Changed to use show_viewport

.gitignore

@@ -1,2 +1,3 @@
 /target
 file.txt
+file*.txt

src/main.rs

@@ -1,7 +1,6 @@
-use eframe::egui;
+use eframe::egui::{self, ScrollArea, TextStyle, Vec2};
 use rfd::FileDialog;
 
-mod ropeintegration;
 mod rope_editor;
 
 fn main() {
@@ -11,7 +10,7 @@ fn main() {
 
 #[derive(Default)]
 struct GCodium {
-    text_buffer: ropeintegration::ERopey,
+    text_buffer: rope_editor::RopeEdit,
 }
 
 impl GCodium {
@@ -27,9 +26,18 @@ impl eframe::App for GCodium {
             if ui.button("Open File").clicked() {
                 let filepath = FileDialog::new().add_filter("text", &["txt"]).set_directory("/").pick_file().expect("File not Selected");
                 let file = std::fs::File::open(filepath).expect("unable to open file");
-                self.text_buffer.rope = ropey::Rope::from_reader(file).expect("unable to read file to rope");
+                self.text_buffer.text = ropey::Rope::from_reader(file).expect("unable to read file to rope");
             }
-            ui.text_edit_multiline(&mut self.text_buffer);
+            
+            let text_style = TextStyle::Monospace;
+            let height = ui.text_style_height(&text_style).to_string();
+            ui.label(height);
+            ScrollArea::both().auto_shrink(false).show_viewport(
+                ui,
+                |ui, viewport| {
+                    self.text_buffer.show(ui, viewport);
+                }
+            )
         });
     }
 }

src/rope_editor.rs

@@ -1,126 +1,54 @@
-use std::{sync::Arc, usize};
+use std::borrow::Cow;
 
-use eframe::egui::{Align2, Color32, Context, EventFilter, FontSelection, Galley, Id, Key, KeyboardShortcut, Margin, Modifiers, NumExt, Shape, TextBuffer, Ui, Vec2, WidgetWithState, text::LayoutJob, text_edit::{TextEditOutput, TextEditState}};
+use eframe::egui::{self, Align2, NumExt, Rect, Sense, TextStyle, Ui, Vec2, pos2, text_edit::TextCursorState};
+use ropey::Rope;
 
-type LayouterFn<'t> = &'t mut dyn FnMut(&Ui, &dyn TextBuffer, f32) -> Arc<Galley>;
+#[derive(Default)]
-
+pub struct RopeEdit {
-pub struct RopeEdit<'t> {
+    pub text: Rope,
-    text: &'t mut dyn TextBuffer,
+    position: usize,
-    //hint_text: String,
-    //hint_text_font: Option<FontSelection>,
-    id: Option<Id>,
-    id_salt: Option<Id>,
-    font_selection: FontSelection,
-    text_color: Option<Color32>,
-    layouter: Option<LayouterFn<'t>>,
-    frame: bool,
-    margin: Margin,
-    desired_width: Option<f32>,
-    desired_height_rows: usize,
-    event_filter: EventFilter,
-    cursor_at_end: bool,
-    min_size: Vec2,
-    align: Align2,
-    char_limit: usize,
-    return_key: Option<KeyboardShortcut>,
-    background_color: Option<Color32>,
 }
 
-impl WidgetWithState for RopeEdit<'_> {
+impl RopeEdit {
-    type State = TextEditState;
+    pub fn new(textbuffer: Rope) -> Self {
-}
+        RopeEdit { 
-
+            text: textbuffer,
-impl RopeEdit<'_> {
+            position: 0,
-    pub fn load_state(ctx: &Context, id: Id) -> Option<TextEditState> {
-        TextEditState::load(ctx, id)
-    }
-
-    pub fn store_state(ctx: &Context, id: Id, state: TextEditState) {
-        state.store(ctx, id);
-    }
-
-    pub fn show(self, ui: &mut Ui) -> TextEditOutput {
-        let frame = self.frame;
-        let where_to_put_background = ui.painter().add(Shape::Noop);
-        let background_color = ui.visuals().text_edit_bg_color();
-        let output = self.show_content(ui);
-    }
-
-    pub fn show_content(self, ui: &mut Ui) -> TextEditOutput {
-        let RopeEdit { 
-            text, 
-            //hint_text, 
-            //hint_text_font, 
-            id, 
-            id_salt, 
-            font_selection, 
-            text_color, 
-            layouter, 
-            frame, 
-            margin, 
-            desired_width, 
-            desired_height_rows, 
-            event_filter, 
-            cursor_at_end, 
-            min_size, 
-            align, 
-            char_limit, 
-            return_key, 
-            background_color
-        } = self;
-
-        let text_color = text_color
-            .or(ui.visuals().override_text_color)
-            // .unwrap_or_else(|| ui.style().interact(&response).text_color()); // too bright
-            .unwrap_or_else(|| ui.visuals().widgets.inactive.text_color());
-
-        let font_id = font_selection.resolve(ui.style());
-        let row_height = ui.fonts_mut(|f| f.row_height(&font_id));
-        const MIN_WIDTH: f32 = 24.0;
-        let available_width = (ui.available_width() - margin.sum().x).at_least(MIN_WIDTH);
-        let desired_width = desired_width.unwrap_or_else(|| ui.spacing().text_edit_width);
-        let wrap_width = if ui.layout().horizontal_justify() {
-            available_width
-        } else {
-            desired_width.min(available_width)
-        };
-
-        let font_id_clone = font_id.clone();
-        let mut default_layouter = move |ui: &Ui, text: &dyn TextBuffer, wrap_width: f32,| {
-            let layout_job = LayoutJob::simple(text, font_id_clone.clone(), text_color, wrap_width)
-        }
-    }
-}
-
-impl<'t> RopeEdit<'t> {
-    pub fn new(text: &'t mut dyn TextBuffer) -> Self {
-        Self { 
-            text, 
-            //hint_text: Default::default(),
-            //hint_text_font: None, 
-            id: None, 
-            id_salt: None, 
-            font_selection: Default::default(), 
-            text_color: None, 
-            layouter: None, 
-            frame: false, 
-            margin: Margin::symmetric(4, 2), 
-            desired_width: None, 
-            desired_height_rows: 4, 
-            event_filter: EventFilter { 
-                tab: false, 
-                horizontal_arrows: true, 
-                vertical_arrows: true, 
-                ..Default::default() 
-            }, 
-            cursor_at_end: true, 
-            min_size: Vec2::ZERO, 
-            align: Align2::LEFT_TOP, 
-            char_limit: usize::MAX, 
-            return_key: Some(KeyboardShortcut::new(Modifiers::NONE, Key::Enter)), 
-            background_color: None
         }
     }
 
+    pub fn show(&mut self, ui: &mut Ui, viewport: Rect) -> () {
+        let font_id = TextStyle::Body.resolve(ui.style());
+        let row_height = ui.fonts_mut(|f| f.row_height(&font_id)) + ui.spacing().item_spacing.y;
+        let num_rows = self.text.len_lines();
 
+        ui.set_height(row_height * num_rows as f32);
+
+        let first_item = (viewport.min.y / row_height).floor().at_least(0.0) as usize;
+        let last_item = (viewport.max.y / row_height).ceil() as usize + 1;
+        let last_item = last_item.at_most(num_rows);
+
+        let mut used_rect = Rect::NOTHING;
+
+        for i in first_item..last_item {
+            let x = ui.min_rect().left();
+            let y = ui.min_rect().top() + i as f32 * row_height;
+            let text: Cow<'_, str> = self.text.get_line(i).unwrap().into();
+
+            let text_rect = ui.painter().text(
+                pos2(x, y), 
+                Align2::LEFT_TOP, 
+                text, 
+                font_id.clone(), 
+                ui.visuals().text_color(),
+            );
+            used_rect |= text_rect;
+        }
+
+        ui.allocate_rect(used_rect, Sense::HOVER);
+    }
+
+    fn show_content() -> () {
+        //let desired_height = ()
+    }
 }

src/ropeintegration.rs

@@ -1,33 +0,0 @@
-use eframe::egui::{self, scroll_area::State};
-use ropey;
-
-#[derive(Default)]
-pub struct ERopey {
-    pub rope: ropey::Rope,
-    viewbuffer: String,
-}
-
-impl egui::widgets::TextBuffer for ERopey {
-    fn is_mutable(&self) -> bool {
-        true
-    }
-
-    fn as_str(&self) -> &str {
-        self.rope.slice(..).as_str().unwrap()
-    }
-
-    fn insert_text(&mut self, text: &str, char_index: usize) -> usize {
-        let first = self.rope.len_chars();
-        self.rope.insert(char_index, text);
-        let second = self.rope.len_chars();
-        second-first
-    }
-
-    fn delete_char_range(&mut self, char_range: std::ops::Range<usize>) {
-        self.rope.remove(char_range);
-    }
-
-    fn type_id(&self) -> std::any::TypeId {
-        std::any::TypeId::of::<Self>()
-    }
-}