看了下公司的系统代码对于根布局decor_layout.xml的修改, 有所获.
前些时候才开始做系统开发的时候, 总想改改系统的源码, 至于原因: 人总是想装装, 在踩过几个别人修改的坑后, 还是觉得在不改源码的基础上, 尽量纳源码为自己所用还是挺好的.
代码如下:
public void wrapDecor(Activity activity) {
mWindow = activity.getWindow();
if(mWindow == null){
Log.e(TAG, "Window is null");
return;
}
View decorView = mWindow.getDecorView();
if (decorView == null) {
Log.e(TAG, "DecorView is null");
return;
}
ViewGroup contentView = (ViewGroup) decorView.findViewById(android.R.id.content);
if (contentView == null) {
Log.e(TAG, "DecorView is null, have you called wrapDecor after Activity#super.onCreate?");
return;
}
final int childCount = contentView.getChildCount();
if (childCount == 0) {
// Maybe called before Activity#setContentView
mPotentialErrorFlag |= FLAG_POTENTIAL_ERROR_SET_CONTENT;
}
View[] children = new View[childCount];
for (int i = 0; i < childCount; i++) {
children[i] = contentView.getChildAt(i);
}
contentView.removeAllViews();
LayoutInflater inflater = LayoutInflater.from(activity);
//===================== begin ========================
// 此处即为自定义的decor_layout.xml文件
View wrapper = inflater.inflate(R.layout.decor_layout, null);
ViewGroup rawContentView = (ViewGroup) wrapper.findViewById(R.id.content);
if (childCount > 0) {
for (View child : children) {
rawContentView.addView(child);
}
}
//change for listActivity, add view first then setContenView
activity.setContentView(wrapper);
//===================== end =======================
// 获取自定义decor_layout中的控件
mOptionsKey = wrapper.findViewById(R.id.feature_bar_options);
// 此处获取的是ActionBar的控件, 由于项目中需要大量使用到ActionBar,
// 此处对覆盖ActionBar对OptionMenu的控制
ActionBarView actionBarView = (ActionBarView) decorView.findViewById(
com.android.internal.R.id.action_bar);
if (actionBarView != null) {
// 覆盖ActionBar对OptionMenu的控制
actionBarView.setOverrideOverflowButton(mOptionsKey);
} else {
Log.d(TAG, "actionBarView is null");
if (mWindow != null) {
Log.d(TAG, "Attempt to invoke setShouldOverrideResources access PhoneWindow");
mWindow.setShouldOverrideResources(true);
} else {
Log.d(TAG, "mWindow is empty, pls check it");
}
}
}
该段代码的核心, 就在上面的 begin 和 end 之间, 代码挺简单, 使用到包装的思想, 也就是包装设计模式.