📰 Show the Sign In promo as a separate card from the section

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SigninPromoItem.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SigninPromoItem.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SigninPromoItem.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SigninPromoItem.java
new file mode 100644
index 0000000000000000000000000000000000000000..69a5f58ea060b00ac162c91e553e96da78d1a234
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SigninPromoItem.java
@@ -0,0 +1,121 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.ntp.cards;
+
+import android.content.Context;
+import android.support.annotation.DrawableRes;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.metrics.RecordUserAction;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ntp.UiConfig;
+import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+import org.chromium.chrome.browser.signin.AccountSigninActivity;
+import org.chromium.chrome.browser.signin.SigninAccessPoint;
+import org.chromium.chrome.browser.signin.SigninManager;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Shows a card prompting the user to sign in. This item is also an {@link ItemGroup}, and calling
+ * {@link #hide()} or {@link #maybeShow()} will control its visibility.
+ */
+public class SigninPromoItem extends StatusItem implements ItemGroup {
+    private final List<NewTabPageItem> mItems = Collections.<NewTabPageItem>singletonList(this);
+    private Observer mChangeObserver;
+
+    /**
+     * Whether the promo should be visible, according to the parent object.
+     *
+     * The {@link NewTabPageAdapter} calls to {@link #maybeShow()} and {@link #hide()} modify this
+     * when the sign in status changes.
+     */
+    private boolean mVisible;
+
+    /**
+     * Whether the user has seen the promo and dismissed it at some point. When this is set,
+     * the promo will never be shown.
+     */
+    private boolean mDismissed;
+
+    public SigninPromoItem() {
+        super(org.chromium.chrome.R.string.snippets_disabled_generic_prompt,
+                org.chromium.chrome.R.string.snippets_disabled_signed_out_instructions,
+                org.chromium.chrome.R.string.sign_in_button);
+        mDismissed = ChromePreferenceManager.getInstance(ContextUtils.getApplicationContext())
+                             .getNewTabPageSigninPromoDismissed();
+        mVisible = !SigninManager.get(ContextUtils.getApplicationContext()).isSignedInOnNative();
+    }
+
+    @Override
+    public List<NewTabPageItem> getItems() {
+        if (mDismissed) return Collections.emptyList();
+        if (!mVisible) return Collections.emptyList();
+        return mItems;
+    }
+
+    @Override
+    public int getType() {
+        return NewTabPageItem.VIEW_TYPE_PROMO;
+    }
+
+    @Override
+    protected void performAction(Context context) {
+        AccountSigninActivity.startIfAllowed(context, SigninAccessPoint.NTP_CONTENT_SUGGESTIONS);
+    }
+
+    /** Sets the {@link Observer} that will be notified when the visibility of the item changes. */
+    public void setObserver(Observer changeObserver) {
+        assert mChangeObserver == null;
+        this.mChangeObserver = changeObserver;
+    }
+
+    /** Attempts to show the sign in promo. If the user dismissed it before, it will not be shown.*/
+    public void maybeShow() {
+        if (mVisible) return;
+        mVisible = true;
+
+        if (mDismissed) return;
+
+        RecordUserAction.record("Signin_Impression_FromNTPContentSuggestions");
+        mChangeObserver.notifyItemInserted(this, 0);
+    }
+
+    /** Hides the sign in promo. */
+    public void hide() {
+        if (!mVisible) return;
+        mVisible = false;
+
+        if (mDismissed) return;
+
+        mChangeObserver.notifyItemRemoved(this, 0);
+    }
+
+    /** Hides the sign in promo and sets a preference to make sure it is not shown again. */
+    public void dismiss() {
+        hide();
+        mDismissed = true;
+        ChromePreferenceManager.getInstance(ContextUtils.getApplicationContext())
+                .setNewTabPageSigninPromoDismissed(true);
+    }
+
+    /**
+     * View Holder for {@link SigninPromoItem}.
+     */
+    public static class ViewHolder extends StatusCardViewHolder {
+        public ViewHolder(NewTabPageRecyclerView parent, UiConfig config) {
+            super(parent, config);
+        }
+
+        @DrawableRes
+        @Override
+        protected int selectBackground(boolean hasCardAbove, boolean hasCardBelow) {
+            assert !hasCardBelow;
+            if (hasCardAbove) return R.drawable.ntp_signin_promo_card_bottom;
+            return R.drawable.ntp_signin_promo_card_single;
+        }
+    }
+}