Android 播放器通知栏样式适配

一、获取通知栏主题颜色

由于调用系统的属性，获取颜色在某些手机上是不兼容的。因此采用先创建一个系统通知栏对象，然后迭代其中的 View 获取对应的颜色。代码如下：

import android.app.Notification;import android.content.Context;import android.support.v4.app.NotificationCompat;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.FrameLayout;import android.widget.TextView;import java.util.ArrayList;import java.util.List;/** * Created by iOnesmile on 06/07/2017. */public class NotificationColor {    private static final String NOTIFICATION_TITLE = "notification_title";    public static final int INVALID_COLOR = -1; // 无效颜色    private static int notificationTitleColor = INVALID_COLOR; // 获取到的颜色缓存    /**     * 获取系统通知栏主标题颜色，根据Activity继承自AppCompatActivity或FragmentActivity采取不同策略。     *     * @param context 上下文环境     * @return 系统主标题颜色     */    public static int getNotificationColor(Context context) {        try {            if (notificationTitleColor == INVALID_COLOR) {                if (context instanceof AppCompatActivity) {                    notificationTitleColor = getNotificationColorCompat(context);                } else {                    notificationTitleColor = getNotificationColorInternal(context);                }            }        } catch (Exception ignored) {        }        return notificationTitleColor;    }    /**     * 通过一个空的Notification拿到Notification.contentView，通过{@link RemoteViews#apply(Context, ViewGroup)}方法返回通知栏消息根布局实例。     *     * @param context 上下文     * @return 系统主标题颜色     */    private static int getNotificationColorInternal(Context context) {        NotificationCompat.Builder builder = new NotificationCompat.Builder(context);        builder.setContentTitle(NOTIFICATION_TITLE);        Notification notification = builder.build();        try {            ViewGroup root = (ViewGroup) notification.contentView.apply(context, new FrameLayout(context));            TextView titleView = (TextView) root.findViewById(android.R.id.title);            if (null == titleView) {                iteratorView(root, new Filter() {                    @Override                    public void filter(View view) {                        if (view instanceof TextView) {                            TextView textView = (TextView) view;                            if (NOTIFICATION_TITLE.equals(textView.getText().toString())) {                                notificationTitleColor = textView.getCurrentTextColor();                            }                        }                    }                });                return notificationTitleColor;            } else {                return titleView.getCurrentTextColor();            }        } catch (Exception e) {            Log.e("NotificationColor", "", e);            return getNotificationColorCompat(context);        }    }    /**     * 使用getNotificationColorInternal()方法，Activity不能继承自AppCompatActivity（实测5.0以下机型可以，5.0及以上机型不行），     * 大致的原因是默认通知布局文件中的ImageView（largeIcon和smallIcon）被替换成了AppCompatImageView，     * 而在5.0及以上系统中，AppCompatImageView的setBackgroundResource(int)未被标记为RemotableViewMethod，导致apply时抛异常。     *     * @param context 上下文     * @return 系统主标题颜色     */    private static int getNotificationColorCompat(Context context) {        try {            NotificationCompat.Builder builder = new NotificationCompat.Builder(context);            Notification notification = builder.build();            int layoutId = notification.contentView.getLayoutId();            ViewGroup root = (ViewGroup) LayoutInflater.from(context).inflate(layoutId, null);            TextView titleView = (TextView) root.findViewById(android.R.id.title);            if (null == titleView) {                return getTitleColorIteratorCompat(root);            } else {                return titleView.getCurrentTextColor();            }        } catch (Exception e) {        }        return INVALID_COLOR;    }    private static void iteratorView(View view, Filter filter) {        if (view == null || filter == null) {            return;        }        filter.filter(view);        if (view instanceof ViewGroup) {            ViewGroup viewGroup = (ViewGroup) view;            for (int i = 0; i < viewGroup.getChildCount(); i++) {                View child = viewGroup.getChildAt(i);                iteratorView(child, filter);            }        }    }    private static int getTitleColorIteratorCompat(View view) {        if (view == null) {            return INVALID_COLOR;        }        List<TextView> textViews = getAllTextViews(view);        int maxTextSizeIndex = findMaxTextSizeIndex(textViews);        if (maxTextSizeIndex != Integer.MIN_VALUE) {            return textViews.get(maxTextSizeIndex).getCurrentTextColor();        }        return INVALID_COLOR;    }    private static int findMaxTextSizeIndex(List<TextView> textViews) {        float max = Integer.MIN_VALUE;        int maxIndex = Integer.MIN_VALUE;        int index = 0;        for (TextView textView : textViews) {            if (max < textView.getTextSize()) {                // 找到字号最大的字体，默认把它设置为主标题字号大小                max = textView.getTextSize();                maxIndex = index;            }            index++;        }        return maxIndex;    }    /**     * 实现遍历View树中的TextView，返回包含TextView的集合。     *     * @param root 根节点     * @return 包含TextView的集合     */    private static List<TextView> getAllTextViews(View root) {        final List<TextView> textViews = new ArrayList<>();        iteratorView(root, new Filter() {            @Override            public void filter(View view) {                if (view instanceof TextView) {                    textViews.add((TextView) view);                }            }        });        return textViews;    }    private interface Filter {        void filter(View view);    }}

二、渲染播放图标

播放器图标的渲染，采用 v4 包中的 tint 方法，代码如下：

public static Bitmap getBitmapByIdAndRender(Context context, int drawableResId, int renderColor) {    Drawable drawable = getDrawable(context, drawableResId);    drawable = tintDrawable(drawable, ColorStateList.valueOf(renderColor));    return drawableToBitmap(drawable);}public static Drawable getDrawable(Context context, int imageRes) {    Drawable drawable = context.getResources().getDrawable(imageRes);    drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());    return drawable;}public static Drawable tintDrawable(Drawable drawable, ColorStateList colors) {    final Drawable wrappedDrawable = DrawableCompat.wrap(drawable);    DrawableCompat.setTintList(wrappedDrawable, colors);    return wrappedDrawable;}

在设置副标题的颜色时，我采用了给主标题设置一个透明度的方式来达到，通过 HSV 模型把颜色和透明度合成一个新的色值：

/** * 把RGB + Alpha合成为一个新的RGB * @param alpha * @param color * @return */public static int getCompoundColor(int alpha, int color) {    float[] hsv = new float[]{0, 0, 1};    Color.colorToHSV(color, hsv);    hsv[2] = (alpha + 0.0f) / 0xFF;    color = Color.HSVToColor(hsv);    return color;}

三、参考链接

Android自定义通知样式适配 http://www.jianshu.com/p/426d85f34561

Android通知栏介绍与适配总结 http://iluhcm.com/2017/03/12/experience-of-adapting-to-android-notifications/