PolicyCompat.java

package com.danxx.mdplayer.widget;

import android.content.Context;
import android.os.Build;
import android.view.Window;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

/**
 * 区分版本，反射创建PhoneWindow或者PolicyManager
 * danxingxi
 */
public class PolicyCompat {
	/*
	 * Private constants
	 */
    private static final String PHONE_WINDOW_CLASS_NAME   = "com.android.internal.policy.PhoneWindow";
    private static final String POLICY_MANAGER_CLASS_NAME = "com.android.internal.policy.PolicyManager";

    
    private PolicyCompat() {
    }


    /*
     * Private methods
     */
    private static Window createPhoneWindow(Context context) {
        try {
            /* Find class */
            Class<?> cls = Class.forName(PHONE_WINDOW_CLASS_NAME);

            /* Get constructor */
            Constructor c = cls.getConstructor(Context.class);

            /* Create instance */
            return (Window)c.newInstance(context);
        }
        catch (ClassNotFoundException e) {
            throw new RuntimeException(PHONE_WINDOW_CLASS_NAME + " could not be loaded", e);
        }
        catch (Exception e) {
            throw new RuntimeException(PHONE_WINDOW_CLASS_NAME + " class could not be instantiated", e);
        }
    }

    private static Window makeNewWindow(Context context) {
        try {
            /* Find class */
            Class<?> cls = Class.forName(POLICY_MANAGER_CLASS_NAME);

	    	/* Find method */
            Method m = cls.getMethod("makeNewWindow", Context.class);

	    	/* Invoke method */
            return (Window)m.invoke(null, context);
        }
        catch (ClassNotFoundException e) {
            throw new RuntimeException(POLICY_MANAGER_CLASS_NAME + " could not be loaded", e);
        }
        catch (Exception e) {
            throw new RuntimeException(POLICY_MANAGER_CLASS_NAME + ".makeNewWindow could not be invoked", e);
        }
    }

    
    /*
     * Public methods
     */
    public static Window createWindow(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
            return createPhoneWindow(context);
        else
            return makeNewWindow(context);
    }
}