Merge "[Autofill Framework] Add a cache to store the last non-empty value when field is cleared" into main

2 files changed, 92 insertions, 15 deletions

diff --git a/services/autofill/java/com/android/server/autofill/Session.java b/services/autofill/java/com/android/server/autofill/Session.java
index 07b16c53ffe8..a8b123518db3 100644
--- a/services/autofill/java/com/android/server/autofill/Session.java
+++ b/services/autofill/java/com/android/server/autofill/Session.java
@@ -1168,6 +1168,7 @@ final class Session implements RemoteFillService.FillServiceCallbacks, ViewState
         return null;
     }
 
+    @GuardedBy("mLock")
     @Nullable
     private AutofillValue findValueFromThisSessionOnlyLocked(@NonNull AutofillId autofillId) {
         final ViewState state = mViewStates.get(autofillId);
@@ -1176,9 +1177,25 @@ final class Session implements RemoteFillService.FillServiceCallbacks, ViewState
             return null;
         }
         AutofillValue value = state.getCurrentValue();
+
+        // Some app clears the form before navigating to another activities. In this case, use the
+        // cached value instead.
+        if (value == null || value.isEmpty()) {
+            AutofillValue candidateSaveValue = state.getCandidateSaveValue();
+            if (candidateSaveValue != null && !candidateSaveValue.isEmpty()) {
+                if (sDebug) {
+                    Slog.d(TAG, "findValueLocked(): current value for " + autofillId
+                            + " is empty, using candidateSaveValue instead.");
+                }
+                return candidateSaveValue;
+            }
+        }
         if (value == null) {
-            if (sDebug) Slog.d(TAG, "findValueLocked(): no current value for " + autofillId);
-            value = getValueFromContextsLocked(autofillId);
+            if (sDebug) {
+                Slog.d(TAG, "findValueLocked(): no current value for " + autofillId
+                        + ", checking value from previous fill contexts");
+                value = getValueFromContextsLocked(autofillId);
+            }
         }
         return value;
     }
@@ -3717,19 +3734,34 @@ final class Session implements RemoteFillService.FillServiceCallbacks, ViewState
 
                 AutofillValue value = viewState.getCurrentValue();
                 if (value == null || value.isEmpty()) {
-                    final AutofillValue initialValue = getValueFromContextsLocked(id);
-                    if (initialValue != null) {
-                        if (sDebug) {
-                            Slog.d(TAG, "Value of required field " + id + " didn't change; "
-                                    + "using initial value (" + initialValue + ") instead");
+                    // Some apps clear the form before navigating to other activities.
+                    // If current value is empty, consider fall back to last cached
+                    // non-empty result first.
+                    final AutofillValue candidateSaveValue =
+                            viewState.getCandidateSaveValue();
+                    if (candidateSaveValue != null && !candidateSaveValue.isEmpty()) {
+                        if (sVerbose) {
+                            Slog.v(TAG, "current value is empty, using cached last non-empty "
+                                    + "value instead");
                         }
-                        value = initialValue;
+                        value = candidateSaveValue;
                     } else {
-                        if (sDebug) {
-                            Slog.d(TAG, "empty value for required " + id );
+                        // If candidate save value is also empty, consider falling back to initial
+                        // value in context.
+                        final AutofillValue initialValue = getValueFromContextsLocked(id);
+                        if (initialValue != null) {
+                            if (sDebug) {
+                                Slog.d(TAG, "Value of required field " + id + " didn't change; "
+                                        + "using initial value (" + initialValue + ") instead");
+                            }
+                            value = initialValue;
+                        } else {
+                            if (sDebug) {
+                                Slog.d(TAG, "empty value for required " + id);
+                            }
+                            allRequiredAreNotEmpty = false;
+                            break;
                         }
-                        allRequiredAreNotEmpty = false;
-                        break;
                     }
                 }
 
@@ -3801,7 +3833,21 @@ final class Session implements RemoteFillService.FillServiceCallbacks, ViewState
                         continue;
                     }
                     if ((viewState.getState() & ViewState.STATE_CHANGED) != 0) {
-                        final AutofillValue currentValue = viewState.getCurrentValue();
+                        AutofillValue currentValue = viewState.getCurrentValue();
+                        if (currentValue == null || currentValue.isEmpty()) {
+                            // Some apps clear the form before navigating to other activities.
+                            // If current value is empty, consider fall back to last cached
+                            // non-empty result instead.
+                            final AutofillValue candidateSaveValue =
+                                    viewState.getCandidateSaveValue();
+                            if (candidateSaveValue != null && !candidateSaveValue.isEmpty()) {
+                                if (sVerbose) {
+                                    Slog.v(TAG, "current value is empty, using cached last "
+                                            + "non-empty value instead");
+                                }
+                                currentValue = candidateSaveValue;
+                            }
+                        }
                         final AutofillValue value = getSanitizedValue(sanitizers, id, currentValue);
                         if (value == null) {
                             if (sDebug) {
@@ -4714,14 +4760,18 @@ final class Session implements RemoteFillService.FillServiceCallbacks, ViewState
     @GuardedBy("mLock")
     private void updateViewStateAndUiOnValueChangedLocked(AutofillId id, AutofillValue value,
             ViewState viewState, int flags) {
+        // Cache the last non-empty value for save purpose. Some apps clear the form before
+        // navigating to other activities.
         if (mIgnoreViewStateResetToEmpty && (value == null || value.isEmpty())
                 && viewState.getCurrentValue() != null && viewState.getCurrentValue().isText()
                 && viewState.getCurrentValue().getTextValue() != null
                 && viewState.getCurrentValue().getTextValue().length() > 1) {
             if (sVerbose) {
-                Slog.v(TAG, "Ignoring view state reset to empty on id " + id);
+                Slog.v(TAG, "value is resetting to empty, caching the last non-empty value");
             }
-            return;
+            viewState.setCandidateSaveValue(viewState.getCurrentValue());
+        } else {
+            viewState.setCandidateSaveValue(null);
         }
         final String textValue;
         if (value == null || !value.isText()) {
diff --git a/services/autofill/java/com/android/server/autofill/ViewState.java b/services/autofill/java/com/android/server/autofill/ViewState.java
index fec5aa531cdd..6ad0eb6ff54f 100644
--- a/services/autofill/java/com/android/server/autofill/ViewState.java
+++ b/services/autofill/java/com/android/server/autofill/ViewState.java
@@ -106,6 +106,15 @@ final class ViewState {
      */
     private FillResponse mSecondaryFillResponse;
     private AutofillValue mCurrentValue;
+
+    /**
+     * Some apps clear the form before navigating to another activity. The mCandidateSaveValue
+     * caches the value when a field with string longer than 2 characters are cleared.
+     *
+     * When showing save UI, if mCurrentValue of view state is empty, session would use
+     * mCandidateSaveValue to prompt save instead.
+     */
+    private AutofillValue mCandidateSaveValue;
     private AutofillValue mAutofilledValue;
     private AutofillValue mSanitizedValue;
     private Rect mVirtualBounds;
@@ -139,6 +148,18 @@ final class ViewState {
         mCurrentValue = value;
     }
 
+    /**
+     * Gets the candidate save value of the view.
+     */
+    @Nullable
+    AutofillValue getCandidateSaveValue() {
+        return mCandidateSaveValue;
+    }
+
+    void setCandidateSaveValue(AutofillValue value) {
+        mCandidateSaveValue = value;
+    }
+
     @Nullable
     AutofillValue getAutofilledValue() {
         return mAutofilledValue;
@@ -268,6 +289,9 @@ final class ViewState {
         if (mCurrentValue != null) {
             builder.append(", currentValue:" ).append(mCurrentValue);
         }
+        if (mCandidateSaveValue != null) {
+            builder.append(", candidateSaveValue:").append(mCandidateSaveValue);
+        }
         if (mAutofilledValue != null) {
             builder.append(", autofilledValue:" ).append(mAutofilledValue);
         }
@@ -302,6 +326,9 @@ final class ViewState {
         if (mAutofilledValue != null) {
             pw.print(prefix); pw.print("autofilledValue:" ); pw.println(mAutofilledValue);
         }
+        if (mCandidateSaveValue != null) {
+            pw.print(prefix); pw.print("candidateSaveValue:"); pw.println(mCandidateSaveValue);
+        }
         if (mSanitizedValue != null) {
             pw.print(prefix); pw.print("sanitizedValue:" ); pw.println(mSanitizedValue);
         }