src/com/android/documentsui/MenuManager.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed 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
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed 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 and
 * limitations under the License.
 */

package com.android.documentsui;

import android.annotation.Nullable;
import android.view.Menu;
import android.view.MenuItem;

import com.android.documentsui.model.RootInfo;

public abstract class MenuManager {

    final State mState;
    final SearchViewManager mSearchManager;

    public MenuManager(SearchViewManager searchManager, State displayState) {
        mSearchManager = searchManager;
        mState = displayState;
    }

    /** @See DirectoryFragment.SelectionModeListener#updateActionMenu */
    public void updateActionMenu(Menu menu, SelectionDetails selection) {
        updateOpen(menu.findItem(R.id.menu_open), selection);
        updateDelete(menu.findItem(R.id.menu_delete), selection);
        updateShare(menu.findItem(R.id.menu_share), selection);
        updateRename(menu.findItem(R.id.menu_rename), selection);
        updateSelectAll(menu.findItem(R.id.menu_select_all), selection);
        updateMoveTo(menu.findItem(R.id.menu_move_to), selection);
        updateCopyTo(menu.findItem(R.id.menu_copy_to), selection);

        Menus.disableHiddenItems(menu);
    }

    /** @See Activity#onPrepareOptionsMenu */
    public void updateOptionMenu(Menu menu, DirectoryDetails directoryDetails) {
        updateCreateDir(menu.findItem(R.id.menu_create_dir), directoryDetails);
        updateSettings(menu.findItem(R.id.menu_settings), directoryDetails);
        updateNewWindow(menu.findItem(R.id.menu_new_window), directoryDetails);
        updateFileSize(menu.findItem(R.id.menu_file_size), directoryDetails);
        updateModePicker(menu.findItem(
                R.id.menu_grid), menu.findItem(R.id.menu_list), directoryDetails);
        updateSort(menu.findItem(R.id.menu_sort),
                menu.findItem(R.id.menu_sort_size),
                directoryDetails);
        updateAdvanced(menu.findItem(R.id.menu_advanced), directoryDetails);

        Menus.disableHiddenItems(menu);
    }

    /** @See DirectoryFragment.onCreateContextMenu */
    public void updateContextMenu(Menu menu,
            @Nullable SelectionDetails selectionDetails,
            DirectoryDetails directoryDetails) {

        MenuItem cut = menu.findItem(R.id.menu_cut_to_clipboard);
        MenuItem copy = menu.findItem(R.id.menu_copy_to_clipboard);
        MenuItem paste = menu.findItem(R.id.menu_paste_from_clipboard);
        MenuItem delete = menu.findItem(R.id.menu_delete);
        MenuItem rename = menu.findItem(R.id.menu_rename);
        MenuItem createDir = menu.findItem(R.id.menu_create_dir);

        if (selectionDetails == null) {
            cut.setEnabled(false);
            copy.setEnabled(false);
            rename.setEnabled(false);
            delete.setEnabled(false);
        } else {
            copy.setEnabled(!selectionDetails.containsPartialFiles());
            cut.setEnabled(
                    !selectionDetails.containsPartialFiles() && selectionDetails.canDelete());
            updateRename(rename, selectionDetails);
            updateDelete(delete, selectionDetails);
        }
        menu.findItem(R.id.menu_paste_from_clipboard)
                .setEnabled(directoryDetails.hasItemsToPaste());
        updateCreateDir(createDir, directoryDetails);

        //Cut, Copy, Paste and Delete should always be visible
        cut.setVisible(true);
        copy.setVisible(true);
        paste.setVisible(true);
        delete.setVisible(true);
    }

    public void updateRootContextMenu(Menu menu, RootInfo root) {
        MenuItem settings = menu.findItem(R.id.menu_settings);
        MenuItem eject = menu.findItem(R.id.menu_eject_root);

        updateSettings(settings, root);
        updateEject(eject, root);
    }

    void updateModePicker(MenuItem grid, MenuItem list, DirectoryDetails directoryDetails) {
        grid.setVisible(mState.derivedMode != State.MODE_GRID);
        list.setVisible(mState.derivedMode != State.MODE_LIST);
    }

    void updateFileSize(MenuItem fileSize, DirectoryDetails directoryDetails) {
        fileSize.setVisible(!mState.forceSize);
        fileSize.setTitle(directoryDetails.getDisplayFileSize()
                ? R.string.menu_file_size_hide : R.string.menu_file_size_show);
    }

    void updateSort(MenuItem sort, MenuItem sortSize, DirectoryDetails directoryDetails) {
        // Search uses backend ranking; no sorting, recents doesn't support sort.
        sort.setEnabled(!directoryDetails.isInRecents() && !mSearchManager.isSearching());
        sort.setVisible(true);
        sortSize.setVisible(mState.getShowSize()); // Only sort by size when file sizes are visible
    }

    void updateAdvanced(MenuItem advanced, DirectoryDetails directoryDetails) {
        advanced.setVisible(mState.showAdvancedOption);
        advanced.setTitle(mState.showAdvancedOption && mState.showAdvanced
                ? R.string.menu_advanced_hide : R.string.menu_advanced_show);
    }

    void updateSettings(MenuItem settings, DirectoryDetails directoryDetails) {
        settings.setVisible(false);
    }

    void updateSettings(MenuItem settings, RootInfo root) {
        settings.setVisible(false);
    }

    void updateEject(MenuItem eject, RootInfo root) {
        eject.setVisible(false);
    }

    void updateNewWindow(MenuItem newWindow, DirectoryDetails directoryDetails) {
        newWindow.setVisible(false);
    }

    void updateOpen(MenuItem open, SelectionDetails selectionDetails) {
        open.setVisible(false);
    }

    void updateShare(MenuItem share, SelectionDetails selectionDetails) {
        share.setVisible(false);
    }

    void updateDelete(MenuItem delete, SelectionDetails selectionDetails) {
        delete.setVisible(false);
    }

    void updateRename(MenuItem rename, SelectionDetails selectionDetails) {
        rename.setVisible(false);
    }

    void updateMoveTo(MenuItem moveTo, SelectionDetails selectionDetails) {
        moveTo.setVisible(false);
    }

    void updateCopyTo(MenuItem copyTo, SelectionDetails selectionDetails) {
        copyTo.setVisible(false);
    }

    abstract void updateSelectAll(MenuItem selectAll, SelectionDetails selectionDetails);
    abstract void updateCreateDir(MenuItem createDir, DirectoryDetails directoryDetails);

    /**
     * Access to meta data about the selection.
     */
    public interface SelectionDetails {
        boolean containsDirectories();

        boolean containsPartialFiles();

        // TODO: Update these to express characteristics instead of answering concrete questions,
        // since the answer to those questions is (or can be) activity specific.
        boolean canDelete();

        boolean canRename();
    }

    public static class DirectoryDetails {
        private final BaseActivity mActivity;

        public DirectoryDetails(BaseActivity activity) {
            mActivity = activity;
        }

        public boolean shouldShowFancyFeatures() {
            return Shared.shouldShowFancyFeatures(mActivity);
        }

        public boolean hasRootSettings() {
            return mActivity.getCurrentRoot().hasSettings();
        }

        public boolean hasItemsToPaste() {
            return false;
        }

        public boolean isInRecents() {
            return mActivity.getCurrentDirectory() == null;
        }

        public boolean canCreateDirectory() {
            return mActivity.canCreateDirectory();
        }

        public boolean getDisplayFileSize() {
            return LocalPreferences.getDisplayFileSize(mActivity);
        }
    }
}