Trait TextBuffer

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pub trait TextBuffer {
Show 22 methods    // Required methods
    fn is_mutable(&self) -> bool;
    fn as_str(&self) -> &str;
    fn insert_text(&mut self, text: &str, char_index: CharIndex) -> usize;
    fn delete_char_range(&mut self, char_range: Range<CharIndex>);
    fn type_id(&self) -> TypeId;

    // Provided methods
    fn char_range(&self, char_range: Range<CharIndex>) -> &str { ... }
    fn byte_index_from_char_index(&self, char_index: CharIndex) -> ByteIndex { ... }
    fn char_index_from_byte_index(&self, byte_index: ByteIndex) -> CharIndex { ... }
    fn clear(&mut self) { ... }
    fn replace_with(&mut self, text: &str) { ... }
    fn take(&mut self) -> String { ... }
    fn insert_text_at(
        &mut self,
        ccursor: &mut CCursor,
        text_to_insert: &str,
        char_limit: usize,
    ) { ... }
    fn decrease_indentation(&mut self, ccursor: &mut CCursor) { ... }
    fn delete_selected(&mut self, cursor_range: &CCursorRange) -> CCursor { ... }
    fn delete_selected_ccursor_range(
        &mut self,
        [min, max]: [CCursor; 2],
    ) -> CCursor { ... }
    fn delete_previous_char(&mut self, ccursor: CCursor) -> CCursor { ... }
    fn delete_next_char(&mut self, ccursor: CCursor) -> CCursor { ... }
    fn delete_previous_word(&mut self, max_ccursor: CCursor) -> CCursor { ... }
    fn delete_next_word(&mut self, min_ccursor: CCursor) -> CCursor { ... }
    fn delete_surrounding_chars(
        &mut self,
        cursor_range: CCursorRange,
        before_chars: usize,
        after_chars: usize,
    ) -> CCursorRange { ... }
    fn delete_paragraph_before_cursor(
        &mut self,
        galley: &Galley,
        cursor_range: &CCursorRange,
    ) -> CCursor { ... }
    fn delete_paragraph_after_cursor(
        &mut self,
        galley: &Galley,
        cursor_range: &CCursorRange,
    ) -> CCursor { ... }
}

Expand description

Trait constraining what types crate::TextEdit may use as an underlying buffer.

Most likely you will use a String which implements TextBuffer.

Required Methods§

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fn is_mutable(&self) -> bool

Can this text be edited?

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fn as_str(&self) -> &str

Returns this buffer as a str.

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fn insert_text(&mut self, text: &str, char_index: CharIndex) -> usize

Inserts text text into this buffer at character index char_index.

§Notes

char_index is a character index, not a byte index.

§Return

Returns how many characters were successfully inserted

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fn delete_char_range(&mut self, char_range: Range<CharIndex>)

Deletes a range of text char_range from this buffer.

§Notes

char_range is a character range, not a byte range.

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fn type_id(&self) -> TypeId

Returns a unique identifier for the implementing type.

This is useful for downcasting from this trait to the implementing type. Here is an example usage:

use egui::TextBuffer;
use std::any::TypeId;

struct ExampleBuffer {}

impl TextBuffer for ExampleBuffer {
    fn is_mutable(&self) -> bool { unimplemented!() }
    fn as_str(&self) -> &str { unimplemented!() }
    fn insert_text(&mut self, text: &str, char_index: egui::text::CharIndex) -> usize { unimplemented!() }
    fn delete_char_range(&mut self, char_range: std::ops::Range<egui::text::CharIndex>) { unimplemented!() }

    // Implement it like the following:
    fn type_id(&self) -> TypeId {
        TypeId::of::<Self>()
    }
}

// Example downcast:
pub fn downcast_example(buffer: &dyn TextBuffer) -> Option<&ExampleBuffer> {
    if buffer.type_id() == TypeId::of::<ExampleBuffer>() {
        unsafe { Some(&*(buffer as *const dyn TextBuffer as *const ExampleBuffer)) }
    } else {
        None
    }
}

Provided Methods§

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fn char_range(&self, char_range: Range<CharIndex>) -> &str

Reads the given character range.

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fn byte_index_from_char_index(&self, char_index: CharIndex) -> ByteIndex

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fn char_index_from_byte_index(&self, byte_index: ByteIndex) -> CharIndex

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fn clear(&mut self)

Clears all characters in this buffer

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fn replace_with(&mut self, text: &str)

Replaces all contents of this string with text

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fn take(&mut self) -> String

Clears all characters in this buffer and returns a string of the contents.

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fn insert_text_at( &mut self, ccursor: &mut CCursor, text_to_insert: &str, char_limit: usize, )

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fn decrease_indentation(&mut self, ccursor: &mut CCursor)

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fn delete_selected(&mut self, cursor_range: &CCursorRange) -> CCursor

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fn delete_selected_ccursor_range(&mut self, [min, max]: [CCursor; 2]) -> CCursor

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fn delete_surrounding_chars( &mut self, cursor_range: CCursorRange, before_chars: usize, after_chars: usize, ) -> CCursorRange

Deletes characters surrounding the current cursor range.

Removes before_chars characters before the selection start and after_chars characters after the selection end. The returned CCursorRange is adjusted to account for the removed characters before the selection.

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