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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (C) 2010 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.view;
import android.compat.annotation.UnsupportedAppUsage;
import android.os.Build;
import android.os.IBinder;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.Slog;
import libcore.util.NativeAllocationRegistry;
/**
* An input channel specifies the file descriptors used to send input events to
* a window in another process. It is Parcelable so that it can be sent
* to the process that is to receive events. Only one thread should be reading
* from an InputChannel at a time.
* @hide
*/
public final class InputChannel implements Parcelable {
private static final String TAG = "InputChannel";
private static final boolean DEBUG = false;
private static final NativeAllocationRegistry sRegistry =
NativeAllocationRegistry.createMalloced(
InputChannel.class.getClassLoader(),
nativeGetFinalizer());
@UnsupportedAppUsage
public static final @android.annotation.NonNull Parcelable.Creator CREATOR
= new Parcelable.Creator() {
public InputChannel createFromParcel(Parcel source) {
InputChannel result = new InputChannel();
result.readFromParcel(source);
return result;
}
public InputChannel[] newArray(int size) {
return new InputChannel[size];
}
};
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
private long mPtr; // used by native code
private static native long[] nativeOpenInputChannelPair(String name);
private static native long nativeGetFinalizer();
private native void nativeDispose(long channel);
private native long nativeReadFromParcel(Parcel parcel);
private native void nativeWriteToParcel(Parcel parcel, long channel);
private native long nativeDup(long channel);
private native IBinder nativeGetToken(long channel);
private native String nativeGetName(long channel);
/**
* Creates an uninitialized input channel.
* It can be initialized by reading from a Parcel or by transferring the state of
* another input channel into this one.
*/
@UnsupportedAppUsage
public InputChannel() {
}
/**
* Set Native input channel object from native space.
* @param nativeChannel the native channel object.
*
* @hide
*/
private void setNativeInputChannel(long nativeChannel) {
if (nativeChannel == 0) {
throw new IllegalArgumentException("Attempting to set native input channel to null.");
}
if (mPtr != 0) {
throw new IllegalArgumentException("Already has native input channel.");
}
if (DEBUG) {
Slog.d(TAG, "setNativeInputChannel : " + String.format("%x", nativeChannel));
}
sRegistry.registerNativeAllocation(this, nativeChannel);
mPtr = nativeChannel;
}
/**
* Creates a new input channel pair. One channel should be provided to the input
* dispatcher and the other to the application's input queue.
* @param name The descriptive (non-unique) name of the channel pair.
* @return A pair of input channels. The first channel is designated as the
* server channel and should be used to publish input events. The second channel
* is designated as the client channel and should be used to consume input events.
*/
public static InputChannel[] openInputChannelPair(String name) {
if (name == null) {
throw new IllegalArgumentException("name must not be null");
}
if (DEBUG) {
Slog.d(TAG, "Opening input channel pair '" + name + "'");
}
InputChannel channels[] = new InputChannel[2];
long[] nativeChannels = nativeOpenInputChannelPair(name);
for (int i = 0; i< 2; i++) {
channels[i] = new InputChannel();
channels[i].setNativeInputChannel(nativeChannels[i]);
}
return channels;
}
/**
* Gets the name of the input channel.
* @return The input channel name.
*/
public String getName() {
String name = nativeGetName(mPtr);
return name != null ? name : "uninitialized";
}
/**
* Disposes the input channel.
* Explicitly releases the reference this object is holding on the input channel.
* When all references are released, the input channel will be closed.
*/
public void dispose() {
nativeDispose(mPtr);
}
/**
* Release the Java objects hold over the native InputChannel. If other references
* still exist in native-land, then the channel may continue to exist.
*/
public void release() {
}
/**
* Creates a copy of this instance to the outParameter. This is used to pass an input channel
* as an out parameter in a binder call.
* @param other The other input channel instance.
*/
public void copyTo(InputChannel outParameter) {
if (outParameter == null) {
throw new IllegalArgumentException("outParameter must not be null");
}
if (outParameter.mPtr != 0) {
throw new IllegalArgumentException("Other object already has a native input channel.");
}
outParameter.setNativeInputChannel(nativeDup(mPtr));
}
/**
* Duplicates the input channel.
*/
public InputChannel dup() {
InputChannel target = new InputChannel();
target.setNativeInputChannel(nativeDup(mPtr));
return target;
}
@Override
public int describeContents() {
return Parcelable.CONTENTS_FILE_DESCRIPTOR;
}
public void readFromParcel(Parcel in) {
if (in == null) {
throw new IllegalArgumentException("in must not be null");
}
long nativeIn = nativeReadFromParcel(in);
if (nativeIn != 0) {
setNativeInputChannel(nativeIn);
}
}
@Override
public void writeToParcel(Parcel out, int flags) {
if (out == null) {
throw new IllegalArgumentException("out must not be null");
}
nativeWriteToParcel(out, mPtr);
if ((flags & PARCELABLE_WRITE_RETURN_VALUE) != 0) {
dispose();
}
}
@Override
public String toString() {
return getName();
}
public IBinder getToken() {
return nativeGetToken(mPtr);
}
}