views::Textfield: Implement yank editing command.

ui/views/controls/textfield/textfield_model.cc

Index: ui/views/controls/textfield/textfield_model.cc
diff --git a/ui/views/controls/textfield/textfield_model.cc b/ui/views/controls/textfield/textfield_model.cc
index 7c6d5917f209fdcfbc0b5bb6c1c71ad1622e0044..6330495b4b6dc1e55be0a79fda714a6c1bc37d40 100644
--- a/ui/views/controls/textfield/textfield_model.cc
+++ b/ui/views/controls/textfield/textfield_model.cc
@@ -15,6 +15,7 @@
 #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 {
 
@@ -263,6 +264,17 @@ gfx::Range GetFirstEmphasizedRange(const ui::CompositionText& composition) {
   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;
@@ -325,13 +337,15 @@ void TextfieldModel::Append(const base::string16& new_text) {
   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;
   }
@@ -339,20 +353,24 @@ bool TextfieldModel::Delete() {
     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;
   }
@@ -360,7 +378,10 @@ bool TextfieldModel::Backspace() {
   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;
@@ -557,6 +578,18 @@ bool TextfieldModel::Transpose() {
   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();
 }