Android 7.0 Launcher3 去掉应用抽屉

年初做过一个项目，有一个需求就是需要将桌面变为单层不需要二级菜单。最近几次有小伙伴有这个问我这个解决办法。现在我将分享给大家。

先上效果图：

功能分解

1. 去除Allapp键，调整HotSeat布局
2. 将所有应用摆在launcher第一层
3. 去掉长按时删除选项

解决方案

一，设置总开关
按照6.0 Launcher3 的模式，添加一个开关，控制是否去掉抽屉。

LauncherAppState类：单例模式，主要在启动的时候用，他初始化了一些对象，并且注册了广播监听器和ContentObserver。为了能灵活切换模式,在此类中添加静态开关。

Launcher3\src\com\android\launcher3\LauncherAppState.java：

 public static boolean isDisableAllApps() {        // Returns false on non-dogfood builds.        return android.os.SystemProperties.get("ro.wind.launcher3.ishome2","0").equals("1");    }

二，Allapp键的加载
在HotSeat里面去掉Allapp键的加载 ，屏蔽isAllAppsButtonRank()占用allapp位置。

1) 不再占用allapp位置
2) 在加载Workspace时,会留出HotSeat的第三个位置给allapp按钮,若不取消该位置的占用,在HotSeat加载时会留出空位。HotSeat的初始化在HotSeat.java中

Launcher3\src\com\android\launcher3\HotSeat.java –>isAllAppsButtonRank()：

public boolean isAllAppsButtonRank(int rank) {        //添加 @{        if (LauncherAppState.isDisableAllApps()) {            return false;            }        //添加 @}        return rank == mAllAppsButtonRank;    }

3) Home2没有抽屉，所以不需要allapp按钮。在HotSeat里面去掉Allapp键的加载，在HotSeat.java 的void resetLayout()中初始化HotSeat布局。在Home2时停止加载Allapp按钮。

Launcher3\src\com\android\launcher3\HotSeat.java –>resetLayout():

void resetLayout() {        mContent.removeAllViewsInLayout();        //添加 @{        if(LauncherAppState.isDisableAllApps()){        //添加 }@        // Add the Apps button        Context context = getContext();        LayoutInflater inflater = LayoutInflater.from(context);        TextView allAppsButton = (TextView)                inflater.inflate(R.layout.all_apps_button, mContent, false);        Drawable d = context.getResources().getDrawable(R.drawable.all_apps_button_icon);        mLauncher.resizeIconDrawable(d);        allAppsButton.setCompoundDrawables(null, d, null, null);        allAppsButton.setContentDescription(context.getString(R.string.all_apps_button_label));        allAppsButton.setOnKeyListener(new HotseatIconKeyEventListener());        if (mLauncher != null) {            mLauncher.setAllAppsButton(allAppsButton);            allAppsButton.setOnTouchListener(mLauncher.getHapticFeedbackTouchListener());            allAppsButton.setOnClickListener(mLauncher);            allAppsButton.setOnLongClickListener(mLauncher);            allAppsButton.setOnFocusChangeListener(mLauncher.mFocusHandler);        }        // Note: We do this to ensure that the hotseat is always laid out in the orientation of        // the hotseat in order regardless of which orientation they were added        int x = getCellXFromOrder(mAllAppsButtonRank);        int y = getCellYFromOrder(mAllAppsButtonRank);        CellLayout.LayoutParams lp = new CellLayout.LayoutParams(x,y,1,1);        lp.canReorder = false;        mContent.addViewToCellLayout(allAppsButton, -1, allAppsButton.getId(), lp, true);        }    }//别漏了这里的 }

三，数据初始化类中更改HotSeat布局

InvariantDeviceProfile.java Launcher3进行布局初始化的一个类。

在有allapp按钮时HotSeat里Hotseat图标数量为五个，没有allapp按钮时Hotseat图标数量应为四个。

Launcher3\src\com\android\launcher3\InvariantDeviceProfile.java:

1）先加个宏控

    //添加 @{    private boolean hasDA = LauncherAppState.isDisableAllApps();    //添加 }@

2)去掉抽屉时，HotSeat的格数为四格，所以不能抛出异常。 （ numHotseatIcons 为偶时不抛异常）

InvariantDeviceProfile( )：

InvariantDeviceProfile(String n, float w, float h, int r, int c, int fr, int fc, int maapc,        // Ensure that we have an odd number of hotseat items (since we need to place all apps)        if (hs % 2 == 0&& !hasDA) {// 在无抽屉情况下不抛异常            throw new RuntimeException("All Device Profiles must have an odd number of hotseat spaces");        }        name = n;         ...   ...    }

3）去掉抽屉的情况下加载不同的布局

getPredefinedDeviceProfiles() :

ArrayList<InvariantDeviceProfile> getPredefinedDeviceProfiles() {        ArrayList<InvariantDeviceProfile> predefinedDeviceProfiles = new ArrayList<>();        // width, height, #rows, #columns, #folder rows, #folder columns,        // iconSize, iconTextSize, #hotseat, #hotseatIconSize, defaultLayoutId.        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Super Short Stubby",                255, 300,     2, 3, 2, 3, 3, 48, 13, 3, 48, R.xml.default_workspace_4x4));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Shorter Stubby",                255, 400,     3, 3, 3, 3, 3, 48, 13, 3, 48, R.xml.default_workspace_4x4));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Short Stubby",                275, 420,     3, 4, 3, 4, 4, 48, 13, (hasDA ? 4 : 5), 48, (hasDA ? R.xml.default_workspace_4x4_no_all_apps : R.xml.default_workspace_4x4 )));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Stubby",                255, 450,     3, 4, 3, 4, 4, 48, 13, (hasDA ? 4 : 5), 48, (hasDA ? R.xml.default_workspace_4x4_no_all_apps : R.xml.default_workspace_4x4 )));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Nexus S",                296, 491.33f, 4, 4, 4, 4, 4, 48, 13,(hasDA ? 4 : 5), 48, (hasDA ? R.xml.default_workspace_4x4_no_all_apps : R.xml.default_workspace_4x4 )));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Nexus 4",                335, 567,     4, 4, 4, 4, 4, DEFAULT_ICON_SIZE_DP, 13, (hasDA ? 4 : 5), 56, (hasDA ? R.xml.default_workspace_4x4_no_all_apps : R.xml.default_workspace_4x4 )));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Nexus 5",                359, 567,     4, 4, 4, 4, 4, DEFAULT_ICON_SIZE_DP, 13,(hasDA ? 4 : 5), 56, (hasDA ? R.xml.default_workspace_4x4_no_all_apps : R.xml.default_workspace_4x4 )));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Large Phone",                406, 694,     5, 5, 4, 4, 4, 64, 14.4f,  5, 56, R.xml.default_workspace_5x5));        // The tablet profile is odd in that the landscape orientation        // also includes the nav bar on the side        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Nexus 7",                575, 904,     5, 6, 4, 5, 4, 72, 14.4f,  7, 60, R.xml.default_workspace_5x6));        // Larger tablet profiles always have system bars on the top & bottom        predefinedDeviceProfiles.add(new InvariantDeviceProfile("Nexus 10",                727, 1207,    5, 6, 4, 5, 4, 76, 14.4f,  7, 64, R.xml.default_workspace_5x6));        predefinedDeviceProfiles.add(new InvariantDeviceProfile("20-inch Tablet",                1527, 2527,   7, 7, 6, 6, 4, 100, 20,  7, 72, R.xml.default_workspace_4x4));        return predefinedDeviceProfiles;    }

5)记得改下 dw_phone_hotseat.xml 的布局 ，因为Hotseat只有5格了。

四，将所有应用放在第一层

launcher3加载流程：进入 LauncherApplication -> LauncherAppState -> 进行初始化环境（通过传递sContext）。进行事件监听&&初始化一些环境。例如：横竖屏、当局语言、像素密度、小部件和快捷图标数据库操作对象、应用图标缓存对象、初始化LauncherMode等。在初始化过后，从Launcher的Oncreate方法入手。mModel.startLoader(mWorkspace.getRestorePage());里加载数据 。在加载完成所有快捷方式后将其余为加载完的应用布局在第一层。

1) 成所有快捷方式后将其余为加载完的应用布局在第一层。

Launcher3\src\com\android\launcher3\LauncherModel.java:

LauncherModel$LoaderTask –> run():

public void run() {            ... ...            // Optimize for end-user experience: if the Launcher is up and // running with the            // All Apps interface in the foreground, load All Apps first. Otherwise, load the            // workspace first (default).            keep_running: {                if (DEBUG_LOADERS) Log.d(TAG, "step 1: loading workspace");                loadAndBindWorkspace();                if (mStopped) {                    LauncherLog.i(TAG, "LoadTask break in the middle, this = " + this);                    break keep_running;                }                waitForIdle();                // second step                if (DEBUG_LOADERS) Log.d(TAG, "step 2: loading all apps");                loadAndBindAllApps();                //添加 @{                if (LauncherAppState.isDisableAllApps()) {                    verifyApplications();                }                //添加 }@            }            // Clear out this reference, otherwise we end up holding it until all of the            // callback runnables are done.            ... ...        }

添加verifyApplications()：

private void verifyApplications() {        final Context context = mApp.getContext();        // Cross reference all the applications in our apps list with items in the workspace        ArrayList<ItemInfo> tmpInfos;        ArrayList<ItemInfo> added = new ArrayList<ItemInfo>();        synchronized (sBgLock) {            for (AppInfo app : mBgAllAppsList.data) {                tmpInfos = getItemInfoForComponentName(app.componentName, app.user);                if (tmpInfos.isEmpty()) {                    // We are missing an application icon, so add this to the workspace                    added.add(app);                    // This is a rare event, so lets log it                    Log.e(TAG, "Missing Application on load: " + app);                }            }        }        if (!added.isEmpty()) {            addAndBindAddedWorkspaceItems(context, added);//7.0 虽然去掉了去抽屉的代码，但留了这个方法给我们。        }    }

五，有新应用添加时更新Workspace

当安装新应用时，我们需要对左面更新，保证安装的应用添加在第一层上。

Launcher3\src\com\android\launcher3\LauncherModel.java:

LauncherModel$PackageUpdatedTask –> run():

public void run() {            if (!mHasLoaderCompletedOnce) {                // Loader has not yet run.                return;            }            final Context context = mApp.getContext();            ... ...            if (added != null) {                // 添加 @{                if(LauncherAppState.isDisableAllApps()){                        final ArrayList<ItemInfo> addedInfos = new ArrayList<ItemInfo>(added);                        addAndBindAddedWorkspaceItems(context, addedInfos);                }else{                // 添加 }@                addAppsToAllApps(context, added);                }                for (AppInfo ai : added) {                    addedOrUpdatedApps.put(ai.componentName, ai);                }            }            ... ...   }

六，去掉长按时的删除选项

长按时，不该有删除选项 。

DeleteDropTarget.java： 中更改长按时的监听，开始时直接屏蔽删除按钮，后来发现应用自身发出的快捷方式无法删除 所以做了如下处理。

Launcher3\src\com\android\launcher3\DeleteDropTarget.java –>supportsDrop():

public static boolean supportsDrop(Object info) {         //添加 @{        if (LauncherAppState.isDisableAllApps()) {                         if (info instanceof ShortcutInfo) {                           ShortcutInfo item = (ShortcutInfo) info;                               return item.itemType != LauncherSettings.BaseLauncherColumns.ITEM_TYPE_APPLICATION;                              }            return info instanceof LauncherAppWidgetInfo;        }        //添加 }@        return (info instanceof ShortcutInfo)                || (info instanceof LauncherAppWidgetInfo)                || (info instanceof FolderInfo);    }

写在最后

到此，Launcher3去掉应用抽屉的改动已经完成。还有很多我们需要去美化的，就比如HotSeat布局自适应等。