1 /* 2 * Copyright (C) 2016 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 17 package com.android.internal.widget; 18 19 import android.annotation.Nullable; 20 import android.content.Context; 21 import android.content.res.TypedArray; 22 import android.graphics.Canvas; 23 import android.util.AttributeSet; 24 import android.view.RemotableViewMethod; 25 import android.view.View; 26 import android.view.ViewGroup; 27 import android.widget.RemoteViews; 28 29 import com.android.internal.R; 30 31 /** 32 * A custom-built layout for the Notification.MessagingStyle. 33 * 34 * Evicts children until they all fit. 35 */ 36 @RemoteViews.RemoteView 37 public class MessagingLinearLayout extends ViewGroup { 38 39 /** 40 * Spacing to be applied between views. 41 */ 42 private int mSpacing; 43 44 private int mMaxDisplayedLines = Integer.MAX_VALUE; 45 46 private MessagingLayout mMessagingLayout; 47 MessagingLinearLayout(Context context, @Nullable AttributeSet attrs)48 public MessagingLinearLayout(Context context, @Nullable AttributeSet attrs) { 49 super(context, attrs); 50 51 final TypedArray a = context.obtainStyledAttributes(attrs, 52 R.styleable.MessagingLinearLayout, 0, 53 0); 54 55 final int N = a.getIndexCount(); 56 for (int i = 0; i < N; i++) { 57 int attr = a.getIndex(i); 58 switch (attr) { 59 case R.styleable.MessagingLinearLayout_spacing: 60 mSpacing = a.getDimensionPixelSize(i, 0); 61 break; 62 } 63 } 64 65 a.recycle(); 66 } 67 68 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)69 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 70 // This is essentially a bottom-up linear layout that only adds children that fit entirely 71 // up to a maximum height. 72 int targetHeight = MeasureSpec.getSize(heightMeasureSpec); 73 switch (MeasureSpec.getMode(heightMeasureSpec)) { 74 case MeasureSpec.UNSPECIFIED: 75 targetHeight = Integer.MAX_VALUE; 76 break; 77 } 78 79 // Now that we know which views to take, fix up the indents and see what width we get. 80 int measuredWidth = mPaddingLeft + mPaddingRight; 81 final int count = getChildCount(); 82 int totalHeight; 83 for (int i = 0; i < count; ++i) { 84 final View child = getChildAt(i); 85 final LayoutParams lp = (LayoutParams) child.getLayoutParams(); 86 lp.hide = true; 87 } 88 89 totalHeight = mPaddingTop + mPaddingBottom; 90 boolean first = true; 91 int linesRemaining = mMaxDisplayedLines; 92 // Starting from the bottom: we measure every view as if it were the only one. If it still 93 // fits, we take it, otherwise we stop there. 94 for (int i = count - 1; i >= 0 && totalHeight < targetHeight; i--) { 95 if (getChildAt(i).getVisibility() == GONE) { 96 continue; 97 } 98 final View child = getChildAt(i); 99 LayoutParams lp = (LayoutParams) getChildAt(i).getLayoutParams(); 100 MessagingChild messagingChild = null; 101 int spacing = mSpacing; 102 if (child instanceof MessagingChild) { 103 messagingChild = (MessagingChild) child; 104 messagingChild.setMaxDisplayedLines(linesRemaining); 105 spacing += messagingChild.getExtraSpacing(); 106 } 107 spacing = first ? 0 : spacing; 108 measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, totalHeight 109 - mPaddingTop - mPaddingBottom + spacing); 110 111 final int childHeight = child.getMeasuredHeight(); 112 int newHeight = Math.max(totalHeight, totalHeight + childHeight + lp.topMargin + 113 lp.bottomMargin + spacing); 114 int measureType = MessagingChild.MEASURED_NORMAL; 115 if (messagingChild != null) { 116 measureType = messagingChild.getMeasuredType(); 117 linesRemaining -= messagingChild.getConsumedLines(); 118 } 119 120 // We never measure the first item as too small, we want to at least show something. 121 boolean isTooSmall = measureType == MessagingChild.MEASURED_TOO_SMALL && !first; 122 boolean isShortened = measureType == MessagingChild.MEASURED_SHORTENED 123 || measureType == MessagingChild.MEASURED_TOO_SMALL && first; 124 if (newHeight <= targetHeight && !isTooSmall) { 125 totalHeight = newHeight; 126 measuredWidth = Math.max(measuredWidth, 127 child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin 128 + mPaddingLeft + mPaddingRight); 129 lp.hide = false; 130 if (isShortened || linesRemaining <= 0) { 131 break; 132 } 133 } else { 134 break; 135 } 136 first = false; 137 } 138 139 setMeasuredDimension( 140 resolveSize(Math.max(getSuggestedMinimumWidth(), measuredWidth), 141 widthMeasureSpec), 142 Math.max(getSuggestedMinimumHeight(), totalHeight)); 143 } 144 145 @Override onLayout(boolean changed, int left, int top, int right, int bottom)146 protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 147 final int paddingLeft = mPaddingLeft; 148 149 int childTop; 150 151 // Where right end of child should go 152 final int width = right - left; 153 final int childRight = width - mPaddingRight; 154 155 final int layoutDirection = getLayoutDirection(); 156 final int count = getChildCount(); 157 158 childTop = mPaddingTop; 159 160 boolean first = true; 161 final boolean shown = isShown(); 162 for (int i = 0; i < count; i++) { 163 final View child = getChildAt(i); 164 if (child.getVisibility() == GONE) { 165 continue; 166 } 167 final LayoutParams lp = (LayoutParams) child.getLayoutParams(); 168 MessagingChild messagingChild = (MessagingChild) child; 169 170 final int childWidth = child.getMeasuredWidth(); 171 final int childHeight = child.getMeasuredHeight(); 172 173 int childLeft; 174 if (layoutDirection == LAYOUT_DIRECTION_RTL) { 175 childLeft = childRight - childWidth - lp.rightMargin; 176 } else { 177 childLeft = paddingLeft + lp.leftMargin; 178 } 179 if (lp.hide) { 180 if (shown && lp.visibleBefore) { 181 // We still want to lay out the child to have great animations 182 child.layout(childLeft, childTop, childLeft + childWidth, 183 childTop + lp.lastVisibleHeight); 184 messagingChild.hideAnimated(); 185 } 186 lp.visibleBefore = false; 187 continue; 188 } else { 189 lp.visibleBefore = true; 190 lp.lastVisibleHeight = childHeight; 191 } 192 193 if (!first) { 194 childTop += mSpacing; 195 } 196 197 childTop += lp.topMargin; 198 child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight); 199 200 childTop += childHeight + lp.bottomMargin; 201 202 first = false; 203 } 204 } 205 206 @Override drawChild(Canvas canvas, View child, long drawingTime)207 protected boolean drawChild(Canvas canvas, View child, long drawingTime) { 208 final LayoutParams lp = (LayoutParams) child.getLayoutParams(); 209 if (lp.hide) { 210 MessagingChild messagingChild = (MessagingChild) child; 211 if (!messagingChild.isHidingAnimated()) { 212 return true; 213 } 214 } 215 return super.drawChild(canvas, child, drawingTime); 216 } 217 218 @Override generateLayoutParams(AttributeSet attrs)219 public LayoutParams generateLayoutParams(AttributeSet attrs) { 220 return new LayoutParams(mContext, attrs); 221 } 222 223 @Override generateDefaultLayoutParams()224 protected LayoutParams generateDefaultLayoutParams() { 225 return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT); 226 227 } 228 229 @Override generateLayoutParams(ViewGroup.LayoutParams lp)230 protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 231 LayoutParams copy = new LayoutParams(lp.width, lp.height); 232 if (lp instanceof MarginLayoutParams) { 233 copy.copyMarginsFrom((MarginLayoutParams) lp); 234 } 235 return copy; 236 } 237 isGone(View view)238 public static boolean isGone(View view) { 239 if (view.getVisibility() == View.GONE) { 240 return true; 241 } 242 final ViewGroup.LayoutParams lp = view.getLayoutParams(); 243 if (lp instanceof MessagingLinearLayout.LayoutParams 244 && ((MessagingLinearLayout.LayoutParams) lp).hide) { 245 return true; 246 } 247 return false; 248 } 249 250 /** 251 * Sets how many lines should be displayed at most 252 */ 253 @RemotableViewMethod setMaxDisplayedLines(int numberLines)254 public void setMaxDisplayedLines(int numberLines) { 255 mMaxDisplayedLines = numberLines; 256 } 257 setMessagingLayout(MessagingLayout layout)258 public void setMessagingLayout(MessagingLayout layout) { 259 mMessagingLayout = layout; 260 } 261 getMessagingLayout()262 public MessagingLayout getMessagingLayout() { 263 return mMessagingLayout; 264 } 265 266 public interface MessagingChild { 267 int MEASURED_NORMAL = 0; 268 int MEASURED_SHORTENED = 1; 269 int MEASURED_TOO_SMALL = 2; 270 getMeasuredType()271 int getMeasuredType(); getConsumedLines()272 int getConsumedLines(); setMaxDisplayedLines(int lines)273 void setMaxDisplayedLines(int lines); hideAnimated()274 void hideAnimated(); isHidingAnimated()275 boolean isHidingAnimated(); getExtraSpacing()276 default int getExtraSpacing() { 277 return 0; 278 } 279 } 280 281 public static class LayoutParams extends MarginLayoutParams { 282 283 public boolean hide = false; 284 public boolean visibleBefore = false; 285 public int lastVisibleHeight; 286 LayoutParams(Context c, AttributeSet attrs)287 public LayoutParams(Context c, AttributeSet attrs) { 288 super(c, attrs); 289 } 290 LayoutParams(int width, int height)291 public LayoutParams(int width, int height) { 292 super(width, height); 293 } 294 } 295 } 296