ResourceResolvers.java
/*
* Copyright 2021 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.
*/
package androidx.wear.tiles.renderer.internal;
import android.annotation.SuppressLint;
import android.graphics.drawable.Drawable;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.concurrent.futures.ResolvableFuture;
import androidx.wear.protolayout.proto.ResourceProto;
import androidx.wear.protolayout.proto.ResourceProto.AndroidImageResourceByResId;
import androidx.wear.protolayout.proto.ResourceProto.InlineImageResource;
import com.google.common.util.concurrent.ListenableFuture;
/**
* Class for resolving resources. Delegates the actual work to different types of resolver classes,
* and allows each type of resolver to be configured individually, as well as instantiation from
* common resolver implementations.
*/
public class ResourceResolvers {
private final ResourceProto.Resources mProtoResources;
@Nullable
private final AndroidImageResourceByResIdResolver mAndroidImageResourceByResIdResolver;
@Nullable private final InlineImageResourceResolver mInlineImageResourceResolver;
ResourceResolvers(
@NonNull ResourceProto.Resources protoResources,
@Nullable AndroidImageResourceByResIdResolver androidImageResourceByResIdResolver,
@Nullable InlineImageResourceResolver inlineImageResourceResolver) {
this.mProtoResources = protoResources;
this.mAndroidImageResourceByResIdResolver = androidImageResourceByResIdResolver;
this.mInlineImageResourceResolver = inlineImageResourceResolver;
}
/** Exception thrown when accessing resources. */
public static final class ResourceAccessException extends Exception {
public ResourceAccessException(@NonNull String description) {
super(description);
}
public ResourceAccessException(@NonNull String description, @NonNull Exception cause) {
super(description, cause);
}
}
/** Interface that can provide a Drawable for an AndroidImageResourceByResId */
public interface AndroidImageResourceByResIdResolver {
/**
* Should immediately return the drawable specified by {@code resource}.
*
* @throws ResourceAccessException If the drawable cannot be found, or has to be loaded
* asynchronously.
*/
@NonNull
Drawable getDrawableOrThrow(@NonNull AndroidImageResourceByResId resource)
throws ResourceAccessException;
/** Get the drawable as specified by {@code resource}. */
@NonNull
ListenableFuture<Drawable> getDrawable(@NonNull AndroidImageResourceByResId resource);
}
/** Interface that can provide a Drawable for an InlineImageResource */
public interface InlineImageResourceResolver {
/**
* Should immediately return the drawable specified by {@code resource}.
*
* @throws ResourceAccessException If the drawable cannot be found, or has to be loaded
* asynchronously.
*/
@NonNull
Drawable getDrawableOrThrow(@NonNull InlineImageResource resource)
throws ResourceAccessException;
/** Get the drawable as specified by {@code resource}. */
@NonNull
ListenableFuture<Drawable> getDrawable(@NonNull InlineImageResource resource);
}
/** Get an empty builder to build {@link ResourceResolvers} with. */
@NonNull
public static Builder builder(@NonNull ResourceProto.Resources protoResources) {
return new Builder(protoResources);
}
/**
* Returns whether the resource specified by {@code protoResourceId} has a placeholder resource
* associated with it.
*/
public boolean hasPlaceholderDrawable(@NonNull String protoResourceId) {
return getPlaceholderResourceId(protoResourceId) != null;
}
/**
* Returns the placeholder drawable for the resource specified by {@code protoResourceId}.
*
* @throws ResourceAccessException If the specified resource does not have a placeholder
* associated, or the placeholder could not be loaded.
* @throws IllegalArgumentException If the specified resource, or its placeholder, does not
* exist.
* @see ResourceResolvers#hasPlaceholderDrawable(String)
*/
@NonNull
public Drawable getPlaceholderDrawableOrThrow(@NonNull String protoResourceId)
throws ResourceAccessException {
String placeholderResourceId = getPlaceholderResourceId(protoResourceId);
if (placeholderResourceId == null) {
throw new ResourceAccessException(
"Resource " + protoResourceId + " does not have a placeholder resource.");
}
ResourceProto.ImageResource placeholderImageResource =
mProtoResources.getIdToImageMap().get(placeholderResourceId);
if (placeholderImageResource == null) {
throw new IllegalArgumentException(
"Resource " + placeholderResourceId + " is not defined in resources bundle");
}
if (placeholderImageResource.hasAndroidResourceByResId()
&& mAndroidImageResourceByResIdResolver != null) {
AndroidImageResourceByResIdResolver resolver = mAndroidImageResourceByResIdResolver;
return resolver.getDrawableOrThrow(
placeholderImageResource.getAndroidResourceByResId());
}
if (placeholderImageResource.hasInlineResource() && mInlineImageResourceResolver != null) {
InlineImageResourceResolver resolver = mInlineImageResourceResolver;
return resolver.getDrawableOrThrow(placeholderImageResource.getInlineResource());
}
throw new ResourceAccessException("Can't find resolver for image resource.");
}
/** Get the drawable corresponding to the given resource ID. */
@NonNull
public ListenableFuture<Drawable> getDrawable(@NonNull String protoResourceId) {
ResourceProto.ImageResource imageResource =
mProtoResources.getIdToImageMap().get(protoResourceId);
if (imageResource == null) {
return createFailedFuture(
new IllegalArgumentException(
"Resource " + protoResourceId + " is not defined in resources bundle"));
}
if (imageResource.hasAndroidResourceByResId()
&& mAndroidImageResourceByResIdResolver != null) {
AndroidImageResourceByResIdResolver resolver = mAndroidImageResourceByResIdResolver;
return resolver.getDrawable(imageResource.getAndroidResourceByResId());
}
if (imageResource.hasInlineResource() && mInlineImageResourceResolver != null) {
InlineImageResourceResolver resolver = mInlineImageResourceResolver;
return resolver.getDrawable(imageResource.getInlineResource());
}
return createFailedFuture(
new ResourceAccessException(
"Can't find resolver for image resource " + protoResourceId));
}
public boolean canImageBeTinted(@NonNull String protoResourceId) {
// Only Android image resources can be tinted for now. This is because we don't really know
// what is in an inline image.
ResourceProto.ImageResource imageResource =
mProtoResources.getIdToImageMap().get(protoResourceId);
if (imageResource == null) {
throw new IllegalArgumentException(
"Resource " + protoResourceId + " is not defined in resources bundle");
}
if (imageResource.hasAndroidResourceByResId()) {
return true;
}
return false;
}
@Nullable
private String getPlaceholderResourceId(@NonNull String originalResourceId) {
ResourceProto.ImageResource imageResource =
mProtoResources.getIdToImageMap().get(originalResourceId);
if (imageResource == null) {
throw new IllegalArgumentException(
"Resource " + originalResourceId + " is not defined in resources bundle");
}
return null;
}
@SuppressLint("RestrictedApi") // TODO(b/183006740): Remove when prefix check is fixed.
static <T> ListenableFuture<T> createImmediateFuture(@NonNull T value) {
ResolvableFuture<T> future = ResolvableFuture.create();
future.set(value);
return future;
}
@SuppressLint("RestrictedApi") // TODO(b/183006740): Remove when prefix check is fixed.
static <T> ListenableFuture<T> createFailedFuture(@NonNull Throwable throwable) {
ResolvableFuture<T> errorFuture = ResolvableFuture.create();
errorFuture.setException(throwable);
return errorFuture;
}
/** Builder for ResourceResolvers */
public static final class Builder {
@NonNull private final ResourceProto.Resources mProtoResources;
@Nullable private AndroidImageResourceByResIdResolver mAndroidImageResourceByResIdResolver;
@Nullable private InlineImageResourceResolver mInlineImageResourceResolver;
Builder(@NonNull ResourceProto.Resources protoResources) {
this.mProtoResources = protoResources;
}
/** Set the resource loader for {@link AndroidImageResourceByResIdResolver} resources. */
@NonNull
@SuppressLint("MissingGetterMatchingBuilder")
public Builder setAndroidImageResourceByResIdResolver(
@NonNull AndroidImageResourceByResIdResolver resolver) {
mAndroidImageResourceByResIdResolver = resolver;
return this;
}
/** Set the resource loader for {@link InlineImageResourceResolver} resources. */
@NonNull
@SuppressLint("MissingGetterMatchingBuilder")
public Builder setInlineImageResourceResolver(
@NonNull InlineImageResourceResolver resolver) {
mInlineImageResourceResolver = resolver;
return this;
}
/** Build a {@link ResourceResolvers} instance. */
@NonNull
public ResourceResolvers build() {
return new ResourceResolvers(
mProtoResources,
mAndroidImageResourceByResIdResolver,
mInlineImageResourceResolver);
}
}
}