如图，需求是增加一个按钮可以隐藏NavigationBar，上滑显示NavigationBar。
参考文章：
Android 8.1平台客制化虚拟导航按键
Android 7.0 虚拟按键（NavigationBar）源码分析（一） 之 View的创建流程
android导航栏隐藏与浮现
1.首先新建一个hide_show.xml,其中systemui:keyCode="142"为事件值，相当与F12.
<?xml version="1.0" encoding="utf-8"?><!-- Copyright (C) The Android Open Source ProjectLicensed under the Apache License, Version 2.0 (the "License");you may not use this file except in compliance with the License.You may obtain a copy of the License at/licenses/LICENSE-2.0Unless required by applicable law or agreed to in writing, softwaredistributed under the License is distributed on an "AS IS" BASIS,WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.See the License for the specific language governing permissions andlimitations under the License.--><com.android.systemui.statusbar.policy.KeyButtonViewxmlns:android="/apk/res/android"xmlns:systemui="/apk/res-auto"android:id="@+id/hide"android:layout_width="@dimen/navigation_key_width"android:layout_height="match_parent"android:layout_weight="0"android:src="@drawable/ic_sysbar_back_ime"systemui:keyCode="142"android:scaleType="center"android:contentDescription="@string/accessibility_home"android:paddingStart="@dimen/navigation_key_padding"android:paddingEnd="@dimen/navigation_key_padding"/>
2.NavigationBarInflaterView.java
增加hide。
public static final String HOME = "home";public static final String RECENT = "recent";public static final String NAVSPACE = "space";public static final String CLIPBOARD = "clipboard";public static final String KEY = "key";public static final String HIDE = "hide";// add by csc for hide navigationbar/// M: BMW @{public static final String RESTORE = "restore";
protected void inflateLayout(String newLayout) {mCurrentLayout = newLayout;if (newLayout == null) {newLayout = getDefaultLayout();}newLayout = "hide;recent;home;back";// add by cscString[] sets = newLayout.split(GRAVITY_SEPARATOR, 4);// mod by csc from 3String[] hide = sets[0].split(BUTTON_SEPARATOR);// add by cscString[] start = sets[1].split(BUTTON_SEPARATOR);String[] center = sets[2].split(BUTTON_SEPARATOR);String[] end = sets[3].split(BUTTON_SEPARATOR);// Inflate these in start to end order or accessibility traversal will be messed up.inflateButtons(hide, (ViewGroup) mRot0.findViewById(R.id.ends_group), false);// add by cscinflateButtons(hide, (ViewGroup) mRot90.findViewById(R.id.ends_group), true);// add by cscinflateButtons(start, (ViewGroup) mRot0.findViewById(R.id.ends_group), false);inflateButtons(start, (ViewGroup) mRot90.findViewById(R.id.ends_group), true);inflateButtons(center, (ViewGroup) mRot0.findViewById(R.id.ends_group), false);inflateButtons(center, (ViewGroup) mRot90.findViewById(R.id.ends_group), true);// delete by csc/* addGravitySpacer((LinearLayout) mRot0.findViewById(R.id.ends_group));addGravitySpacer((LinearLayout) mRot90.findViewById(R.id.ends_group));*/inflateButtons(end, (ViewGroup) mRot0.findViewById(R.id.ends_group), false);inflateButtons(end, (ViewGroup) mRot90.findViewById(R.id.ends_group), true);}
其中，为了布局把center_group改为ends_group，将space去掉(注释addGravitySpacer)。
inflateButton方法里面增加：
else if (HIDE.equals(button)){// add by csc for hide navigationBarLog.d("chenshichun"," "+this.getClass().getCanonicalName()+" ::::::HIDE:button::");v = inflater.inflate(R.layout.hide_show, parent, false);}
3.NavigationBarView.java
mBarTransitions = new NavigationBarTransitions(this);mButtonDisatchers.put(R.id.hide, new ButtonDispatcher(R.id.hide));// add by csc for hide navigationbargetHideButton().setLongClickable(false);// add by csc for hide navigationbarmButtonDisatchers.put(R.id.back, new ButtonDispatcher(R.id.back));mButtonDisatchers.put(R.id.home, new ButtonDispatcher(R.id.home));mButtonDisatchers.put(R.id.recent_apps, new ButtonDispatcher(R.id.recent_apps));
public ButtonDispatcher getBackButton() {return mButtonDisatchers.get(R.id.back);}public ButtonDispatcher getHomeButton() {return mButtonDisatchers.get(R.id.home);}public ButtonDispatcher getHideButton() {// add by cscreturn mButtonDisatchers.get(R.id.hide);}
到这里可以在界面上显示按钮。接下来加上点击事件。
4.PhoneWindowManager.java
在interceptKeyBeforeDispatching方法里面增加F12的监听事件，这时候为隐藏事件：
else if(keyCode == KeyEvent.KEYCODE_F12){// add by cscIntent hideNavigationBarIntent = new Intent("HIDE_NAVIGATION_BAR");mContext.sendBroadcast(hideNavigationBarIntent);return -1;}
上滑显示事件：
mSystemGestures = new SystemGesturesPointerEventListener(context,new SystemGesturesPointerEventListener.Callbacks() {@Overridepublic void onSwipeFromTop() {/// M: Disable gesture in immersive mode. {@if (isGestureIsolated()) {return;}/// @}if (mStatusBar != null) {requestTransientBars(mStatusBar);}}@Overridepublic void onSwipeFromBottom() {/// M: Disable gesture in immersive mode. {@if (isGestureIsolated()) {return;}/// @}if (mNavigationBar != null && mNavigationBarOnBottom) {requestTransientBars(mNavigationBar);}/*add by csc*/Intent intent = new Intent();intent.setAction("SHOW_NAVIGATION_BAR");mContext.sendBroadcast(intent);}
5.PhoneStatusBar.java
该类处理导航栏的隐藏或显示。
先注册广播：
filter.addAction("HIDE_NAVIGATION_BAR");// add by cscfilter.addAction("SHOW_NAVIGATION_BAR");// add by csc
else if(action.equals("HIDE_NAVIGATION_BAR")&&mWindowManager!=null&&mNavigationBarView!=null&&mNavigationBarView.getParent()!=null){mWindowManager.removeView(mNavigationBarView);mNavigationBarView = null ;isNavigationShow = false;}else if(action.equals("SHOW_NAVIGATION_BAR")){if(isNavigationShow){return ;}showNavigationBar();isNavigationShow = true;}
public void showNavigationBar() {mNavigationBarView =(NavigationBarView) View.inflate(mContext, R.layout.navigation_bar, null);prepareNavigationBarView();addNavigationBar();//防止在桌面时上拉出导航栏时，导航栏背景为黑色mNavigationBarView.setBackgroundColor(Color.TRANSPARENT);}
protected void addNavigationBar() {if (DEBUG) Log.v(TAG, "addNavigationBar: about to add " + mNavigationBarView);if (mNavigationBarView == null) return;prepareNavigationBarView();if(mNavigationBarView!=null && mNavigationBarView.getParent()==null) {// add by cscmWindowManager.addView(mNavigationBarView, getNavigationBarLayoutParams());}}
ok。
