src/main/java/com/google/android/libraries/feed/piet/TemplateBinder.java - feed - Git at Google

 // Copyright 2018 The Feed Authors.
 //
 // 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 com.google.android.libraries.feed.piet;

 import static com.google.android.libraries.feed.common.Validators.checkNotNull;
 import static com.google.android.libraries.feed.common.Validators.checkState;

 import android.view.View;
 import com.google.search.now.ui.piet.ElementsProto.BindingContext;
 import com.google.search.now.ui.piet.PietProto.PietSharedState;
 import com.google.search.now.ui.piet.PietProto.Stylesheet;
 import com.google.search.now.ui.piet.PietProto.Template;
 import java.util.List;

 /**
  * Methods to enable creation and binding of Templates.
  *
  * <p>This class creates and binds adapters for templates allowing for reuse of full template
  * layouts as a unit. Release and recycling is handled by the ElementAdapterFactory.
  */
 class TemplateBinder {

   private final KeyedRecyclerPool<ElementAdapter<? extends View, ?>> templateRecyclerPool;
   private final ElementAdapterFactory adapterFactory;

   TemplateBinder(
       KeyedRecyclerPool<ElementAdapter<? extends View, ?>> templateRecyclerPool,
       ElementAdapterFactory adapterFactory) {
     this.templateRecyclerPool = templateRecyclerPool;
     this.adapterFactory = adapterFactory;
   }

   /** Higher-performance method that creates and binds an adapter for a template all at once. */
   ElementAdapter<? extends View, ?> createAndBindTemplateAdapter(
       TemplateAdapterModel model, FrameContext frameContext) {
     // Create the template context for use in both create and bind
     // This is a modestly expensive operation, and calling createTemplateAdapter followed by
     // bindTemplateAdapter would do it twice.
     FrameContext templateContext =
         frameContext.createTemplateContext(model.getTemplate(), model.getBindingContext());

     TemplateKey templateKey = makeTemplateKey(model, frameContext);
     ElementAdapter<? extends View, ?> adapter = templateRecyclerPool.get(templateKey);

     if (adapter == null) {
       // Create new adapter
       adapter =
           adapterFactory.createAdapterForElement(model.getTemplate().getElement(), templateContext);

       adapter.setKey(templateKey);
     }

     adapter.bindModel(model.getTemplate().getElement(), templateContext);

     return adapter;
   }

   ElementAdapter<? extends View, ?> createTemplateAdapter(
       TemplateAdapterModel model, FrameContext frameContext) {
     TemplateKey templateKey = makeTemplateKey(model, frameContext);
     ElementAdapter<? extends View, ?> adapter = templateRecyclerPool.get(templateKey);

     if (adapter == null) {
       // Make new FrameContext here
       FrameContext templateContext =
           frameContext.createTemplateContext(model.getTemplate(), model.getBindingContext());

       // Create new adapter
       adapter =
           adapterFactory.createAdapterForElement(model.getTemplate().getElement(), templateContext);

       adapter.setKey(templateKey);
     }

     return adapter;
   }

   void bindTemplateAdapter(
       ElementAdapter<? extends View, ?> adapter,
       TemplateAdapterModel model,
       FrameContext frameContext) {
     TemplateKey templateKey = makeTemplateKey(model, frameContext);

     checkNotNull(adapter.getKey(), "Adapter key was null; not initialized correctly?");
     checkState(
         adapter.getKey() instanceof TemplateKey,
         "bindTemplateAdapter only applicable for template adapters");
     checkState(templateKey.equals(adapter.getKey()), "Template keys did not match");

     FrameContext templateContext =
         frameContext.createTemplateContext(model.getTemplate(), model.getBindingContext());

     adapter.bindModel(model.getTemplate().getElement(), templateContext);
   }

   private static TemplateKey makeTemplateKey(
       TemplateAdapterModel model, FrameContext frameContext) {
     return new TemplateKey(
         model.getTemplate(),
         frameContext.getPietSharedStates(),
         frameContext.getMediaQueryStylesheets(model.getTemplate()));
   }

   /**
    * Determines whether two templates are compatible for recycling. We're going to call the hash
    * code good enough for performance reasons (.equals() is expensive), and hope we don't get a lot
    * of collisions.
    */
   @SuppressWarnings({"ReferenceEquality", "EqualsUsingHashCode"})
   static boolean templateEquals(/*@Nullable*/ Template template1, /*@Nullable*/ Template template2) {
     if (template1 == template2) {
       return true;
     } else if (template1 == null || template2 == null) {
       return false;
     }
     return template1.hashCode() == template2.hashCode();
   }

   /** Wrap the Template proto object as the recycler key. */
   static class TemplateKey extends RecyclerKey {
     private final Template template;
     /*@Nullable*/ private final List<PietSharedState> pietSharedStates;

     // If the Template references Stylesheets that have MediaQueryConditions on them, they need to
     // be part of the key.
     private final List<Stylesheet> mediaQueryBasedStylesheets;

     TemplateKey(
         Template template,
         /*@Nullable*/ List<PietSharedState> pietSharedStates,
         List<Stylesheet> mediaQueryBasedStylesheets) {
       this.template = template;
       this.pietSharedStates = pietSharedStates;
       this.mediaQueryBasedStylesheets = mediaQueryBasedStylesheets;
     }

     /** Equals checks the hashCode of the component fields to avoid expensive proto equals. */
     @SuppressWarnings({"ReferenceEquality", "EqualsUsingHashCode"})
     @Override
     public boolean equals(/*@Nullable*/ Object o) {
       if (this == o) {
         return true;
       }
       if (!(o instanceof TemplateKey)) {
         return false;
       }

       TemplateKey that = (TemplateKey) o;

       // Check that Templates are equal
       if (!templateEquals(template, that.template)) {
         return false;
       }
       // Check that PietSharedStates are equal or both null
       if (that.pietSharedStates == null ^ this.pietSharedStates == null) {
         return false;
       }
       if (this.pietSharedStates != null
           && that.pietSharedStates != null
           && (this.pietSharedStates.size() != that.pietSharedStates.size()
               || this.pietSharedStates.hashCode() != that.pietSharedStates.hashCode())) {
         return false;
       }
       // Check that stylesheets are equal or both empty
       if (that.mediaQueryBasedStylesheets.isEmpty() ^ this.mediaQueryBasedStylesheets.isEmpty()) {
         return false;
       }
       return this.mediaQueryBasedStylesheets == that.mediaQueryBasedStylesheets
           || this.mediaQueryBasedStylesheets.hashCode()
               == that.mediaQueryBasedStylesheets.hashCode();
     }

     @Override
     public int hashCode() {
       int result = template.hashCode();
       result = 31 * result + (pietSharedStates != null ? pietSharedStates.hashCode() : 0);
       result =
           31 * result
               + (mediaQueryBasedStylesheets != null ? mediaQueryBasedStylesheets.hashCode() : 0);
       return result;
     }
   }

   static class TemplateAdapterModel {
     private final Template template;
     private final BindingContext bindingContext;

     TemplateAdapterModel(Template template, BindingContext bindingContext) {
       this.template = template;
       this.bindingContext = bindingContext;
     }

     TemplateAdapterModel(
         String templateId, FrameContext frameContext, BindingContext bindingContext) {
       this.template =
           checkNotNull(
               frameContext.getTemplate(templateId), "Template was not found: %s", templateId);
       this.bindingContext = bindingContext;
     }

     public Template getTemplate() {
       return template;
     }

     BindingContext getBindingContext() {
       return bindingContext;
     }

     @SuppressWarnings({"ReferenceEquality", "EqualsUsingHashCode"})
     @Override
     public boolean equals(/*@Nullable*/ Object o) {
       if (this == o) {
         return true;
       }
       if (!(o instanceof TemplateAdapterModel)) {
         return false;
       }

       TemplateAdapterModel that = (TemplateAdapterModel) o;

       return templateEquals(template, that.template)
           && (bindingContext == that.bindingContext
               || (bindingContext.getBindingValuesCount()
                       == that.bindingContext.getBindingValuesCount()
                   && bindingContext.hashCode() == that.bindingContext.hashCode()));
     }

     @Override
     public int hashCode() {
       int result = template.hashCode();
       result = 31 * result + bindingContext.hashCode();
       return result;
     }
   }
 }
	// Copyright 2018 The Feed Authors.
	//
	// 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 com.google.android.libraries.feed.piet;

	import static com.google.android.libraries.feed.common.Validators.checkNotNull;
	import static com.google.android.libraries.feed.common.Validators.checkState;

	import android.view.View;
	import com.google.search.now.ui.piet.ElementsProto.BindingContext;
	import com.google.search.now.ui.piet.PietProto.PietSharedState;
	import com.google.search.now.ui.piet.PietProto.Stylesheet;
	import com.google.search.now.ui.piet.PietProto.Template;
	import java.util.List;

	/**
	* Methods to enable creation and binding of Templates.
	*
	* <p>This class creates and binds adapters for templates allowing for reuse of full template
	* layouts as a unit. Release and recycling is handled by the ElementAdapterFactory.
	*/
	class TemplateBinder {

	private final KeyedRecyclerPool<ElementAdapter<? extends View, ?>> templateRecyclerPool;
	private final ElementAdapterFactory adapterFactory;

	TemplateBinder(
	KeyedRecyclerPool<ElementAdapter<? extends View, ?>> templateRecyclerPool,
	ElementAdapterFactory adapterFactory) {
	this.templateRecyclerPool = templateRecyclerPool;
	this.adapterFactory = adapterFactory;
	}

	/** Higher-performance method that creates and binds an adapter for a template all at once. */
	ElementAdapter<? extends View, ?> createAndBindTemplateAdapter(
	TemplateAdapterModel model, FrameContext frameContext) {
	// Create the template context for use in both create and bind
	// This is a modestly expensive operation, and calling createTemplateAdapter followed by
	// bindTemplateAdapter would do it twice.
	FrameContext templateContext =
	frameContext.createTemplateContext(model.getTemplate(), model.getBindingContext());

	TemplateKey templateKey = makeTemplateKey(model, frameContext);
	ElementAdapter<? extends View, ?> adapter = templateRecyclerPool.get(templateKey);

	if (adapter == null) {
	// Create new adapter
	adapter =
	adapterFactory.createAdapterForElement(model.getTemplate().getElement(), templateContext);

	adapter.setKey(templateKey);
	}

	adapter.bindModel(model.getTemplate().getElement(), templateContext);

	return adapter;
	}

	ElementAdapter<? extends View, ?> createTemplateAdapter(
	TemplateAdapterModel model, FrameContext frameContext) {
	TemplateKey templateKey = makeTemplateKey(model, frameContext);
	ElementAdapter<? extends View, ?> adapter = templateRecyclerPool.get(templateKey);

	if (adapter == null) {
	// Make new FrameContext here
	FrameContext templateContext =
	frameContext.createTemplateContext(model.getTemplate(), model.getBindingContext());

	// Create new adapter
	adapter =
	adapterFactory.createAdapterForElement(model.getTemplate().getElement(), templateContext);

	adapter.setKey(templateKey);
	}

	return adapter;
	}

	void bindTemplateAdapter(
	ElementAdapter<? extends View, ?> adapter,
	TemplateAdapterModel model,
	FrameContext frameContext) {
	TemplateKey templateKey = makeTemplateKey(model, frameContext);

	checkNotNull(adapter.getKey(), "Adapter key was null; not initialized correctly?");
	checkState(
	adapter.getKey() instanceof TemplateKey,
	"bindTemplateAdapter only applicable for template adapters");
	checkState(templateKey.equals(adapter.getKey()), "Template keys did not match");

	FrameContext templateContext =
	frameContext.createTemplateContext(model.getTemplate(), model.getBindingContext());

	adapter.bindModel(model.getTemplate().getElement(), templateContext);
	}

	private static TemplateKey makeTemplateKey(
	TemplateAdapterModel model, FrameContext frameContext) {
	return new TemplateKey(
	model.getTemplate(),
	frameContext.getPietSharedStates(),
	frameContext.getMediaQueryStylesheets(model.getTemplate()));
	}

	/**
	* Determines whether two templates are compatible for recycling. We're going to call the hash
	* code good enough for performance reasons (.equals() is expensive), and hope we don't get a lot
	* of collisions.
	*/
	@SuppressWarnings({"ReferenceEquality", "EqualsUsingHashCode"})
	static boolean templateEquals(/@Nullable/ Template template1, /@Nullable/ Template template2) {
	if (template1 == template2) {
	return true;
	} else if (template1 == null \|\| template2 == null) {
	return false;
	}
	return template1.hashCode() == template2.hashCode();
	}

	/** Wrap the Template proto object as the recycler key. */
	static class TemplateKey extends RecyclerKey {
	private final Template template;
	/@Nullable/ private final List<PietSharedState> pietSharedStates;

	// If the Template references Stylesheets that have MediaQueryConditions on them, they need to
	// be part of the key.
	private final List<Stylesheet> mediaQueryBasedStylesheets;

	TemplateKey(
	Template template,
	/@Nullable/ List<PietSharedState> pietSharedStates,
	List<Stylesheet> mediaQueryBasedStylesheets) {
	this.template = template;
	this.pietSharedStates = pietSharedStates;
	this.mediaQueryBasedStylesheets = mediaQueryBasedStylesheets;
	}

	/** Equals checks the hashCode of the component fields to avoid expensive proto equals. */
	@SuppressWarnings({"ReferenceEquality", "EqualsUsingHashCode"})
	@Override
	public boolean equals(/@Nullable/ Object o) {
	if (this == o) {
	return true;
	}
	if (!(o instanceof TemplateKey)) {
	return false;
	}

	TemplateKey that = (TemplateKey) o;

	// Check that Templates are equal
	if (!templateEquals(template, that.template)) {
	return false;
	}
	// Check that PietSharedStates are equal or both null
	if (that.pietSharedStates == null ^ this.pietSharedStates == null) {
	return false;
	}
	if (this.pietSharedStates != null
	&& that.pietSharedStates != null
	&& (this.pietSharedStates.size() != that.pietSharedStates.size()
	\|\| this.pietSharedStates.hashCode() != that.pietSharedStates.hashCode())) {
	return false;
	}
	// Check that stylesheets are equal or both empty
	if (that.mediaQueryBasedStylesheets.isEmpty() ^ this.mediaQueryBasedStylesheets.isEmpty()) {
	return false;
	}
	return this.mediaQueryBasedStylesheets == that.mediaQueryBasedStylesheets
	\|\| this.mediaQueryBasedStylesheets.hashCode()
	== that.mediaQueryBasedStylesheets.hashCode();
	}

	@Override
	public int hashCode() {
	int result = template.hashCode();
	result = 31 * result + (pietSharedStates != null ? pietSharedStates.hashCode() : 0);
	result =
	31 * result
	+ (mediaQueryBasedStylesheets != null ? mediaQueryBasedStylesheets.hashCode() : 0);
	return result;
	}
	}

	static class TemplateAdapterModel {
	private final Template template;
	private final BindingContext bindingContext;

	TemplateAdapterModel(Template template, BindingContext bindingContext) {
	this.template = template;
	this.bindingContext = bindingContext;
	}

	TemplateAdapterModel(
	String templateId, FrameContext frameContext, BindingContext bindingContext) {
	this.template =
	checkNotNull(
	frameContext.getTemplate(templateId), "Template was not found: %s", templateId);
	this.bindingContext = bindingContext;
	}

	public Template getTemplate() {
	return template;
	}

	BindingContext getBindingContext() {
	return bindingContext;
	}

	@SuppressWarnings({"ReferenceEquality", "EqualsUsingHashCode"})
	@Override
	public boolean equals(/@Nullable/ Object o) {
	if (this == o) {
	return true;
	}
	if (!(o instanceof TemplateAdapterModel)) {
	return false;
	}

	TemplateAdapterModel that = (TemplateAdapterModel) o;

	return templateEquals(template, that.template)
	&& (bindingContext == that.bindingContext
	\|\| (bindingContext.getBindingValuesCount()
	== that.bindingContext.getBindingValuesCount()
	&& bindingContext.hashCode() == that.bindingContext.hashCode()));
	}

	@Override
	public int hashCode() {
	int result = template.hashCode();
	result = 31 * result + bindingContext.hashCode();
	return result;
	}
	}
	}