[Autofill/Autocomplete Feature] Substring matching instead of prefix matching.

components/autofill/content/renderer/password_autofill_agent.cc

Index: components/autofill/content/renderer/password_autofill_agent.cc
diff --git a/components/autofill/content/renderer/password_autofill_agent.cc b/components/autofill/content/renderer/password_autofill_agent.cc
index f0dcefd80475482fc096bf1c14839fd18cab75d4..3447a3d51c2e94d3b08a97021f27f5ae0dc5c007 100644
--- a/components/autofill/content/renderer/password_autofill_agent.cc
+++ b/components/autofill/content/renderer/password_autofill_agent.cc
@@ -17,6 +17,7 @@
 #include "components/autofill/content/renderer/renderer_save_password_progress_logger.h"
 #include "components/autofill/core/common/autofill_constants.h"
 #include "components/autofill/core/common/autofill_switches.h"
+#include "components/autofill/core/common/autofill_util.h"
 #include "components/autofill/core/common/form_field_data.h"
 #include "components/autofill/core/common/password_form.h"
 #include "components/autofill/core/common/password_form_fill_data.h"
@@ -225,7 +226,8 @@ bool DoUsernamesMatch(const base::string16& username1,
                       bool exact_match) {
   if (exact_match)
     return username1 == username2;
-  return base::StartsWith(username1, username2, true);
+  return base::StartsWith(username1, username2, true) ||
+         ContainsTokenThatStartsWith(username1, username2, true);

[please use gerrit instead, 2015/06/28 00:43:03]

1) Change ContainsTokenThatStartsWith() to use base::StartsWith() internally,
when command line switch |kEnableSuggestionsWithSubstringMatch| is off.

2) Use only ContainsTokenThatStartsWith() here.

[Pritam Nikam, 2015/06/29 15:38:21]

We do rank suggestions based on MFU, moving |base::StartsWith()| inside
|ContainsTokenThatStartsWith()| will go for a toss, and we may endup in writing
more code to handle it.

[please use gerrit instead, 2015/06/29 22:06:28]

Do we ever use ContainsTokenThatStartsWith() without "base::StartsWith() ||"
beforehand?

[Pritam Nikam, 2015/06/30 15:05:50]

Yes. We have to treat both cases seperatly for below cases:
1. components/password_manager/core/browser/password_autofill_manager.cc
2. components/autofill/core/browser/personal_data_manager.cc

 }
 
 // Returns |true| if the given element is editable. Otherwise, returns |false|.
@@ -415,8 +417,14 @@ bool FillUserNameAndPassword(
     username_element->setAutofilled(true);
 
     if (set_selection) {
-      username_element->setSelectionRange(current_username.length(),
-                                          username.length());
+      if (IsFeatureSubstringMatchEnabled()) {

[please use gerrit instead, 2015/06/28 00:43:03]

Use PreviewSuggestion() here.

[Pritam Nikam, 2015/06/29 15:38:21]

Acknowledged.


I'm getting some problem here, shall address it soon.

[please use gerrit instead, 2015/06/29 22:06:28]

I can help you resolve the issue if you describe it.

[Pritam Nikam, 2015/06/30 15:05:50]

For password forms, we autocomplets the suggestion as we type into username
field.

Considering this requirement workflow order should be:

A. Set the input filed with suggestion text.
username_element->setValue(username, true);

B. Apply text selection based on suggestion and current input.
if (set_selection) {
  if (IsFeatureSubstringMatchEnabled()) {
    size_t start =
        autofill::GetTextSelectionStart(username, current_username);
    username_element->setSelectionRange(start, username.length());
  } else {
    username_element->setSelectionRange(current_username.length(),
                                        username.length());
}

This requirement mandates us to pass an extra parameter |current_username| (old
field contents) along with |username| (filed suggestion) and |username_element|
(text field node) to utility function |PreviewSuggestion()|.

I was trying if we can somehow skip doing so. Now I've changed prototype as
below:

void PreviewSuggestion(WebFormControlElement* input_element,
                       const base::string16& suggestion,
                       const base::string16& user_input);

+        size_t start =
+            autofill::GetTextSelectionStart(username, current_username);
+        username_element->setSelectionRange(start, username.length());
+      } else {
+        username_element->setSelectionRange(current_username.length(),
+                                            username.length());
+      }
     }
   } else if (current_username != username) {
     // If the username can't be filled and it doesn't match a saved password
@@ -791,13 +799,22 @@ bool PasswordAutofillAgent::PreviewSuggestion(
     return false;
   }
 
+  base::string16 current_username = username_element.value();
+  base::string16 suggested_username = username;

[please use gerrit instead, 2015/06/28 00:43:03]

No need for these temporary variables on lines 802-803. Is there?

[Pritam Nikam, 2015/06/29 15:38:21]

Done.

[please use gerrit instead, 2015/06/29 22:06:28]

They're still here. I think you were planning to remove them but forgot.

[Pritam Nikam, 2015/06/30 15:05:50]

Done.

Yes, I forgot to get rid of these.

   was_username_autofilled_ = username_element.isAutofilled();
   username_selection_start_ = username_element.selectionStart();
   username_element.setSuggestedValue(username);
   username_element.setAutofilled(true);
-  username_element.setSelectionRange(
-      username_selection_start_,
-      username_element.suggestedValue().length());
+
+  if (IsFeatureSubstringMatchEnabled()) {

[please use gerrit instead, 2015/06/28 00:43:03]

Use PreviewSuggestion() here.

[Pritam Nikam, 2015/06/29 15:38:21]

Done.

+    size_t start =
+        autofill::GetTextSelectionStart(suggested_username, current_username);
+    username_element.setSelectionRange(start, suggested_username.length());
+    was_username_autofilled_ = start;
+  } else {
+    username_element.setSelectionRange(
+        username_selection_start_, username_element.suggestedValue().length());
+  }
 
   was_password_autofilled_ = password_info->password_field.isAutofilled();
   password_info->password_field.setSuggestedValue(password);