/*
* Copyright (C) 2015 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 android.databinding;
import android.app.Activity;
import android.support.annotation.Nullable;
import android.view.InflateException;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
/**
* Utility class to create {@link ViewDataBinding} from layouts.
*/
public class DataBindingUtil {
private static DataBinderMapper sMapper = new DataBinderMapper();
private static DataBindingComponent sDefaultComponent = null;
/**
* Prevent DataBindingUtil from being instantiated.
*/
private DataBindingUtil() {}
/**
* Set the default {@link DataBindingComponent} to use for data binding.
* <p>
* <code>bindingComponent</code> may be passed as the first parameter of binding adapters.
* <p>
* When instance method BindingAdapters are used, the class instance for the binding adapter
* is retrieved from the DataBindingComponent.
*/
public static void setDefaultComponent(DataBindingComponent bindingComponent) {
sDefaultComponent = bindingComponent;
}
/**
* Returns the default {@link DataBindingComponent} used in data binding. This can be
* <code>null</code> if no default was set in
* {@link #setDefaultComponent(DataBindingComponent)}.
*
* @return the default {@link DataBindingComponent} used in data binding. This can be
* <code>null</code> if no default was set in
* {@link #setDefaultComponent(DataBindingComponent)}.
*/
public static DataBindingComponent getDefaultComponent() {
return sDefaultComponent;
}
/**
* Inflates a binding layout and returns the newly-created binding for that layout.
* This uses the DataBindingComponent set in
* {@link #setDefaultComponent(DataBindingComponent)}.
* <p>
* Use this version only if <code>layoutId</code> is unknown in advance. Otherwise, use
* the generated Binding's inflate method to ensure type-safe inflation.
*
* @param inflater The LayoutInflater used to inflate the binding layout.
* @param layoutId The layout resource ID of the layout to inflate.
* @param parent Optional view to be the parent of the generated hierarchy
* (if attachToParent is true), or else simply an object that provides
* a set of LayoutParams values for root of the returned hierarchy
* (if attachToParent is false.)
* @param attachToParent Whether the inflated hierarchy should be attached to the
* parent parameter. If false, parent is only used to create
* the correct subclass of LayoutParams for the root view in the XML.
* @return The newly-created binding for the inflated layout or <code>null</code> if
* the layoutId wasn't for a binding layout.
* @throws InflateException When a merge layout was used and attachToParent was false.
* @see #setDefaultComponent(DataBindingComponent)
*/
public static <T extends ViewDataBinding> T inflate(LayoutInflater inflater, int layoutId,
@Nullable ViewGroup parent, boolean attachToParent) {
return inflate(inflater, layoutId, parent, attachToParent, sDefaultComponent);
}
/**
* Inflates a binding layout and returns the newly-created binding for that layout.
* <p>
* Use this version only if <code>layoutId</code> is unknown in advance. Otherwise, use
* the generated Binding's inflate method to ensure type-safe inflation.
*
* @param inflater The LayoutInflater used to inflate the binding layout.
* @param layoutId The layout resource ID of the layout to inflate.
* @param parent Optional view to be the parent of the generated hierarchy
* (if attachToParent is true), or else simply an object that provides
* a set of LayoutParams values for root of the returned hierarchy
* (if attachToParent is false.)
* @param attachToParent Whether the inflated hierarchy should be attached to the
* parent parameter. If false, parent is only used to create
* the correct subclass of LayoutParams for the root view in the XML.
* @param bindingComponent The DataBindingComponent to use in the binding.
* @return The newly-created binding for the inflated layout or <code>null</code> if
* the layoutId wasn't for a binding layout.
* @throws InflateException When a merge layout was used and attachToParent was false.
*/
public static <T extends ViewDataBinding> T inflate(
LayoutInflater inflater, int layoutId, @Nullable ViewGroup parent,
boolean attachToParent, DataBindingComponent bindingComponent) {
final boolean useChildren = parent != null && attachToParent;
final int startChildren = useChildren ? parent.getChildCount() : 0;
final View view = inflater.inflate(layoutId, parent, attachToParent);
if (useChildren) {
final int endChildren = parent.getChildCount();
final int childrenAdded = endChildren - startChildren;
if (childrenAdded == 1) {
final View childView = parent.getChildAt(endChildren - 1);
return bind(bindingComponent, childView, layoutId);
} else {
final View[] children = new View[childrenAdded];
for (int i = 0; i < childrenAdded; i++) {
children[i] = parent.getChildAt(i + startChildren);
}
return bind(bindingComponent, children, layoutId);
}
} else {
return bind(bindingComponent, view, layoutId);
}
}
/**
* Returns the binding for the given layout root or creates a binding if one
* does not exist. This uses the DataBindingComponent set in
* {@link #setDefaultComponent(DataBindingComponent)}.
* <p>
* Prefer using the generated Binding's <code>bind</code> method to ensure type-safe inflation
* when it is known that <code>root</code> has not yet been bound.
*
* @param root The root View of the inflated binding layout.
* @return A ViewDataBinding for the given root View. If one already exists, the
* existing one will be returned.
* @throws IllegalArgumentException when root is not from an inflated binding layout.
* @see #getBinding(View)
*/
@SuppressWarnings("unchecked")
public static <T extends ViewDataBinding> T bind(View root) {
return bind(root, sDefaultComponent);
}
/**
* Returns the binding for the given layout root or creates a binding if one
* does not exist.
* <p>
* Prefer using the generated Binding's <code>bind</code> method to ensure type-safe inflation
* when it is known that <code>root</code> has not yet been bound.
*
* @param root The root View of the inflated binding layout.
* @param bindingComponent The DataBindingComponent to use in data binding.
* @return A ViewDataBinding for the given root View. If one already exists, the
* existing one will be returned.
* @throws IllegalArgumentException when root is not from an inflated binding layout.
* @see #getBinding(View)
*/
@SuppressWarnings("unchecked")
public static <T extends ViewDataBinding> T bind(View root,
DataBindingComponent bindingComponent) {
T binding = getBinding(root);
if (binding != null) {
return binding;
}
Object tagObj = root.getTag();
if (!(tagObj instanceof String)) {
throw new IllegalArgumentException("View is not a binding layout");
} else {
String tag = (String) tagObj;
int layoutId = sMapper.getLayoutId(tag);
if (layoutId == 0) {
throw new IllegalArgumentException("View is not a binding layout");
}
return (T) sMapper.getDataBinder(bindingComponent, root, layoutId);
}
}
@SuppressWarnings("unchecked")
static <T extends ViewDataBinding> T bind(DataBindingComponent bindingComponent, View[] roots,
int layoutId) {
return (T) sMapper.getDataBinder(bindingComponent, roots, layoutId);
}
static <T extends ViewDataBinding> T bind(DataBindingComponent bindingComponent, View root,
int layoutId) {
return (T) sMapper.getDataBinder(bindingComponent, root, layoutId);
}
/**
* Retrieves the binding responsible for the given View. If <code>view</code> is not a
* binding layout root, its parents will be searched for the binding. If there is no binding,
* <code>null</code> will be returned.
* <p>
* This differs from {@link #getBinding(View)} in that findBinding takes any view in the
* layout and searches for the binding associated with the root. <code>getBinding</code>
* takes only the root view.
*
* @param view A <code>View</code> in the bound layout.
* @return The ViewDataBinding associated with the given view or <code>null</code> if
* view is not part of a bound layout.
*/
public static <T extends ViewDataBinding> T findBinding(View view) {
while (view != null) {
ViewDataBinding binding = ViewDataBinding.getBinding(view);
if (binding != null) {
return (T) binding;
}
Object tag = view.getTag();
if (tag instanceof String) {
String tagString = (String) tag;
if (tagString.startsWith("layout") && tagString.endsWith("_0")) {
final char nextChar = tagString.charAt(6);
final int slashIndex = tagString.indexOf('/', 7);
boolean isUnboundRoot = false;
if (nextChar == '/') {
// only one slash should exist
isUnboundRoot = slashIndex == -1;
} else if (nextChar == '-' && slashIndex != -1) {
int nextSlashIndex = tagString.indexOf('/', slashIndex + 1);
// only one slash should exist
isUnboundRoot = nextSlashIndex == -1;
}
if (isUnboundRoot) {
// An inflated, but unbound layout
return null;
}
}
}
ViewParent viewParent = view.getParent();
if (viewParent instanceof View) {
view = (View) viewParent;
} else {
view = null;
}
}
return null;
}
/**
* Retrieves the binding responsible for the given View layout root. If there is no binding,
* <code>null</code> will be returned. This uses the DataBindingComponent set in
* {@link #setDefaultComponent(DataBindingComponent)}.
*
* @param view The root <code>View</code> in the layout with binding.
* @return The ViewDataBinding associated with the given view or <code>null</code> if
* either the view is not a root View for a layout or view hasn't been bound.
*/
public static <T extends ViewDataBinding> T getBinding(View view) {
return (T) ViewDataBinding.getBinding(view);
}
/**
* Set the Activity's content view to the given layout and return the associated binding.
* The given layout resource must not be a merge layout.
*
* @param activity The Activity whose content View should change.
* @param layoutId The resource ID of the layout to be inflated, bound, and set as the
* Activity's content.
* @return The binding associated with the inflated content view.
*/
public static <T extends ViewDataBinding> T setContentView(Activity activity, int layoutId) {
return setContentView(activity, layoutId, sDefaultComponent);
}
/**
* Set the Activity's content view to the given layout and return the associated binding.
* The given layout resource must not be a merge layout.
*
* @param bindingComponent The DataBindingComponent to use in data binding.
* @param activity The Activity whose content View should change.
* @param layoutId The resource ID of the layout to be inflated, bound, and set as the
* Activity's content.
* @return The binding associated with the inflated content view.
*/
public static <T extends ViewDataBinding> T setContentView(Activity activity, int layoutId,
DataBindingComponent bindingComponent) {
// Force the content view to exist if it didn't already.
View decorView = activity.getWindow().getDecorView();
ViewGroup contentView = (ViewGroup) decorView.findViewById(android.R.id.content);
T binding = inflate(activity.getLayoutInflater(), layoutId, contentView, false,
bindingComponent);
activity.setContentView(binding.getRoot(), binding.getRoot().getLayoutParams());
return binding;
}
/**
* Converts the given BR id to its string representation which might be useful for logging
* purposes.
*
* @param id The integer id, which should be a field from BR class.
* @return The name if the BR id or null if id is out of bounds.
*/
public static String convertBrIdToString(int id) {
return sMapper.convertBrIdToString(id);
}
}