| /* |
| * Copyright (C) 2014 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 com.android.systemui.statusbar.phone; |
| |
| import android.content.Context; |
| import android.util.AttributeSet; |
| import android.view.MotionEvent; |
| import android.view.View; |
| import android.widget.ScrollView; |
| |
| /** |
| * A scroll view which can be observed for scroll change events. |
| */ |
| public class ObservableScrollView extends ScrollView { |
| |
| private Listener mListener; |
| private int mLastOverscrollAmount; |
| private boolean mTouchEnabled = true; |
| private boolean mHandlingTouchEvent; |
| private float mLastX; |
| private float mLastY; |
| private boolean mBlockFlinging; |
| private boolean mTouchCancelled; |
| |
| public ObservableScrollView(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| } |
| |
| public void setListener(Listener listener) { |
| mListener = listener; |
| } |
| |
| public void setTouchEnabled(boolean touchEnabled) { |
| mTouchEnabled = touchEnabled; |
| } |
| |
| public boolean isScrolledToBottom() { |
| return getScrollY() == getMaxScrollY(); |
| } |
| |
| public boolean isHandlingTouchEvent() { |
| return mHandlingTouchEvent; |
| } |
| |
| private int getMaxScrollY() { |
| int scrollRange = 0; |
| if (getChildCount() > 0) { |
| View child = getChildAt(0); |
| scrollRange = Math.max(0, |
| child.getHeight() - (getHeight() - mPaddingBottom - mPaddingTop)); |
| } |
| return scrollRange; |
| } |
| |
| @Override |
| public boolean onTouchEvent(MotionEvent ev) { |
| mHandlingTouchEvent = true; |
| mLastX = ev.getX(); |
| mLastY = ev.getY(); |
| boolean result = super.onTouchEvent(ev); |
| mHandlingTouchEvent = false; |
| return result; |
| } |
| |
| @Override |
| public boolean onInterceptTouchEvent(MotionEvent ev) { |
| mHandlingTouchEvent = true; |
| mLastX = ev.getX(); |
| mLastY = ev.getY(); |
| boolean result = super.onInterceptTouchEvent(ev); |
| mHandlingTouchEvent = false; |
| return result; |
| } |
| |
| @Override |
| public boolean dispatchTouchEvent(MotionEvent ev) { |
| if (ev.getAction() == MotionEvent.ACTION_DOWN) { |
| if (!mTouchEnabled) { |
| mTouchCancelled = true; |
| return false; |
| } |
| mTouchCancelled = false; |
| } else if (mTouchCancelled) { |
| return false; |
| } else if (!mTouchEnabled) { |
| MotionEvent cancel = MotionEvent.obtain(ev); |
| cancel.setAction(MotionEvent.ACTION_CANCEL); |
| super.dispatchTouchEvent(cancel); |
| cancel.recycle(); |
| mTouchCancelled = true; |
| return false; |
| } |
| return super.dispatchTouchEvent(ev); |
| } |
| |
| @Override |
| protected void onScrollChanged(int l, int t, int oldl, int oldt) { |
| super.onScrollChanged(l, t, oldl, oldt); |
| if (mListener != null) { |
| mListener.onScrollChanged(); |
| } |
| } |
| |
| @Override |
| protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, |
| int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, |
| boolean isTouchEvent) { |
| mLastOverscrollAmount = Math.max(0, scrollY + deltaY - getMaxScrollY()); |
| return super.overScrollBy(deltaX, deltaY, scrollX, scrollY, scrollRangeX, scrollRangeY, |
| maxOverScrollX, maxOverScrollY, isTouchEvent); |
| } |
| |
| public void setBlockFlinging(boolean blockFlinging) { |
| mBlockFlinging = blockFlinging; |
| } |
| |
| @Override |
| public void fling(int velocityY) { |
| if (!mBlockFlinging) { |
| super.fling(velocityY); |
| } |
| } |
| |
| @Override |
| protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) { |
| super.onOverScrolled(scrollX, scrollY, clampedX, clampedY); |
| if (mListener != null && mLastOverscrollAmount > 0) { |
| mListener.onOverscrolled(mLastX, mLastY, mLastOverscrollAmount); |
| } |
| } |
| |
| public interface Listener { |
| void onScrollChanged(); |
| void onOverscrolled(float lastX, float lastY, int amount); |
| } |
| } |