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.deskclock.settings;
18 
19 import android.content.Context;
20 import androidx.annotation.NonNull;
21 import androidx.core.content.ContextCompat;
22 import androidx.preference.DropDownPreference;
23 import android.util.AttributeSet;
24 import android.view.View;
25 import android.view.ViewGroup;
26 import android.widget.ArrayAdapter;
27 
28 import com.android.deskclock.R;
29 import com.android.deskclock.Utils;
30 
31 /**
32  * Bend {@link DropDownPreference} to support
33  * <a href="https://material.google.com/components/menus.html#menus-behavior">Simple Menus</a>.
34  */
35 public class SimpleMenuPreference extends DropDownPreference {
36 
37     private SimpleMenuAdapter mAdapter;
38 
SimpleMenuPreference(Context context)39     public SimpleMenuPreference(Context context) {
40         this(context, null);
41     }
42 
SimpleMenuPreference(Context context, AttributeSet attrs)43     public SimpleMenuPreference(Context context, AttributeSet attrs) {
44         this(context, attrs, R.attr.dropdownPreferenceStyle);
45     }
46 
SimpleMenuPreference(Context context, AttributeSet attrs, int defStyle)47     public SimpleMenuPreference(Context context, AttributeSet attrs, int defStyle) {
48         this(context, attrs, defStyle, 0);
49     }
50 
SimpleMenuPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)51     public SimpleMenuPreference(Context context, AttributeSet attrs, int defStyleAttr,
52             int defStyleRes) {
53         super(context, attrs, defStyleAttr, defStyleRes);
54     }
55 
56     @Override
createAdapter()57     protected ArrayAdapter createAdapter() {
58         mAdapter = new SimpleMenuAdapter(getContext(), R.layout.simple_menu_dropdown_item);
59         return mAdapter;
60     }
61 
restoreOriginalOrder(CharSequence[] array, int lastSelectedOriginalPosition)62     private static void restoreOriginalOrder(CharSequence[] array,
63             int lastSelectedOriginalPosition) {
64         final CharSequence item = array[0];
65         System.arraycopy(array, 1, array, 0, lastSelectedOriginalPosition);
66         array[lastSelectedOriginalPosition] = item;
67     }
68 
swapSelectedToFront(CharSequence[] array, int position)69     private static void swapSelectedToFront(CharSequence[] array, int position) {
70         final CharSequence item = array[position];
71         System.arraycopy(array, 0, array, 1, position);
72         array[0] = item;
73     }
74 
setSelectedPosition(CharSequence[] array, int lastSelectedOriginalPosition, int position)75     private static void setSelectedPosition(CharSequence[] array, int lastSelectedOriginalPosition,
76             int position) {
77         final CharSequence item = array[position];
78         restoreOriginalOrder(array, lastSelectedOriginalPosition);
79         final int originalPosition = Utils.indexOf(array, item);
80         swapSelectedToFront(array, originalPosition);
81     }
82 
83     @Override
setSummary(CharSequence summary)84     public void setSummary(CharSequence summary) {
85         final CharSequence[] entries = getEntries();
86         final int index = Utils.indexOf(entries, summary);
87         if (index == -1) {
88             throw new IllegalArgumentException("Illegal Summary");
89         }
90         final int lastSelectedOriginalPosition = mAdapter.getLastSelectedOriginalPosition();
91         mAdapter.setSelectedPosition(index);
92         setSelectedPosition(entries, lastSelectedOriginalPosition, index);
93         setSelectedPosition(getEntryValues(), lastSelectedOriginalPosition, index);
94         super.setSummary(summary);
95     }
96 
97     private final static class SimpleMenuAdapter extends ArrayAdapter<CharSequence> {
98 
99         /** The original position of the last selected element */
100         private int mLastSelectedOriginalPosition = 0;
101 
SimpleMenuAdapter(Context context, int resource)102         SimpleMenuAdapter(Context context, int resource) {
103             super(context, resource);
104         }
105 
restoreOriginalOrder()106         private void restoreOriginalOrder() {
107             final CharSequence item = getItem(0);
108             remove(item);
109             insert(item, mLastSelectedOriginalPosition);
110         }
111 
swapSelectedToFront(int position)112         private void swapSelectedToFront(int position) {
113             final CharSequence item = getItem(position);
114             remove(item);
115             insert(item, 0);
116             mLastSelectedOriginalPosition = position;
117         }
118 
getLastSelectedOriginalPosition()119         int getLastSelectedOriginalPosition() {
120             return mLastSelectedOriginalPosition;
121         }
122 
setSelectedPosition(int position)123         void setSelectedPosition(int position) {
124             setNotifyOnChange(false);
125             final CharSequence item = getItem(position);
126             restoreOriginalOrder();
127             final int originalPosition = getPosition(item);
128             swapSelectedToFront(originalPosition);
129             notifyDataSetChanged();
130         }
131 
132         @Override
getDropDownView(int position, View convertView, @NonNull ViewGroup parent)133         public View getDropDownView(int position, View convertView, @NonNull ViewGroup parent) {
134             final View view = super.getDropDownView(position, convertView, parent);
135             if (position == 0) {
136                 view.setBackgroundColor(ContextCompat.getColor(getContext(), R.color.white_08p));
137             } else {
138                 view.setBackgroundColor(ContextCompat.getColor(getContext(), R.color.transparent));
139             }
140             return view;
141         }
142     }
143 }
144