FragmentLayoutInflaterFactory.java
/*
* Copyright 2019 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.fragment.app;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.R;
import androidx.fragment.app.strictmode.FragmentStrictMode;
class FragmentLayoutInflaterFactory implements LayoutInflater.Factory2 {
private static final String TAG = FragmentManager.TAG;
final FragmentManager mFragmentManager;
FragmentLayoutInflaterFactory(FragmentManager fragmentManager) {
mFragmentManager = fragmentManager;
}
@Nullable
@Override
public View onCreateView(@NonNull String name, @NonNull Context context,
@NonNull AttributeSet attrs) {
return onCreateView(null, name, context, attrs);
}
@Nullable
@Override
public View onCreateView(@Nullable final View parent, @NonNull String name,
@NonNull Context context, @NonNull AttributeSet attrs) {
if (FragmentContainerView.class.getName().equals(name)) {
return new FragmentContainerView(context, attrs, mFragmentManager);
}
if (!"fragment".equals(name)) {
return null;
}
String fname = attrs.getAttributeValue(null, "class");
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Fragment);
if (fname == null) {
fname = a.getString(R.styleable.Fragment_android_name);
}
int id = a.getResourceId(R.styleable.Fragment_android_id, View.NO_ID);
String tag = a.getString(R.styleable.Fragment_android_tag);
a.recycle();
if (fname == null || !FragmentFactory.isFragmentClass(context.getClassLoader(), fname)) {
// Invalid support lib fragment; let the device's framework handle it.
// This will allow android.app.Fragments to do the right thing.
return null;
}
int containerId = parent != null ? parent.getId() : 0;
if (containerId == View.NO_ID && id == View.NO_ID && tag == null) {
throw new IllegalArgumentException(attrs.getPositionDescription()
+ ": Must specify unique android:id, android:tag, or "
+ "have a parent with an id for " + fname);
}
// If we restored from a previous state, we may already have
// instantiated this fragment from the state and should use
// that instance instead of making a new one.
Fragment fragment = id != View.NO_ID ? mFragmentManager.findFragmentById(id) : null;
if (fragment == null && tag != null) {
fragment = mFragmentManager.findFragmentByTag(tag);
}
if (fragment == null && containerId != View.NO_ID) {
fragment = mFragmentManager.findFragmentById(containerId);
}
final FragmentStateManager fragmentStateManager;
if (fragment == null) {
fragment = mFragmentManager.getFragmentFactory().instantiate(
context.getClassLoader(), fname);
fragment.mFromLayout = true;
fragment.mFragmentId = id != 0 ? id : containerId;
fragment.mContainerId = containerId;
fragment.mTag = tag;
fragment.mInLayout = true;
fragment.mFragmentManager = mFragmentManager;
fragment.mHost = mFragmentManager.getHost();
fragment.onInflate(mFragmentManager.getHost().getContext(), attrs,
fragment.mSavedFragmentState);
fragmentStateManager = mFragmentManager.addFragment(fragment);
if (FragmentManager.isLoggingEnabled(Log.VERBOSE)) {
Log.v(FragmentManager.TAG, "Fragment " + fragment + " has been inflated via "
+ "the <fragment> tag: id=0x" + Integer.toHexString(id));
}
} else if (fragment.mInLayout) {
// A fragment already exists and it is not one we restored from
// previous state.
throw new IllegalArgumentException(attrs.getPositionDescription()
+ ": Duplicate id 0x" + Integer.toHexString(id)
+ ", tag " + tag + ", or parent id 0x" + Integer.toHexString(containerId)
+ " with another fragment for " + fname);
} else {
// This fragment was retained from a previous instance; get it
// going now.
fragment.mInLayout = true;
fragment.mFragmentManager = mFragmentManager;
fragment.mHost = mFragmentManager.getHost();
// Give the Fragment the attributes to initialize itself.
fragment.onInflate(mFragmentManager.getHost().getContext(), attrs,
fragment.mSavedFragmentState);
fragmentStateManager = mFragmentManager.createOrGetFragmentStateManager(fragment);
if (FragmentManager.isLoggingEnabled(Log.VERBOSE)) {
Log.v(FragmentManager.TAG, "Retained Fragment " + fragment + " has been "
+ "re-attached via the <fragment> tag: id=0x" + Integer.toHexString(id));
}
}
FragmentStrictMode.onFragmentTagUsage(fragment, (ViewGroup) parent);
// Explicitly set the container for the fragment as we already know
// the parent that the fragment will be added to by the LayoutInflater
fragment.mContainer = (ViewGroup) parent;
// The <fragment> tag is the one case where we:
// 1) Move the Fragment to CREATED even if the FragmentManager isn't yet CREATED
fragmentStateManager.moveToExpectedState();
// 2) Create the Fragment's view despite not always moving to ACTIVITY_CREATED
fragmentStateManager.ensureInflatedView();
if (fragment.mView == null) {
throw new IllegalStateException("Fragment " + fname
+ " did not create a view.");
}
if (id != 0) {
fragment.mView.setId(id);
}
if (fragment.mView.getTag() == null) {
fragment.mView.setTag(tag);
}
// Fragments added via the <fragment> tag cannot move above VIEW_CREATED
// during inflation. Instead, we'll wait for the view to be attached to
// window and its parent view and trigger moveToExpectedState() at that point.
fragment.mView.addOnAttachStateChangeListener(
new View.OnAttachStateChangeListener() {
@Override
public void onViewAttachedToWindow(View v) {
Fragment fragment = fragmentStateManager.getFragment();
fragmentStateManager.moveToExpectedState();
SpecialEffectsController controller = SpecialEffectsController
.getOrCreateController((ViewGroup) fragment.mView.getParent(),
mFragmentManager);
controller.forceCompleteAllOperations();
}
@Override
public void onViewDetachedFromWindow(View v) { }
}
);
return fragment.mView;
}
}