Files
komp_ac/canvas/src/textarea/widget.rs
2025-08-18 19:42:31 +02:00

353 lines
9.8 KiB
Rust

// src/textarea/widget.rs
#[cfg(feature = "gui")]
use ratatui::{
buffer::Buffer,
layout::{Alignment, Rect},
style::Style,
text::{Line, Span},
widgets::{
Block, BorderType, Borders, Paragraph, StatefulWidget, Widget,
},
};
#[cfg(feature = "gui")]
use crate::data_provider::DataProvider;
#[cfg(feature = "gui")]
use crate::textarea::state::{
compute_h_scroll_with_padding,
count_wrapped_rows_indented,
TextAreaState,
TextOverflowMode,
};
#[cfg(feature = "gui")]
use unicode_width::UnicodeWidthChar;
#[cfg(feature = "gui")]
#[derive(Debug, Clone)]
pub struct TextArea<'a> {
pub(crate) block: Option<Block<'a>>,
pub(crate) style: Style,
pub(crate) border_type: BorderType,
}
#[cfg(feature = "gui")]
impl<'a> Default for TextArea<'a> {
fn default() -> Self {
Self {
block: Some(
Block::default()
.borders(Borders::ALL)
.border_type(BorderType::Rounded),
),
style: Style::default(),
border_type: BorderType::Rounded,
}
}
}
#[cfg(feature = "gui")]
impl<'a> TextArea<'a> {
pub fn block(mut self, block: Block<'a>) -> Self {
self.block = Some(block);
self
}
pub fn style(mut self, style: Style) -> Self {
self.style = style;
self
}
pub fn border_type(mut self, ty: BorderType) -> Self {
self.border_type = ty;
if let Some(b) = &mut self.block {
*b = b.clone().border_type(ty);
}
self
}
}
#[cfg(feature = "gui")]
fn display_width(s: &str) -> u16 {
s.chars()
.map(|c| UnicodeWidthChar::width(c).unwrap_or(0) as u16)
.sum()
}
#[cfg(feature = "gui")]
fn display_cols_up_to(s: &str, char_count: usize) -> u16 {
let mut cols: u16 = 0;
for (i, ch) in s.chars().enumerate() {
if i >= char_count {
break;
}
cols = cols.saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
}
cols
}
#[cfg(feature = "gui")]
fn slice_by_display_cols(s: &str, start_cols: u16, max_cols: u16) -> String {
if max_cols == 0 {
return String::new();
}
let mut current_cols: u16 = 0;
let mut output = String::new();
let mut taken: u16 = 0;
let mut started = false;
for ch in s.chars() {
let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
if !started {
if current_cols.saturating_add(w) <= start_cols {
current_cols = current_cols.saturating_add(w);
continue;
} else {
started = true;
}
}
if taken.saturating_add(w) > max_cols {
break;
}
output.push(ch);
taken = taken.saturating_add(w);
current_cols = current_cols.saturating_add(w);
}
output
}
#[cfg(feature = "gui")]
fn clip_window_with_indicator_padded(
text: &str,
view_width: u16,
indicator: char,
start_cols: u16,
) -> Line<'static> {
if view_width == 0 {
return Line::from("");
}
let total = display_width(text);
// Left indicator if we scrolled
let show_left = start_cols > 0;
let left_cols: u16 = if show_left { 1 } else { 0 };
// Capacity for text if we also need a right indicator
let cap_with_right = view_width.saturating_sub(left_cols + 1);
// Do we still have content beyond this window?
let remaining = total.saturating_sub(start_cols);
let show_right = remaining > cap_with_right;
// Final capacity for visible text
let max_visible = if show_right {
cap_with_right
} else {
view_width.saturating_sub(left_cols)
};
let visible = slice_by_display_cols(text, start_cols, max_visible);
let mut spans: Vec<Span> = Vec::new();
if show_left {
spans.push(Span::raw(indicator.to_string()));
}
// Visible text
spans.push(Span::raw(visible.clone()));
// Place $ flush-right
if show_right {
let used_cols = left_cols + display_width(&visible);
let right_pos = view_width.saturating_sub(1);
let filler = right_pos.saturating_sub(used_cols);
if filler > 0 {
spans.push(Span::raw(" ".repeat(filler as usize)));
}
spans.push(Span::raw(indicator.to_string()));
}
Line::from(spans)
}
#[cfg(feature = "gui")]
fn wrap_segments_with_indent(
s: &str,
width: u16,
indent: u16,
) -> Vec<String> {
let mut segments: Vec<String> = Vec::new();
if width == 0 {
segments.push(String::new());
return segments;
}
let indent = indent.min(width.saturating_sub(1));
let cont_cap = width.saturating_sub(indent);
let indent_str = " ".repeat(indent as usize);
let mut buf = String::new();
let mut used: u16 = 0;
let mut first = true;
for ch in s.chars() {
let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
let cap = if first { width } else { cont_cap };
// Early-wrap: wrap before filling the last cell (and avoid empty segment)
if used > 0 && used.saturating_add(w) >= cap {
segments.push(buf);
buf = String::new();
used = 0;
first = false;
if indent > 0 {
buf.push_str(&indent_str);
used = indent;
}
}
buf.push(ch);
used = used.saturating_add(w);
}
segments.push(buf);
segments
}
// Map visual row offset to (logical line, intra segment)
#[cfg(feature = "gui")]
fn resolve_start_line_and_intra_indented(
state: &TextAreaState,
inner: Rect,
) -> (usize, u16) {
let provider = state.editor.data_provider();
let total = provider.line_count();
if total == 0 {
return (0, 0);
}
let wrap = matches!(state.overflow_mode, TextOverflowMode::Wrap);
let width = inner.width;
let target_vis = state.scroll_y;
if !wrap {
let start = (target_vis as usize).min(total);
return (start, 0);
}
let indent = state.wrap_indent_cols;
let mut acc: u16 = 0;
for i in 0..total {
let s = provider.field_value(i);
let rows = count_wrapped_rows_indented(s, width, indent);
if acc.saturating_add(rows) > target_vis {
let intra = target_vis.saturating_sub(acc);
return (i, intra);
}
acc = acc.saturating_add(rows);
}
(total.saturating_sub(1), 0)
}
#[cfg(feature = "gui")]
impl<'a> StatefulWidget for TextArea<'a> {
type State = TextAreaState;
fn render(self, area: Rect, buf: &mut Buffer, state: &mut Self::State) {
state.ensure_visible(area, self.block.as_ref());
let inner = if let Some(b) = &self.block {
b.clone().render(area, buf);
b.inner(area)
} else {
area
};
let edited_now = state.take_edited_flag();
let wrap_mode = matches!(state.overflow_mode, TextOverflowMode::Wrap);
let provider = state.editor.data_provider();
let total = provider.line_count();
let (start, intra) = resolve_start_line_and_intra_indented(state, inner);
let mut display_lines: Vec<Line> = Vec::new();
if total == 0 || start >= total {
if let Some(ph) = &state.placeholder {
display_lines.push(Line::from(Span::raw(ph.clone())));
}
} else if wrap_mode {
// manual pre-wrap path (unchanged)
let mut rows_left = inner.height;
let indent = state.wrap_indent_cols;
let mut i = start;
while i < total && rows_left > 0 {
let s = provider.field_value(i);
let segments = wrap_segments_with_indent(s, inner.width, indent);
let skip = if i == start { intra as usize } else { 0 };
for seg in segments.into_iter().skip(skip) {
display_lines.push(Line::from(Span::raw(seg)));
rows_left = rows_left.saturating_sub(1);
if rows_left == 0 {
break;
}
}
i += 1;
}
} else {
// Indicator mode: full inner width; RIGHT_PAD only affects cursor clamp and h-scroll
let end = (start.saturating_add(inner.height as usize)).min(total);
for i in start..end {
let s = provider.field_value(i);
match state.overflow_mode {
TextOverflowMode::Wrap => unreachable!(),
TextOverflowMode::Indicator { ch } => {
let fits = display_width(s) <= inner.width;
let start_cols = if i == state.current_field() {
let col_idx = state.display_cursor_position();
let cursor_cols = display_cols_up_to(s, col_idx);
let (target_h, _left_cols) =
compute_h_scroll_with_padding(cursor_cols, inner.width);
if fits {
if edited_now { target_h } else { 0 }
} else {
target_h.max(state.h_scroll)
}
} else {
0
};
display_lines.push(clip_window_with_indicator_padded(
s,
inner.width,
ch,
start_cols,
));
}
}
}
}
let p = Paragraph::new(display_lines)
.alignment(Alignment::Left)
.style(self.style);
// No Paragraph::wrap/scroll in wrap mode — we pre-wrap.
p.render(inner, buf);
}
}