Support placeholder text in NativeTextfieldViews.

ui/views/controls/textfield/native_textfield_views.cc

Index: ui/views/controls/textfield/native_textfield_views.cc
diff --git a/ui/views/controls/textfield/native_textfield_views.cc b/ui/views/controls/textfield/native_textfield_views.cc
index eabfd3f3158a8e510a3dc3c71a1d6a844bcddb46..d408770cdcec815e4f87c68394fc4871f8cf1e51 100644
--- a/ui/views/controls/textfield/native_textfield_views.cc
+++ b/ui/views/controls/textfield/native_textfield_views.cc
@@ -5,6 +5,7 @@
 #include "ui/views/controls/textfield/native_textfield_views.h"
 
 #include <algorithm>
+#include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ -830,6 +831,16 @@ void NativeTextfieldViews::PaintTextAndCursor(gfx::Canvas* canvas) {
           textfield_->cursor_color());
   // Draw the text, cursor, and selection.
   GetRenderText()->Draw(canvas);
+
+  // Draw placeholder text if needed.
+  if (model_->GetText().empty() &&
+      !textfield_->placeholder_text().empty()) {
+    canvas->DrawStringInt(
+        textfield_->placeholder_text(),
+        GetRenderText()->GetFont(),
+        textfield_->placeholder_text_color(),
+        GetRenderText()->display_rect());

[oshima, 2012/05/14 21:07:24]

does this work with RTL text?

[xiyuan, 2012/05/14 21:13:30]

Think it should. 

The code paints the placehold text when user has not input anything into the
Textfield. That is, the field is empty and it's not attempting to paint some
text concatenated with another string.

Do we need to do anything special for RTL? Thought canvas->DrawStringInt handles
that. 

[oshima, 2012/05/14 22:05:36]

It does, but DrawStringInt and RenderText handle the text direction slightly
different way,
and I wanted to make sure there is no issue. I'm guessing that if the
placeholder text is LTR, it will print it in LTR, but i thing this isn't really
issue because it must have the correct text. LGTM

+  }
   canvas->Restore();
 }
 
@@ -1097,7 +1108,7 @@ void NativeTextfieldViews::HandleMousePressEvent(const MouseEvent& event) {
     initiating_drag_ = false;
     bool can_drag = true;
 
-    switch(aggregated_clicks_) {
+    switch (aggregated_clicks_) {
       case 0:
         if (can_drag && GetRenderText()->IsPointInSelection(event.location()))
           initiating_drag_ = true;