphs.len().saturating_sub(1)) + 1;
for (para_idx, _) in paragraphs
.iter()
.enumerate()
.take(end_paragraph)
.skip(start.paragraph)
{
let para = &paragraphs[para_idx];
let mut para_text = String::new();
let para_char_count: usize = para
.children()
.iter()
.map(|span| span.text.chars().count())
.sum();
let range_start = if para_idx == start.paragraph {
start.char_offset
} else {
0
};
let range_end = if para_idx == end.paragraph {
end.char_offset
} else {
para_char_count
};
if range_start < range_end {
let mut char_pos = 0;
for span in para.children() {
let span_len = span.text.chars().count();
let span_start = char_pos;
let span_end = char_pos + span_len;
let sel_start = range_start.max(span_start);
let sel_end = range_end.min(span_end);
if sel_start < sel_end {
let rel_start = sel_start - span_start;
let rel_end = sel_end - span_start;
let text: String = span
.text
.chars()
.skip(rel_start)
.take(rel_end - rel_start)
.collect();
para_text.push_str(&text);
}
char_pos += span_len;
}
}
if !para_text.is_empty() {
if !result.is_empty() {
result.push('\n');
}
result.push_str(&para_text);
}
}
let mut bytes = result.into_bytes();
bytes.push(0);
crate::mem::write_bytes(bytes)
})
}
#[no_mangle]
pub extern "C" fn text_editor_get_selection(buffer_ptr: *mut u32) -> u32 {
with_state!(state, {
if !state.text_editor_state.is_active {
return 0;
}
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(2) = sel.focus.paragraph as u32;
*buffer_ptr.add(3) = sel.focus.char_offset as u32;
}
1
})
}
// ============================================================================
// HELPERS: Cursor & Selection
// ============================================================================
fn get_cursor_rect(text_content: &TextContent, cursor: &TextCursor, shape: &Shape) -> Option<Rect> {
let paragraphs = text_content.paragraphs();
if cursor.paragraph >= paragraphs.len() {
return None;
}
let layout_paragraphs: Vec<_> = text_content.layout.paragraphs.iter().flatten().collect();
let total_height: f32 = layout_paragraphs.iter().map(|p| p.height()).sum();
let valign_offset = match shape.vertical_align() {
VerticalAlign::Center => (shape.selrect().height() - total_height) / 2.0,
VerticalAlign::Bottom => shape.selrect().height() - total_height,
_ => 0.0,
};
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;
use skia_safe::textlayout::{RectHeightStyle, RectWidthStyle};
let rects = laid_out_para.get_rects_for_range(
char_pos..char_pos,
RectHeightStyle::Tight,
RectWidthStyle::Tight,
);
let (x, height) = if !rects.is_empty() {
(rects[0].rect.left(), rects[0].rect.height())
} else {
let pos = laid_out_para.get_glyph_position_at_coordinate((0.0, 0.0));
let height = laid_out_para.height();
(pos.position as f32, height)
};
let cursor_width = 2.0;
let selrect = shape.selrect();
let base_x = selrect.x();
let base_y = selrect.y() + y_offset;
return Some(Rect::from_xywh(base_x + x, base_y, cursor_width, height));
}
y_offset += laid_out_para.height();
}
None
}
/// Get selection rectangles for a given selection.
fn get_selection_rects(
text_content: &TextContent,
selection: &TextSelection,
shape: &Shape,
) -> Vec<Rect> {
let mut rects = Vec::new();
let start = selection.start();
let end = selection.end();
let paragraphs = text_content.paragraphs();
let layout_paragraphs: Vec<_> = text_content.layout.paragraphs.iter().flatten().collect();
let selrect = shape.selrect();
let total_height: f32 = layout_paragraphs.iter().map(|p| p.height()).sum();
let valign_offset = match shape.vertical_align() {
VerticalAlign::Center => (selrect.height() - total_height) / 2.0,
VerticalAlign::Bottom => selrect.height() - total_height,
_ => 0.0,
};
let mut y_offset = valign_offset;
for (para_idx, laid_out_para) in layout_paragraphs.iter().enumerate() {
let para_height = laid_out_para.height();
if para_idx < start.paragraph || para_idx > end.paragraph {
y_offset += para_height;
continue;
}
if para_idx >= paragraphs.len() {
y_offset += para_height;
continue;
}
let para = &paragraphs[para_idx];
let para_char_count: usize = para
.children()
.iter()
.map(|span| span.text.chars().count())
.sum();
let range_start = if para_idx == start.paragraph {
start.char_offset
} else {
0
};
let range_end = if para_idx == end.paragraph {
end.char_offset
} else {
para_char_count
};
if range_start < range_end {
use skia_safe::textlayout::{RectHeightStyle, RectWidthStyle};
let text_boxes = laid_out_para.get_rects_for_range(
range_start..range_end,
RectHeightStyle::Tight,
RectWidthStyle::Tight,
);
for text_box in text_boxes {
let r = text_box.rect;
rects.push(Rect::from_xywh(
selrect.x() + r.left(),
selrect.y() + y_offset + r.top(),
r.width(),
r.height(),
));
}
}
y_offset += para_height;
}
rects
}
/// Get total character count in a paragraph.
fn paragraph_char_count(para: &Paragraph) -> usize {
para.children()
.iter()
.map(|span| span.text.chars().count())
.sum()
}
/// Clamp a cursor position to valid bounds within the text content.
fn clamp_cursor(cursor: TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
if paragraphs.is_empty() {
return TextCursor::new(0, 0);
}
let para_idx = cursor.paragraph.min(paragraphs.len() - 1);
let para_len = paragraph_char_count(&paragraphs[para_idx]);
let char_offset = cursor.char_offset.min(para_len);
TextCursor::new(para_idx, char_offset)
}
/// Move cursor left by one character.
fn move_cursor_left(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
if cursor.char_offset > 0 {
TextCursor::new(cursor.paragraph, cursor.char_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)
} else {
*cursor
}
}
/// Move cursor right by one character.
fn move_cursor_right(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
let para = &paragraphs[cursor.paragraph];
let char_count = paragraph_char_count(para);
if cursor.char_offset < char_count {
TextCursor::new(cursor.paragraph, cursor.char_offset + 1)
} else if cursor.paragraph < paragraphs.len() - 1 {
TextCursor::new(cursor.paragraph + 1, 0)
} else {
*cursor
}
}
/// Move cursor up by one line.
fn move_cursor_up(
cursor: &TextCursor,
paragraphs: &[Paragraph],
_text_content: &TextContent,
_shape: &Shape,
) -> TextCursor {
// 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);
TextCursor::new(prev_para, new_offset)
} else {
TextCursor::new(cursor.paragraph, 0)
}
}
/// Move cursor down by one line.
fn move_cursor_down(
cursor: &TextCursor,
paragraphs: &[Paragraph],
_text_content: &TextContent,
_shape: &Shape,
) -> TextCursor {
// 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);
TextCursor::new(next_para, new_offset)
} else {
let char_count = paragraph_char_count(&paragraphs[cursor.paragraph]);
TextCursor::new(cursor.paragraph, char_count)
}
}
/// Move cursor to start of current line.
fn move_cursor_line_start(cursor: &TextCursor, _paragraphs: &[Paragraph]) -> TextCursor {
// TODO: Implement proper line-start using line metrics
TextCursor::new(cursor.paragraph, 0)
}
/// Move cursor to end of current line.
fn move_cursor_line_end(cursor: &TextCursor, paragraphs: &[Paragraph]) -> TextCursor {
// TODO: Implement proper line-end using line metrics
let char_count = paragraph_char_count(&paragraphs[cursor.paragraph]);
TextCursor::new(cursor.paragraph, char_count)
}
// ============================================================================
// HELPERS: Text Modification
// ============================================================================
fn find_span_at_offset(para: &Paragraph, char_offset: usize) -> Option<(usize, usize)> {
let children = para.children();
let mut accumulated = 0;
for (span_idx, span) in children.iter().enumerate() {
let span_len = span.text.chars().count();
if char_offset <= accumulated + span_len {
return Some((span_idx, char_offset - accumulated));
}
accumulated += span_len;
}
if !children.is_empty() {
let last_idx = children.len() - 1;
let last_len = children[last_idx].text.chars().count();
return Some((last_idx, last_len));
}
None
}
/// Insert text at a cursor position. Returns the new character offset after insertion.
fn insert_text_at_cursor(
text_content: &mut TextContent,
cursor: &TextCursor,
text: &str,
) -> Option<usize> {
let paragraphs = text_content.paragraphs_mut();
if cursor.paragraph >= paragraphs.len() {
return None;
}
let para = &mut paragraphs[cursor.paragraph];
let children = para.children_mut();
if children.is_empty() {
return None;
}
if children.len() == 1 && children[0].text.is_empty() {
children[0].set_text(text.to_string());
return Some(text.chars().count());
}
let (span_idx, offset_in_span) = find_span_at_offset(para, cursor.char_offset)?;
let children = para.children_mut();
let span = &mut children[span_idx];
let mut new_text = span.text.clone();
let byte_offset = new_text
.char_indices()
.nth(offset_in_span)
.map(|(i, _)| i)
.unwrap_or(new_text.len());
new_text.insert_str(byte_offset, text);
span.set_text(new_text);
Some(cursor.char_offset + text.chars().count())
}
/// Delete a range of text specified by a selection.
fn delete_selection_range(text_content: &mut TextContent, selection: &TextSelection) {
let start = selection.start();
let end = selection.end();
let paragraphs = text_content.paragraphs_mut();
if start.paragraph >= paragraphs.len() {
return;
}
if start.paragraph == end.paragraph {
delete_range_in_paragraph(
&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_para_len,
);
delete_range_in_paragraph(&mut paragraphs[end.paragraph], 0, end.char_offset);
if end.paragraph < paragraphs.len() {
let end_para_children: Vec<_> =
paragraphs[end.paragraph].children_mut().drain(..).collect();
paragraphs[start.paragraph]
.children_mut()
.extend(end_para_children);
}
if end.paragraph < paragraphs.len() {
paragraphs.drain((start.paragraph + 1)..=end.paragraph);
}
let children = paragraphs[start.paragraph].children_mut();
let has_content = children.iter().any(|span| !span.text.is_empty());
if has_content {
children.retain(|span| !span.text.is_empty());
} else if children.len() > 1 {
children.truncate(1);
}
}
}
/// Delete a range of characters within a single paragraph.
fn delete_range_in_paragraph(para: &mut Paragraph, start_offset: usize, end_offset: usize) {
if start_offset >= end_offset {
return;
}
let mut accumulated = 0;
let mut delete_start_span = None;
let mut delete_end_span = None;
for (idx, span) in para.children().iter().enumerate() {
let span_len = span.text.chars().count();
let span_end = accumulated + span_len;
if delete_start_span.is_none() && start_offset < span_end {
delete_start_span = Some((idx, start_offset - accumulated));
}
if end_offset <= span_end {
delete_end_span = Some((idx, end_offset - accumulated));
break;
}
accumulated += span_len;
}
let Some((start_span_idx, start_in_span)) = delete_start_span else {
return;
};
let Some((end_span_idx, end_in_span)) = delete_end_span else {
return;
};
let children = para.children_mut();
if start_span_idx == end_span_idx {
let span = &mut children[start_span_idx];
let text = span.text.clone();
let chars: Vec<char> = text.chars().collect();
let start_clamped = start_in_span.min(chars.len());
let end_clamped = end_in_span.min(chars.len());
let new_text: String = chars[..start_clamped]
.iter()
.chain(chars[end_clamped..].iter())
.collect();
span.set_text(new_text);
} else {
let start_span = &mut children[start_span_idx];
let text = start_span.text.clone();
let start_char_count = text.chars().count();
let start_clamped = start_in_span.min(start_char_count);
let new_text: String = text.chars().take(start_clamped).collect();
start_span.set_text(new_text);
let end_span = &mut children[end_span_idx];
let text = end_span.text.clone();
let end_char_count = text.chars().count();
let end_clamped = end_in_span.min(end_char_count);
let new_text: String = text.chars().skip(end_clamped).collect();
end_span.set_text(new_text);
if end_span_idx > start_span_idx + 1 {
children.drain((start_span_idx + 1)..end_span_idx);
}
}
let has_content = children.iter().any(|span| !span.text.is_empty());
if has_content {
children.retain(|span| !span.text.is_empty());
} else if !children.is_empty() {
children.truncate(1);
}
}
/// Delete the character before the cursor. Returns the new cursor position.
fn delete_char_before(text_content: &mut TextContent, cursor: &TextCursor) -> Option<TextCursor> {
if cursor.char_offset > 0 {
let paragraphs = text_content.paragraphs_mut();
let para = &mut paragraphs[cursor.paragraph];
let delete_pos = cursor.char_offset - 1;
delete_range_in_paragraph(para, delete_pos, cursor.char_offset);
Some(TextCursor::new(cursor.paragraph, delete_pos))
} else if cursor.paragraph > 0 {
let prev_para_idx = cursor.paragraph - 1;
let paragraphs = text_content.paragraphs_mut();
let prev_para_len = paragraph_char_count(&paragraphs[prev_para_idx]);
let current_children: Vec<_> = paragraphs[cursor.paragraph]
.children_mut()
.drain(..)
.collect();
paragraphs[prev_para_idx]
.children_mut()
.extend(current_children);
paragraphs.remove(cursor.paragraph);
Some(TextCursor::new(prev_para_idx, prev_para_len))
} else {
None
}
}
/// Delete the character after the cursor.
fn delete_char_after(text_content: &mut TextContent, cursor: &TextCursor) {
let paragraphs = text_content.paragraphs_mut();
if cursor.paragraph >= paragraphs.len() {
return;
}
let para_len = paragraph_char_count(&paragraphs[cursor.paragraph]);
if cursor.char_offset < para_len {
let para = &mut paragraphs[cursor.paragraph];
delete_range_in_paragraph(para, cursor.char_offset, cursor.char_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();
paragraphs[cursor.paragraph]
.children_mut()
.extend(next_children);
paragraphs.remove(next_para_idx);
}
}
/// 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 {
let paragraphs = text_content.paragraphs_mut();
if cursor.paragraph >= paragraphs.len() {
return false;
}
let para = &paragraphs[cursor.paragraph];
let Some((span_idx, offset_in_span)) = find_span_at_offset(para, cursor.char_offset) else {
return false;
};
let mut new_para_children = Vec::new();
let children = para.children();
let current_span = &children[span_idx];
let span_text = current_span.text.clone();
let chars: Vec<char> = span_text.chars().collect();
if offset_in_span < chars.len() {
let after_text: String = chars[offset_in_span..].iter().collect();
let mut new_span = current_span.clone();
new_span.set_text(after_text);
new_para_children.push(new_span);
}
for child in children.iter().skip(span_idx + 1) {
new_para_children.push(child.clone());
}
if new_para_children.is_empty() {
let mut empty_span = current_span.clone();
empty_span.set_text(String::new());
new_para_children.push(empty_span);
}
let text_align = para.text_align();
let text_direction = para.text_direction();
let text_decoration = para.text_decoration();
let text_transform = para.text_transform();
let line_height = para.line_height();
let letter_spacing = para.letter_spacing();
let para = &mut paragraphs[cursor.paragraph];
let children = para.children_mut();
children.truncate(span_idx + 1);
if !children.is_empty() {
let span = &mut children[span_idx];
let text = span.text.clone();
let new_text: String = text.chars().take(offset_in_span).collect();
span.set_text(new_text);
}
let new_para = crate::shapes::Paragraph::new(
text_align,
text_direction,
text_decoration,
text_transform,
line_height,
letter_spacing,
new_para_children,
);
paragraphs.insert(cursor.paragraph + 1, new_para);
true
}