[Downloads] Expose basic download history to UI

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

Index: chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java b/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
new file mode 100644
index 0000000000000000000000000000000000000000..910146d7c3eda617750134753dedddfa75bac8dc
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java
@@ -0,0 +1,137 @@
+// 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.download.ui;
+
+import android.content.Context;
+import android.support.v7.widget.RecyclerView;
+import android.text.TextUtils;
+import android.text.format.Formatter;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.download.DownloadItem;
+import org.chromium.chrome.browser.util.UrlUtilities;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** Bridges the user's download history and the UI used to display it. */
+public class DownloadHistoryAdapter
+        extends RecyclerView.Adapter<DownloadHistoryAdapter.ViewHolder> {
+
+    /** Holds onto a View that displays information about a downloaded file. */
+    static class ViewHolder extends RecyclerView.ViewHolder {
+        public ImageView mIconView;
+        public TextView mFilenameView;
+        public TextView mHostnameView;
+        public TextView mFilesizeView;
+
+        public ViewHolder(View itemView) {
+            super(itemView);
+            mIconView = (ImageView) itemView.findViewById(R.id.icon_view);
+            mFilenameView = (TextView) itemView.findViewById(R.id.filename_view);
+            mHostnameView = (TextView) itemView.findViewById(R.id.hostname_view);
+            mFilesizeView = (TextView) itemView.findViewById(R.id.filesize_view);
+        }
+    }
+
+    private static final int FILETYPE_OTHER = 0;
+    private static final int FILETYPE_PAGE = 1;
+    private static final int FILETYPE_VIDEO = 2;
+    private static final int FILETYPE_AUDIO = 3;
+    private static final int FILETYPE_IMAGE = 4;
+    private static final int FILETYPE_DOCUMENT = 5;
+
+    private static final String MIMETYPE_VIDEO = "video";
+    private static final String MIMETYPE_AUDIO = "audio";
+    private static final String MIMETYPE_IMAGE = "image";
+    private static final String MIMETYPE_DOCUMENT = "text";
+
+    private final List<DownloadItem> mDownloadItems = new ArrayList<>();
+
+    /** Called when the user's download history has been gathered into a List of DownloadItems. */
+    public void onAllDownloadsRetrieved(DownloadItem[] list) {
+        mDownloadItems.clear();
+        for (DownloadItem item : list) mDownloadItems.add(item);
+        notifyDataSetChanged();
+    }
+
+    @Override
+    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+        View v = LayoutInflater.from(parent.getContext()).inflate(
+                R.layout.download_history_adapter_view, parent, false);
+        return new ViewHolder(v);
+    }
+
+    @Override
+    public void onBindViewHolder(ViewHolder holder, int position) {
+        Context context = holder.mFilesizeView.getContext();
+
+        DownloadItem item = mDownloadItems.get(position);
+        holder.mFilenameView.setText(item.getDownloadInfo().getFileName());
+        holder.mHostnameView.setText(
+                UrlUtilities.formatUrlForSecurityDisplay(item.getDownloadInfo().getUrl(), false));
+        holder.mFilesizeView.setText(
+                Formatter.formatFileSize(context, item.getDownloadInfo().getContentLength()));
+
+        // Pick what icon to display for the item.
+        int fileType = convertMimeTypeToFileType(item.getDownloadInfo().getMimeType());
+        int iconResource = R.drawable.ic_drive_file_white_24dp;
+        switch (fileType) {
+            case FILETYPE_PAGE:
+                iconResource = R.drawable.ic_drive_site_white_24dp;
+                break;
+            case FILETYPE_VIDEO:
+                iconResource = R.drawable.ic_music_video_white_24dp;
+                break;
+            case FILETYPE_AUDIO:
+                iconResource = R.drawable.ic_music_note_white_24dp;
+                break;
+            case FILETYPE_IMAGE:
+                iconResource = R.drawable.ic_image_white_24dp;
+                break;
+            case FILETYPE_DOCUMENT:
+                iconResource = R.drawable.ic_drive_file_white_24dp;
+                break;
+            default:
+        }
+
+        holder.mIconView.setImageResource(iconResource);
+    }
+
+    @Override
+    public int getItemCount() {
+        return mDownloadItems.size();
+    }
+
+    /** Clears out all of the downloads tracked by the Adapter. */
+    public void clear() {
+        mDownloadItems.clear();
+    }
+
+    /** Identifies the type of file represented by the given MIME type string. */
+    private static int convertMimeTypeToFileType(String mimeType) {
+        if (TextUtils.isEmpty(mimeType)) return FILETYPE_OTHER;
+
+        String[] pieces = mimeType.toLowerCase().split("/");
+        if (pieces.length != 2) return FILETYPE_OTHER;
+
+        if (MIMETYPE_VIDEO.equals(pieces[0])) {
+            return FILETYPE_VIDEO;
+        } else if (MIMETYPE_AUDIO.equals(pieces[0])) {
+            return FILETYPE_AUDIO;
+        } else if (MIMETYPE_IMAGE.equals(pieces[0])) {
+            return FILETYPE_IMAGE;
+        } else if (MIMETYPE_DOCUMENT.equals(pieces[0])) {
+            return FILETYPE_DOCUMENT;
+        } else {
+            return FILETYPE_OTHER;
+        }
+    }
+}