NavigationBar.java revision 0ceb8d53e39ebb5bc103863787afb39ec5c41ad8 
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.annotation.TargetApi;
20import android.content.Context;
21import android.content.res.TypedArray;
22import android.graphics.Color;
23import android.os.Build.VERSION_CODES;
24import android.support.annotation.StyleableRes;
25import android.util.AttributeSet;
26import android.view.ContextThemeWrapper;
27import android.view.View;
28import android.widget.Button;
29import android.widget.LinearLayout;
30
31import com.android.setupwizardlib.R;
32
33/**
34 * Custom navigation bar for use with setup wizard. This bar contains a back button, more button and
35 * next button. By default, the more button is hidden, and typically the next button will be hidden
36 * if the more button is shown.
37 *
38 * @see com.android.setupwizardlib.template.RequireScrollMixin
39 */
40public class NavigationBar extends LinearLayout implements View.OnClickListener {
41
42    /**
43     * An interface to listen to events of the navigation bar, namely when the user clicks on the
44     * back or next button.
45     */
46    public interface NavigationBarListener {
47        void onNavigateBack();
48        void onNavigateNext();
49    }
50
51    private static int getNavbarTheme(Context context) {
52        // Normally we can automatically guess the theme by comparing the foreground color against
53        // the background color. But we also allow specifying explicitly using suwNavBarTheme.
54        TypedArray attributes = context.obtainStyledAttributes(
55                new int[] {
56                        R.attr.suwNavBarTheme,
57                        android.R.attr.colorForeground,
58                        android.R.attr.colorBackground });
59        @StyleableRes int suwNavBarTheme = 0;
60        @StyleableRes int colorForeground = 1;
61        @StyleableRes int colorBackground = 2;
62        int theme = attributes.getResourceId(suwNavBarTheme, 0);
63        if (theme == 0) {
64            // Compare the value of the foreground against the background color to see if current
65            // theme is light-on-dark or dark-on-light.
66            float[] foregroundHsv = new float[3];
67            float[] backgroundHsv = new float[3];
68            Color.colorToHSV(attributes.getColor(colorForeground, 0), foregroundHsv);
69            Color.colorToHSV(attributes.getColor(colorBackground, 0), backgroundHsv);
70            boolean isDarkBg = foregroundHsv[2] > backgroundHsv[2];
71            theme = isDarkBg ? R.style.SuwNavBarThemeDark : R.style.SuwNavBarThemeLight;
72        }
73        attributes.recycle();
74        return theme;
75    }
76
77    private static Context getThemedContext(Context context) {
78        final int theme = getNavbarTheme(context);
79        return new ContextThemeWrapper(context, theme);
80    }
81
82    private Button mNextButton;
83    private Button mBackButton;
84    private Button mMoreButton;
85    private NavigationBarListener mListener;
86
87    public NavigationBar(Context context) {
88        super(getThemedContext(context));
89        init();
90    }
91
92    public NavigationBar(Context context, AttributeSet attrs) {
93        super(getThemedContext(context), attrs);
94        init();
95    }
96
97    @TargetApi(VERSION_CODES.HONEYCOMB)
98    public NavigationBar(Context context, AttributeSet attrs, int defStyleAttr) {
99        super(getThemedContext(context), attrs, defStyleAttr);
100        init();
101    }
102
103    // All the constructors delegate to this init method. The 3-argument constructor is not
104    // available in LinearLayout before v11, so call super with the exact same arguments.
105    private void init() {
106        View.inflate(getContext(), R.layout.suw_navbar_view, this);
107        mNextButton = (Button) findViewById(R.id.suw_navbar_next);
108        mBackButton = (Button) findViewById(R.id.suw_navbar_back);
109        mMoreButton = (Button) findViewById(R.id.suw_navbar_more);
110    }
111
112    public Button getBackButton() {
113        return mBackButton;
114    }
115
116    public Button getNextButton() {
117        return mNextButton;
118    }
119
120    public Button getMoreButton() {
121        return mMoreButton;
122    }
123
124    public void setNavigationBarListener(NavigationBarListener listener) {
125        mListener = listener;
126        if (mListener != null) {
127            getBackButton().setOnClickListener(this);
128            getNextButton().setOnClickListener(this);
129        }
130    }
131
132    @Override
133    public void onClick(View view) {
134        if (mListener != null) {
135            if (view == getBackButton()) {
136                mListener.onNavigateBack();
137            } else if (view == getNextButton()) {
138                mListener.onNavigateNext();
139            }
140        }
141    }
142}
143