Auto merge of #10350 - mbrubeck:selection-chars, r=SimonSapin

Fix some char/byte bugs in textinput

Fixes #9569. r? @SimonSapin or @Ms2ger

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This commit is contained in:
bors-servo 2016-04-02 20:53:26 +05:30
commit c0bfcc5155
3 changed files with 167 additions and 35 deletions

View file

@ -11,6 +11,7 @@
#![feature(custom_attribute)]
#![feature(custom_derive)]
#![feature(fnbox)]
#![feature(iter_arith)]
#![feature(mpsc_select)]
#![feature(nonzero)]
#![feature(on_unimplemented)]

View file

@ -42,6 +42,9 @@ pub struct TextInput<T: ClipboardProvider> {
multiline: bool,
#[ignore_heap_size_of = "Can't easily measure this generic type"]
clipboard_provider: T,
/// The maximum number of UTF-16 code units this text input is allowed to hold.
///
/// https://html.spec.whatwg.org/multipage/#attr-fe-maxlength
pub max_length: Option<usize>
}
@ -107,6 +110,32 @@ fn is_printable_key(key: Key) -> bool {
}
}
/// The length in bytes of the first n characters in a UTF-8 string.
///
/// If the string has fewer than n characters, returns the length of the whole string.
fn len_of_first_n_chars(text: &str, n: usize) -> usize {
match text.char_indices().take(n).last() {
Some((index, ch)) => index + ch.len_utf8(),
None => 0
}
}
/// The length in bytes of the first n code units a string when encoded in UTF-16.
///
/// If the string is fewer than n code units, returns the length of the whole string.
fn len_of_first_n_code_units(text: &str, n: usize) -> usize {
let mut utf8_len = 0;
let mut utf16_len = 0;
for c in text.chars() {
utf16_len += c.len_utf16();
if utf16_len > n {
break;
}
utf8_len += c.len_utf8();
}
utf8_len
}
impl<T: ClipboardProvider> TextInput<T> {
/// Instantiate a new text input control
pub fn new(lines: Lines, initial: DOMString, clipboard_provider: T, max_length: Option<usize>) -> TextInput<T> {
@ -155,6 +184,9 @@ impl<T: ClipboardProvider> TextInput<T> {
})
}
/// Return the selection range as UTF-8 byte offsets from the start of the content.
///
/// If there is no selection, returns an empty range at the insertion point.
pub fn get_absolute_selection_range(&self) -> Range<usize> {
match self.get_sorted_selection() {
Some((begin, _end)) =>
@ -165,44 +197,51 @@ impl<T: ClipboardProvider> TextInput<T> {
}
pub fn get_selection_text(&self) -> Option<String> {
self.get_sorted_selection().map(|(begin, end)| {
if begin.line != end.line {
let mut s = String::new();
s.push_str(&self.lines[begin.line][begin.index..]);
for (_, line) in self.lines.iter().enumerate().filter(|&(i, _)| begin.line < i && i < end.line) {
s.push_str("\n");
s.push_str(line);
}
s.push_str("\n");
s.push_str(&self.lines[end.line][..end.index]);
s
} else {
self.lines[begin.line][begin.index..end.index].to_owned()
}
})
let text = self.fold_selection_slices(String::new(), |s, slice| s.push_str(slice));
if text.is_empty() {
return None
}
Some(text)
}
/// The length of the selected text in UTF-8 bytes.
fn selection_len(&self) -> usize {
if let Some((begin, end)) = self.get_sorted_selection() {
let prefix = &self.lines[begin.line][0..begin.index];
let suffix = &self.lines[end.line][end.index..];
let lines_prefix = &self.lines[..begin.line];
let lines_suffix = &self.lines[end.line + 1..];
self.fold_selection_slices(0, |len, slice| *len += slice.len())
}
self.len() - (prefix.chars().count() +
suffix.chars().count() +
lines_prefix.iter().fold(0, |m, i| m + i.chars().count() + 1) +
lines_suffix.iter().fold(0, |m, i| m + i.chars().count() + 1))
} else {
0
/// The length of the selected text in UTF-16 code units.
fn selection_utf16_len(&self) -> usize {
self.fold_selection_slices(0usize,
|len, slice| *len += slice.chars().map(char::len_utf16).sum())
}
/// Run the callback on a series of slices that, concatenated, make up the selected text.
///
/// The accumulator `acc` can be mutated by the callback, and will be returned at the end.
fn fold_selection_slices<B, F: FnMut(&mut B, &str)>(&self, mut acc: B, mut f: F) -> B {
match self.get_sorted_selection() {
Some((begin, end)) if begin.line == end.line => {
f(&mut acc, &self.lines[begin.line][begin.index..end.index])
}
Some((begin, end)) => {
f(&mut acc, &self.lines[begin.line][begin.index..]);
for line in &self.lines[begin.line + 1 .. end.line] {
f(&mut acc, "\n");
f(&mut acc, line);
}
f(&mut acc, "\n");
f(&mut acc, &self.lines[end.line][..end.index])
}
None => {}
}
acc
}
pub fn replace_selection(&mut self, insert: DOMString) {
if let Some((begin, end)) = self.get_sorted_selection() {
let allowed_to_insert_count = if let Some(max_length) = self.max_length {
let len_after_selection_replaced = self.len() - self.selection_len();
if len_after_selection_replaced > max_length {
let len_after_selection_replaced = self.utf16_len() - self.selection_utf16_len();
if len_after_selection_replaced >= max_length {
// If, after deleting the selection, the len is still greater than the max
// length, then don't delete/insert anything
return
@ -213,8 +252,8 @@ impl<T: ClipboardProvider> TextInput<T> {
usize::MAX
};
let last_char_to_insert = min(allowed_to_insert_count, insert.chars().count());
let chars_to_insert = (&insert[0 .. last_char_to_insert]).to_owned();
let last_char_index = len_of_first_n_code_units(&*insert, allowed_to_insert_count);
let chars_to_insert = &insert[..last_char_index];
self.clear_selection();
@ -225,7 +264,7 @@ impl<T: ClipboardProvider> TextInput<T> {
let lines_suffix = &self.lines[end.line + 1..];
let mut insert_lines = if self.multiline {
chars_to_insert.split('\n').map(|s| DOMString::from(s.to_owned())).collect()
chars_to_insert.split('\n').map(|s| DOMString::from(s)).collect()
} else {
vec!(DOMString::from(chars_to_insert))
};
@ -288,11 +327,14 @@ impl<T: ClipboardProvider> TextInput<T> {
return;
}
let col = self.lines[self.edit_point.line][..self.edit_point.index].chars().count();
self.edit_point.line = target_line as usize;
self.edit_point.index = min(self.current_line_length(), self.edit_point.index);
self.edit_point.index = len_of_first_n_chars(&self.lines[self.edit_point.line], col);
}
/// Adjust the editing point position by a given number of columns. If the adjustment
/// Adjust the editing point position by a given number of bytes. If the adjustment
/// requested is larger than is available in the current line, the editing point is
/// adjusted vertically and the process repeats with the remaining adjustment requested.
pub fn adjust_horizontal(&mut self, adjust: isize, select: Selection) {
@ -329,7 +371,7 @@ impl<T: ClipboardProvider> TextInput<T> {
self.perform_horizontal_adjustment(adjust, select);
}
// Return whether to cancel the caret move
/// Return whether to cancel the caret move
fn adjust_selection_for_horizontal_change(&mut self, adjust: Direction, select: Selection)
-> bool {
if select == Selection::Selected {
@ -479,9 +521,24 @@ impl<T: ClipboardProvider> TextInput<T> {
}
}
/// The length of the content in bytes.
pub fn len(&self) -> usize {
self.lines.iter().fold(0, |m, l| {
m + l.len() + 1
m + l.len() + 1 // + 1 for the '\n'
}) - 1
}
/// The length of the content in bytes.
pub fn utf16_len(&self) -> usize {
self.lines.iter().fold(0, |m, l| {
m + l.chars().map(char::len_utf16).sum::<usize>() + 1 // + 1 for the '\n'
}) - 1
}
/// The length of the content in chars.
pub fn char_count(&self) -> usize {
self.lines.iter().fold(0, |m, l| {
m + l.chars().count() + 1 // + 1 for the '\n'
}) - 1
}
@ -510,10 +567,12 @@ impl<T: ClipboardProvider> TextInput<T> {
self.selection_begin = None;
}
/// Get the insertion point as a byte offset from the start of the content.
pub fn get_absolute_insertion_point(&self) -> usize {
self.get_absolute_point_for_text_point(&self.edit_point)
}
/// Convert a TextPoint into a byte offset from the start of the content.
pub fn get_absolute_point_for_text_point(&self, text_point: &TextPoint) -> usize {
self.lines.iter().enumerate().fold(0, |acc, (i, val)| {
if i < text_point.line {
@ -524,6 +583,7 @@ impl<T: ClipboardProvider> TextInput<T> {
}) + text_point.index
}
/// Convert a byte offset from the start of the content into a TextPoint.
pub fn get_text_point_for_absolute_point(&self, abs_point: usize) -> TextPoint {
let mut index = abs_point;
let mut line = 0;