Fix scrolling with cursor

examples/editor-libcosmic/src/text_box.rs

@@ -157,7 +157,12 @@ where
         let mut buffer = self.buffer.lock().unwrap();
         let mut cache = self.cache.lock().unwrap();
 
-        buffer.shape_until_cursor();
+        if buffer.cursor_moved {
+            buffer.shape_until_cursor();
+            buffer.cursor_moved = false;
+        } else {
+            buffer.shape_until_scroll();
+        }
 
         let buffer_x = layout.bounds().x;
         let buffer_y = layout.bounds().y;

examples/editor-orbclient/src/main.rs

@@ -73,13 +73,15 @@ fn main() {
     let mut mouse_y = -1;
     let mut mouse_left = false;
 
-    //Lets do this once and rely on events for the rest.
-    buffer.shape_until_cursor();
-
     loop {
         let mut force_drag = true;
 
-        buffer.shape_until_scroll();
+        if buffer.cursor_moved {
+            buffer.shape_until_cursor();
+            buffer.cursor_moved = false;
+        } else {
+            buffer.shape_until_scroll();
+        }
 
         if buffer.redraw {
             let instant = Instant::now();
@@ -203,8 +205,6 @@ fn main() {
                         } else if mouse_y + 5 >= window.height() as i32 {
                             buffer.action(TextAction::Scroll { lines: 3 });
                             window_async = true;
-                        } else {
-                            buffer.shape_until_cursor()
                         }
 
                         force_drag = false;
@@ -218,8 +218,6 @@ fn main() {
                                 x: mouse_x - line_x,
                                 y: mouse_y,
                             });
-
-                            buffer.shape_until_cursor()
                         }
                         force_drag = false;
                     }

examples/editor-test/src/main.rs

@@ -9,7 +9,12 @@ fn redraw(window: &mut Window, buffer: &mut TextBuffer<'_>, swash_cache: &mut Sw
     let bg_color = Color::rgb(0x34, 0x34, 0x34);
     let font_color = Color::rgb(0xFF, 0xFF, 0xFF);
 
-    buffer.shape_until_cursor();
+    if buffer.cursor_moved {
+        buffer.shape_until_cursor();
+        buffer.cursor_moved = false;
+    } else {
+        buffer.shape_until_scroll();
+    }
 
     if buffer.redraw {
         let instant = Instant::now();

src/buffer.rs

@@ -246,6 +246,7 @@ pub struct TextBuffer<'a> {
     scroll: i32,
     cursor: TextCursor,
     select_opt: Option<TextCursor>,
+    pub cursor_moved: bool,
     pub redraw: bool,
 }
 
@@ -266,6 +267,7 @@ impl<'a> TextBuffer<'a> {
             scroll: 0,
             cursor: TextCursor::default(),
             select_opt: None,
+            cursor_moved: false,
             redraw: false,
         };
         buffer.set_text("");
@@ -323,20 +325,9 @@ impl<'a> TextBuffer<'a> {
                 self.width
             );
             if line_i == self.cursor.line.get() {
-                for layout_line in layout {
-                    let mut found = false;
-                    for glyph in layout_line.glyphs.iter() {
-                        if glyph.start <= self.cursor.index {
-                            found = true;
-                            break;
-                        }
-                    }
-                    if found {
-                        layout_i += 1;
-                    } else {
-                        break;
-                    }
-                }
+                let layout_cursor = self.layout_cursor(&self.cursor);
+                layout_i += layout_cursor.layout as i32;
+                break;
             } else {
                 layout_i += layout.len() as i32;
             }
@@ -559,6 +550,8 @@ impl<'a> TextBuffer<'a> {
 
     /// Perform a [TextAction] on the buffer
     pub fn action(&mut self, action: TextAction) {
+        let mut old_cursor = self.cursor;
+
         match action {
             TextAction::Previous => {
                 let line = &mut self.lines[self.cursor.line.get()];
@@ -786,6 +779,10 @@ impl<'a> TextBuffer<'a> {
                 self.shape_until_scroll();
             }
         }
+
+        if old_cursor != self.cursor {
+            self.cursor_moved = true;
+        }
     }
 
     /// Convert x, y position to TextCursor (hit detection)