TextEditor: Go-to-line now shows line in middle of view (#4008)

Libraries/LibGUI/TextEditor.cpp

@@ -96,9 +96,10 @@ void TextEditor::create_actions()
             "Go to line...", { Mod_Ctrl, Key_L }, Gfx::Bitmap::load_from_file("/res/icons/16x16/go-forward.png"), [this](auto&) {
                 String value;
                 if (InputBox::show(value, window(), "Line:", "Go to line") == InputBox::ExecOK) {
-                    auto line_number = value.to_uint();
-                    if (line_number.has_value())
-                        set_cursor(line_number.value() - 1, 0);
+                    auto line_target = value.to_uint();
+                    if (line_target.has_value()) {
+                        set_cursor_and_focus_line(line_target.value() - 1, 0);
+                    }
                 }
             },
             this);
@@ -1156,6 +1157,24 @@ Gfx::IntRect TextEditor::line_content_rect(size_t line_index) const
     };
 }
 
+void TextEditor::set_cursor_and_focus_line(size_t line, size_t column)
+{
+    u_int index_max = line_count() - 1;
+    set_cursor(line, column);
+    if (line > 1 && line < index_max) {
+        int headroom = frame_inner_rect().height() / 3;
+        do {
+            auto line_data = m_line_visual_data[line];
+            headroom -= line_data.visual_rect.height();
+            line--;
+        } while (line > 0 && headroom > 0);
+
+        Gfx::IntRect rect = { 0, line_content_rect(line).y(),
+            1, frame_inner_rect().height() };
+        scroll_into_view(rect, false, true);
+    }
+}
+
 void TextEditor::update_cursor()
 {
     update(line_widget_rect(m_cursor.line()));

Libraries/LibGUI/TextEditor.h

@@ -154,6 +154,7 @@ public:
 
     void add_custom_context_menu_action(Action&);
 
+    void set_cursor_and_focus_line(size_t line, size_t column);
     void set_cursor(size_t line, size_t column);
     void set_cursor(const TextPosition&);