Adjust AppWidgetProviderInfo#getDescription to return CharSequence.

Also add more developer docs.

Test: atest AppWidgetServiceImplTest#testLoadDescription passed
Bug: b/180015383
Change-Id: Ie6fff9d880ba4721bf6babcd51acaa8fc9bd3cd9

core/api/current.txt

@@ -8426,7 +8426,7 @@ package android.appwidget {
     method public int describeContents();
     method public final android.os.UserHandle getProfile();
     method @NonNull public android.content.pm.ActivityInfo getProviderInfo();
-    method @Nullable public final String loadDescription(@NonNull android.content.Context);
+    method @Nullable public final CharSequence loadDescription(@NonNull android.content.Context);
     method public final android.graphics.drawable.Drawable loadIcon(@NonNull android.content.Context, int);
     method public final String loadLabel(android.content.pm.PackageManager);
     method public final android.graphics.drawable.Drawable loadPreviewImage(@NonNull android.content.Context, int);
@@ -8444,7 +8444,7 @@ package android.appwidget {
     field public static final int WIDGET_FEATURE_RECONFIGURABLE = 1; // 0x1
     field public int autoAdvanceViewId;
     field public android.content.ComponentName configure;
-    field @IdRes public int descriptionResource;
+    field @IdRes public int descriptionRes;
     field public int icon;
     field public int initialKeyguardLayout;
     field public int initialLayout;

core/java/android/appwidget/AppWidgetProviderInfo.java

@@ -332,12 +332,13 @@ public class AppWidgetProviderInfo implements Parcelable {
 
     /**
      * Resource id for the description of the AppWidget.
+     *
      * <p>This field corresponds to the <code>android:description</code> attribute in the AppWidget
      * meta-data file.
      */
     @SuppressLint("MutableBareField")
     @IdRes
-    public int descriptionResource;
+    public int descriptionRes;
 
     /**
      * Flags indicating various features supported by the widget. These are hints to the widget
@@ -385,7 +386,7 @@ public class AppWidgetProviderInfo implements Parcelable {
         this.widgetCategory = in.readInt();
         this.providerInfo = in.readTypedObject(ActivityInfo.CREATOR);
         this.widgetFeatures = in.readInt();
-        this.descriptionResource = in.readInt();
+        this.descriptionRes = in.readInt();
     }
 
     /**
@@ -442,14 +443,22 @@ public class AppWidgetProviderInfo implements Parcelable {
         return loadDrawable(context, density, previewImage, false);
     }
 
-    /** Loads localized description for the app widget. */
+    /**
+     * Loads localized description for the app widget.
+     *
+     * <p>Description is intended to be displayed in the UI of the widget picker.
+     *
+     * @param context Context for accessing resources.
+     *
+     * @return CharSequence for app widget description for the current locale.
+     */
     @Nullable
-    public final String loadDescription(@NonNull Context context) {
-        if (ResourceId.isValid(descriptionResource)) {
+    public final CharSequence loadDescription(@NonNull Context context) {
+        if (ResourceId.isValid(descriptionRes)) {
             return context.getPackageManager()
                     .getText(
                             providerInfo.packageName,
-                            descriptionResource,
+                            descriptionRes,
                             providerInfo.applicationInfo)
                     .toString()
                     .trim();
@@ -499,7 +508,7 @@ public class AppWidgetProviderInfo implements Parcelable {
         out.writeInt(this.widgetCategory);
         out.writeTypedObject(this.providerInfo, flags);
         out.writeInt(this.widgetFeatures);
-        out.writeInt(this.descriptionResource);
+        out.writeInt(this.descriptionRes);
     }
 
     @Override
@@ -528,7 +537,7 @@ public class AppWidgetProviderInfo implements Parcelable {
         that.widgetCategory = this.widgetCategory;
         that.providerInfo = this.providerInfo;
         that.widgetFeatures = this.widgetFeatures;
-        that.descriptionResource = this.descriptionResource;
+        that.descriptionRes = this.descriptionRes;
         return that;
     }
 

services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java

@@ -2673,7 +2673,7 @@ class AppWidgetServiceImpl extends IAppWidgetService.Stub implements WidgetBacku
                     AppWidgetProviderInfo.WIDGET_CATEGORY_HOME_SCREEN);
             info.widgetFeatures = sa.getInt(
                     com.android.internal.R.styleable.AppWidgetProviderInfo_widgetFeatures, 0);
-            info.descriptionResource = sa.getResourceId(
+            info.descriptionRes = sa.getResourceId(
                     com.android.internal.R.styleable.AppWidgetProviderInfo_description,
                     Resources.ID_NULL);
             sa.recycle();