Undo selection.

ui/views/controls/textfield/textfield_model.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/textfield/textfield_model.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 17 matching lines @@
   enum Type {
     INSERT_EDIT,
     DELETE_EDIT,
     REPLACE_EDIT,
   };
 
   virtual ~Edit() {}
 
   // Revert the change made by this edit in |model|.
   void Undo(TextfieldModel* model) {
+
+    size_t selection_end = old_text_start_ + old_text_.length();
+    gfx::Range selection_range = delete_backward_ ? gfx::Range(selection_end, old_text_start_) : gfx::Range(old_text_start_, selection_end);
     model->ModifyText(new_text_start_, new_text_end(),
                       old_text_, old_text_start_,
-                      old_cursor_pos_);
+                      selection_range);
   }
 
   // Apply the change of this edit to the |model|.
   void Redo(TextfieldModel* model) {
     model->ModifyText(old_text_start_, old_text_end(),
                       new_text_, new_text_start_,
-                      new_cursor_pos_);
+                      gfx::Range(new_cursor_pos_));
   }
 
   // Try to merge the |edit| into this edit and returns true on success. The
   // merged edit will be deleted after redo and should not be reused.
   bool Merge(const Edit* edit) {
     // Don't merge if previous edit is DELETE. This happens when a
     // user deletes characters then hits return. In this case, the
     // delete should be treated as separate edit that can be undone
     // and should not be merged with the replace edit.
     if (type_ != DELETE_EDIT && edit->force_merge()) {
@@ skipping 424 matching lines @@
   base::string16 old = text();
   size_t old_cursor = GetCursorPosition();
   (*current_edit_)->Redo(this);
   return old != text() || old_cursor != GetCursorPosition();
 }
 
 bool TextfieldModel::Cut() {
   if (!HasCompositionText() && HasSelection() && !render_text_->obscured()) {
     ui::ScopedClipboardWriter(
         ui::CLIPBOARD_TYPE_COPY_PASTE).WriteText(GetSelectedText());
-    // A trick to let undo/redo handle cursor correctly.
-    // Undoing CUT moves the cursor to the end of the change rather
-    // than beginning, unlike Delete/Backspace.
-    // TODO(oshima): Change Delete/Backspace to use DeleteSelection,
-    // update DeleteEdit and remove this trick.
-    const gfx::Range& selection = render_text_->selection();
-    render_text_->SelectRange(gfx::Range(selection.end(), selection.start()));
     DeleteSelection();
     return true;
   }
   return false;
 }
 
 bool TextfieldModel::Copy() {
   if (!HasCompositionText() && HasSelection() && !render_text_->obscured()) {
     ui::ScopedClipboardWriter(
         ui::CLIPBOARD_TYPE_COPY_PASTE).WriteText(GetSelectedText());
@@ skipping 252 matching lines @@
   } else {
     current_edit_++;
   }
   return false;
 }
 
 void TextfieldModel::ModifyText(size_t delete_from,
                                 size_t delete_to,
                                 const base::string16& new_text,
                                 size_t new_text_insert_at,
-                                size_t new_cursor_pos) {
+                                gfx::Range selection_range) {
   DCHECK_LE(delete_from, delete_to);
   base::string16 old_text = text();
   ClearComposition();
   if (delete_from != delete_to)
     render_text_->SetText(old_text.erase(delete_from, delete_to - delete_from));
   if (!new_text.empty())
     render_text_->SetText(old_text.insert(new_text_insert_at, new_text));
-  render_text_->SetCursorPosition(new_cursor_pos);
-  // TODO(oshima): Select text that was just undone, like Mac (but not GTK).
+
+  // Both result in different caret affinities for an empty range with non 0
+  // position.
+  if(selection_range.is_empty())
+    render_text_->SetCursorPosition(selection_range.start());
+  else
+    render_text_->SelectRange(selection_range);
 }
 
 }  // namespace views