add loading shimmer for preview image

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

drawable_resources/ic_image-outline.svg

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="24" height="24" viewBox="0 0 24 24"><path d="M19,19H5V5H19M19,3H5A2,2 0 0,0 3,5V19A2,2 0 0,0 5,21H19A2,2 0 0,0 21,19V5A2,2 0 0,0 19,3M13.96,12.29L11.21,15.83L9.25,13.47L6.5,17H17.5L13.96,12.29Z" /></svg>

src/main/java/com/owncloud/android/ui/preview/PreviewImageFragment.java

@@ -46,6 +46,7 @@ import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;
@@ -117,6 +118,7 @@ public class PreviewImageFragment extends FileFragment implements Injectable {
     private TextView mMultiListMessage;
     private TextView mMultiListHeadline;
     private ImageView mMultiListIcon;
+    private FrameLayout mMultiListProgress;
 
     private Boolean showResizedImage;
 
@@ -216,6 +218,7 @@ public class PreviewImageFragment extends FileFragment implements Injectable {
         multiListMessage = binding.emptyList.emptyListViewText;
         multiListHeadline = binding.emptyList.emptyListViewHeadline;
         multiListIcon = binding.emptyList.emptyListIcon;
+        mMultiListProgress = view.findViewById(R.id.empty_list_progress);
     }
 
     /**
@@ -699,11 +702,12 @@ public class PreviewImageFragment extends FileFragment implements Injectable {
     }
 
     private void setMultiListLoadingMessage() {
-        if (multiListContainer != null) {
+        if (mMultiListContainer != null) {
-            multiListHeadline.setText(R.string.file_list_loading);
+            mMultiListHeadline.setText("");
-            multiListMessage.setText("");
+            mMultiListMessage.setText("");
 
             mMultiListIcon.setVisibility(View.GONE);
+            mMultiListProgress.setVisibility(View.VISIBLE);
         }
     }
 
@@ -719,6 +723,7 @@ public class PreviewImageFragment extends FileFragment implements Injectable {
 
             mMultiListMessage.setVisibility(View.VISIBLE);
             mMultiListIcon.setVisibility(View.VISIBLE);
+            mMultiListProgress.setVisibility(View.GONE);
         }
     }
 

src/main/res/drawable/ic_image_outline.xml

@@ -0,0 +1,8 @@
+<!-- drawable/image_outline.xml -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:height="24dp"
+    android:width="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path android:fillColor="#000" android:pathData="M19,19H5V5H19M19,3H5A2,2 0 0,0 3,5V19A2,2 0 0,0 5,21H19A2,2 0 0,0 21,19V5A2,2 0 0,0 19,3M13.96,12.29L11.21,15.83L9.25,13.47L6.5,17H17.5L13.96,12.29Z" />
+</vector>

src/main/res/layout/preview_image_fragment.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?><!--
-<!--
   ownCloud Android client application
 
   Copyright (C) 2015  ownCloud Inc.
@@ -19,6 +18,7 @@
 -->
 
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/top"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ -33,7 +33,78 @@
         android:contentDescription="@string/preview_image_description"
         android:src="@drawable/image_fail" />
 
-    <include
+    <LinearLayout
-        android:id="@+id/emptyList"
+        android:id="@+id/empty_list_view"
-        layout="@layout/empty_list" />
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:layout_margin="@dimen/standard_margin"
+        android:gravity="center_vertical|center_horizontal"
+        android:orientation="vertical"
+        android:paddingBottom="@dimen/standard_double_margin">
+
+        <ImageView
+            android:id="@+id/empty_list_icon"
+            android:layout_width="@dimen/empty_list_icon_layout_width"
+            android:layout_height="@dimen/empty_list_icon_layout_height"
+            android:contentDescription="@string/file_list_folder"
+            android:src="@drawable/ic_list_empty_folder"
+            android:visibility="gone" />
+
+        <FrameLayout
+            android:id="@+id/empty_list_progress"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:visibility="gone">
+
+            <com.elyeproj.loaderviewlibrary.LoaderImageView
+                android:layout_width="@dimen/empty_list_icon_layout_width"
+                android:layout_height="@dimen/empty_list_icon_layout_width"
+                android:layout_gravity="center_horizontal"
+                android:contentDescription="@null"
+                app:corners="24" />
+
+            <ImageView
+                android:layout_width="@dimen/empty_list_icon_layout_width"
+                android:layout_height="@dimen/empty_list_icon_layout_height"
+                android:contentDescription="@null"
+                android:src="@drawable/ic_image_outline"
+                app:tint="@color/fg_inverse" />
+
+        </FrameLayout>
+
+        <TextView
+            android:id="@+id/empty_list_view_headline"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:ellipsize="end"
+            android:gravity="center"
+            android:maxLines="2"
+            android:paddingTop="@dimen/standard_padding"
+            android:paddingBottom="@dimen/standard_half_padding"
+            android:text="@string/file_list_loading"
+            android:textSize="26sp" />
+
+        <TextView
+            android:id="@+id/empty_list_view_text"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:ellipsize="end"
+            android:gravity="center"
+            android:paddingTop="@dimen/standard_half_padding"
+            android:paddingBottom="@dimen/standard_half_padding"
+            android:text="@string/file_list_empty"
+            android:visibility="gone" />
+
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/empty_list_view_action"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="@dimen/standard_half_margin"
+            android:theme="@style/Button.Primary"
+            android:visibility="gone"
+            app:cornerRadius="@dimen/button_corner_radius" />
+    </LinearLayout>
 </RelativeLayout>