[Download Home] Displaying offline page bundle per day

chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadItemGroup.java

+// Copyright 2017 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.ui;
+
+import org.chromium.chrome.browser.download.ui.DownloadHistoryAdapter.SubsectionHeader;
+import org.chromium.chrome.browser.download.ui.DownloadHistoryItemWrapper.OfflinePageItemWrapper;
+import org.chromium.chrome.browser.widget.DateDividedAdapter;
+import org.chromium.chrome.browser.widget.DateDividedAdapter.TimedItem;
+
+/**
+ * A bucket of downloaded items with the same date. It also holds the suggested offline items which
+ * are shown at the end of the list for that date.
+ */
+public class DownloadItemGroup extends DateDividedAdapter.ItemGroup {
+    public DownloadItemGroup(long timestamp) {
+        super(timestamp);
+    }
+
+    private boolean isSuggestedOfflinePage(TimedItem timedItem) {
+        if (timedItem instanceof OfflinePageItemWrapper) {
+            return ((OfflinePageItemWrapper) timedItem).isSuggested();
+        }
+
+        return false;
+    }
+
+    @Override
+    public int compareItem(TimedItem lhs, TimedItem rhs) {
+        int lhsOrder = order(lhs);
+        int rhsOrder = order(rhs);
+
+        if (lhsOrder != rhsOrder) {
+            return lhsOrder < rhsOrder ? -1 : 1;
+        }
+
+        return super.compareItem(lhs, rhs);
+    }
+
+    /**
+     * A sorting helper function based on the item type. The items in the list view are placed from
+     * the top in the following order: download items, suggested pages header, suggested pages.
+     * @param timedItem The item to be displayed.
+     * @return An integer based on the item type which is to be used for sorting.
+     */
+    private int order(TimedItem timedItem) {
+        if (isSuggestedOfflinePage(timedItem)) {
+            return 2;
+        } else if (timedItem instanceof SubsectionHeader) {
+            return 1;
+        } else {
+            return 0;
+        }
+    }
+}