众所周知，statusbar显示在设备的顶部，那怎么改变statusbar的方向呢？
2017年的时候，有在后视镜上做过把statusbar由顶部移到右边，现在我把方法简单的记录下来，statusbar的运行是一个很复杂的流程，所以定制statusbar不是一个很简单的事。
说到statusbar，做android系统开发的软件开发工程师第一个想到的就是SystemUI，说到SystemUI就会想到navigation bar，statusbar，notification。如果对SystemUI有一点了解的话就会知道navigation bar和statusbar的流程大致是一样的，而且navigation bar可以显示在设备的底部或者右侧，因此，我们只要跟踪到navigation bar的方向显示，statusbar的方向显示修改就易如反掌了。
接下来说说navigation bar的方向显示。
navigation bar的方向是在PhoneWindowManager.java控制的，是在beginLayoutLw()函数。
mNavigationBar.computeFrameLw(mTmpNavigationFrame, mTmpNavigationFrame,
mTmpNavigationFrame, mTmpNavigationFrame, mTmpNavigationFrame, dcf,
mTmpNavigationFrame);//navigation bar在设备上显示坐标
mNavigationBarOnBottom = (!mNavigationBarCanMove || displayWidth < displayHeight);//判断是否显示在底部，为true，显示在底部，false显示在右侧。
追踪到navigation bar的流程，继续往下看，哈哈，发现到statusbar方向控制的代码，我把这段代码贴下来。
// apply any navigation bar insets
pf.left = df.left = of.left = mUnrestrictedScreenLeft;
pf.top = df.top = of.top = mUnrestrictedScreenTop;
pf.right = df.right = of.right = mUnrestrictedScreenWidth + mUnrestrictedScreenLeft;
pf.bottom = df.bottom = of.bottom = mUnrestrictedScreenHeight
+ mUnrestrictedScreenTop;
vf.left = mStableLeft;
vf.top = mStableTop;
vf.right = mStableRight;
vf.bottom = mStableBottom;
mStatusBarLayer = mStatusBar.getSurfaceLayer();
// Let the status bar determine its size.
mStatusBar.computeFrameLw(pf, df, vf, vf, vf, dcf, vf);
客户需求是把statusbar的方向移到右边，navigation bar的方向移动左边，这里navigation bar暂不作考虑，贴出status bar修改的代码。
static final Rect mTemStatusBarFrame=new Rect();
mTemStatusBarFrame.set(displayWidth-overscanRight-mStatusBarHeight, 0,displayWidth-overscanRight, displayHeight);
// apply any navigation bar insets
/* pf.left = df.left = of.left = mUnrestrictedScreenLeft;
pf.top = df.top = of.top = mUnrestrictedScreenTop;
pf.right = df.right = of.right = mUnrestrictedScreenWidth + mUnrestrictedScreenLeft;
pf.bottom = df.bottom = of.bottom = mUnrestrictedScreenHeight
+ mUnrestrictedScreenTop;
vf.left = mStableLeft;
vf.top = mStableTop;
vf.right = mStableRight;
vf.bottom = mStableBottom;*/
mStatusBarLayer = mStatusBar.getSurfaceLayer();
// Let the status bar determine its size.
// mStatusBar.computeFrameLw(pf, df, vf, vf, vf, dcf, vf);
mStatusBar.computeFrameLw(mTemStatusBarFrame, mTemStatusBarFrame, mTemStatusBarFrame, mTemStatusBarFrame, mTemStatusBarFrame, dcf, mTemStatusBarFrame);
当然，不是这么简单的事，其他参数的坐标值也都需要修改，例如mStableTop，mStableRight，mDockTop等参数值都需要修改，我在这里就不一一说明了，只给大家提供一个入口点。
改了statusbar的方向，接下来就是statusbar布局修改了，接下来进入到SystemUI，statusbar的布局涉及到super_status_bar.xml、status_bar.xml、status_bar_ticker.xml、system_icons.xml、signal_cluster_view.xml。statusbar是通过StatusBarWindowManager.java的add(View statusBarView, int barHeight) 画出来。
public void add(View statusBarView, int barHeight) {
// Now that the status bar window encompasses the sliding panel and its
// translucent backdrop, the entire thing is made TRANSLUCENT and is
// hardware-accelerated.
mLp = new WindowManager.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
barHeight,
WindowManager.LayoutParams.TYPE_STATUS_BAR,
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
| WindowManager.LayoutParams.FLAG_TOUCHABLE_WHEN_WAKING
| WindowManager.LayoutParams.FLAG_SPLIT_TOUCH
| WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
| WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS,
PixelFormat.TRANSLUCENT);
mLp.flags |= WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
mLp.gravity = Gravity.TOP;
mLp.softInputMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE;
mLp.setTitle(“StatusBar”);
mLp.packageName = mContext.getPackageName();
mStatusBarView = statusBarView;
mBarHeight = barHeight;
mWindowManager.addView(mStatusBarView, mLp);
mLpChanged = new WindowManager.LayoutParams();
mLpChanged.copyFrom(mLp);
}
修改成
public void add(View statusBarView, int barHeight) {
// Now that the status bar window encompasses the sliding panel and its
// translucent backdrop, the entire thing is made TRANSLUCENT and is
// hardware-accelerated.
mLp = new WindowManager.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT,
/* barHeight,*/
WindowManager.LayoutParams.TYPE_STATUS_BAR,
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
| WindowManager.LayoutParams.FLAG_TOUCHABLE_WHEN_WAKING
| WindowManager.LayoutParams.FLAG_SPLIT_TOUCH
| WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
| WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS,
PixelFormat.TRANSLUCENT);
mLp.flags |= WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
mLp.gravity = Gravity.RIGHT;
mLp.softInputMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE;
mLp.setTitle(“StatusBar”);
mLp.packageName = mContext.getPackageName();
mStatusBarView = statusBarView;
mBarHeight = barHeight;
mWindowManager.addView(mStatusBarView, mLp);
mLpChanged = new WindowManager.LayoutParams();
mLpChanged.copyFrom(mLp);
}
到此，statusbar分析结束了，这只是一个简单的修改，我之前的客制化是有把下拉状态栏和通知功能都去掉了的，如果下拉状态栏和通知不去掉的话，statusbar由顶部移到两侧是行不通的。