[Android NTP] Allow overlapping snap scroll regions.

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java
index 79a6a435b77c693134925d517c8aed9411119b51..dfef4c60ca5d9c7059fea43ffdde56dd6518545b 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java
@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.ntp.cards;
 
+import android.content.res.Resources;
 import android.support.test.filters.MediumTest;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.ViewHolder;
@@ -14,6 +15,7 @@ import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.RetryOnFailure;
 import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.UrlConstants;
 import org.chromium.chrome.browser.ntp.ContextMenuManager;
 import org.chromium.chrome.browser.ntp.NTPTileSource;
@@ -117,7 +119,6 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
 
     @MediumTest
     @Feature({"NewTabPage"})
-    @CommandLineFlags.Add("enable-features=NTPSnippets")
     public void testClickSuggestion() throws InterruptedException {
         setSuggestionsAndWaitForUpdate(10);
         List<SnippetArticle> suggestions = mSource.getSuggestionsForCategory(TEST_CATEGORY);
@@ -137,7 +138,6 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
 
     @MediumTest
     @Feature({"NewTabPage"})
-    @CommandLineFlags.Add("enable-features=NTPSnippets,NTPSuggestionsSectionDismissal")
     public void testAllDismissed() throws InterruptedException, TimeoutException {
         setSuggestionsAndWaitForUpdate(3);
         assertEquals(3, mSource.getSuggestionsForCategory(TEST_CATEGORY).size());
@@ -170,7 +170,6 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
 
     @MediumTest
     @Feature({"NewTabPage"})
-    @CommandLineFlags.Add("enable-features=NTPSnippets")
     public void testDismissArticleWithContextMenu() throws InterruptedException, TimeoutException {
         setSuggestionsAndWaitForUpdate(10);
         List<SnippetArticle> suggestions = mSource.getSuggestionsForCategory(TEST_CATEGORY);
@@ -190,7 +189,6 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
 
     @MediumTest
     @Feature({"NewTabPage"})
-    @CommandLineFlags.Add("enable-features=NTPSnippets,NTPSuggestionsSectionDismissal")
     public void testDismissStatusCardWithContextMenu()
             throws InterruptedException, TimeoutException {
         setSuggestionsAndWaitForUpdate(0);
@@ -211,7 +209,6 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
 
     @MediumTest
     @Feature({"NewTabPage"})
-    @CommandLineFlags.Add("enable-features=NTPSnippets,NTPSuggestionsSectionDismissal")
     public void testDismissActionItemWithContextMenu()
             throws InterruptedException, TimeoutException {
         setSuggestionsAndWaitForUpdate(0);
@@ -229,6 +226,70 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
         assertArrayEquals(new int[0], mSource.getCategories());
     }
 
+    @MediumTest
+    @Feature({"NewTabPage"})
+    @CommandLineFlags.Add({"disable-features=" + ChromeFeatureList.NTP_CONDENSED_LAYOUT})
+    public void testSnapScrollNoCondensedLayout() {
+        setSuggestionsAndWaitForUpdate(0);
+
+        Resources res = getInstrumentation().getTargetContext().getResources();
+        int toolbarHeight = res.getDimensionPixelSize(R.dimen.toolbar_height_no_shadow)
+                + res.getDimensionPixelSize(R.dimen.toolbar_progress_bar_height);
+        View searchBox = getNtpView().findViewById(R.id.search_box);
+        int searchBoxTop = searchBox.getTop() + searchBox.getPaddingTop();
+        int searchBoxTransitionLength =
+                res.getDimensionPixelSize(R.dimen.ntp_search_box_transition_length);
+
+        // Two different snapping regions with the default behavior: snapping back up to the
+        // watershed point in the middle, snapping forward after that.
+        assertEquals(0, getSnapPosition(0));
+        assertEquals(0, getSnapPosition(toolbarHeight / 2 - 1));
+        assertEquals(toolbarHeight, getSnapPosition(toolbarHeight / 2));
+        assertEquals(toolbarHeight, getSnapPosition(toolbarHeight));
+        assertEquals(toolbarHeight + 1, getSnapPosition(toolbarHeight + 1));
+
+        assertEquals(searchBoxTop - searchBoxTransitionLength - 1,

[PEConn, 2017/02/21 14:43:24]

It might increase readability to add convenience methods and change these lines
to:

assertNoSnapFrom(0)
assertNoSnapFrom(toolbarHeight)

assertSnapTo(toolbarHeight / 2 - 1, 0)

But I'm not too fussed.

[Bernhard Bauer, 2017/02/21 15:04:34]

The one thing I don't like about that is that it won't fail with a useful error
message if the assertion happens in a different method -- assertEquals together
with the line number gives the most information.

+                getSnapPosition(searchBoxTop - searchBoxTransitionLength - 1));
+        assertEquals(searchBoxTop - searchBoxTransitionLength,
+                getSnapPosition(searchBoxTop - searchBoxTransitionLength));
+        assertEquals(searchBoxTop - searchBoxTransitionLength,
+                getSnapPosition(searchBoxTop - searchBoxTransitionLength / 2 - 1));
+        assertEquals(searchBoxTop, getSnapPosition(searchBoxTop - searchBoxTransitionLength / 2));
+        assertEquals(searchBoxTop, getSnapPosition(searchBoxTop));
+        assertEquals(searchBoxTop + 1, getSnapPosition(searchBoxTop + 1));
+    }
+
+    @MediumTest
+    @Feature({"NewTabPage"})
+    @CommandLineFlags.Add({"enable-features=" + ChromeFeatureList.NTP_CONDENSED_LAYOUT})
+    public void testSnapScrollCondensedLayout() {
+        setSuggestionsAndWaitForUpdate(0);
+
+        Resources res = getInstrumentation().getTargetContext().getResources();
+        int toolbarHeight = res.getDimensionPixelSize(R.dimen.toolbar_height_no_shadow)
+                + res.getDimensionPixelSize(R.dimen.toolbar_progress_bar_height);
+        View searchBox = getNtpView().findViewById(R.id.search_box);
+        int searchBoxTop = searchBox.getTop() + searchBox.getPaddingTop();
+        int searchBoxTransitionLength =
+                res.getDimensionPixelSize(R.dimen.ntp_search_box_transition_length);
+
+        // With the condensed layout, the snapping regions overlap, so the effect is that of a
+        // single snapping region.
+        assertEquals(0, getSnapPosition(0));
+        assertEquals(0, getSnapPosition(toolbarHeight / 2 - 1));
+        assertEquals(searchBoxTop, getSnapPosition(toolbarHeight / 2));
+        assertEquals(searchBoxTop, getSnapPosition(searchBoxTop - searchBoxTransitionLength));
+        assertEquals(searchBoxTop, getSnapPosition(toolbarHeight));
+        assertEquals(searchBoxTop, getSnapPosition(searchBoxTop));
+        assertEquals(searchBoxTop + 1, getSnapPosition(searchBoxTop + 1));
+    }
+
+    private int getSnapPosition(int scrollPosition) {
+        NewTabPageView ntpView = getNtpView();
+        return getRecyclerView().calculateSnapPosition(
+                scrollPosition, ntpView.findViewById(R.id.search_box), ntpView.getHeight());
+    }
+
     private NewTabPageView getNtpView() {
         return mNtp.getNewTabPageView();
     }