android字节跳动屏幕适配,Android屏幕适配-第三篇（今日头条适配方案）

r囧r小猫 2022-10-16 05:49 1216阅读 0赞

今天记录的笔记是今日头条的适配方案原理以及开源库”AndroidAutoSize“的实现剖析！(备注：此文仅供自己参考，全文全是文字，如果读者读起来比较生涩难懂，建议阅读引入文章)

此篇文章是通过阅读《骚年你的屏幕适配方式该升级了!-今日头条适配方案》理解的整理。感谢作者JessYan

适配的前提是你需要知道安卓适配的基础知识和基本方法 《Android屏幕适配-第一篇(基础知识)》、《Android屏幕适配-第二篇(你要知道的适配基本操作)》

你需要知道的关键字：density、dip、px、dp(dpi)

今日头条适配原理：density=(当前屏幕分辨率宽或高(单位px))/(ui设计稿宽或高(单位dp))

这个表示的是1dp在当前分辨率下的所对于的像素

真正的view大小： realWidth=(ui设计稿上的宽度)\*density

如何使用，例子：如设置一个view大小为100dpx100dp，通过上面的公式可得到宽为100\*density高为100\*density

假设当前分辨率为720x1280,设计搞的尺寸为360x640,当前density=2

假设当前分辨率为480x800,设计搞的尺寸为360x640,当前density=1.333

分辨率为720x1280下 view宽度=100\*2 px,占整体宽度的比例为0.278(约等于)

分辨率为480x800下 view宽度=100\*1.33 px,占整体宽度的比例为0.278(约等于)

比例近乎相同

AndroidAutoSize分析

设置设计稿 宽或高

初始化配置，通过启动一个ContenProvider来启动默认配置

/\*\*

\* ================================================

\* 通过声明 \{@link ContentProvider\} 自动完成初始化

\* Created by JessYan on 2018/8/19 11:55

\* Contact me

\* Follow me

\* ================================================

\*/

public class InitProvider extends ContentProvider \{

@Override

public boolean onCreate() \{

AutoSizeConfig.getInstance()

.setLog(true)

.init((Application) getContext().getApplicationContext())

.setUseDeviceSize(false);

return true;

//其他代码忽略...

然后会调用此方法

AutoSizeConfig init(final Application application, boolean isBaseOnWidth, AutoAdaptStrategy strategy) \{

Preconditions.checkArgument(mInitDensity == -1, "AutoSizeConfig\#init() can only be called once");

Preconditions.checkNotNull(application, "application == null");

this.mApplication = application;

this.isBaseOnWidth = isBaseOnWidth;

final DisplayMetrics displayMetrics = Resources.getSystem().getDisplayMetrics();

getMetaData(application);

isVertical = application.getResources().getConfiguration().orientation == Configuration.ORIENTATION\_PORTRAIT;

int\[\] screenSize = ScreenUtils.getScreenSize(application);

mScreenWidth = screenSize\[0\];

mScreenHeight = screenSize\[1\];

mStatusBarHeight = ScreenUtils.getStatusBarHeight();

LogUtils.d("designWidthInDp = " + mDesignWidthInDp + ", designHeightInDp = " + mDesignHeightInDp + ", screenWidth = " + mScreenWidth + ", screenHeight = " + mScreenHeight);

mInitDensity = displayMetrics.density;

mInitDensityDpi = displayMetrics.densityDpi;

mInitScaledDensity = displayMetrics.scaledDensity;

mInitXdpi = displayMetrics.xdpi;

application.registerComponentCallbacks(new ComponentCallbacks() \{

@Override

public void onConfigurationChanged(Configuration newConfig) \{

if (newConfig != null) \{

if (newConfig.fontScale > 0) \{

mInitScaledDensity =

Resources.getSystem().getDisplayMetrics().scaledDensity;

LogUtils.d("initScaledDensity = " + mInitScaledDensity + " on ConfigurationChanged");

isVertical = newConfig.orientation == Configuration.ORIENTATION\_PORTRAIT;

int\[\] screenSize = ScreenUtils.getScreenSize(application);

mScreenWidth = screenSize\[0\];

mScreenHeight = screenSize\[1\];

@Override

public void onLowMemory() \{

\});

....

//注意看这句代码是

mActivityLifecycleCallbacks = new ActivityLifecycleCallbacksImpl(strategy == null ? new WrapperAutoAdaptStrategy(new DefaultAutoAdaptStrategy()) : strategy);

application.registerActivityLifecycleCallbacks(mActivityLifecycleCallbacks);

....

return this;

ActivityLifecycleCallbacksImpl这里面有很多核心代码

/\*\*

\* ================================================

\* \{@link ActivityLifecycleCallbacksImpl\} 可用来代替在 BaseActivity 中加入适配代码的传统方式

\* \{@link ActivityLifecycleCallbacksImpl\} 这种方案类似于 AOP, 面向接口, 侵入性低, 方便统一管理, 扩展性强, 并且也支持适配三方库的 \{@link Activity\}

\* Created by JessYan on 2018/8/8 14:32

\* Contact me

\* Follow me

\* ================================================

\*/

public class ActivityLifecycleCallbacksImpl implements Application.ActivityLifecycleCallbacks \{

/\*\*

\* 屏幕适配逻辑策略类

\*/

private AutoAdaptStrategy mAutoAdaptStrategy;

/\*\*

\* 让 \{@link Fragment\} 支持自定义适配参数

\*/

private FragmentLifecycleCallbacksImpl mFragmentLifecycleCallbacks;

public ActivityLifecycleCallbacksImpl(AutoAdaptStrategy autoAdaptStrategy) \{

mFragmentLifecycleCallbacks = new FragmentLifecycleCallbacksImpl(autoAdaptStrategy);

mAutoAdaptStrategy = autoAdaptStrategy;

@Override

public void onActivityCreated(Activity activity, Bundle savedInstanceState) \{

if (AutoSizeConfig.getInstance().isCustomFragment()) \{

if (activity instanceof FragmentActivity) \{

((FragmentActivity) activity).getSupportFragmentManager().registerFragmentLifecycleCallbacks(mFragmentLifecycleCallbacks, true);

//Activity 中的 setContentView(View) 一定要在 super.onCreate(Bundle); 之后执行

if (mAutoAdaptStrategy != null) \{

mAutoAdaptStrategy.applyAdapt(activity, activity);

@Override

public void onActivityStarted(Activity activity) \{

if (mAutoAdaptStrategy != null) \{

mAutoAdaptStrategy.applyAdapt(activity, activity);

...

/\*\*

\* 设置屏幕适配逻辑策略类

\* @param autoAdaptStrategy \{@link AutoAdaptStrategy\}

\*/

public void setAutoAdaptStrategy(AutoAdaptStrategy autoAdaptStrategy) \{

mAutoAdaptStrategy = autoAdaptStrategy;

mFragmentLifecycleCallbacks.setAutoAdaptStrategy(autoAdaptStrategy);

DefaultAutoAdaptStrategy里面干了什么事情

/\*\*

\* ================================================

\* 屏幕适配逻辑策略默认实现类, 可通过 \{@link AutoSizeConfig\#init(Application, boolean, AutoAdaptStrategy)\}

\* 和 \{@link AutoSizeConfig\#setAutoAdaptStrategy(AutoAdaptStrategy)\} 切换策略

\* @see AutoAdaptStrategy

\* Created by JessYan on 2018/8/9 15:57

\* Contact me

\* Follow me

\* ================================================

\*/

public class DefaultAutoAdaptStrategy implements AutoAdaptStrategy \{

@Override

public void applyAdapt(Object target, Activity activity) \{

//检查是否开启了外部三方库的适配模式, 只要不主动调用 ExternalAdaptManager 的方法, 下面的代码就不会执行

if (AutoSizeConfig.getInstance().getExternalAdaptManager().isRun()) \{

if (AutoSizeConfig.getInstance().getExternalAdaptManager().isCancelAdapt(target.getClass())) \{

LogUtils.w(String.format(Locale.ENGLISH, "%s canceled the adaptation!", target.getClass().getName()));

AutoSize.cancelAdapt(activity);

return;

\} else \{

ExternalAdaptInfo info = AutoSizeConfig.getInstance().getExternalAdaptManager()

.getExternalAdaptInfoOfActivity(target.getClass());

if (info != null) \{

LogUtils.d(String.format(Locale.ENGLISH, "%s used %s for adaptation!", target.getClass().getName(), ExternalAdaptInfo.class.getName()));

AutoSize.autoConvertDensityOfExternalAdaptInfo(activity, info);

return;

//如果 target 实现 CancelAdapt 接口表示放弃适配, 所有的适配效果都将失效

if (target instanceof CancelAdapt) \{

LogUtils.w(String.format(Locale.ENGLISH, "%s canceled the adaptation!", target.getClass().getName()));

AutoSize.cancelAdapt(activity);

return;

//如果 target 实现 CustomAdapt 接口表示该 target 想自定义一些用于适配的参数, 从而改变最终的适配效果

if (target instanceof CustomAdapt) \{

LogUtils.d(String.format(Locale.ENGLISH, "%s implemented by %s!", target.getClass().getName(), CustomAdapt.class.getName()));

AutoSize.autoConvertDensityOfCustomAdapt(activity, (CustomAdapt) target);

\} else \{

LogUtils.d(String.format(Locale.ENGLISH, "%s used the global configuration.", target.getClass().getName()));

AutoSize.autoConvertDensityOfGlobal(activity);

AutoSize

public static void autoConvertDensityOfCustomAdapt(Activity activity, CustomAdapt customAdapt) \{

Preconditions.checkNotNull(customAdapt, "customAdapt == null");

float sizeInDp = customAdapt.getSizeInDp();

//如果 CustomAdapt\#getSizeInDp() 返回 0, 则使用在 AndroidManifest 上填写的设计图尺寸

if (sizeInDp <= 0) \{

if (customAdapt.isBaseOnWidth()) \{

sizeInDp = AutoSizeConfig.getInstance().getDesignWidthInDp();

\} else \{

sizeInDp = AutoSizeConfig.getInstance().getDesignHeightInDp();

autoConvertDensity(activity, sizeInDp, customAdapt.isBaseOnWidth());

/\*\*

\* 这里是今日头条适配方案的核心代码, 核心在于根据当前设备的实际情况做自动计算并转换 \{@link DisplayMetrics\#density\}、

\* \{@link DisplayMetrics\#scaledDensity\}、\{@link DisplayMetrics\#densityDpi\} 这三个值, 额外增加 \{@link DisplayMetrics\#xdpi\}

\* 以支持单位 \{@code pt\}、\{@code in\}、\{@code mm\}

\* @param activity \{@link Activity\}

\* @param sizeInDp 设计图上的设计尺寸, 单位 dp, 如果 \{@param isBaseOnWidth\} 设置为 \{@code true\},

\* \{@param sizeInDp\} 则应该填写设计图的总宽度, 如果 \{@param isBaseOnWidth\} 设置为 \{@code false\},

\* \{@param sizeInDp\} 则应该填写设计图的总高度

\* @param isBaseOnWidth 是否按照宽度进行等比例适配, \{@code true\} 为以宽度进行等比例适配, \{@code false\} 为以高度进行等比例适配

\* @see 今日头条官方适配方案

\*/

public static void autoConvertDensity(Activity activity, float sizeInDp, boolean isBaseOnWidth) \{

Preconditions.checkNotNull(activity, "activity == null");

float subunitsDesignSize = isBaseOnWidth ? AutoSizeConfig.getInstance().getUnitsManager().getDesignWidth()

: AutoSizeConfig.getInstance().getUnitsManager().getDesignHeight();

subunitsDesignSize = subunitsDesignSize > 0 ? subunitsDesignSize : sizeInDp;

int screenSize = isBaseOnWidth ? AutoSizeConfig.getInstance().getScreenWidth()

: AutoSizeConfig.getInstance().getScreenHeight();

String key = sizeInDp + "|" + subunitsDesignSize + "|" + isBaseOnWidth + "|"

\+ AutoSizeConfig.getInstance().isUseDeviceSize() + "|"

\+ AutoSizeConfig.getInstance().getInitScaledDensity() + "|"

\+ screenSize;

DisplayMetricsInfo displayMetricsInfo = mCache.get(key);

float targetDensity = 0;

int targetDensityDpi = 0;

float targetScaledDensity = 0;

float targetXdpi = 0;

if (displayMetricsInfo == null) \{

if (isBaseOnWidth) \{

targetDensity = AutoSizeConfig.getInstance().getScreenWidth() \* 1.0f / sizeInDp;

\} else \{

targetDensity = AutoSizeConfig.getInstance().getScreenHeight() \* 1.0f / sizeInDp;

float scale = AutoSizeConfig.getInstance().isExcludeFontScale() ? 1 : AutoSizeConfig.getInstance().

getInitScaledDensity() \* 1.0f / AutoSizeConfig.getInstance().getInitDensity();

targetScaledDensity = targetDensity \* scale;

targetDensityDpi = (int) (targetDensity \* 160);

if (isBaseOnWidth) \{

targetXdpi = AutoSizeConfig.getInstance().getScreenWidth() \* 1.0f / subunitsDesignSize;

\} else \{

targetXdpi = AutoSizeConfig.getInstance().getScreenHeight() \* 1.0f / subunitsDesignSize;

mCache.put(key, new DisplayMetricsInfo(targetDensity, targetDensityDpi, targetScaledDensity, targetXdpi));

\} else \{

targetDensity = displayMetricsInfo.getDensity();

targetDensityDpi = displayMetricsInfo.getDensityDpi();

targetScaledDensity = displayMetricsInfo.getScaledDensity();

targetXdpi = displayMetricsInfo.getXdpi();

setDensity(activity, targetDensity, targetDensityDpi, targetScaledDensity, targetXdpi);

LogUtils.d(String.format(Locale.ENGLISH, "The %s has been adapted! \\n%s Info: isBaseOnWidth = %s, %s = %f, %s = %f, targetDensity = %f, targetScaledDensity = %f, targetDensityDpi = %d, targetXdpi = %f"

, activity.getClass().getName(), activity.getClass().getSimpleName(), isBaseOnWidth, isBaseOnWidth ? "designWidthInDp"

: "designHeightInDp", sizeInDp, isBaseOnWidth ? "designWidthInSubunits" : "designHeightInSubunits", subunitsDesignSize

, targetDensity, targetScaledDensity, targetDensityDpi, targetXdpi));

由此可见autoConvertDensity()方法是核心代码

这里还匹配了pt in mm 为单位的适配

private static void setDensity(DisplayMetrics displayMetrics, float density, int densityDpi, float scaledDensity, float xdpi) \{

if (AutoSizeConfig.getInstance().getUnitsManager().isSupportDP()) \{

displayMetrics.density = density;

displayMetrics.densityDpi = densityDpi;

if (AutoSizeConfig.getInstance().getUnitsManager().isSupportSP()) \{

displayMetrics.scaledDensity = scaledDensity;

switch (AutoSizeConfig.getInstance().getUnitsManager().getSupportSubunits()) \{