android 7.0平台客制化虚拟导航按键(隐藏NavigationBar，上滑显示NavigationBar)

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.

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 csc
        String[] sets = newLayout.split(GRAVITY_SEPARATOR, 4);// mod by csc from 3
        String[] hide = sets[0].split(BUTTON_SEPARATOR);// add by csc
        String[] 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 csc
        inflateButtons(hide, (ViewGroup) mRot90.findViewById(R.id.ends_group), true);// add by csc

        inflateButtons(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 navigationBar
            Log.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 navigationbar
        getHideButton().setLongClickable(false);// add by csc for hide navigationbar
        mButtonDisatchers.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 csc
        return 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 csc
            Intent hideNavigationBarIntent = new Intent("HIDE_NAVIGATION_BAR");
            mContext.sendBroadcast(hideNavigationBarIntent);
            return -1;
        }

上滑显示事件：

mSystemGestures = new SystemGesturesPointerEventListener(context,
                new SystemGesturesPointerEventListener.Callbacks() {
                    @Override
                    public void onSwipeFromTop() {
                        /// M: Disable gesture in immersive mode. {@
                        if (isGestureIsolated()) {
                            return;
                        }
                        /// @}
                        if (mStatusBar != null) {
                            requestTransientBars(mStatusBar);
                        }
                    }
                    @Override
                    public 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 csc
   filter.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 csc

            mWindowManager.addView(mNavigationBarView, getNavigationBarLayoutParams());
        }
    }

ok。