private static Context mContext;

public static boolean isDisableAllApps() {
  if (mContext != null) {
   return Settings.System.getInt(mContext.getContentResolver(), 
    "sys.launcher3.is_full_app", 0) == 1;
  }
  return true;
 }

<uses-permission android:name="android.permission.WRITE_SETTINGS" />

/**
  * This fragment shows the launcher preferences.
  */
 public static class LauncherSettingsFragment extends PreferenceFragment {
 .....
 @Override
 public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
 ....
   //讀取保存的值，初始化 SwitchPreference 的初始狀態(tài)，是否選中
   int isFull = Settings.System.getInt(getActivity().getContentResolver(), 
    "sys.launcher3.is_full_app", 0);
   Log.d("Launcher3", "sys.launcher3.is_full_app="+isFull);
   SwitchPreference fullSwitch = (SwitchPreference) findPreference("pref_is_full_app");
   fullSwitch.setChecked(isFull==1);
  }
 //add for change is_full_app value
 @Override
 public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
   boolean result = true;
   final String key = preference.getKey();
    if ("pref_is_full_app".equals(key)) {
    boolean checked = ((SwitchPreference) preference).isChecked();
    Settings.System.putInt(getActivity().getContentResolver(), "sys.launcher3.is_full_app",
      checked ? 1 : 0);
    Log.e("Launcher3", "SwitchPreference checked="+checked);
    // Value has changed
    ProgressDialog.show(getActivity(),
      null /* title */,
      getActivity().getString(R.string.full_app_override_progress),
      true /* indeterminate */,
      false /* cancelable */);
    new LooperExecutor(LauncherModel.getWorkerLooper()).execute(
      new OverrideApplyHandler(getActivity()));
   }
   return result;
  }
}

 //add for change is_full_app value
 private static class OverrideApplyHandler implements Runnable {
  private final Context mContext;
  private OverrideApplyHandler(Context context) {
   mContext = context;
  }
  @Override
  public void run() {
   // Clear the icon cache.
   LauncherAppState.getInstance(mContext).getIconCache().clear();
   // Wait for it
   try {
    Thread.sleep(1000);
   } catch (Exception e) {
    Log.e("Launcher3", "Error waiting", e);
   }
   // Schedule an alarm before we kill ourself.
   Intent homeIntent = new Intent(Intent.ACTION_MAIN)
     .addCategory(Intent.CATEGORY_HOME)
     .setPackage(mContext.getPackageName())
     .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
   PendingIntent pi = PendingIntent.getActivity(mContext, 42,
     homeIntent, PendingIntent.FLAG_CANCEL_CURRENT | PendingIntent.FLAG_ONE_SHOT);
   mContext.getSystemService(AlarmManager.class).setExact(
     AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime() + 50, pi);
   //clear data will kill process
   Intent intent = new Intent("com.android.action.CLEAR_APP_DATA");
   intent.putExtra("pkgName", "com.android.launcher3");
   intent.addFlags(0x01000000);
   mContext.sendBroadcast(intent);
   Log.i("Launcher3", "Clearing user data com.android.launcher3");
   // Kill process
   android.os.Process.killProcess(android.os.Process.myPid());
  }
 }

 <SwitchPreference
  android:key="pref_is_full_app"
  android:title="@string/is_full_app_title"
  android:summary="@string/is_full_app_desc"
  android:defaultValue="false"
  android:persistent="true" />

 <profile
  launcher:name="Tablet"
  launcher:minWidthDps="376"
  launcher:minHeightDps="586"
  launcher:numRows="4"
  launcher:numColumns="5"
  launcher:numFolderRows="4"
  launcher:numFolderColumns="5"
  launcher:iconSize="50"
  launcher:iconTextSize="11"
  launcher:numHotseatIcons="5"
  launcher:defaultLayoutId="@xml/default_workspace_tb_5x6"
  />
 <profile
  launcher:name="Tablet_no_all_app"
  launcher:minWidthDps="380"
  launcher:minHeightDps="590"
  launcher:numRows="4"
  launcher:numColumns="5"
  launcher:numFolderRows="4"
  launcher:numFolderColumns="5"
  launcher:iconSize="50"
  launcher:iconTextSize="11"
  launcher:numHotseatIcons="4"
  launcher:defaultLayoutId="@xml/default_workspace_tb_5x6_no_all_app"
  />

public InvariantDeviceProfile(Context context) {
  WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
  Display display = wm.getDefaultDisplay();
  DisplayMetrics dm = new DisplayMetrics();
  display.getMetrics(dm);
  Point smallestSize = new Point();
  Point largestSize = new Point();
  display.getCurrentSizeRange(smallestSize, largestSize);
  // This guarantees that width < height
  minWidthDps = Utilities.dpiFromPx(Math.min(smallestSize.x, smallestSize.y), dm);
  minHeightDps = Utilities.dpiFromPx(Math.min(largestSize.x, largestSize.y), dm);
  Log.i("Launcher3.profiles", "orignalminWidthDps="+minWidthDps + " orignalminHeightDps="+minHeightDps);
  
  //add for load no_all_app xml
  if (LauncherAppState.isDisableAllApps()) {
   Log.e("Launcher3.profiles", "load no all app profiles");
   //對應(yīng) device_profiles.xml 中 Tablet_no_all_app 的值
   minWidthDps = 380.0f;
   minHeightDps = 590.0f;
  }
  .....
}

void resetLayout(boolean hasVerticalHotseat) {
  mContent.removeAllViewsInLayout();
  mHasVerticalHotseat = hasVerticalHotseat;
  InvariantDeviceProfile idp = mLauncher.getDeviceProfile().inv;
  if (hasVerticalHotseat) {
   mContent.setGridSize(1, idp.numHotseatIcons);
  } else {
   mContent.setGridSize(idp.numHotseatIcons, 1);
  }

  //if (!FeatureFlags.NO_ALL_APPS_ICON) {
  /// add for check is need allappbutton
  if (!LauncherAppState.isDisableAllApps()) {
   // Add the Apps button
   Context context = getContext();
   DeviceProfile grid = mLauncher.getDeviceProfile();

  ...
}

public void run() {
  synchronized (this) {
   // Skip fast if we are already stopped.
   if (mStopped) {
    return;
   }
  }
  ....
  // second step
  TraceHelper.partitionSection(TAG, "step 2.1: loading all apps");
  loadAllApps();
  //add for load all app on workspace
  if (LauncherAppState.isDisableAllApps()) {
   android.util.Log.e("Launcher3", "verifyApplications()");
   verifyApplications();
  }
  ....
}
 //add for load all app on workspace
private void verifyApplications() {
  final Context context = mApp.getContext();
  ArrayList<Pair<ItemInfo, Object>> installQueue = new ArrayList<>();
  final List<UserHandle> profiles = mUserManager.getUserProfiles();
  for (UserHandle user : profiles) {
   final List<LauncherActivityInfo> apps = mLauncherApps.getActivityList(null, user);
   ArrayList<InstallShortcutReceiver.PendingInstallShortcutInfo> added = new ArrayList<InstallShortcutReceiver.PendingInstallShortcutInfo>();
   synchronized (this) {
    for (LauncherActivityInfo app : apps) {
     InstallShortcutReceiver.PendingInstallShortcutInfo pendingInstallShortcutInfo = new InstallShortcutReceiver.PendingInstallShortcutInfo(app, context);
     added.add(pendingInstallShortcutInfo);
     installQueue.add(pendingInstallShortcutInfo.getItemInfo());
    }
   }
   if (!added.isEmpty()) {
    mApp.getModel().addAndBindAddedWorkspaceItems(installQueue);
   }
  }
 }

@Override
 public final void run() {
  if (!mModel.isModelLoaded()) {
   if (DEBUG_TASKS) {
    Log.d(TAG, "Ignoring model task since loader is pending=" + this);
   }
   // Loader has not yet run.
   //annotaion for load all app on workspace
   // return;
  }
  execute(mApp, mDataModel, mAllAppsList);
 }

public void execute(LauncherAppState app, BgDataModel dataModel, AllAppsList appsList) {
 ....
  final ArrayList<AppInfo> addedOrModified = new ArrayList<>();
 addedOrModified.addAll(appsList.added);
 //add for load new install app on workspace 
 if (LauncherAppState.isDisableAllApps()) {
  android.util.Log.e("cczLauncher3", "updateToWorkSpace()");
  updateToWorkSpace(context, app, appsList);
 }
 ...
}
//add for load new install app on workspace
public void updateToWorkSpace(Context context, LauncherAppState app , AllAppsList appsList){
   ArrayList<Pair<ItemInfo, Object>> installQueue = new ArrayList<>();
  final List<UserHandle> profiles = UserManagerCompat.getInstance(context).getUserProfiles();
  ArrayList<InstallShortcutReceiver.PendingInstallShortcutInfo> added 
  = new ArrayList<InstallShortcutReceiver.PendingInstallShortcutInfo>();
  
  for (UserHandle user : profiles) {
   final List<LauncherActivityInfo> apps = LauncherAppsCompat.getInstance(context).getActivityList(null, user);
   synchronized (this) {
    for (LauncherActivityInfo info : apps) {
     for (AppInfo appInfo : appsList.added) {
      if(info.getComponentName().equals(appInfo.componentName)){
       InstallShortcutReceiver.PendingInstallShortcutInfo mPendingInstallShortcutInfo 
       = new InstallShortcutReceiver.PendingInstallShortcutInfo(info,context);
       added.add(mPendingInstallShortcutInfo);
       installQueue.add(mPendingInstallShortcutInfo.getItemInfo());
      }
     }
    }
   }
  }
  if (!added.isEmpty()) {
   app.getModel().addAndBindAddedWorkspaceItems(installQueue);
  }
 }

private void setTextBasedOnDragSource(ItemInfo item) {
  if (!TextUtils.isEmpty(mText)) {
   mText = getResources().getString(item.id != ItemInfo.NO_ID
     ? R.string.remove_drop_target_label
     : android.R.string.cancel);
   //add for hide deletedroptarget
   if (LauncherAppState.isDisableAllApps()) {
    android.util.Log.e("Launcher3", "hide delete drop target");
    mText = getResources().getString(isCanDrop(item)
       ? R.string.remove_drop_target_label
       : android.R.string.cancel);
   }
   requestLayout();
  }
 }
 private void setControlTypeBasedOnDragSource(ItemInfo item) {
  mControlType = item.id != ItemInfo.NO_ID ? ControlType.REMOVE_TARGET
    : ControlType.CANCEL_TARGET;
  //add for hide deletedroptarget [S]
  if (LauncherAppState.isDisableAllApps()) {
   mControlType = isCanDrop(item) ? ControlType.REMOVE_TARGET
    : ControlType.CANCEL_TARGET;
  }  
 }
public void onAccessibilityDrop(View view, ItemInfo item) {
  // Remove the item from launcher and the db, we can ignore the containerInfo in this call
  // because we already remove the drag view from the folder (if the drag originated from
  // a folder) in Folder.beginDrag()
  //add if juge is need remove item from workspace
  if (!LauncherAppState.isDisableAllApps() || isCanDrop(item)) {
   mLauncher.removeItem(view, item, true /* deleteFromDb */);
   mLauncher.getWorkspace().stripEmptyScreens();
   mLauncher.getDragLayer()
     .announceForAccessibility(getContext().getString(R.string.item_removed));
  }
}
private boolean isCanDrop(ItemInfo item){
  return !(item.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION ||
    item.itemType == LauncherSettings.Favorites.ITEM_TYPE_FOLDER);
}

private void drop(DropTarget dropTarget, Runnable flingAnimation) {
 ....
 boolean accepted = false;
  if (dropTarget != null) {
   dropTarget.onDragExit(mDragObject);
   if (dropTarget.acceptDrop(mDragObject)) {
    if (flingAnimation != null) {
     flingAnimation.run();
    } else {
     dropTarget.onDrop(mDragObject, mOptions);
    }
    accepted = true;
    //add for cancel canceldroptarget handle
    if (LauncherAppState.isDisableAllApps() && dropTarget instanceof DeleteDropTarget &&
      isNeedCancelDrag(mDragObject.dragInfo)) {
     cancelDrag();
    }
   }
  }
  ...
}
private boolean isNeedCancelDrag(ItemInfo item){
  return (item.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION ||
    item.itemType == LauncherSettings.Favorites.ITEM_TYPE_FOLDER);
 }

vendor\mediatek\proprietary\packages\apps\Launcher3\quickstep\src\com\android\launcher3

canInterceptTouch() 中增加判斷是否直接攔截
@Override
 protected boolean canInterceptTouch(MotionEvent ev) {
  //add for forbidden workspace drag change GradientView alph
  if (LauncherAppState.isDisableAllApps()){
   android.util.Log.e("Launcher3", "canInterceptTouch()");
   return false;
  } 
  if (mCurrentAnimation != null) {
   // If we are already animating from a previous state, we can intercept.
   return true;
  }
  if (AbstractFloatingView.getTopOpenView(mLauncher) != null) {
   return false;
  }
  if (mLauncher.isInState(ALL_APPS)) {
   // In all-apps only listen if the container cannot scroll itself
   return mLauncher.getAppsView().shouldContainerScroll(ev);
  } else if (mLauncher.isInState(NORMAL)) {
   return true;
  } else if (mLauncher.isInState(OVERVIEW)) {
   RecentsView rv = mLauncher.getOverviewPanel();
   return ev.getY() > (rv.getBottom() - rv.getPaddingBottom());
  } else {
   return false;
  }
 }

<com.android.launcher3.pageindicators.PageIndicatorDots
   android:id="@+id/page_indicator"
   android:layout_width="match_parent"
   android:layout_height="4dp"
   android:layout_gravity="bottom|center_horizontal"
   android:theme="@style/HomeScreenElementTheme" />
vendor\mediatek\proprietary\packages\apps\Launcher3\src\com\android\launcher3

public class PageIndicatorDots extends View implements PageIndicator, Insettable {
// add for change WorkspacePageIndicator line to dot
 @Override
 public void setInsets(Rect insets) {
  DeviceProfile grid = mLauncher.getDeviceProfile();
  FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) getLayoutParams();
  if (grid.isVerticalBarLayout()) {
   Rect padding = grid.workspacePadding;
   lp.leftMargin = padding.left + grid.workspaceCellPaddingXPx;
   lp.rightMargin = padding.right + grid.workspaceCellPaddingXPx;
   lp.bottomMargin = padding.bottom;
  } else {
   lp.leftMargin = lp.rightMargin = 0;
   lp.gravity = Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM;
   lp.bottomMargin = grid.hotseatBarSizePx + insets.bottom;
  }
  setLayoutParams(lp);
 }
 @Override
 public void setScroll(int currentScroll, int totalScroll) {
  if (mNumPages > 1) {
   if (mIsRtl) {
    currentScroll = totalScroll - currentScroll;
   }
   int scrollPerPage = totalScroll / (mNumPages - 1);
   // add for change WorkspacePageIndicator line to dot
   if (scrollPerPage == 0) {
    return;
   }
   int pageToLeft = currentScroll / scrollPerPage;
   int pageToLeftScroll = pageToLeft * scrollPerPage;
   int pageToRightScroll = pageToLeftScroll + scrollPerPage;
  ...
}

@Override
 public void onStateEnabled(Launcher launcher) {
  Workspace ws = launcher.getWorkspace();
  ws.showPageIndicatorAtCurrentScroll();
  //annotaion for WorkspacePageIndicator line to dot
  // ws.getPageIndicator().setShouldAutoHide(false);
  // Prevent any Un/InstallShortcutReceivers from updating the db while we are
  // in spring loaded mode
  InstallShortcutReceiver.enableInstallQueue(InstallShortcutReceiver.FLAG_DRAG_AND_DROP);
  launcher.getRotationHelper().setCurrentStateRequest(REQUEST_LOCK);
 }
 @Override
 public void onStateDisabled(final Launcher launcher) {
  //annotaion for WorkspacePageIndicator line to dot
  // launcher.getWorkspace().getPageIndicator().setShouldAutoHide(true);
  // Re-enable any Un/InstallShortcutReceiver and now process any queued items
  InstallShortcutReceiver.disableAndFlushInstallQueue(
    InstallShortcutReceiver.FLAG_DRAG_AND_DROP, launcher);
 }