Android4.0的StatusBar和NavigationBar

主要是注意平板和手机之间布局的区别：
几个关键的java类
SystemUIService
PhoneWindowManager
WindowManagerPolicy
PhoneStatusBar
TabletStatusBar
NavigationBar

SystemUIService-->onCreate中判断加载平板布局还是手机布局
 [java]
 // Pick status bar or system bar.
 IWindowManager wm = IWindowManager.Stub.asInte易做图ce(
 ServiceManager.getService(Context.WINDOW_SERVICE));
 try {
 SERVICES[0] = wm.canStatusBarHide()
 ? R.string.config_statusBarComponent
 : R.string.config_systemBarComponent;
 } catch (RemoteException e) {
 Slog.w(TAG, "Failing checking whether status bar can hide", e);
 }

// Pick status bar or system bar.
 IWindowManager wm = IWindowManager.Stub.asInte易做图ce(
 ServiceManager.getService(Context.WINDOW_SERVICE));
 try {
 SERVICES[0] = wm.canStatusBarHide()
 ? R.string.config_statusBarComponent
 : R.string.config_systemBarComponent;
 } catch (RemoteException e) {
 Slog.w(TAG, "Failing checking whether status bar can hide", e);
 } 然后在frameworks\base\packages\systemui\res\values\config.xml中
 [html] view plaincopyprint? <string name="config_statusBarComponent" translatable="false">com.android.systemui.statusbar.phone.PhoneStatusBar</string>
 <string name="config_systemBarComponent" translatable="false">com.android.systemui.statusbar.tablet.TabletStatusBar</string>

<string name="config_statusBarComponent" translatable="false">com.android.systemui.statusbar.phone.PhoneStatusBar</string>
<string name="config_systemBarComponent" translatable="false">com.android.systemui.statusbar.tablet.TabletStatusBar</string>

然后通过类加载器加载PhoneStatusBar或者TabletStatusBar。也就是手机的状态栏还是平板的状态栏。
 判断的关键就在wm.canStatusBarHide()这个方法里面。
 我们跳过几个类后最后跟进到PhoneWindowManager中：
[java]
 public boolean canStatusBarHide() {
 return mStatusBarCanHide;
 }

public boolean canStatusBarHide() {
return mStatusBarCanHide;
} mStatusBarCanHide是一个成员变量，修改它值得地方在：

public void setInitialDisplaySize(int width, int height) {...}中。
[java]
 int shortSizeDp = shortSize
 * DisplayMetrics.DENSITY_DEFAULT
 / DisplayMetrics.DENSITY_DEVICE;
 mStatusBarCanHide = shortSizeDp < 600;
 mStatusBarHeight = mContext.getResources().getDimensionPixelSize(
 mStatusBarCanHide
 ? com.android.internal.R.dimen.status_bar_height
 : com.android.internal.R.dimen.system_bar_height);

 mHasNavigationBar = mContext.getResources().getBoolean(
 com.android.internal.R.bool.config_showNavigationBar);
 // Allow a system property to override this. Used by the emulator.
 // See also hasNavigationBar().
 String navBarOverride = SystemProperties.get("qemu.hw.mainkeys");
 if (! "".equals(navBarOverride)) {
 if (navBarOverride.equals("1")) mHasNavigationBar = false;
 else if (navBarOverride.equals("0")) mHasNavigationBar = true;
 }

int shortSizeDp = shortSize
 * DisplayMetrics.DENSITY_DEFAULT
 / DisplayMetrics.DENSITY_DEVICE;
 mStatusBarCanHide = shortSizeDp < 600;
 mStatusBarHeight = mContext.getResources().getDimensionPixelSize(
 mStatusBarCanHide
 ? com.android.internal.R.dimen.status_bar_height
 : com.android.internal.R.dimen.system_bar_height);

        mHasNavigationBar = mContext.getResources().getBoolean(
                com.android.internal.R.bool.config_showNavigationBar);
        // Allow a system property to override this. Used by the emulator.
        // See also hasNavigationBar().
    &

补充：移动开发 , Android ,