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
17package android.widget;
18
19import android.content.Context;
20import android.graphics.drawable.Drawable;
21import android.util.AttributeSet;
22import android.view.View;
23
24import com.android.internal.widget.ViewPager;
25
26import java.util.ArrayList;
27import java.util.function.Predicate;
28
29/**
30 * This displays a list of months in a calendar format with selectable days.
31 */
32class DayPickerViewPager extends ViewPager {
33    private final ArrayList<View> mMatchParentChildren = new ArrayList<>(1);
34
35    public DayPickerViewPager(Context context) {
36        this(context, null);
37    }
38
39    public DayPickerViewPager(Context context, AttributeSet attrs) {
40        this(context, attrs, 0);
41    }
42
43    public DayPickerViewPager(Context context, AttributeSet attrs, int defStyleAttr) {
44        this(context, attrs, defStyleAttr, 0);
45    }
46
47    public DayPickerViewPager(Context context, AttributeSet attrs, int defStyleAttr,
48            int defStyleRes) {
49        super(context, attrs, defStyleAttr, defStyleRes);
50    }
51
52    @Override
53    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
54        populate();
55
56        // Everything below is mostly copied from FrameLayout.
57        int count = getChildCount();
58
59        final boolean measureMatchParentChildren =
60                MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.EXACTLY ||
61                        MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.EXACTLY;
62
63        int maxHeight = 0;
64        int maxWidth = 0;
65        int childState = 0;
66
67        for (int i = 0; i < count; i++) {
68            final View child = getChildAt(i);
69            if (child.getVisibility() != GONE) {
70                measureChild(child, widthMeasureSpec, heightMeasureSpec);
71                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
72                maxWidth = Math.max(maxWidth, child.getMeasuredWidth());
73                maxHeight = Math.max(maxHeight, child.getMeasuredHeight());
74                childState = combineMeasuredStates(childState, child.getMeasuredState());
75                if (measureMatchParentChildren) {
76                    if (lp.width == LayoutParams.MATCH_PARENT ||
77                            lp.height == LayoutParams.MATCH_PARENT) {
78                        mMatchParentChildren.add(child);
79                    }
80                }
81            }
82        }
83
84        // Account for padding too
85        maxWidth += getPaddingLeft() + getPaddingRight();
86        maxHeight += getPaddingTop() + getPaddingBottom();
87
88        // Check against our minimum height and width
89        maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
90        maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
91
92        // Check against our foreground's minimum height and width
93        final Drawable drawable = getForeground();
94        if (drawable != null) {
95            maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
96            maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
97        }
98
99        setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, childState),
100                resolveSizeAndState(maxHeight, heightMeasureSpec,
101                        childState << MEASURED_HEIGHT_STATE_SHIFT));
102
103        count = mMatchParentChildren.size();
104        if (count > 1) {
105            for (int i = 0; i < count; i++) {
106                final View child = mMatchParentChildren.get(i);
107
108                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
109                final int childWidthMeasureSpec;
110                final int childHeightMeasureSpec;
111
112                if (lp.width == LayoutParams.MATCH_PARENT) {
113                    childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
114                            getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
115                            MeasureSpec.EXACTLY);
116                } else {
117                    childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
118                            getPaddingLeft() + getPaddingRight(),
119                            lp.width);
120                }
121
122                if (lp.height == LayoutParams.MATCH_PARENT) {
123                    childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
124                            getMeasuredHeight() - getPaddingTop() - getPaddingBottom(),
125                            MeasureSpec.EXACTLY);
126                } else {
127                    childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec,
128                            getPaddingTop() + getPaddingBottom(),
129                            lp.height);
130                }
131
132                child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
133            }
134        }
135
136        mMatchParentChildren.clear();
137    }
138
139    @Override
140    protected <T extends View> T findViewByPredicateTraversal(Predicate<View> predicate,
141            View childToSkip) {
142        if (predicate.test(this)) {
143            return (T) this;
144        }
145
146        // Always try the selected view first.
147        final DayPickerPagerAdapter adapter = (DayPickerPagerAdapter) getAdapter();
148        final SimpleMonthView current = adapter.getView(getCurrent());
149        if (current != childToSkip && current != null) {
150            final View v = current.findViewByPredicate(predicate);
151            if (v != null) {
152                return (T) v;
153            }
154        }
155
156        final int len = getChildCount();
157        for (int i = 0; i < len; i++) {
158            final View child = getChildAt(i);
159
160            if (child != childToSkip && child != current) {
161                final View v = child.findViewByPredicate(predicate);
162
163                if (v != null) {
164                    return (T) v;
165                }
166            }
167        }
168
169        return null;
170    }
171
172}
173