Download Home : Added section titles

1- Modified the mutator logic to maintain the items in a date/section
   ordered hierarchical form
2- The mutator will add views for sections, section separators and
   date separators.

Several other smaller details such as :
1 - First section should have less spacing between the preceding date.
2 - The last date/section shouldn't have a separator.


Bug: 866307
Change-Id: I6eca116c26f403760160d016655fad3c05278c3a
Reviewed-on: https://chromium-review.googlesource.com/1151062
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581045}

chrome/android/java/res/layout/download_manager_date_item.xml

@@ -7,11 +7,10 @@
 <TextView xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:paddingTop="4dp"
-    android:paddingBottom="4dp"
-    android:paddingStart="12dp"
+    android:paddingTop="@dimen/download_manager_section_title_padding_top"
+    android:paddingBottom="@dimen/download_manager_section_title_padding_bottom"
+    android:paddingStart="@dimen/list_item_default_margin"
     android:maxLines="1"
     android:gravity="start|center_vertical"
-    android:textAppearance="@style/BlackTitle2"
-    android:textAlignment="viewStart"
-    />
+    android:textAppearance="@style/BlackTitle1"
+    android:textAlignment="viewStart" />
\ No newline at end of file
\ No newline at end of file

chrome/android/java/res/layout/download_manager_date_separator.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2018 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.
+-->
+
+<View
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    style="@style/Divider"
+    android:minHeight="2dp" />
\ No newline at end of file

chrome/android/java/res/layout/download_manager_section_header.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2018 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.
+-->
+
+<TextView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:paddingTop="@dimen/download_manager_section_title_padding_top"
+    android:paddingBottom="@dimen/download_manager_section_title_padding_bottom"
+    android:paddingStart="@dimen/list_item_default_margin"
+    android:gravity="start|center_vertical"
+    android:textAppearance="@style/BlackHint2"
+    android:textAlignment="viewStart" />
\ No newline at end of file

chrome/android/java/res/layout/download_manager_section_separator.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2018 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.
+-->
+
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:background="@android:color/white"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <View
+        style="@style/Divider"
+        android:layout_marginStart="16dp" />
+
+</FrameLayout>
\ No newline at end of file

chrome/android/java/res/values/dimens.xml

@@ -584,6 +584,10 @@
     <dimen name="download_manager_prefetch_thumbnail_size">114dp</dimen>
     <dimen name="download_manager_prefetch_horizontal_margin">16dp</dimen>
     <dimen name="download_manager_prefetch_vertical_margin">12dp</dimen>
+    <dimen name="download_manager_section_title_padding_top">16dp</dimen>
+    <dimen name="download_manager_section_title_padding_top_condensed">0dp</dimen>
+    <dimen name="download_manager_section_title_padding_bottom">0dp</dimen>
+    <dimen name="download_manager_section_title_padding_image">8dp</dimen>
 
     <!-- Navigation history popup dimensions -->
     <dimen name="navigation_popup_width">312dp</dimen>

chrome/android/java/src/org/chromium/chrome/browser/download/home/filter/Filters.java

@@ -39,7 +39,7 @@ public class Filters {
      * @param filter The {@link OfflineItem#filter} type to convert.
      * @return       The corresponding {@link FilterType}.
      */
-    public static @FilterType int fromOfflineItem(@OfflineItemFilter int filter) {
+    public static @FilterType Integer fromOfflineItem(@OfflineItemFilter int filter) {
         switch (filter) {
             case OfflineItemFilter.FILTER_PAGE:
                 return FilterType.SITES;

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/BatchListObservable.java

@@ -8,13 +8,14 @@ import android.support.annotation.Nullable;
 import android.support.v7.util.BatchingListUpdateCallback;
 import android.support.v7.util.ListUpdateCallback;
 
-import org.chromium.chrome.browser.modelutil.ListObservableImpl;
+import org.chromium.chrome.browser.modelutil.SimpleListObservable;
 
 /**
- * Helper class to batch updates to ListObservable before notifying observers.
+ * Helper class to batch updates to SimpleListObservable before notifying observers.
  * @see BatchingListUpdateCallback
+ * @param <T> The object type that this class manages in a list.
  */
-public abstract class BatchListObservable extends ListObservableImpl<Void> {
+public abstract class BatchListObservable<T> extends SimpleListObservable<T> {
     final BatchingListUpdateCallback mBatchingCallback;
 
     /** Creates a new BatchListObservable instance. */

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/DateOrderedListMediator.java

@@ -72,7 +72,7 @@ class DateOrderedListMediator {
                 boolean selected = mSelectionDelegate.isItemSelected(item);
                 item.showSelectedAnimation = selected && !item.selected;
                 item.selected = selected;
-                mModel.setItem(i, item);
+                mModel.update(i, item);
             }
             mModel.dispatchLastEvent();
             mModel.getProperties().setValue(

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/ListItem.java

@@ -14,6 +14,10 @@ import java.util.Date;
 
 /** An abstract class that represents a variety of possible list items to show in downloads home. */
 public abstract class ListItem {
+    private static final long DATE_SEPARATOR_HASH_CODE_OFFSET = 10;
+    private static final long SECTION_SEPARATOR_HASH_CODE_OFFSET = 100;
+    private static final long SECTION_HEADER_HASH_CODE_OFFSET = 1000;
+
     public final long stableId;
 
     /** Indicates that we are in multi-select mode and the item is currently selected. */
@@ -66,6 +70,65 @@ public abstract class ListItem {
         }
     }
 
+    /** A {@link ListItem} representing a section header. */
+    public static class SectionHeaderListItem extends DateListItem {
+        public final int filter;
+        public boolean isFirstSectionOfDay;
+
+        /**
+         * Creates a {@link SectionHeaderListItem} instance for a given {@code filter} and
+         * {@code timestamp}.
+         */
+        public SectionHeaderListItem(int filter, long timestamp) {
+            super(generateStableId(timestamp, filter), new Date(timestamp));
+            this.filter = filter;
+        }
+
+        @VisibleForTesting
+        static long generateStableId(long timestamp, int filter) {
+            long hash = new Date(timestamp).hashCode();
+            return hash + filter + SECTION_HEADER_HASH_CODE_OFFSET;
+        }
+    }
+
+    /** A {@link ListItem} representing a divider that separates sections and dates. */
+    public static class SeparatorViewListItem extends DateListItem {
+        private final boolean mIsDateDivider;
+
+        /**
+         * Creates a separator to be shown at the end of a given date.
+         * @param timestamp The date corresponding to this group of downloads.
+         */
+        public SeparatorViewListItem(long timestamp) {
+            super(generateStableId(timestamp), new Date(timestamp));
+            mIsDateDivider = true;
+        }
+
+        /**
+         * Creates a separator to be shown at the end of a section for a given section on a given
+         * date.
+         * @param timestamp The date corresponding to the section.
+         * @param filter The type of downloads contained in this section.
+         */
+        public SeparatorViewListItem(long timestamp, int filter) {
+            super(generateStableId(timestamp, filter), new Date(timestamp));
+            mIsDateDivider = false;
+        }
+
+        /** Whether this view represents a date divider. */
+        public boolean isDateDivider() {
+            return mIsDateDivider;
+        }
+
+        private static long generateStableId(long timestamp) {
+            return ((long) (new Date(timestamp).hashCode())) + DATE_SEPARATOR_HASH_CODE_OFFSET;
+        }
+
+        private static long generateStableId(long timestamp, int filter) {
+            return generateStableId(timestamp) + filter + SECTION_SEPARATOR_HASH_CODE_OFFSET;
+        }
+    }
+
     /** A {@link ListItem} that involves a {@link OfflineItem}. */
     public static class OfflineItemListItem extends DateListItem {
         public final OfflineItem item;

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/ListItemModel.java

@@ -4,20 +4,14 @@
 
 package org.chromium.chrome.browser.download.home.list;
 
-import org.chromium.chrome.browser.modelutil.ListObservable;
 import org.chromium.chrome.browser.modelutil.PropertyModel;
-import org.chromium.chrome.browser.modelutil.SimpleList;
-
-import java.util.ArrayList;
-import java.util.List;
 
 /**
  * This model represents the data required to build a list UI around a set of {@link ListItem}s.
- * This includes (1) a {@link ListObservable} implementation and (2) exposing a
+ * This includes (1) a {@link BatchListObservable} implementation and (2) exposing a
  * {@link PropertyModel} for shared item properties and general list information.
  */
-class ListItemModel extends BatchListObservable implements SimpleList<ListItem> {
-    private final List<ListItem> mItems = new ArrayList<>();
+class ListItemModel extends BatchListObservable<ListItem> {
     private final PropertyModel mListProperties = new PropertyModel(ListProperties.ALL_KEYS);
 
     /**
@@ -27,33 +21,4 @@ class ListItemModel extends BatchListObservable implements SimpleList<ListItem>
     public PropertyModel getProperties() {
         return mListProperties;
     }
-
-    /** Adds {@code item} to this list at {@code index}. */
-    public void addItem(int index, ListItem item) {
-        mItems.add(index, item);
-        notifyItemInserted(index);
-    }
-
-    /** Removes the {@link ListItem} at {@code index}. */
-    public void removeItem(int index) {
-        mItems.remove(index);
-        notifyItemRemoved(index);
-    }
-
-    /** Sets the {@link ListItem} at {@code index} to {@code item}. */
-    public void setItem(int index, ListItem item) {
-        mItems.set(index, item);
-        notifyItemChanged(index);
-    }
-
-    // SimpleList implementation.
-    @Override
-    public ListItem get(int index) {
-        return mItems.get(index);
-    }
-
-    @Override
-    public int size() {
-        return mItems.size();
-    }
-}
+}
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/ListUtils.java

@@ -5,7 +5,9 @@
 package org.chromium.chrome.browser.download.home.list;
 
 import android.support.annotation.IntDef;
+import android.support.annotation.StringRes;
 
+import org.chromium.chrome.R;
 import org.chromium.chrome.browser.download.home.list.ListItem.DateListItem;
 import org.chromium.chrome.browser.download.home.list.ListItem.OfflineItemListItem;
 import org.chromium.chrome.browser.download.home.list.ListItem.ViewListItem;
@@ -19,7 +21,8 @@ import java.lang.annotation.RetentionPolicy;
 public class ListUtils {
     /** The potential types of list items that could be displayed. */
     @IntDef({ViewType.DATE, ViewType.IN_PROGRESS, ViewType.GENERIC, ViewType.VIDEO, ViewType.IMAGE,
-            ViewType.CUSTOM_VIEW, ViewType.PREFETCH})
+            ViewType.CUSTOM_VIEW, ViewType.PREFETCH, ViewType.SECTION_HEADER,
+            ViewType.SEPARATOR_DATE, ViewType.SEPARATOR_SECTION})
     @Retention(RetentionPolicy.SOURCE)
     public @interface ViewType {
         int DATE = 0;
@@ -29,6 +32,9 @@ public class ListUtils {
         int IMAGE = 4;
         int CUSTOM_VIEW = 5;
         int PREFETCH = 6;
+        int SECTION_HEADER = 7;
+        int SEPARATOR_DATE = 8;
+        int SEPARATOR_SECTION = 9;
     }
 
     private ListUtils() {}
@@ -42,6 +48,12 @@ public class ListUtils {
      */
     public static @ViewType int getViewTypeForItem(ListItem item) {
         if (item instanceof ViewListItem) return ViewType.CUSTOM_VIEW;
+        if (item instanceof ListItem.SectionHeaderListItem) return ViewType.SECTION_HEADER;
+        if (item instanceof ListItem.SeparatorViewListItem) {
+            ListItem.SeparatorViewListItem separator = (ListItem.SeparatorViewListItem) item;
+            return separator.isDateDivider() ? ViewType.SEPARATOR_DATE : ViewType.SEPARATOR_SECTION;
+        }
+
         if (item instanceof DateListItem) {
             if (item instanceof OfflineItemListItem) {
                 OfflineItemListItem offlineItem = (OfflineItemListItem) item;
@@ -76,6 +88,28 @@ public class ListUtils {
         return ViewType.GENERIC;
     }
 
+    /**
+     * @return The id of the string to be displayed as the section header for the given filter.
+     */
+    public static @StringRes int getTextForSection(int filter) {
+        switch (filter) {
+            case OfflineItemFilter.FILTER_PAGE:
+                return R.string.download_manager_ui_pages;
+            case OfflineItemFilter.FILTER_IMAGE:
+                return R.string.download_manager_ui_images;
+            case OfflineItemFilter.FILTER_VIDEO:
+                return R.string.download_manager_ui_video;
+            case OfflineItemFilter.FILTER_AUDIO:
+                return R.string.download_manager_ui_audio;
+            case OfflineItemFilter.FILTER_OTHER:
+                return R.string.download_manager_ui_other;
+            case OfflineItemFilter.FILTER_DOCUMENT:
+                return R.string.download_manager_ui_documents;
+            default:
+                return R.string.download_manager_ui_all_downloads;
+        }
+    }
+
     /**
      * Analyzes a {@link ListItem} and finds the best span size based on the current state.  Span
      * size determines how many columns this {@link ListItem}'s {@link View} will take up in the

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/holder/ListItemViewHolder.java

@@ -43,6 +43,12 @@ public abstract class ListItemViewHolder extends ViewHolder {
                 return new CustomViewHolder(parent);
             case ListUtils.ViewType.PREFETCH:
                 return PrefetchViewHolder.create(parent);
+            case ListUtils.ViewType.SECTION_HEADER:
+                return SectionTitleViewHolder.create(parent);
+            case ListUtils.ViewType.SEPARATOR_DATE:
+                return SeparatorViewHolder.create(parent, true);
+            case ListUtils.ViewType.SEPARATOR_SECTION:
+                return SeparatorViewHolder.create(parent, false);
         }
 
         assert false;

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/holder/SectionTitleViewHolder.java

+// Copyright 2018 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.download.home.list.holder;
+
+import android.content.res.Resources;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.download.home.list.ListItem;
+import org.chromium.chrome.browser.download.home.list.ListUtils;
+import org.chromium.chrome.browser.modelutil.PropertyModel;
+import org.chromium.components.offline_items_collection.OfflineItemFilter;
+
+/**
+ * A {@link ViewHolder} specifically meant to display a section header.
+ */
+public class SectionTitleViewHolder extends ListItemViewHolder {
+    /** Create a new {@link SectionTitleViewHolder} instance. */
+    public static SectionTitleViewHolder create(ViewGroup parent) {
+        View view = LayoutInflater.from(parent.getContext())
+                            .inflate(R.layout.download_manager_section_header, null);
+        return new SectionTitleViewHolder(view);
+    }
+
+    private SectionTitleViewHolder(View view) {
+        super(view);
+    }
+
+    // ListItemViewHolder implementation.
+    @Override
+    public void bind(PropertyModel properties, ListItem item) {
+        ListItem.SectionHeaderListItem sectionItem = (ListItem.SectionHeaderListItem) item;
+        ((TextView) itemView).setText(ListUtils.getTextForSection(sectionItem.filter));
+
+        boolean isPhoto = sectionItem.filter == OfflineItemFilter.FILTER_IMAGE;
+        Resources resources = itemView.getContext().getResources();
+
+        int paddingTop = resources.getDimensionPixelSize(isPhoto
+                        ? R.dimen.download_manager_section_title_padding_image
+                        : R.dimen.download_manager_section_title_padding_top);
+        int paddingBottom = resources.getDimensionPixelSize(isPhoto
+                        ? R.dimen.download_manager_section_title_padding_image
+                        : R.dimen.download_manager_section_title_padding_bottom);
+
+        if (sectionItem.isFirstSectionOfDay) {
+            paddingTop = resources.getDimensionPixelSize(
+                    R.dimen.download_manager_section_title_padding_top_condensed);
+        }
+
+        itemView.setPadding(
+                itemView.getPaddingLeft(), paddingTop, itemView.getPaddingRight(), paddingBottom);
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/holder/SeparatorViewHolder.java

+// Copyright 2018 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.download.home.list.holder;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.download.home.list.ListItem;
+import org.chromium.chrome.browser.modelutil.PropertyModel;
+
+/**
+ * A {@link ViewHolder} specifically meant to display a separator.
+ */
+public class SeparatorViewHolder extends ListItemViewHolder {
+    /**
+     * Creates a new {@link SeparatorViewHolder} instance.
+     * @param isDateDivider Whether the divider is between dates or individual sections.
+     */
+    public static SeparatorViewHolder create(ViewGroup parent, boolean isDateDivider) {
+        View dividerView =
+                LayoutInflater.from(parent.getContext())
+                        .inflate(isDateDivider ? R.layout.download_manager_date_separator
+                                               : R.layout.download_manager_section_separator,
+                                null);
+        return new SeparatorViewHolder(dividerView);
+    }
+
+    private SeparatorViewHolder(View view) {
+        super(view);
+    }
+
+    // ListItemViewHolder implementation.
+    @Override
+    public void bind(PropertyModel properties, ListItem item) {}
+}

chrome/android/java_sources.gni

@@ -495,6 +495,8 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/download/home/list/holder/ListItemViewHolder.java",
   "java/src/org/chromium/chrome/browser/download/home/list/holder/MoreButtonViewHolder.java",
   "java/src/org/chromium/chrome/browser/download/home/list/holder/PrefetchViewHolder.java",
+  "java/src/org/chromium/chrome/browser/download/home/list/holder/SectionTitleViewHolder.java",
+  "java/src/org/chromium/chrome/browser/download/home/list/holder/SeparatorViewHolder.java",
   "java/src/org/chromium/chrome/browser/download/home/list/holder/ThumbnailAwareViewHolder.java",
   "java/src/org/chromium/chrome/browser/download/home/list/holder/VideoViewHolder.java",
   "java/src/org/chromium/chrome/browser/download/home/list/ListProperties.java",

chrome/android/junit/src/org/chromium/chrome/browser/download/home/filter/FiltersTest.java

@@ -18,17 +18,17 @@ import org.chromium.components.offline_items_collection.OfflineItemFilter;
 public class FiltersTest {
     @Test
     public void testFilterConversions() {
-        Assert.assertEquals(
-                Filters.FilterType.SITES, Filters.fromOfflineItem(OfflineItemFilter.FILTER_PAGE));
-        Assert.assertEquals(
-                Filters.FilterType.VIDEOS, Filters.fromOfflineItem(OfflineItemFilter.FILTER_VIDEO));
-        Assert.assertEquals(
-                Filters.FilterType.MUSIC, Filters.fromOfflineItem(OfflineItemFilter.FILTER_AUDIO));
-        Assert.assertEquals(
-                Filters.FilterType.IMAGES, Filters.fromOfflineItem(OfflineItemFilter.FILTER_IMAGE));
-        Assert.assertEquals(
-                Filters.FilterType.OTHER, Filters.fromOfflineItem(OfflineItemFilter.FILTER_OTHER));
-        Assert.assertEquals(Filters.FilterType.OTHER,
+        Assert.assertEquals(Integer.valueOf(Filters.FilterType.SITES),
+                Filters.fromOfflineItem(OfflineItemFilter.FILTER_PAGE));
+        Assert.assertEquals(Integer.valueOf(Filters.FilterType.VIDEOS),
+                Filters.fromOfflineItem(OfflineItemFilter.FILTER_VIDEO));
+        Assert.assertEquals(Integer.valueOf(Filters.FilterType.MUSIC),
+                Filters.fromOfflineItem(OfflineItemFilter.FILTER_AUDIO));
+        Assert.assertEquals(Integer.valueOf(Filters.FilterType.IMAGES),
+                Filters.fromOfflineItem(OfflineItemFilter.FILTER_IMAGE));
+        Assert.assertEquals(Integer.valueOf(Filters.FilterType.OTHER),
+                Filters.fromOfflineItem(OfflineItemFilter.FILTER_OTHER));
+        Assert.assertEquals(Integer.valueOf(Filters.FilterType.OTHER),
                 Filters.fromOfflineItem(OfflineItemFilter.FILTER_DOCUMENT));
     }
 }
\ No newline at end of file