NavigationBar.java revision 2646e1d82ec6d133b35b775f044e156fca6d9d75 
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 com.android.setupwizardlib.view;
18
19import android.content.Context;
20import android.content.res.TypedArray;
21import android.graphics.Color;
22import android.util.AttributeSet;
23import android.view.ContextThemeWrapper;
24import android.view.View;
25import android.widget.Button;
26import android.widget.LinearLayout;
27
28import com.android.setupwizardlib.R;
29
30public class NavigationBar extends LinearLayout implements View.OnClickListener {
31
32    public interface NavigationBarListener {
33        void onNavigateBack();
34        void onNavigateNext();
35    }
36
37    private static int getNavbarTheme(Context context) {
38        // Normally we can automatically guess the theme by comparing the foreground color against
39        // the background color. But we also allow specifying explicitly using suwNavBarTheme.
40        TypedArray attributes = context.obtainStyledAttributes(
41                new int[] {
42                        R.attr.suwNavBarTheme,
43                        android.R.attr.colorForeground,
44                        android.R.attr.colorBackground });
45        int theme = attributes.getResourceId(0, 0);
46        if (theme == 0) {
47            // Compare the value of the foreground against the background color to see if current
48            // theme is light-on-dark or dark-on-light.
49            float[] foregroundHsv = new float[3];
50            float[] backgroundHsv = new float[3];
51            Color.colorToHSV(attributes.getColor(1, 0), foregroundHsv);
52            Color.colorToHSV(attributes.getColor(2, 0), backgroundHsv);
53            boolean isDarkBg = foregroundHsv[2] > backgroundHsv[2];
54            theme = isDarkBg ? R.style.SuwNavBarThemeDark : R.style.SuwNavBarThemeLight;
55        }
56        attributes.recycle();
57        return theme;
58    }
59
60    private static Context getThemedContext(Context context) {
61        final int theme = getNavbarTheme(context);
62        return new ContextThemeWrapper(context, theme);
63    }
64
65    private Button mNextButton;
66    private Button mBackButton;
67    private NavigationBarListener mListener;
68
69    public NavigationBar(Context context) {
70        this(context, null);
71    }
72
73    public NavigationBar(Context context, AttributeSet attrs) {
74        this(context, attrs, 0);
75    }
76
77    public NavigationBar(Context context, AttributeSet attrs, int defStyleAttr) {
78        super(getThemedContext(context), attrs, defStyleAttr);
79        View.inflate(getContext(), R.layout.suw_navbar_view, this);
80        mNextButton = (Button) findViewById(R.id.suw_navbar_next);
81        mBackButton = (Button) findViewById(R.id.suw_navbar_back);
82    }
83
84    public Button getBackButton() {
85        return mBackButton;
86    }
87
88    public Button getNextButton() {
89        return mNextButton;
90    }
91
92    public void setNavigationBarListener(NavigationBarListener listener) {
93        mListener = listener;
94        if (mListener != null) {
95            getBackButton().setOnClickListener(this);
96            getNextButton().setOnClickListener(this);
97        }
98    }
99
100    @Override
101    public void onClick(View view) {
102        if (mListener != null) {
103            if (view == getBackButton()) {
104                mListener.onNavigateBack();
105            } else if (view == getNextButton()) {
106                mListener.onNavigateNext();
107            }
108        }
109    }
110
111    public static class NavButton extends Button {
112
113        public NavButton(Context context) {
114            this(context, null);
115        }
116
117        public NavButton(Context context, AttributeSet attrs) {
118            super(context, attrs);
119        }
120
121        @Override
122        public void setEnabled(boolean enabled) {
123            super.setEnabled(enabled);
124            // The color of the button is #de000000 / #deffffff when enabled. When disabled, apply
125            // additional 23% alpha, so the overall opacity is 20%.
126            setAlpha(enabled ? 1.0f : 0.23f);
127        }
128    }
129
130}
131