From 91bec536ac5a86ff48167fbe71ed7346d9c6fe4e Mon Sep 17 00:00:00 2001
From: Ben Kwa <kenobi@google.com>
Date: Wed, 16 Sep 2015 13:15:38 -0700
Subject: [PATCH] DocumentsUI: Add an error screen to DirectoryFragment.

- Reorganize the directory fragment.
- Repurpose the "empty" view to hold a message and a button.
- Message is set to the "No items" message if a directory is empty.
- Message is set to the error message if a query error occurs.
- Don't close DocumentsUI when a query error occurs.

Change-Id: I4e1e96f23040606b410ac746252dcb0ab9286f04
---
 .../res/layout/fragment_directory.xml         | 99 ++++++++++---------
 packages/DocumentsUI/res/values/strings.xml   |  3 +-
 .../documentsui/DirectoryFragment.java        | 51 +++++-----
 .../android/documentsui/DirectoryView.java    |  4 +-
 4 files changed, 85 insertions(+), 72 deletions(-)

diff --git a/packages/DocumentsUI/res/layout/fragment_directory.xml b/packages/DocumentsUI/res/layout/fragment_directory.xml
index b02349a693f62..45cb34db54e0f 100644
--- a/packages/DocumentsUI/res/layout/fragment_directory.xml
+++ b/packages/DocumentsUI/res/layout/fragment_directory.xml
@@ -17,61 +17,70 @@
 <com.android.documentsui.DirectoryView xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="@color/material_grey_50">
+    android:background="@color/material_grey_50"
+    android:orientation="vertical"
+    android:animateLayoutChanges="true">
 
-    <TextView
-        android:id="@android:id/empty"
+    <ProgressBar
+        android:id="@+id/progressbar"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:gravity="center"
-        android:text="@string/empty"
-        android:visibility="gone"
-        style="@android:style/TextAppearance.Material.Subhead" />
+        android:layout_height="wrap_content"
+        android:indeterminate="true"
+        style="@style/TrimmedHorizontalProgressBar"
+        android:visibility="gone"/>
+  
+    <FrameLayout
+        android:id="@+id/container_message_bar"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:elevation="8dp"
+        android:background="@color/material_grey_50"
+        android:visibility="gone"/>
 
+    <!-- The empty directory view -->
     <LinearLayout
-        android:id="@+id/content"
+        android:id="@android:id/empty"
+        android:gravity="center"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical"
-        android:animateLayoutChanges="true">
-
-        <ProgressBar
-            android:id="@+id/progressbar"
-            android:layout_width="match_parent"
+        android:visibility="gone">
+        
+        <TextView
+            android:id="@+id/message"
+            android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:indeterminate="true"
-            style="@style/TrimmedHorizontalProgressBar"
-            android:visibility="gone"/>
+            android:text="@string/empty"
+            style="@android:style/TextAppearance.Material.Subhead" />
 
-        <FrameLayout
-            android:id="@+id/container_message_bar"
-            android:layout_width="match_parent"
+         <Button
+            android:id="@+id/button_retry"
+            android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:elevation="8dp"
-            android:background="@color/material_grey_50"
-            android:visibility="gone"/>
-
-        <!-- This FrameLayout works around b/24189541 -->
-        <FrameLayout
-            android:layout_width="match_parent"
-            android:layout_height="match_parent">
-
-            <android.support.v7.widget.RecyclerView
-                android:id="@+id/recyclerView"
-                android:scrollbars="vertical"
-                android:layout_width="match_parent"
-                android:layout_height="match_parent"
-                android:paddingStart="@dimen/grid_padding_horiz"
-                android:paddingEnd="@dimen/grid_padding_horiz"
-                android:paddingTop="@dimen/grid_padding_vert"
-                android:paddingBottom="@dimen/grid_padding_vert"
-                android:clipToPadding="false"
-                android:scrollbarStyle="outsideOverlay"
-                android:drawSelectorOnTop="true"
-                android:background="@color/directory_background" />
-
-        </FrameLayout>
-
+            android:text="@string/button_retry"
+            style="?android:attr/buttonBarPositiveButtonStyle" />
+        
     </LinearLayout>
+    
+    <!-- This FrameLayout works around b/24189541 -->
+    <FrameLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <android.support.v7.widget.RecyclerView
+            android:id="@+id/recyclerView"
+            android:scrollbars="vertical"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:paddingStart="@dimen/grid_padding_horiz"
+            android:paddingEnd="@dimen/grid_padding_horiz"
+            android:paddingTop="@dimen/grid_padding_vert"
+            android:paddingBottom="@dimen/grid_padding_vert"
+            android:clipToPadding="false"
+            android:scrollbarStyle="outsideOverlay"
+            android:drawSelectorOnTop="true"
+            android:background="@color/directory_background" />
+
+    </FrameLayout>
 
 </com.android.documentsui.DirectoryView>
diff --git a/packages/DocumentsUI/res/values/strings.xml b/packages/DocumentsUI/res/values/strings.xml
index 28018f8eceece..a12edf397178e 100644
--- a/packages/DocumentsUI/res/values/strings.xml
+++ b/packages/DocumentsUI/res/values/strings.xml
@@ -81,7 +81,8 @@
     <string name="button_move">Move</string>
     <!-- Button label that hides the error bar [CHAR LIMIT=24] -->
     <string name="button_dismiss">Dismiss</string>
-
+    <string name="button_retry">Try Again</string>
+    
     <!-- Mode that sorts documents by their display name alphabetically [CHAR LIMIT=24] -->
     <string name="sort_name">By name</string>
     <!-- Mode that sorts documents by their last modified time in descending order; most recent first [CHAR LIMIT=24] -->
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java b/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java
index 1a17b6c639974..a891cfdc718e4 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java
@@ -369,21 +369,6 @@ public class DirectoryFragment extends Fragment {
 
             @Override
             public void onLoadFinished(Loader<DirectoryResult> loader, DirectoryResult result) {
-                if (result == null || result.exception != null) {
-                    // onBackPressed does a fragment transaction, which can't be done inside
-                    // onLoadFinished
-                    mHandler.post(new Runnable() {
-                        @Override
-                        public void run() {
-                            final Activity activity = getActivity();
-                            if (activity != null) {
-                                activity.onBackPressed();
-                            }
-                        }
-                    });
-                    return;
-                }
-
                 if (!isAdded()) return;
 
                 mModel.update(result);
@@ -900,6 +885,29 @@ public class DirectoryFragment extends Fragment {
         }
     }
 
+    void showEmptyView() {
+        mEmptyView.setVisibility(View.VISIBLE);
+        mRecView.setVisibility(View.GONE);
+        TextView msg = (TextView) mEmptyView.findViewById(R.id.message);
+        msg.setText(R.string.empty);
+        // No retry button for the empty view.
+        mEmptyView.findViewById(R.id.button_retry).setVisibility(View.GONE);
+    }
+
+    void showErrorView() {
+        mEmptyView.setVisibility(View.VISIBLE);
+        mRecView.setVisibility(View.GONE);
+        TextView msg = (TextView) mEmptyView.findViewById(R.id.message);
+        msg.setText(R.string.query_error);
+        // TODO: Enable this once the retry button does something.
+        mEmptyView.findViewById(R.id.button_retry).setVisibility(View.GONE);
+    }
+
+    void showRecyclerView() {
+        mEmptyView.setVisibility(View.GONE);
+        mRecView.setVisibility(View.VISIBLE);
+    }
+
     private final class DocumentsAdapter extends RecyclerView.Adapter<DocumentHolder> {
 
         private final Context mContext;
@@ -1955,21 +1963,16 @@ public class DirectoryFragment extends Fragment {
             mProgressBar.setVisibility(model.isLoading() ? View.VISIBLE : View.GONE);
 
             if (model.isEmpty()) {
-                mEmptyView.setVisibility(View.VISIBLE);
-                mRecView.setVisibility(View.GONE);
+                showEmptyView();
             } else {
-                mEmptyView.setVisibility(View.GONE);
-                mRecView.setVisibility(View.VISIBLE);
+                showRecyclerView();
+                mAdapter.notifyDataSetChanged();
             }
-
-            mAdapter.notifyDataSetChanged();
         }
 
         @Override
         public void onModelUpdateFailed(Exception e) {
-            // TODO: deal with catastrophic update failures
-            String error = getString(R.string.query_error);
-            mAdapter.notifyDataSetChanged();
+            showErrorView();
         }
     }
 }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DirectoryView.java b/packages/DocumentsUI/src/com/android/documentsui/DirectoryView.java
index 4893652c4849f..000b92a0b1a54 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DirectoryView.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DirectoryView.java
@@ -18,9 +18,9 @@ package com.android.documentsui;
 
 import android.content.Context;
 import android.util.AttributeSet;
-import android.widget.FrameLayout;
+import android.widget.LinearLayout;
 
-public class DirectoryView extends FrameLayout {
+public class DirectoryView extends LinearLayout {
     private float mPosition = 0f;
 
     private int mWidth;