From fa20dcafb5a55dbf6b0f338bff8c9b2f2378e62d Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Sun, 25 Aug 2019 14:04:46 +0200
Subject: [PATCH] GTextEditor: Simplify computation of visual selection
 start/end

Add Line::visual_line_containing(int column) to easily convert a column
number into a visual line index.
---
 Libraries/LibGUI/GTextEditor.cpp | 41 +++++++++++++++-----------------
 Libraries/LibGUI/GTextEditor.h   |  1 +
 2 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/Libraries/LibGUI/GTextEditor.cpp b/Libraries/LibGUI/GTextEditor.cpp
index 2a25fdd0f6..42b0eaaa5d 100644
--- a/Libraries/LibGUI/GTextEditor.cpp
+++ b/Libraries/LibGUI/GTextEditor.cpp
@@ -362,30 +362,15 @@ void GTextEditor::paint_event(GPaintEvent& event)
         int first_visual_line_with_selection = -1;
         int last_visual_line_with_selection = -1;
         if (physical_line_has_selection) {
-            if (selection.start().line() < line_index) {
+            if (selection.start().line() < line_index)
                 first_visual_line_with_selection = 0;
-            } else {
-                int visual_line_index = 0;
-                line.for_each_visual_line([&](const Rect&, const StringView& view, int start_of_visual_line) {
-                    if (selection.start().column() >= start_of_visual_line && ((selection.start().column() - start_of_visual_line) < view.length()))
-                        return IterationDecision::Break;
-                    ++visual_line_index;
-                    return IterationDecision::Continue;
-                });
-                first_visual_line_with_selection = visual_line_index;
-            }
-            if (selection.end().line() > line_index) {
+            else
+                first_visual_line_with_selection = line.visual_line_containing(selection.start().column());
+
+            if (selection.end().line() > line_index)
                 last_visual_line_with_selection = line.m_visual_line_breaks.size();
-            } else {
-                int visual_line_index = 0;
-                line.for_each_visual_line([&](const Rect&, const StringView& view, int start_of_visual_line) {
-                    if (selection.end().column() >= start_of_visual_line && ((selection.end().column() - start_of_visual_line) < view.length()))
-                        return IterationDecision::Break;
-                    ++visual_line_index;
-                    return IterationDecision::Continue;
-                });
-                last_visual_line_with_selection = visual_line_index;
-            }
+            else
+                last_visual_line_with_selection = line.visual_line_containing(selection.end().column());
         }
 
         int selection_start_column_within_line = selection.start().line() == line_index ? selection.start().column() : 0;
@@ -1416,3 +1401,15 @@ void GTextEditor::set_line_wrapping_enabled(bool enabled)
     recompute_all_visual_lines();
     update();
 }
+
+int GTextEditor::Line::visual_line_containing(int column) const
+{
+    int visual_line_index = 0;
+    for_each_visual_line([&](const Rect&, const StringView& view, int start_of_visual_line) {
+        if (column >= start_of_visual_line && ((column - start_of_visual_line) < view.length()))
+            return IterationDecision::Break;
+        ++visual_line_index;
+        return IterationDecision::Continue;
+    });
+    return visual_line_index;
+}
diff --git a/Libraries/LibGUI/GTextEditor.h b/Libraries/LibGUI/GTextEditor.h
index 98b8587924..74a5345bb5 100644
--- a/Libraries/LibGUI/GTextEditor.h
+++ b/Libraries/LibGUI/GTextEditor.h
@@ -203,6 +203,7 @@ private:
         void truncate(int length);
         void clear();
         void recompute_visual_lines();
+        int visual_line_containing(int column) const;
 
         template<typename Callback>
         void for_each_visual_line(Callback) const;