在上一节中讲解了动态换肤的原理以及动态换肤的基本实现,本篇文章来讲解动态换肤扩展(Fragment、状态栏、自定义view、字体).

Fragment 扩展

Fragment 不用设置fractory2,只要activity中设置了fractory2就不用在设置就可以实现换肤,所以fragment不用任何修改.那么是为什么呢?

我们都知道在fragment是通过,onCreateView 传递一个LayoutInflater,来实现view的加载

  1. override fun onCreateView(
  2.         inflater: LayoutInflater,
  3.         container: ViewGroup?,
  4.         savedInstanceState: Bundle?
  5.     ): View? {
  6.         return inflater.inflate(R.layout.fragment_music, container, false)
  7.     }

那么这个LayoutInflater 是从哪里来的呢? 相信大家也能猜出个大概,其实就是和加载Fragment的Activity有关,我们看一下系统的Fragment源码

  1.     @Deprecated
  2.     @NonNull
  3.     @RestrictTo(LIBRARY_GROUP_PREFIX)
  4.     public LayoutInflater getLayoutInflater(@Nullable Bundle savedFragmentState) {
  5.         if (mHost == null) {
  6.             throw new IllegalStateException("onGetLayoutInflater() cannot be executed until the "
  7.                     + "Fragment is attached to the FragmentManager.");
  8.         }
  9.         LayoutInflater result = mHost.onGetLayoutInflater();
  10.         LayoutInflaterCompat.setFactory2(result, mChildFragmentManager.getLayoutInflaterFactory());
  11.         return result;
  12.     }

在上述代码中,Fragment通过 mHost 的 onGetLayoutInflater 获取的,我们来看一下这个 mHost 是什么? mhost是一个接口类FragmentHostCallback. 代码如下,可以看出Fragment的很多操作都和mHost有关,包括获取上下文等操作,那么我们就可以断定这个mHost 肯定是从Activity中传递过来的

  1.        // Host this fragment is attached to.
  2.     FragmentHostCallback mHost;
  3.     @Nullable
  4.     public Context getContext() {
  5.         return mHost == null ? null : mHost.getContext();
  6.     }
  7.  @Nullable
  8.     final public FragmentActivity getActivity() {
  9.         return mHost == null ? null : (FragmentActivity) mHost.getActivity();
  10.     }
  12. .....

FragmentActivity 的源码如下: FrgmentActivity 的代码中实现了FragmentHostCallback,那么Framgment的 mHost 其实就是FragmentActivity的实现接口类

  1.  class HostCallbacks extends FragmentHostCallback<FragmentActivity> implements
  2.             ViewModelStoreOwner,
  3.             OnBackPressedDispatcherOwner {
  4.         public HostCallbacks() {
  5.             super(FragmentActivity.this /*fragmentActivity*/);
  6.         }
  8. .....
  9.         @Override
  10.         @NonNull
  11.         public LayoutInflater onGetLayoutInflater() {
  12.             return FragmentActivity.this.getLayoutInflater().cloneInContext(FragmentActivity.this);
  13.         }
  15.      ......
  16.     }

也就是说mHost.onGetLayoutInflater();其实调用的就是如下代码

  1. public LayoutInflater onGetLayoutInflater() {
  2.             return FragmentActivity.this.getLayoutInflater().cloneInContext(FragmentActivity.this);
  3.         }
  5.   /**
  6.      * Convenience for calling
  7.      * {@link android.view.Window#getLayoutInflater}.
  8.      */
  9.     @NonNull
  10.     public LayoutInflater getLayoutInflater() {
  11.         return getWindow().getLayoutInflater();
  12.     }

那么具体实现的LayoutInflater就是PhoneLayoutInfalter,代码如下:

  1. public class PhoneLayoutInflater extends LayoutInflater {
  2.     private static final String[] sClassPrefixList = {
  3.         "android.widget.",
  4.         "android.webkit.",
  5.         "android.app."
  6.     };
  8.     /**
  9.      * Instead of instantiating directly, you should retrieve an instance
  10.      * through {@link Context#getSystemService}
  11.      *
  12.      * @param context The Context in which in which to find resources and other
  13.      *                application-specific things.
  14.      *
  15.      * @see Context#getSystemService
  16.      */
  17.     public PhoneLayoutInflater(Context context) {
  18.         super(context);
  19.     }
  21.     protected PhoneLayoutInflater(LayoutInflater original, Context newContext) {
  22.         super(original, newContext);
  23.     }
  25.     /** Override onCreateView to instantiate names that correspond to the
  26.         widgets known to the Widget factory. If we don't find a match,
  27.         call through to our super class.
  28.     */
  29.     @Override protected View onCreateView(String name, AttributeSet attrs) throws ClassNotFoundException {
  30.         for (String prefix : sClassPrefixList) {
  31.             try {
  32.                 View view = createView(name, prefix, attrs);
  33.                 if (view != null) {
  34.                     return view;
  35.                 }
  36.             } catch (ClassNotFoundException e) {
  37.                 // In this case we want to let the base class take a crack
  38.                 // at it.
  39.             }
  40.         }
  42.         return super.onCreateView(name, attrs);
  43.     }
  45.     public LayoutInflater cloneInContext(Context newContext) {
  46.         return new PhoneLayoutInflater(this, newContext);
  47.     }
  48. }

PhoneLayoutInfalter实现流程和LayoutInfalter的流程是一样的,只不过通过cloneInContext,重新new了一个LayoutInflater 也相当于克隆了一个LayoutInflater,调用了Layoutflater的一个构造方法,同时也将factory2进行了赋值.

  1. protected LayoutInflater(LayoutInflater original, Context newContext) {
  2.         mContext = newContext;
  3.         mFactory = original.mFactory;
  4.         mFactory2 = original.mFactory2;
  5.         mPrivateFactory = original.mPrivateFactory;
  6.         setFilter(original.mFilter);
  7.     }

那么我们再回到Fragment中的getLayoutInflater中,不知道大家有没有发现Fragment又重新对factory2进行了赋值,那么为什么我们还能动态换肤成功呢?

  1.  public LayoutInflater getLayoutInflater(@Nullable Bundle savedFragmentState) {
  2.         if (mHost == null) {
  3.             throw new IllegalStateException("onGetLayoutInflater() cannot be executed until the "
  4.                     + "Fragment is attached to the FragmentManager.");
  5.         }
  6.         LayoutInflater result = mHost.onGetLayoutInflater();
  7.         LayoutInflaterCompat.setFactory2(result, mChildFragmentManager.getLayoutInflaterFactory());
  8.         return result;
  9.     }

我们来看一下setFactory2的实现如下: 很显然当第二次进行赋值时mFactory不等于空,而是new FactoryMerger进行了赋值,将两个factory进行了合并

  1.     public void setFactory2(Factory2 factory) {
  2.         if (mFactorySet) {
  3.             throw new IllegalStateException("A factory has already been set on this LayoutInflater");
  4.         }
  5.         if (factory == null) {
  6.             throw new NullPointerException("Given factory can not be null");
  7.         }
  8.         mFactorySet = true;
  9.         if (mFactory == null) {
  10.             mFactory = mFactory2 = factory;
  11.         } else {
  12.             mFactory = mFactory2 = new FactoryMerger(factory, factory, mFactory, mFactory2);
  13.         }
  14.     }

看如下代码,会先对第一次赋值对mF12进行加载view操作如果返回为空,就使用第二此赋值对f1进行加载view操作.调用了Factory2的onCreateView(parent, name, context, attrs)方法

  1. private static class FactoryMerger implements Factory2 {
  2.         private final Factory mF1, mF2;
  3.         private final Factory2 mF12, mF22;
  5.         FactoryMerger(Factory f1, Factory2 f12, Factory f2, Factory2 f22) {
  6.             mF1 = f1;
  7.             mF2 = f2;
  8.             mF12 = f12;
  9.             mF22 = f22;
  10.         }
  12.         public View onCreateView(String name, Context context, AttributeSet attrs) {
  13.             View v = mF1.onCreateView(name, context, attrs);
  14.             if (v != null) return v;
  15.             return mF2.onCreateView(name, context, attrs);
  16.         }
  18.         public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
  19.             View v = mF12 != null ? mF12.onCreateView(parent, name, context, attrs)
  20.                     : mF1.onCreateView(name, context, attrs);
  21.             if (v != null) return v;
  22.             return mF22 != null ? mF22.onCreateView(parent, name, context, attrs)
  23.                     : mF2.onCreateView(name, context, attrs);
  24.         }
  25.     }
  26. .........
  27.             View view;
  28.             if (mFactory2 != null) {
  29.                 view = mFactory2.onCreateView(parent, name, context, attrs);
  30.             } else if (mFactory != null) {
  31.                 view = mFactory.onCreateView(name, context, attrs);
  32.             } else {
  33.                 view = null;
  34.             }

综上,Fragment加载view会先加载我们自定义的Factory2,如果返回为空就使用Fragment设置的Factory2,所以Fragment 动态换肤不需要做任何处理.

状态栏扩展

状态栏的颜色改变,我们只需要通过代码动态修改状态栏的颜色即可,获取在style中的设置然后,在Activity的onCreate和动态更新皮肤的时候在SkinLayoutFactory进行调用如下方法即可.

  1.  private static int[] APPCOMPAT_COLOR_PRINARY_DARK_ATIRS = {
  2.             androidx.appcompat.R.attr.colorPrimaryDark
  3.     };
  5.     //高优先级
  6.     private static int[] STATUSBAR_COLOR_ATTRS = {
  7.             android.R.attr.statusBarColor, android.R.attr.navigationBarColor
  8.     };
  10.     //更新状态栏
  11.     @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
  12.     public static void updateStatusBar(Activity activity) {
  13.         int[] statusBarColorIDs = getResId(activity, STATUSBAR_COLOR_ATTRS);
  14.         if (statusBarColorIDs[0] == 0) {//如果没有配置状态栏颜色则读取colorPrimaryDark
  15.             int statusBarColorID = getResId(activity, APPCOMPAT_COLOR_PRINARY_DARK_ATIRS)[0];
  16.             if (statusBarColorID != 0) {
  17.                 //读取皮肤包中的颜色值
  18.                 int color = SkinResources.getInstance().getColor(statusBarColorID);
  19.                 activity.getWindow().setStatusBarColor(color);
  20.             }
  21.         } else {
  22.             activity.getWindow().setStatusBarColor(SkinResources.getInstance().getColor(statusBarColorIDs[0]));
  23.         }
  24.         if (statusBarColorIDs[1] != 0) {
  25.             activity.getWindow().setNavigationBarColor(SkinResources.getInstance().getColor
  26.                     (statusBarColorIDs[1]));
  27.         }
  28.     }

字体扩展

如何实现对皮肤包中对字体更改呢? 我们需要定义一个自定义的属性,在attrs中自定义一个属性,然后这个属性值就是字体的文件地址一般都放在assets/font中

  1.   <!-- 设置自定义属性 自定义字体 -->
  2.     <attr name="skinTypeFace" format="string" />

然后在App中的style基础的theme中设置,在strings中 设置string属性,这样我们就可以在皮肤包中设置string 属性动态的修改为皮肤包资源的字体文件

  1.   <style name="BaseTheme" parent="Theme.AppCompat.Light.NoActionBar">
  2.         <!-- Customize your theme here. -->
  3.         <item name="colorPrimary">@color/colorPrimary</item>
  4.         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
  5.         <item name="colorAccent">@color/colorAccent</item>
  6.         <item name="skinTypeFace">@string/typeface</item>
  7.     </style>
  9.     <style name="AppTheme" parent="BaseTheme"></style>

从资源中找到字体文件,代码如下:

  1. private static int[] TYPRFACE_ATTR = {R.attr.skinTypeFace}; 
  2. public static Typeface updateTypeface(Activity activity) {
  3.         int skinTypefaceId = getResId(activity, TYPRFACE_ATTR)[0];
  4.         return SkinResources.getInstance().getTypeface(skinTypefaceId);
  5.     }
  7.  public Typeface getTypeface(int resId) {
  8.         String skinTypefacePath = getString(resId);
  9.         if (TextUtils.isEmpty(skinTypefacePath)) {
  10.             return Typeface.DEFAULT;
  11.         }
  12.         try {
  13.             Typeface typeface;
  14.             if (isDefalueSkin) {
  15.                 typeface = Typeface.createFromAsset(mAppResources.getAssets(), skinTypefacePath);
  16.                 return typeface;
  18.             }
  19.             typeface = Typeface.createFromAsset(mSkinResources.getAssets(), skinTypefacePath);
  20.             return typeface;
  21.         } catch (RuntimeException e) {
  22.         }
  23.         return Typeface.DEFAULT;
  24.     }

我们获取到Typeface 设置到TextView 中去. 这段代码是很基础的,在SkinAttribute中我们拿到了需要采集的view,更换皮肤时会对采集的view集合进行遍历,判断是否为TextView,如果是TextView则进行设置setTypeface.这样就实现了字体的替换.

  1. if (view instanceof TextView) {
  2.                 ((TextView) view).setTypeface(typeface);
  3.             }

这样上述代码我们就实现了全局的字体更换.那么面对变态的需求如何实现局部的字体更换呢?

在上述中我们自定义了一个属性

  2.      <attr name="skinTypeFace" format="string" />

然后在指定的使用不同字体的view,设置该属性

  1. <Button
  2.         skinTypeFace="@string/typeface2"
  3.         android:layout_width="match_parent"
  4.         android:layout_height="wrap_content"
  5.         android:layout_marginTop="8dp"
  6.         android:gravity="center"
  7.         android:text="测试文字颜色与selector换肤"
  8.         android:textColor="@color/selector_color_test"
  9.         android:textSize="22sp"
  10.         tools:ignore="MissingPrefix" />

这样我们只需要在皮肤包中的string.xml中添加typeface2,设置字体路径,然后在SkinAttribute中添加要采集的属性skinTypeFace

  1. static {
  2.         mAttributes.add("background");
  3.         mAttributes.add("src");
  5.         mAttributes.add("textColor");
  6.         mAttributes.add("drawableLeft");
  7.         mAttributes.add("drawableTop");
  8.         mAttributes.add("drawableRight");
  9.         mAttributes.add("drawableBottom");
  10.         mAttributes.add("skinTypeFace");
  11.     }

在使用皮肤包的时候,applySkin判断skinTypeFace属性是否存在,如果存在则获取Typeface进行设置.

  1. case "skinTypeFace"://布局的字体更换
  2. Typeface typeface1 = SkinResources.getInstance().getTypeface(skinPair.resId);
  3. applySkinTypeface(typeface1);
  4. break;

这样我们就实现了局部字体的更换.

自定义view扩展

关于自定义view,就需要实现一个接口类,然后自己去实现换肤

  1. public interface SkinViewSupport {
  2.     void applySkin();
  3. }

如自定义TabLayout,通过SkinResources来获取资源ID的值进行赋值即可

  1. public class MyTabLayout extends TabLayout implements SkinViewSupport {
  3.     int tabIndicatorColorResId;
  4.     int tabTextColorResId;
  6.     public MyTabLayout(Context context) {
  7.         this(context, null, 0);
  8.     }
  10.     public MyTabLayout(Context context, AttributeSet attrs) {
  11.         this(context, attrs, 0);
  12.     }
  14.     public MyTabLayout(Context context, AttributeSet attrs, int defStyleAttr) {
  15.         super(context, attrs, defStyleAttr);
  16.         TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TabLayout,
  17.                 defStyleAttr, 0);
  18.         tabIndicatorColorResId = a.getResourceId(R.styleable.TabLayout_tabIndicatorColor, 0);
  19.         tabTextColorResId = a.getResourceId(R.styleable.TabLayout_tabTextColor, 0);
  20.         a.recycle();
  21.     }
  23.     @Override
  24.     public void applySkin() {
  25.         if (tabIndicatorColorResId != 0) {
  26.             int color = SkinResources.getInstance().getColor(tabIndicatorColorResId);
  27.             setSelectedTabIndicatorColor(color);
  28.         }
  30.         if (tabTextColorResId != 0) {
  31.             ColorStateList colorStateList = SkinResources.getInstance().getColorStateList(tabTextColorResId);
  32.             setTabTextColors(colorStateList);
  33.         }
  34.     }
  35. }

同时需要在SkinAttribute中,将其添加到采集到view集合中去,确保其被添加到集合中.

  1. else if (view instanceof TextView || view instanceof SkinViewSupport) {
  2.             //没有属性满足 但是需要修改字体
  3.             SkinView skinView = new SkinView(view, mSkinPars);
  4.             skinView.applySkin(typeface);
  5.             skinViews.add(skinView);
  6.         }

在更换皮肤时,遍历采集的view,在字体之后添加此方法,让自定义view自己去实现换肤

  1.  private void applySkinSupportView() {
  2.             if (view instanceof SkinViewSupport) {
  3.                 ((SkinViewSupport) view).applySkin();
  4.             }
  5.         }