views::Textfield: Implement yank editing command.

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"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
 #include "ui/gfx/range/range.h"
 #include "ui/gfx/utf16_indexing.h"
+#include "ui/views/views_delegate.h"
 
 namespace views {
 
 namespace internal {
 
 // Edit holds state information to undo/redo editing changes. Editing operations
 // are merged when possible, like when characters are typed in sequence. Calling
 // Commit() marks an edit as an independent operation that shouldn't be merged.
 class Edit {
  public:
@@ skipping 228 matching lines @@
 // there is no such a range.
 gfx::Range GetFirstEmphasizedRange(const ui::CompositionText& composition) {
   for (size_t i = 0; i < composition.underlines.size(); ++i) {
     const ui::CompositionUnderline& underline = composition.underlines[i];
     if (underline.thick)
       return gfx::Range(underline.start_offset, underline.end_offset);
   }
   return gfx::Range::InvalidRange();
 }
 
+// Helper functions to get/set the kill buffer.
+const base::string16& GetKillBuffer() {
+  DCHECK(ViewsDelegate::GetInstance());
+  return ViewsDelegate::GetInstance()->kill_buffer();
+}
+
+void SetKillBuffer(const base::string16& kill_buffer) {
+  if(ViewsDelegate::GetInstance())

[tapted, 2016/07/20 06:32:21]

nit: space after `if`

[karandeepb, 2016/07/20 07:51:30]

Done. Forgot to run git cl format!

+    ViewsDelegate::GetInstance()->set_kill_buffer(kill_buffer);
+}
+
 }  // namespace
 
 using internal::Edit;
 using internal::DeleteEdit;
 using internal::InsertEdit;
 using internal::ReplaceEdit;
 using internal::MergeType;
 using internal::DO_NOT_MERGE;
 using internal::FORCE_MERGE;
 using internal::MERGEABLE;
@@ skipping 42 matching lines @@
     ConfirmCompositionText();
   size_t save = GetCursorPosition();
   MoveCursor(gfx::LINE_BREAK,
              render_text_->GetVisualDirectionOfLogicalEnd(),
              false);
   InsertText(new_text);
   render_text_->SetCursorPosition(save);
   ClearSelection();
 }
 
-bool TextfieldModel::Delete() {
+bool TextfieldModel::Delete(bool add_to_kill_buffer) {
   if (HasCompositionText()) {
     // No undo/redo for composition text.
     CancelCompositionText();
     return true;
   }
   if (HasSelection()) {
+    if (add_to_kill_buffer)
+      SetKillBuffer(GetSelectedText());
     DeleteSelection();
     return true;
   }
   if (text().length() > GetCursorPosition()) {
     size_t cursor_position = GetCursorPosition();
     size_t next_grapheme_index = render_text_->IndexOfAdjacentGrapheme(
         cursor_position, gfx::CURSOR_FORWARD);
-    ExecuteAndRecordDelete(gfx::Range(cursor_position, next_grapheme_index),
-                           true);
+    gfx::Range range_to_delete(cursor_position, next_grapheme_index);
+    if (add_to_kill_buffer)
+      SetKillBuffer(GetTextFromRange(range_to_delete));
+    ExecuteAndRecordDelete(range_to_delete, true);
     return true;
   }
   return false;
 }
 
-bool TextfieldModel::Backspace() {
+bool TextfieldModel::Backspace(bool add_to_kill_buffer) {
   if (HasCompositionText()) {
     // No undo/redo for composition text.
     CancelCompositionText();
     return true;
   }
   if (HasSelection()) {
+    if (add_to_kill_buffer)
+      SetKillBuffer(GetSelectedText());
     DeleteSelection();
     return true;
   }
   size_t cursor_position = GetCursorPosition();
   if (cursor_position > 0) {
     // Delete one code point, which may be two UTF-16 words.
     size_t previous_char = gfx::UTF16OffsetToIndex(text(), cursor_position, -1);
-    ExecuteAndRecordDelete(gfx::Range(cursor_position, previous_char), true);
+    gfx::Range range_to_delete(cursor_position, previous_char);
+    if (add_to_kill_buffer)
+      SetKillBuffer(GetTextFromRange(range_to_delete));
+    ExecuteAndRecordDelete(range_to_delete, true);
     return true;
   }
   return false;
 }
 
 size_t TextfieldModel::GetCursorPosition() const {
   return render_text_->cursor_position();
 }
 
 void TextfieldModel::MoveCursor(gfx::BreakType break_type,
@@ skipping 176 matching lines @@
 
   SelectRange(gfx::Range(prev, next));
   base::string16 text = GetSelectedText();
   base::string16 transposed_text =
       text.substr(cur - prev) + text.substr(0, cur - prev);
 
   InsertTextInternal(transposed_text, false);
   return true;
 }
 
+bool TextfieldModel::Yank() {
+  if(!ViewsDelegate::GetInstance())

[tapted, 2016/07/20 06:32:21]

nit: space after `if` (but also can this be reached in the current code or
tests? it's probably better just to hit the DCHECK if something invokes Yank
without a ViewsDelegate)

[karandeepb, 2016/07/20 07:51:30]

The ViewsDelegate is initialized in
ChromeBrowserMainExtraPartsViews::ToolkitInitialized() and so probably this
can't be reached. But I think this is safer. Most places in the code base also
use an if-check before accessing the ViewsDelegate instance.

+    return false;
+
+  const base::string16& kill_buffer = GetKillBuffer();
+  if (!kill_buffer.empty() || HasSelection()) {
+    InsertTextInternal(kill_buffer, false);
+    return true;
+  }
+  return false;
+}
+
 bool TextfieldModel::HasSelection() const {
   return !render_text_->selection().is_empty();
 }
 
 void TextfieldModel::DeleteSelection() {
   DCHECK(!HasCompositionText());
   DCHECK(HasSelection());
   ExecuteAndRecordDelete(render_text_->selection(), false);
 }
 
@@ skipping 234 matching lines @@
   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).
 }
 
 }  // namespace views