| /* |
| * 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.widget; |
| |
| import android.os.SystemClock; |
| import android.view.MotionEvent; |
| import android.view.View; |
| import android.view.ViewConfiguration; |
| import android.view.ViewParent; |
| |
| import com.android.internal.view.menu.ShowableListMenu; |
| |
| /** |
| * Abstract class that forwards touch events to a {@link ShowableListMenu}. |
| * |
| * @hide |
| */ |
| public abstract class ForwardingListener |
| implements View.OnTouchListener, View.OnAttachStateChangeListener { |
| |
| /** Scaled touch slop, used for detecting movement outside bounds. */ |
| private final float mScaledTouchSlop; |
| |
| /** Timeout before disallowing intercept on the source's parent. */ |
| private final int mTapTimeout; |
| |
| /** Timeout before accepting a long-press to start forwarding. */ |
| private final int mLongPressTimeout; |
| |
| /** Source view from which events are forwarded. */ |
| private final View mSrc; |
| |
| /** Runnable used to prevent conflicts with scrolling parents. */ |
| private Runnable mDisallowIntercept; |
| |
| /** Runnable used to trigger forwarding on long-press. */ |
| private Runnable mTriggerLongPress; |
| |
| /** Whether this listener is currently forwarding touch events. */ |
| private boolean mForwarding; |
| |
| /** The id of the first pointer down in the current event stream. */ |
| private int mActivePointerId; |
| |
| public ForwardingListener(View src) { |
| mSrc = src; |
| src.setLongClickable(true); |
| src.addOnAttachStateChangeListener(this); |
| |
| mScaledTouchSlop = ViewConfiguration.get(src.getContext()).getScaledTouchSlop(); |
| mTapTimeout = ViewConfiguration.getTapTimeout(); |
| |
| // Use a medium-press timeout. Halfway between tap and long-press. |
| mLongPressTimeout = (mTapTimeout + ViewConfiguration.getLongPressTimeout()) / 2; |
| } |
| |
| /** |
| * Returns the popup to which this listener is forwarding events. |
| * <p> |
| * Override this to return the correct popup. If the popup is displayed |
| * asynchronously, you may also need to override |
| * {@link #onForwardingStopped} to prevent premature cancellation of |
| * forwarding. |
| * |
| * @return the popup to which this listener is forwarding events |
| */ |
| public abstract ShowableListMenu getPopup(); |
| |
| @Override |
| public boolean onTouch(View v, MotionEvent event) { |
| final boolean wasForwarding = mForwarding; |
| final boolean forwarding; |
| if (wasForwarding) { |
| forwarding = onTouchForwarded(event) || !onForwardingStopped(); |
| } else { |
| forwarding = onTouchObserved(event) && onForwardingStarted(); |
| |
| if (forwarding) { |
| // Make sure we cancel any ongoing source event stream. |
| final long now = SystemClock.uptimeMillis(); |
| final MotionEvent e = MotionEvent.obtain(now, now, MotionEvent.ACTION_CANCEL, |
| 0.0f, 0.0f, 0); |
| mSrc.onTouchEvent(e); |
| e.recycle(); |
| } |
| } |
| |
| mForwarding = forwarding; |
| return forwarding || wasForwarding; |
| } |
| |
| @Override |
| public void onViewAttachedToWindow(View v) { |
| } |
| |
| @Override |
| public void onViewDetachedFromWindow(View v) { |
| mForwarding = false; |
| mActivePointerId = MotionEvent.INVALID_POINTER_ID; |
| |
| if (mDisallowIntercept != null) { |
| mSrc.removeCallbacks(mDisallowIntercept); |
| } |
| } |
| |
| /** |
| * Called when forwarding would like to start. |
| * <p> |
| * By default, this will show the popup returned by {@link #getPopup()}. |
| * It may be overridden to perform another action, like clicking the |
| * source view or preparing the popup before showing it. |
| * |
| * @return true to start forwarding, false otherwise |
| */ |
| protected boolean onForwardingStarted() { |
| final ShowableListMenu popup = getPopup(); |
| if (popup != null && !popup.isShowing()) { |
| popup.show(); |
| } |
| return true; |
| } |
| |
| /** |
| * Called when forwarding would like to stop. |
| * <p> |
| * By default, this will dismiss the popup returned by |
| * {@link #getPopup()}. It may be overridden to perform some other |
| * action. |
| * |
| * @return true to stop forwarding, false otherwise |
| */ |
| protected boolean onForwardingStopped() { |
| final ShowableListMenu popup = getPopup(); |
| if (popup != null && popup.isShowing()) { |
| popup.dismiss(); |
| } |
| return true; |
| } |
| |
| /** |
| * Observes motion events and determines when to start forwarding. |
| * |
| * @param srcEvent motion event in source view coordinates |
| * @return true to start forwarding motion events, false otherwise |
| */ |
| private boolean onTouchObserved(MotionEvent srcEvent) { |
| final View src = mSrc; |
| if (!src.isEnabled()) { |
| return false; |
| } |
| |
| final int actionMasked = srcEvent.getActionMasked(); |
| switch (actionMasked) { |
| case MotionEvent.ACTION_DOWN: |
| mActivePointerId = srcEvent.getPointerId(0); |
| |
| if (mDisallowIntercept == null) { |
| mDisallowIntercept = new DisallowIntercept(); |
| } |
| src.postDelayed(mDisallowIntercept, mTapTimeout); |
| |
| if (mTriggerLongPress == null) { |
| mTriggerLongPress = new TriggerLongPress(); |
| } |
| src.postDelayed(mTriggerLongPress, mLongPressTimeout); |
| break; |
| case MotionEvent.ACTION_MOVE: |
| final int activePointerIndex = srcEvent.findPointerIndex(mActivePointerId); |
| if (activePointerIndex >= 0) { |
| final float x = srcEvent.getX(activePointerIndex); |
| final float y = srcEvent.getY(activePointerIndex); |
| |
| // Has the pointer moved outside of the view? |
| if (!src.pointInView(x, y, mScaledTouchSlop)) { |
| clearCallbacks(); |
| |
| // Don't let the parent intercept our events. |
| src.getParent().requestDisallowInterceptTouchEvent(true); |
| return true; |
| } |
| } |
| break; |
| case MotionEvent.ACTION_CANCEL: |
| case MotionEvent.ACTION_UP: |
| clearCallbacks(); |
| break; |
| } |
| |
| return false; |
| } |
| |
| private void clearCallbacks() { |
| if (mTriggerLongPress != null) { |
| mSrc.removeCallbacks(mTriggerLongPress); |
| } |
| |
| if (mDisallowIntercept != null) { |
| mSrc.removeCallbacks(mDisallowIntercept); |
| } |
| } |
| |
| private void onLongPress() { |
| clearCallbacks(); |
| |
| final View src = mSrc; |
| if (!src.isEnabled() || src.isLongClickable()) { |
| // Ignore long-press if the view is disabled or has its own |
| // handler. |
| return; |
| } |
| |
| if (!onForwardingStarted()) { |
| return; |
| } |
| |
| // Don't let the parent intercept our events. |
| src.getParent().requestDisallowInterceptTouchEvent(true); |
| |
| // Make sure we cancel any ongoing source event stream. |
| final long now = SystemClock.uptimeMillis(); |
| final MotionEvent e = MotionEvent.obtain(now, now, MotionEvent.ACTION_CANCEL, 0, 0, 0); |
| src.onTouchEvent(e); |
| e.recycle(); |
| |
| mForwarding = true; |
| } |
| |
| /** |
| * Handles forwarded motion events and determines when to stop |
| * forwarding. |
| * |
| * @param srcEvent motion event in source view coordinates |
| * @return true to continue forwarding motion events, false to cancel |
| */ |
| private boolean onTouchForwarded(MotionEvent srcEvent) { |
| final View src = mSrc; |
| final ShowableListMenu popup = getPopup(); |
| if (popup == null || !popup.isShowing()) { |
| return false; |
| } |
| |
| final DropDownListView dst = (DropDownListView) popup.getListView(); |
| if (dst == null || !dst.isShown()) { |
| return false; |
| } |
| |
| // Convert event to destination-local coordinates. |
| final MotionEvent dstEvent = MotionEvent.obtainNoHistory(srcEvent); |
| src.toGlobalMotionEvent(dstEvent); |
| dst.toLocalMotionEvent(dstEvent); |
| |
| // Forward converted event to destination view, then recycle it. |
| final boolean handled = dst.onForwardedEvent(dstEvent, mActivePointerId); |
| dstEvent.recycle(); |
| |
| // Always cancel forwarding when the touch stream ends. |
| final int action = srcEvent.getActionMasked(); |
| final boolean keepForwarding = action != MotionEvent.ACTION_UP |
| && action != MotionEvent.ACTION_CANCEL; |
| |
| return handled && keepForwarding; |
| } |
| |
| private class DisallowIntercept implements Runnable { |
| @Override |
| public void run() { |
| final ViewParent parent = mSrc.getParent(); |
| if (parent != null) { |
| parent.requestDisallowInterceptTouchEvent(true); |
| } |
| } |
| } |
| |
| private class TriggerLongPress implements Runnable { |
| @Override |
| public void run() { |
| onLongPress(); |
| } |
| } |
| } |