[Autofill Assistant] Change update method for chips.

Before, chips were replaced as a list. Now they are compared one by one,
if they are "the same", only the chip's |enabled| state is updated.

Bug: b/144075373
Change-Id: I7e9e970217faa85e66c559194fe0159f98d67a4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2027908Reviewed-by: Clemens Arbesser <arbesser@google.com>
Reviewed-by: Mathias Carlen <mcarlen@chromium.org>
Commit-Queue: Sandro Maggi <sandromaggi@google.com>
Cr-Commit-Position: refs/heads/master@{#737310}

chrome/android/features/autofill_assistant/java/src/org/chromium/chrome/browser/autofill_assistant/AssistantBottomBarCoordinator.java

@@ -220,6 +220,10 @@ class AssistantBottomBarCoordinator
                 });
     }
 
+    AssistantCarouselCoordinator getActionsCarouselCoordinator() {
+        return mActionsCoordinator;
+    }
+
     private void setupAnimations(AssistantModel model, ViewGroup rootView) {
         // Animate when the chip in the header changes.
         model.getHeaderModel().addObserver((source, propertyKey) -> {

chrome/android/features/autofill_assistant/java/src/org/chromium/chrome/browser/autofill_assistant/AutofillAssistantUiController.java

@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.autofill_assistant;
 
 import android.content.Context;
 import android.support.annotation.Nullable;
+import android.view.View;
 
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ -14,6 +15,7 @@ import org.chromium.base.task.PostTask;
 import org.chromium.chrome.autofill_assistant.R;
 import org.chromium.chrome.browser.ActivityTabProvider;
 import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.autofill_assistant.carousel.AssistantCarouselCoordinator;
 import org.chromium.chrome.browser.autofill_assistant.carousel.AssistantCarouselModel;
 import org.chromium.chrome.browser.autofill_assistant.carousel.AssistantChip;
 import org.chromium.chrome.browser.autofill_assistant.carousel.AssistantChip.Type;
@@ -25,6 +27,7 @@ import org.chromium.chrome.browser.ui.messages.snackbar.SnackbarManager.Snackbar
 import org.chromium.chrome.browser.widget.bottomsheet.BottomSheetController;
 import org.chromium.content_public.browser.UiThreadTaskTraits;
 import org.chromium.content_public.browser.WebContents;
+import org.chromium.ui.modelutil.ListModel;
 
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -300,13 +303,16 @@ class AutofillAssistantUiController {
     @CalledByNative
     private void setActions(List<AssistantChip> chips) {
         AssistantCarouselModel model = getModel().getActionsModel();
-        setChips(model, chips);
+        // TODO(b/144075373): Move this to AssistantActionsCarouselCoordinator.
+        setChips(model, chips,
+                mCoordinator.getBottomBarCoordinator().getActionsCarouselCoordinator());
         setHeaderChip(chips);
     }
 
     @CalledByNative
     private void setSuggestions(List<AssistantChip> chips) {
-        setChips(getModel().getSuggestionsModel(), chips);
+        // TODO(b/144075373): Move this to AssistantSuggestionsCarouselCoordinator.
+        setChips(getModel().getSuggestionsModel(), chips, /* carouselCoordinator= */ null);
     }
 
     private void setHeaderChip(List<AssistantChip> chips) {
@@ -322,13 +328,55 @@ class AutofillAssistantUiController {
         getModel().getHeaderModel().set(AssistantHeaderModel.CHIP, headerChip);
     }
 
-    private void setChips(AssistantCarouselModel model, List<AssistantChip> chips) {
-        // We apply the minimum set of operations on the current chips to transform it in the target
-        // list of chips. When testing for chip equivalence, we only compare their type and text but
-        // all substitutions will still be applied so we are sure we display the given {@code chips}
-        // with their associated callbacks.
-        EditDistance.transform(model.getChipsModel(), chips,
-                (a, b) -> a.getType() == b.getType() && a.getText().equals(b.getText()));
+    /**
+     * Returns |true| if all chips in the list are considered equal, meaning the same except their
+     * |isDisabled()| state.
+     */
+    private boolean areChipsEqual(ListModel<AssistantChip> oldChips, List<AssistantChip> newChips) {
+        if (oldChips.size() != newChips.size()) {
+            return false;
+        }
+
+        for (int i = 0; i < oldChips.size(); ++i) {
+            AssistantChip oldChip = oldChips.get(i);
+            AssistantChip newChip = newChips.get(i);
+
+            if (!oldChip.equals(newChip)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    private void setChips(AssistantCarouselModel model, List<AssistantChip> newChips,
+            @Nullable AssistantCarouselCoordinator carouselCoordinator) {
+        ListModel<AssistantChip> oldChips = model.getChipsModel();
+        if (carouselCoordinator == null || !areChipsEqual(oldChips, newChips)) {
+            // We apply the minimum set of operations on the current chips to transform it in the
+            // target list of chips. When testing for chip equivalence, we only compare their type
+            // and text but all substitutions will still be applied so we are sure we display the
+            // given {@code chips} with their associated callbacks.
+            EditDistance.transform(oldChips, newChips, AssistantChip::equals);
+        } else {
+            for (int i = 0; i < oldChips.size(); ++i) {
+                AssistantChip oldChip = oldChips.get(i);
+                AssistantChip newChip = newChips.get(i);
+
+                // We assume that the enabled state is the only thing that may change.
+                if (oldChip.isDisabled() == newChip.isDisabled()) {
+                    continue;
+                }
+
+                View view = carouselCoordinator.getView().getLayoutManager().findViewByPosition(i);
+                if (view == null) {
+                    oldChips.update(i, newChip);
+                } else {
+                    oldChip.setDisabled(newChip.isDisabled());
+                    view.setEnabled(!newChip.isDisabled());
+                }
+            }
+        }
     }
 
     @CalledByNative

chrome/android/features/autofill_assistant/java/src/org/chromium/chrome/browser/autofill_assistant/carousel/AssistantActionsCarouselCoordinator.java

@@ -7,7 +7,6 @@ package org.chromium.chrome.browser.autofill_assistant.carousel;
 import static org.chromium.chrome.browser.autofill_assistant.AssistantTagsForTesting.RECYCLER_VIEW_TAG;
 
 import android.content.Context;
-import android.support.v7.widget.DefaultItemAnimator;
 import android.support.v7.widget.OrientationHelper;
 import android.support.v7.widget.RecyclerView;
 import android.view.View;
@@ -68,10 +67,6 @@ public class AssistantActionsCarouselCoordinator implements AssistantCarouselCoo
                 new SimpleRecyclerViewMcp<>(model.getChipsModel(),
                         AssistantChipViewHolder::getViewType, AssistantChipViewHolder::bind),
                 AssistantChipViewHolder::create));
-
-        // Disabling change animations to avoid chips that blink when setting the same, unchanged,
-        // set of chips.
-        ((DefaultItemAnimator) mView.getItemAnimator()).setSupportsChangeAnimations(false);
     }
 
     @Override

chrome/android/features/autofill_assistant/java/src/org/chromium/chrome/browser/autofill_assistant/carousel/AssistantChip.java

@@ -56,7 +56,7 @@ public class AssistantChip {
     private final String mText;
 
     /** Whether this chip is enabled or not. */
-    private final boolean mDisabled;
+    private boolean mDisabled;
 
     /**
      * Whether this chip is sticky. A sticky chip will be a candidate to be displayed in the header
@@ -93,6 +93,15 @@ public class AssistantChip {
         return mDisabled;
     }
 
+    /**
+     * Set the disabled state of the {@link AssistantChip} object. Changing this flag will not
+     * affect the view this chip is bound to. Use this to keep the model and view in sync, if
+     * the view's state changes.
+     */
+    public void setDisabled(boolean disabled) {
+        mDisabled = disabled;
+    }
+
     public boolean isSticky() {
         return mSticky;
     }
@@ -100,4 +109,18 @@ public class AssistantChip {
     public Runnable getSelectedListener() {
         return mSelectedListener;
     }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+        if (!(other instanceof AssistantChip)) {
+            return false;
+        }
+
+        AssistantChip that = (AssistantChip) other;
+        return this.getType() == that.getType() && this.getText().equals(that.getText())
+                && this.getIcon() == that.getIcon() && this.isSticky() == that.isSticky();
+    }
 }

chrome/android/features/autofill_assistant/javatests/src/org/chromium/chrome/browser/autofill_assistant/AutofillAssistantActionsCarouselUiTest.java

@@ -18,7 +18,6 @@ import static org.hamcrest.Matchers.allOf;
 
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.MediumTest;
-import android.support.v7.widget.DefaultItemAnimator;
 import android.widget.LinearLayout;
 
 import org.junit.Before;
@@ -76,11 +75,6 @@ public class AutofillAssistantActionsCarouselUiTest {
         AssistantCarouselModel model = new AssistantCarouselModel();
         AssistantActionsCarouselCoordinator coordinator = createCoordinator(model);
 
-        TestThreadUtils.runOnUiThreadBlocking(() -> {
-            assertThat(((DefaultItemAnimator) coordinator.getView().getItemAnimator())
-                               .getSupportsChangeAnimations(),
-                    is(false));
-        });
         assertThat(model.getChipsModel().size(), is(0));
         assertThat(coordinator.getView().getAdapter().getItemCount(), is(0));
     }