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 
DialogViewAnimator(Context context)33     public DialogViewAnimator(Context context) {
34         super(context);
35     }
36 
DialogViewAnimator(Context context, AttributeSet attrs)37     public DialogViewAnimator(Context context, AttributeSet attrs) {
38         super(context, attrs);
39     }
40 
41     @Override
onMeasure(int widthMeasureSpec, int heightMeasureSpec)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