expert-app/app/src/main/java/cn/shangyu/gdxzExpert/utils/DensityUtil.java

/*
 *  Copyright (c) 2015 The CCP project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a Beijing Speedtong Information Technology Co.,Ltd license
 *  that can be found in the LICENSE file in the root of the web site.
 *
 *   http://www.yuntongxun.com
 *
 *  An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */package cn.shangyu.gdxzExpert.utils;

import android.app.Activity;
import android.content.Context;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.WindowManager;

import java.lang.reflect.Method;

import cn.shangyu.gdxzExpert.application.BaseApplication;

/**
 * Created by Jorstin on 2015/3/18.
 */
public class DensityUtil {

    // 根据屏幕密度转换
    private static float mPixels = 0.0F;
    private static float density = -1.0F;

    /**
     *
     * @param context
     * @param pixels
     * @return
     */
    public static int getDisplayMetrics(Context context, float pixels) {
        if (mPixels == 0.0F)
            mPixels = context.getResources().getDisplayMetrics().density;
        return (int) (0.5F + pixels * mPixels);
    }


    public static int getImageWeidth(Context context , float pixels) {
        LogUtil.e("screen width " + context.getResources().getDisplayMetrics().widthPixels);
        return context.getResources().getDisplayMetrics().widthPixels - 66 - getDisplayMetrics(context, pixels);
    }

    /**
     * 像素转化dip
     * @param context
     * @param pxValue
     * @return
     */
    public static int px2dip(Context context, float pxValue){

        final float scale = context.getResources().getDisplayMetrics().density;

        return (int)(pxValue / scale + 0.5f);

    }

    /**
     * dip转化像素
     * @param dipValue
     * @return
     */
    public static int dip2px(float dipValue){
        final float scale = Resources.getSystem().getDisplayMetrics().density;
        return (int)(dipValue * scale + 0.5f);

    }

    /**
     * @param context
     * @param height
     * @return
     */
    public static int getMetricsDensity(Context context , float height) {
        DisplayMetrics localDisplayMetrics = new DisplayMetrics();
        ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE))
                .getDefaultDisplay().getMetrics(localDisplayMetrics);
        return Math.round(height * localDisplayMetrics.densityDpi / 160.0F);
    }


    public static int fromDPToPix(Context context, int dp) {
        return Math.round(getDensity(context) * dp);
    }

    /**
     * @param context
     * @return
     */
    public static float getDensity(Context context) {
        if (context == null)
            context = BaseApplication.getInstance().getApplicationContext();
        if (density < 0.0F)
            density = context.getResources().getDisplayMetrics().density;
        return density;
    }

    public static int round(Context context, int paramInt) {
        return Math.round(paramInt / getDensity(context));
    }

    /**
     * 保持字体大小不随系统设置变化（用在界面加载之前）
     * 要重写Activity的attachBaseContext()
     */
    public static Context attachBaseContext(Context context, float fontScale) {
        Configuration config = context.getResources().getConfiguration();
        //正确写法
        config.fontScale = fontScale;
        return context.createConfigurationContext(config);
    }

    /**
     * 保持字体大小不随系统设置变化（用在界面加载之前）
     * 要重写Activity的getResources()
     */
    public static Resources getResources(Context context, Resources resources, float fontScale) {
        Configuration config = resources.getConfiguration();
        if(config.fontScale != fontScale) {
            config.fontScale = fontScale;
            return context.createConfigurationContext(config).getResources();
        } else {
            return resources;
        }
    }

    /**
     * 保存字体大小，后通知界面重建，它会触发attachBaseContext，来改变字号
     */
    public static void recreate(Activity activity) {
        activity.recreate();
    }


        /**
         * 系统设置"显示大小"时原有UI样式保持不变：
         * <p>
         * 1、当调节手机系统"显示大小"【调大】的时候，相应的dpi会变大【dp = (dpi/160) * px】,此时dp就会变大，所以相应的UI布局就会变大。
         * 2、当调节手机系统"分辨率"【调小】的时候，相应的dpi会变小【比如由480-->320】。如果此时使用技术手段使dpi保持不变，那么相同的dp就会占用更多的px，所以UI布局就会变大。
         *
         * @param context
         */
        public static void setDefaultDisplay(Context context) {
            if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
                Configuration origConfig = context.getResources().getConfiguration();
                //获取手机出厂时默认的densityDpi【注释1】
                origConfig.densityDpi = getDefaultDisplayDensity();

                context.getResources().updateConfiguration(origConfig, context.getResources().getDisplayMetrics());
            }
        }

        public static int getDefaultDisplayDensity() {
            try {
                Class clazz = Class.forName("android.view.WindowManagerGlobal");
                Method method = clazz.getMethod("getWindowManagerService");
                method.setAccessible(true);
                Object iwm = method.invoke(clazz);
                Method getInitialDisplayDensity = iwm.getClass().getMethod("getInitialDisplayDensity", int.class);
                getInitialDisplayDensity.setAccessible(true);
                Object densityDpi = getInitialDisplayDensity.invoke(iwm, Display.DEFAULT_DISPLAY);
                return (int) densityDpi;
            } catch (Exception e) {
                e.printStackTrace();
                return -1;
            }
        }



}