Add loading state to the image preview UI

Preview headline loading label is based on the target intent's mime
type.
Circular indeterminated indicator gets shown for loading previews.

Bug: 292157413
Test: manual testing with ShareTest app; unit tests.
Change-Id: I55ec1036a65720fa73c18828fc7a7686de70fa57

1 files changed, 32 insertions, 0 deletions

diff --git a/java/res/layout/image_preview_loading_item.xml b/java/res/layout/image_preview_loading_item.xml
new file mode 100644
index 00000000..85020e9a
--- /dev/null
+++ b/java/res/layout/image_preview_loading_item.xml
@@ -0,0 +1,32 @@
+<!--
+  ~ Copyright (C) 2023 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
+    android:layout_width="@dimen/chooser_preview_image_width"
+    android:layout_height="@dimen/chooser_preview_image_height_tall">
+
+    <ProgressBar
+        android:id="@+id/loading_indicator"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:indeterminate="true"
+        android:indeterminateTint="?androidprv:attr/materialColorPrimary"
+        android:indeterminateTintMode="src_in" />
+
+</FrameLayout>