From 4425db7ca312854dc198e5b83005e088215b658c Mon Sep 17 00:00:00 2001
From: Krzosa Karol <krzosa.karol@gmail.com>
Date: Mon, 1 Jul 2024 07:16:11 +0200
Subject: [PATCH] Fix cursor offsetting after change

---
 src/text_editor/layout.cpp | 32 ++++++++++++++++++--------------
 src/text_editor/main.cpp   |  5 ++---
 2 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/src/text_editor/layout.cpp b/src/text_editor/layout.cpp
index f113327..3137857 100644
--- a/src/text_editor/layout.cpp
+++ b/src/text_editor/layout.cpp
@@ -352,29 +352,33 @@ void AfterEdit(Window *window, Array<Edit> edits) {
     Assert(entry->cursors.len);
     Assert(entry->edits.len);
 
+    for (int64_t i = 0; i < edits.len - 1; i += 1) {
+        Assert(edits[i].range.min <= edits[i + 1].range.min);
+    }
+
+    // @todo: add undo fixing
+
+    //
     // Offset all cursors by edits
+    //
+    Scratch       scratch;
+    Array<Cursor> new_cursors = window->cursors.tight_copy(scratch);
     ForItem(edit, edits) {
         int64_t remove_size = GetRangeSize(edit.range);
         int64_t insert_size = edit.string.len;
         int64_t offset      = insert_size - remove_size;
 
-        ForItem(cursor, window->cursors) {
-            if (edit.range.min == cursor.range.min) {
-                if (GetRangeSize(edit.range)) {
-                    cursor.range.min += edit.string.len;
-                } else {
-                    cursor.range.min += offset;
-                }
-                cursor.range.max = cursor.range.min;
-            } else if (edit.range.min <= cursor.range.min) {
-                if (GetRangeSize(edit.range)) {
-                    cursor.range.min += edit.string.len;
-                }
-                cursor.range.min += offset;
-                cursor.range.max = cursor.range.min;
+        for (int64_t i = 0; i < window->cursors.len; i += 1) {
+            Cursor &old_cursor = window->cursors.data[i];
+            Cursor &new_cursor = new_cursors.data[i];
+            if (old_cursor.range.min == edit.range.min) {
+                new_cursor.range.min = new_cursor.range.max = new_cursor.range.min + insert_size;
+            } else if (old_cursor.range.min > edit.range.min) {
+                new_cursor.range.min = new_cursor.range.max = new_cursor.range.min + offset;
             }
         }
     }
+    for (int64_t i = 0; i < window->cursors.len; i += 1) window->cursors[i] = new_cursors[i];
 
     // Make sure all cursors are in range
     For(window->cursors) it.range = Clamp(window->buffer, it.range);
diff --git a/src/text_editor/main.cpp b/src/text_editor/main.cpp
index 1b42a06..f779026 100644
--- a/src/text_editor/main.cpp
+++ b/src/text_editor/main.cpp
@@ -405,11 +405,10 @@ int main() {
 
                 BeforeEdit(focused_window);
                 Array<Edit> edits = {FrameArena};
-                For(focused_window->cursors) {
-                    AddEdit(&edits, it.range, string);
-                }
+                For(focused_window->cursors) AddEdit(&edits, it.range, string);
                 ApplyEdits(focused_window, edits);
                 AfterEdit(focused_window, edits);
+                // For(focused_window->cursors) it.range.min = it.range.max = MoveRight(focused_window->buffer, it.range.min);
             }
             EventRecording_SimulateGetCharPressed(focused_window);
         }