/*
* 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.os.Parcel;
import android.os.Parcelable;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Common base class for input events.
*/
public abstract class InputEvent implements Parcelable {
/** @hide */
protected static final int PARCEL_TOKEN_MOTION_EVENT = 1;
/** @hide */
protected static final int PARCEL_TOKEN_KEY_EVENT = 2;
// Next sequence number.
private static final AtomicInteger mNextSeq = new AtomicInteger();
/** @hide */
protected int mSeq;
/** @hide */
protected boolean mRecycled;
private static final boolean TRACK_RECYCLED_LOCATION = false;
private RuntimeException mRecycledLocation;
/*package*/ InputEvent() {
mSeq = mNextSeq.getAndIncrement();
}
/**
* Gets the id for the device that this event came from. An id of
* zero indicates that the event didn't come from a physical device
* and maps to the default keymap. The other numbers are arbitrary and
* you shouldn't depend on the values.
*
* @return The device id.
* @see InputDevice#getDevice
*/
public abstract int getDeviceId();
/**
* Gets the device that this event came from.
*
* @return The device, or null if unknown.
*/
public final InputDevice getDevice() {
return InputDevice.getDevice(getDeviceId());
}
/**
* Gets the source of the event.
*
* @return The event source or {@link InputDevice#SOURCE_UNKNOWN} if unknown.
* @see InputDevice#getSources
*/
public abstract int getSource();
/**
* Modifies the source of the event.
*
* @param source The new source.
* @hide
*/
public abstract void setSource(int source);
/**
* Determines whether the event is from the given source.
*
* @param source The input source to check against. This can be a specific device type, such as
* {@link InputDevice#SOURCE_TOUCH_NAVIGATION}, or a more generic device class, such as
* {@link InputDevice#SOURCE_CLASS_POINTER}.
* @return Whether the event is from the given source.
*/
public boolean isFromSource(int source) {
return (getSource() & source) == source;
}
/**
* Copies the event.
*
* @return A deep copy of the event.
* @hide
*/
public abstract InputEvent copy();
/**
* Recycles the event.
* This method should only be used by the system since applications do not
* expect {@link KeyEvent} objects to be recycled, although {@link MotionEvent}
* objects are fine. See {@link KeyEvent#recycle()} for details.
* @hide
*/
public void recycle() {
if (TRACK_RECYCLED_LOCATION) {
if (mRecycledLocation != null) {
throw new RuntimeException(toString() + " recycled twice!", mRecycledLocation);
}
mRecycledLocation = new RuntimeException("Last recycled here");
} else {
if (mRecycled) {
throw new RuntimeException(toString() + " recycled twice!");
}
mRecycled = true;
}
}
/**
* Conditionally recycled the event if it is appropriate to do so after
* dispatching the event to an application.
*
* If the event is a {@link MotionEvent} then it is recycled.
*
* If the event is a {@link KeyEvent} then it is NOT recycled, because applications
* expect key events to be immutable so once the event has been dispatched to
* the application we can no longer recycle it.
* @hide
*/
public void recycleIfNeededAfterDispatch() {
recycle();
}
/**
* Reinitializes the event on reuse (after recycling).
* @hide
*/
protected void prepareForReuse() {
mRecycled = false;
mRecycledLocation = null;
mSeq = mNextSeq.getAndIncrement();
}
/**
* Gets a private flag that indicates when the system has detected that this input event
* may be inconsistent with respect to the sequence of previously delivered input events,
* such as when a key up event is sent but the key was not down or when a pointer
* move event is sent but the pointer is not down.
*
* @return True if this event is tainted.
* @hide
*/
public abstract boolean isTainted();
/**
* Sets a private flag that indicates when the system has detected that this input event
* may be inconsistent with respect to the sequence of previously delivered input events,
* such as when a key up event is sent but the key was not down or when a pointer
* move event is sent but the pointer is not down.
*
* @param tainted True if this event is tainted.
* @hide
*/
public abstract void setTainted(boolean tainted);
/**
* Retrieve the time this event occurred,
* in the {@link android.os.SystemClock#uptimeMillis} time base.
*
* @return Returns the time this event occurred,
* in the {@link android.os.SystemClock#uptimeMillis} time base.
*/
public abstract long getEventTime();
/**
* Retrieve the time this event occurred,
* in the {@link android.os.SystemClock#uptimeMillis} time base but with
* nanosecond (instead of millisecond) precision.
* <p>
* The value is in nanosecond precision but it may not have nanosecond accuracy.
* </p>
*
* @return Returns the time this event occurred,
* in the {@link android.os.SystemClock#uptimeMillis} time base but with
* nanosecond (instead of millisecond) precision.
*
* @hide
*/
public abstract long getEventTimeNano();
/**
* Marks the input event as being canceled.
*
* @hide
*/
public abstract void cancel();
/**
* Gets the unique sequence number of this event.
* Every input event that is created or received by a process has a
* unique sequence number. Moreover, a new sequence number is obtained
* each time an event object is recycled.
*
* Sequence numbers are only guaranteed to be locally unique within a process.
* Sequence numbers are not preserved when events are parceled.
*
* @return The unique sequence number of this event.
* @hide
*/
public int getSequenceNumber() {
return mSeq;
}
public int describeContents() {
return 0;
}
public static final Parcelable.Creator<InputEvent> CREATOR
= new Parcelable.Creator<InputEvent>() {
public InputEvent createFromParcel(Parcel in) {
int token = in.readInt();
if (token == PARCEL_TOKEN_KEY_EVENT) {
return KeyEvent.createFromParcelBody(in);
} else if (token == PARCEL_TOKEN_MOTION_EVENT) {
return MotionEvent.createFromParcelBody(in);
} else {
throw new IllegalStateException("Unexpected input event type token in parcel.");
}
}
public InputEvent[] newArray(int size) {
return new InputEvent[size];
}
};
}
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