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      1 /*
      2  * Copyright (C) 2015 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.content.Context;
     20 import android.graphics.drawable.Drawable;
     21 import android.util.AttributeSet;
     22 import android.view.View;
     23 import android.widget.ViewAnimator;
     24 
     25 import java.util.ArrayList;
     26 
     27 /**
     28  * ViewAnimator with a more reasonable handling of MATCH_PARENT.
     29  */
     30 public class DialogViewAnimator extends ViewAnimator {
     31     private final ArrayList<View> mMatchParentChildren = new ArrayList<>(1);
     32 
     33     public DialogViewAnimator(Context context) {
     34         super(context);
     35     }
     36 
     37     public DialogViewAnimator(Context context, AttributeSet attrs) {
     38         super(context, attrs);
     39     }
     40 
     41     @Override
     42     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
     43         final boolean measureMatchParentChildren =
     44                 MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.EXACTLY ||
     45                         MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.EXACTLY;
     46 
     47         int maxHeight = 0;
     48         int maxWidth = 0;
     49         int childState = 0;
     50 
     51         // First measure all children and record maximum dimensions where the
     52         // spec isn't MATCH_PARENT.
     53         final int count = getChildCount();
     54         for (int i = 0; i < count; i++) {
     55             final View child = getChildAt(i);
     56             if (getMeasureAllChildren() || child.getVisibility() != GONE) {
     57                 final LayoutParams lp = (LayoutParams) child.getLayoutParams();
     58                 final boolean matchWidth = lp.width == LayoutParams.MATCH_PARENT;
     59                 final boolean matchHeight = lp.height == LayoutParams.MATCH_PARENT;
     60                 if (measureMatchParentChildren && (matchWidth || matchHeight)) {
     61                     mMatchParentChildren.add(child);
     62                 }
     63 
     64                 measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, 0);
     65 
     66                 // Measured dimensions only count against the maximum
     67                 // dimensions if they're not MATCH_PARENT.
     68                 int state = 0;
     69 
     70                 if (measureMatchParentChildren && !matchWidth) {
     71                     maxWidth = Math.max(maxWidth, child.getMeasuredWidth()
     72                             + lp.leftMargin + lp.rightMargin);
     73                     state |= child.getMeasuredWidthAndState() & MEASURED_STATE_MASK;
     74                 }
     75 
     76                 if (measureMatchParentChildren && !matchHeight) {
     77                     maxHeight = Math.max(maxHeight, child.getMeasuredHeight()
     78                             + lp.topMargin + lp.bottomMargin);
     79                     state |= (child.getMeasuredHeightAndState() >> MEASURED_HEIGHT_STATE_SHIFT)
     80                             & (MEASURED_STATE_MASK >> MEASURED_HEIGHT_STATE_SHIFT);
     81                 }
     82 
     83                 childState = combineMeasuredStates(childState, state);
     84             }
     85         }
     86 
     87         // Account for padding too.
     88         maxWidth += getPaddingLeft() + getPaddingRight();
     89         maxHeight += getPaddingTop() + getPaddingBottom();
     90 
     91         // Check against our minimum height and width.
     92         maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
     93         maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
     94 
     95         // Check against our foreground's minimum height and width.
     96         final Drawable drawable = getForeground();
     97         if (drawable != null) {
     98             maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
     99             maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
    100         }
    101 
    102         setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, childState),
    103                 resolveSizeAndState(maxHeight, heightMeasureSpec,
    104                         childState << MEASURED_HEIGHT_STATE_SHIFT));
    105 
    106         // Measure remaining MATCH_PARENT children again using real dimensions.
    107         final int matchCount = mMatchParentChildren.size();
    108         for (int i = 0; i < matchCount; i++) {
    109             final View child = mMatchParentChildren.get(i);
    110             final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
    111 
    112             final int childWidthMeasureSpec;
    113             if (lp.width == LayoutParams.MATCH_PARENT) {
    114                 childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
    115                         getMeasuredWidth() - getPaddingLeft() - getPaddingRight()
    116                                 - lp.leftMargin - lp.rightMargin,
    117                         MeasureSpec.EXACTLY);
    118             } else {
    119                 childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
    120                         getPaddingLeft() + getPaddingRight() + lp.leftMargin + lp.rightMargin,
    121                         lp.width);
    122             }
    123 
    124             final int childHeightMeasureSpec;
    125             if (lp.height == LayoutParams.MATCH_PARENT) {
    126                 childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
    127                         getMeasuredHeight() - getPaddingTop() - getPaddingBottom()
    128                                 - lp.topMargin - lp.bottomMargin,
    129                         MeasureSpec.EXACTLY);
    130             } else {
    131                 childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec,
    132                         getPaddingTop() + getPaddingBottom() + lp.topMargin + lp.bottomMargin,
    133                         lp.height);
    134             }
    135 
    136             child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
    137         }
    138 
    139         mMatchParentChildren.clear();
    140     }
    141 }
    142