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。