From 10afbd3e4f230b064a130d4272bf8c46ff925a97 Mon Sep 17 00:00:00 2001
From: Krzosa Karol <krzosa.karol@gmail.com>
Date: Sun, 23 Jun 2024 09:17:54 +0200
Subject: [PATCH] Port Seek word, add ctrl+left

---
 src/text_editor/buffer.cpp | 49 +++++++++++++++++++++++++++++++++++
 src/text_editor/main.cpp   | 53 ++++++++++++++++++++++++++------------
 2 files changed, 86 insertions(+), 16 deletions(-)

diff --git a/src/text_editor/buffer.cpp b/src/text_editor/buffer.cpp
index 9302102..25fb421 100644
--- a/src/text_editor/buffer.cpp
+++ b/src/text_editor/buffer.cpp
@@ -369,6 +369,55 @@ int64_t FindPos(Buffer &buffer, int64_t line_number, int64_t column) {
     return result;
 }
 
+int64_t Seek(Buffer &buffer, int64_t pos, int64_t direction = ITERATE_FORWARD) {
+    Assert(direction == ITERATE_FORWARD || direction == ITERATE_BACKWARD);
+    // ( - inclusive
+    // < - non-inclusive
+
+    int64_t min = 0;
+    int64_t max = 0;
+    char    c   = 0;
+    if (direction == ITERATE_FORWARD) {
+        // (pos + 1, end>
+        min = AdjustUTF8Pos(buffer, pos + 1, ITERATE_FORWARD);
+        max = buffer.len;
+        c   = GetChar(buffer, min);
+    } else {
+        // (0, pos>
+        max = pos;
+        min = 0;
+
+        int64_t next = AdjustUTF8Pos(buffer, max - 1, ITERATE_BACKWARD);
+        c            = GetChar(buffer, next);
+    }
+
+    bool standing_on_whitespace = IsWhitespace(c);
+    bool seek_whitespace        = standing_on_whitespace == false;
+    bool seek_word              = standing_on_whitespace;
+
+    int64_t    result   = max;
+    BufferIter iter     = Iterate(buffer, {min, max}, direction);
+    int64_t    prev_pos = iter.pos;
+    for (; IsValid(iter); Advance(&iter)) {
+        bool char_is_whitespace = iter.item < 255 && IsWhitespace(iter.item);
+
+        if (seek_word && char_is_whitespace == false) {
+            result = prev_pos;
+            break;
+        }
+        if (seek_whitespace && char_is_whitespace) {
+            if (direction == ITERATE_FORWARD) {
+                result = iter.pos;
+            } else {
+                result = prev_pos;
+            }
+            break;
+        }
+        prev_pos = iter.pos;
+    }
+    return result;
+}
+
 void RunBufferTests() {
     Scratch scratch;
     {
diff --git a/src/text_editor/main.cpp b/src/text_editor/main.cpp
index 9c006ad..1e4484e 100644
--- a/src/text_editor/main.cpp
+++ b/src/text_editor/main.cpp
@@ -105,6 +105,21 @@ int64_t MoveUp(Buffer &buffer, int64_t pos) {
     return new_pos;
 }
 
+void UpdateCursorsAfterEdit(Window *window, Array<Edit> edits) {
+    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.min) {
+                cursor.min += offset;
+                cursor.max = cursor.min;
+            }
+        }
+    }
+}
+
 int main() {
     InitScratch();
     RunBufferTests();
@@ -168,7 +183,11 @@ int main() {
             }
             if (IsKeyPressed(KEY_RIGHT) || IsKeyPressedRepeat(KEY_RIGHT)) {
                 For(focused_window->cursors) {
-                    it.max = it.min = MoveRight(focused_window->buffer, it.min);
+                    if (IsKeyDown(KEY_LEFT_CONTROL)) {
+                        it.max = it.min = Seek(focused_window->buffer, it.min, ITERATE_FORWARD);
+                    } else {
+                        it.max = it.min = MoveRight(focused_window->buffer, it.min);
+                    }
                 }
             }
             if (IsKeyPressed(KEY_DOWN) || IsKeyPressedRepeat(KEY_DOWN)) {
@@ -196,8 +215,22 @@ int main() {
                 }
             }
 
-            // Handle user input chars
-            for (int c = GetCharPressed(); c; c = GetCharPressed()) {
+            if (IsKeyPressed(KEY_BACKSPACE) || IsKeyPressedRepeat(KEY_BACKSPACE)) {
+                Array<Edit> edits  = {FrameArena};
+                String      string = {};
+                For(focused_window->cursors) {
+                    int64_t pos = MoveLeft(focused_window->buffer, it.min);
+                    AddEdit(&edits, {pos, it.min}, string);
+                }
+                ApplyEdits(&focused_window->buffer, edits);
+                UpdateCursorsAfterEdit(focused_window, edits);
+            }
+
+            // Handle user input
+            for (;;) {
+                int c = GetCharPressed();
+                if (!c) break;
+
                 String     string = "?";
                 UTF8Result utf8   = UTF32ToUTF8((uint32_t)c);
                 if (utf8.error == 0) {
@@ -209,19 +242,7 @@ int main() {
                     AddEdit(&edits, it, string);
                 }
                 ApplyEdits(&focused_window->buffer, edits);
-
-                ForItem(edit, edits) {
-                    int64_t remove_size = GetRangeSize(edit.range);
-                    int64_t add_size    = string.len;
-                    int64_t offset      = add_size - remove_size;
-
-                    ForItem(cursor, focused_window->cursors) {
-                        if (edit.range.min <= cursor.min) {
-                            cursor.min += offset;
-                            cursor.max = cursor.min;
-                        }
-                    }
-                }
+                UpdateCursorsAfterEdit(focused_window, edits);
             }
         }