LibGUI: Unindent selected text on shift+tab press

Selected text is unindented when Shift+Tab is pressed. Select text,
indent it with Tab, then unindent with Shift+Tab.

1 files changed, 21 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGUI/TextEditor.cpp b/Userland/Libraries/LibGUI/TextEditor.cpp
index f61aabff25..698935fe75 100644
--- a/Userland/Libraries/LibGUI/TextEditor.cpp
+++ b/Userland/Libraries/LibGUI/TextEditor.cpp
@@ -869,6 +869,10 @@ void TextEditor::keydown_event(KeyEvent& event)
 
     if (event.key() == KeyCode::Key_Tab) {
         if (has_selection()) {
+            if (event.modifiers() == Mod_Shift) {
+                unindent_selection();
+                return;
+            }
             if (is_indenting_selection()) {
                 indent_selection();
                 return;
@@ -988,6 +992,23 @@ void TextEditor::indent_selection()
     }
 }
 
+void TextEditor::unindent_selection()
+{
+    auto const selection_start = m_selection.start() > m_selection.end() ? m_selection.end() : m_selection.start();
+    auto const selection_end = m_selection.end() > m_selection.start() ? m_selection.end() : m_selection.start();
+
+    if (current_line().first_non_whitespace_column() != 0) {
+        if (current_line().first_non_whitespace_column() > m_soft_tab_width && selection_start.column() != 0) {
+            m_selection.set_start({ selection_start.line(), selection_start.column() - m_soft_tab_width });
+            m_selection.set_end({ selection_end.line(), selection_end.column() - m_soft_tab_width });
+        } else if (selection_start.column() != 0) {
+            m_selection.set_start({ selection_start.line(), selection_start.column() - current_line().leading_spaces() });
+            m_selection.set_end({ selection_end.line(), selection_end.column() - current_line().leading_spaces() });
+        }
+        execute<UnindentSelection>(m_soft_tab_width, TextRange(selection_start, selection_end));
+    }
+}
+
 void TextEditor::delete_previous_word()
 {
     TextRange to_erase(document().first_word_before(m_cursor, true), m_cursor);