ExpandableView.java revision a5eaa6034dd48fab0f5a232c09ebed35f359963e
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License 15 */ 16 17package com.android.systemui.statusbar; 18 19import android.content.Context; 20import android.util.AttributeSet; 21import android.view.MotionEvent; 22import android.view.View; 23import android.widget.FrameLayout; 24 25/** 26 * An abstract view for expandable views. 27 */ 28public abstract class ExpandableView extends FrameLayout { 29 30 private OnHeightChangedListener mOnHeightChangedListener; 31 protected int mActualHeight; 32 protected int mClipTopAmount; 33 private boolean mActualHeightInitialized; 34 35 public ExpandableView(Context context, AttributeSet attrs) { 36 super(context, attrs); 37 } 38 39 @Override 40 protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 41 super.onLayout(changed, left, top, right, bottom); 42 if (!mActualHeightInitialized && mActualHeight == 0) { 43 mActualHeight = getHeight(); 44 } 45 mActualHeightInitialized = true; 46 } 47 48 @Override 49 public boolean dispatchTouchEvent(MotionEvent ev) { 50 if (filterMotionEvent(ev)) { 51 return super.dispatchTouchEvent(ev); 52 } 53 return false; 54 } 55 56 private boolean filterMotionEvent(MotionEvent event) { 57 return event.getActionMasked() != MotionEvent.ACTION_DOWN 58 || event.getY() > mClipTopAmount && event.getY() < mActualHeight; 59 } 60 61 /** 62 * Sets the actual height of this notification. This is different than the laid out 63 * {@link View#getHeight()}, as we want to avoid layouting during scrolling and expanding. 64 * 65 * @param actualHeight The height of this notification. 66 * @param notifyListeners Whether the listener should be informed about the change. 67 */ 68 public void setActualHeight(int actualHeight, boolean notifyListeners) { 69 mActualHeight = actualHeight; 70 if (notifyListeners) { 71 notifyHeightChanged(); 72 } 73 } 74 75 public void setActualHeight(int actualHeight) { 76 setActualHeight(actualHeight, true); 77 } 78 79 /** 80 * See {@link #setActualHeight}. 81 * 82 * @return The current actual height of this notification. 83 */ 84 public int getActualHeight() { 85 return mActualHeight; 86 } 87 88 /** 89 * @return The maximum height of this notification. 90 */ 91 public int getMaxHeight() { 92 return getHeight(); 93 } 94 95 /** 96 * @return The minimum height of this notification. 97 */ 98 public int getMinHeight() { 99 return getHeight(); 100 } 101 102 /** 103 * Sets the notification as dimmed. The default implementation does nothing. 104 * 105 * @param dimmed Whether the notification should be dimmed. 106 * @param fade Whether an animation should be played to change the state. 107 */ 108 public void setDimmed(boolean dimmed, boolean fade) { 109 } 110 111 /** 112 * @return The desired notification height. 113 */ 114 public int getIntrinsicHeight() { 115 return getHeight(); 116 } 117 118 /** 119 * Sets the amount this view should be clipped from the top. This is used when an expanded 120 * notification is scrolling in the top or bottom stack. 121 * 122 * @param clipTopAmount The amount of pixels this view should be clipped from top. 123 */ 124 public void setClipTopAmount(int clipTopAmount) { 125 mClipTopAmount = clipTopAmount; 126 } 127 128 public int getClipTopAmount() { 129 return mClipTopAmount; 130 } 131 132 public void setOnHeightChangedListener(OnHeightChangedListener listener) { 133 mOnHeightChangedListener = listener; 134 } 135 136 /** 137 * @return Whether we can expand this views content. 138 */ 139 public boolean isContentExpandable() { 140 return false; 141 } 142 143 public void notifyHeightChanged() { 144 if (mOnHeightChangedListener != null) { 145 mOnHeightChangedListener.onHeightChanged(this); 146 } 147 } 148 149 /** 150 * A listener notifying when {@link #getActualHeight} changes. 151 */ 152 public interface OnHeightChangedListener { 153 void onHeightChanged(ExpandableView view); 154 } 155} 156