From f6def74b296521bbf3e79fa059c97626b3c2f550 Mon Sep 17 00:00:00 2001
From: SparkyTD <45818400+SparkyTD@users.noreply.github.com>
Date: Wed, 30 Apr 2025 21:57:34 +0300
Subject: [PATCH] impr: Fix word bound selection and 'MoveHome' behavior in the
 pattern editor (#2193)

### Problem description
This PR addresses two small issues regarding the cursor in the pattern
editor (TextEditor.cpp):

1. It was not possible to move the cursor to the start of a line, if it
contained leading white space characters. With my fix, the editor will
behave more like other code editors. Pressing Home once will jump to the
first non-whitespace character (as it did before), but pressing it again
will jump to column 0. Subsequent presses will alternate between the two
positions.
2. When expanding a selection with Ctrl+Shift+{Left/Right}, the new
selection position would skip an additional word, resulting in the
cursor landing "inside" the selection. This PR fixes this bug.

### Implementation description
1. To fix the first issue, I simply added a condition in
`TextEditor::MoveHome` to check if the cursor is already on the first
meaningful character, or on one of the whitespaces preceding it, in
which case the jump offset is set to 0. If we're already on column 0,
then jump forwards to the first non-whitespace character.
2. This bug was happening because the word boundary jump calculations
were essentially happening twice. Once in
`TextEditor::MoveLeft`/`TextEditor::MoveRight`, and then a second time
in `TextEditor::SetSelection`, leading to the selection skipping an
additional word. I fixed this by replacing the ternary operator with
just `SelectionMode::Normal`.

---------

Co-authored-by: paxcut <53811119+paxcut@users.noreply.github.com>
---
 .../imgui/ColorTextEditor/source/TextEditor.cpp  | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/lib/third_party/imgui/ColorTextEditor/source/TextEditor.cpp b/lib/third_party/imgui/ColorTextEditor/source/TextEditor.cpp
index 301ed796c..9f96ed676 100644
--- a/lib/third_party/imgui/ColorTextEditor/source/TextEditor.cpp
+++ b/lib/third_party/imgui/ColorTextEditor/source/TextEditor.cpp
@@ -1790,7 +1790,7 @@ void TextEditor::MoveLeft(int aAmount, bool aSelect, bool aWordMode) {
         }
     } else
         mInteractiveStart = mInteractiveEnd = mState.mCursorPosition;
-    SetSelection(mInteractiveStart, mInteractiveEnd, aSelect && aWordMode ? SelectionMode::Word : SelectionMode::Normal);
+    SetSelection(mInteractiveStart, mInteractiveEnd, SelectionMode::Normal);
 
     EnsureCursorVisible();
 }
@@ -1846,7 +1846,7 @@ void TextEditor::MoveRight(int aAmount, bool aSelect, bool aWordMode) {
         }
     } else
         mInteractiveStart = mInteractiveEnd = mState.mCursorPosition;
-    SetSelection(mInteractiveStart, mInteractiveEnd, aSelect && aWordMode ? SelectionMode::Word : SelectionMode::Normal);
+    SetSelection(mInteractiveStart, mInteractiveEnd, SelectionMode::Normal);
 
     EnsureCursorVisible();
 }
@@ -1883,9 +1883,19 @@ void TextEditor::MoveHome(bool aSelect) {
     ResetCursorBlinkTime();
     auto oldPos = mState.mCursorPosition;
     auto &line = mLines[mState.mCursorPosition.mLine];
+    if (line.size() == 0)
+        return;
+
+    auto limit = oldPos.mColumn != 0 ? oldPos.mColumn : line.size();
+
     auto home=0;
-    while (isspace(line[home].mChar))
+    while (home < limit && isspace(line[home].mChar))
         home++;
+
+    if (home == oldPos.mColumn) {
+        home = 0;
+    }
+
     SetCursorPosition(Coordinates(mState.mCursorPosition.mLine, home));
     if (mState.mCursorPosition != oldPos) {
         if (aSelect) {