[KeyboardEvent] Add embedder APIs to translate between Dom |key| enum and strings

content/child/blink_platform_impl.cc

Index: content/child/blink_platform_impl.cc
diff --git a/content/child/blink_platform_impl.cc b/content/child/blink_platform_impl.cc
index 78939bb0167d693444707233ea5ba300d1cc7eb3..9c87777d0758caeca30573143c6c77fc881c2384 100644
--- a/content/child/blink_platform_impl.cc
+++ b/content/child/blink_platform_impl.cc
@@ -71,6 +71,7 @@
 #include "third_party/WebKit/public/web/WebSecurityOrigin.h"
 #include "ui/base/layout.h"
 #include "ui/events/gestures/blink/web_gesture_curve_impl.h"
+#include "ui/events/keycodes/dom/dom_key.h"
 #include "ui/events/keycodes/dom/keycode_converter.h"
 
 using blink::WebData;
@@ -1392,4 +1393,23 @@ int BlinkPlatformImpl::domEnumFromCodeString(const WebString& code) {
       code.utf8().data()));
 }
 
+WebString BlinkPlatformImpl::domKeyStringFromEnum(int dom_key) {
+  if (dom_key < DOM_KEY_PRINT_NON_DIFF) {

[Habib Virji, 2015/06/24 14:32:13]

This is to check if it is printable character. The limit is quite high to cover
printable character.

+    std::string dom_key_char = base::StringPrintf("%c", dom_key);

[Habib Virji, 2015/06/24 14:32:13]

This was needed as we needed to convert int to char value. Using std::to_string
will give back integer in string format. 

+    return WebString::fromUTF8(dom_key_char);
+  } else {
+    return WebString::fromUTF8(ui::KeycodeConverter::DomKeyToKeyString(
+        static_cast<ui::DomKey>(dom_key - DOM_KEY_PRINT_NON_DIFF)));

[Habib Virji, 2015/06/24 14:32:13]

Here value is decremented to get correct mapping to enum value.

+  }
+}
+
+int BlinkPlatformImpl::domKeyEnumFromString(const WebString& key) {
+  ui::DomKey dom_key =
+      ui::KeycodeConverter::KeyStringToDomKey(key.utf8().data());
+  if (ui::DomKey::NONE == dom_key) {

[Habib Virji, 2015/06/24 14:32:13]

KeyStringToDomKey is returning DomKey::NONE if it does not find value matching
in the DOM key table.

+    return key.at(0);

[Habib Virji, 2015/06/24 14:32:13]

This is to convert back printable character to int value.

+  }
+  return static_cast<int>(dom_key);
+}
+
 }  // namespace content