Comment Pouvez-vous implémenter Multi-sélection et Actionmode contextuel dans ActionBarSherlock?

Voilà ce que j'ai fait.

Modifier: Plus d'un an s'est écoulé depuis que j'ai découvert que la réponse précédente avait beaucoup de code inutile (woops) et que la chose CAB peut être réalisée avec beaucoup moins d'effort et un code plus propre, alors j'ai pris du temps et l'ai mis à jour

Le LibraryFragment ListView doit être défini avec le mode de choix "none"

<ListView
    android:id="@android:id/list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:choiceMode="none"/>

L'élément de liste devrait avoir un ?attr / activatedBackgroundIndicator premier plan afin de dessiner automatiquement une superposition semi-transparente en surbrillance sur la liste.setItemChecked (pos, true)

List_item_library.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:foreground="?attr/activatedBackgroundIndicator"
    android:paddingBottom="5dp"
    android:paddingTop="5dp" >

....

Le ListFragment

import android.support.v4.app.DialogFragment;
import com.actionbarsherlock.app.SherlockListFragment;
import com.actionbarsherlock.view.ActionMode;
import com.actionbarsherlock.view.Menu;

public final class LibraryFragment
        extends SherlockListFragment
{

    private MyListAdapter adapter;
    private ListView list;

    // if ActoinMode is null - assume we are in normal mode
    private ActionMode actionMode;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        View v = inflater.inflate(R.layout.fragment_library, null);
        this.list = (ListView) v.findViewById(android.R.id.list);
        this.initListView();
        return v;
    }

    @Override
    public void onPause()
    {
        super.onPause();
        if (this.actionMode != null) {
            this.actionMode.finish();
        }
    }

    @Override
    public void onResume() {
        super.onResume();
        updateData();
    }

    // update ListView
    protected void updateData()
    {
        if (adapter == null) {
            return;
        }
        adapter.clear();
        // my kinda stuff :)
        File[] items = scan();
        if (items != null) {
            adapter.updateData(items);
            if (actionMode != null) {
                actionMode.invalidate();
            }
        }
        // if empty - finish action mode.
        if (actionMode != null && (files == null || files.length == 0)) {
            actionMode.finish();
        }
    }

    private void initListView()
    {
        this.adapter = new MyAdapter(getActivity());
        this.list.setAdapter(adapter);
        this.list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener()
        {

            @Override
            public boolean onItemLongClick(AdapterView<?> arg0,
                    View arg1, int arg2, long arg3)
            {
                if (actionMode != null) {
                    // if already in action mode - do nothing
                    return false;
                }
                // set checked selected item and enter multi selection mode
                list.setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE);
                list.setItemChecked(arg2, true);

                getSherlockActivity().startActionMode(
                        new ActionModeCallback());
                return true;
            }
        });
        this.list.setOnItemClickListener(new AdapterView.OnItemClickListener()
        {
            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                    long arg3)
            {
                if (actionMode != null) {
                    // the items are auomatically "checked" becaise we've set AbsListView.CHOICE_MODE_MULTIPLE before
                    // starting action mode, so the only thing we have to care about is invalidating the actionmode
                    actionMode.invalidate(); //invalidate title and menus.
                } else {
                    // do whatever you should on item click
                }
            }
        });
    }


    // all our ActionMode stuff here :)
    private final class ActionModeCallback
            implements ActionMode.Callback
    {

        // " selected" string resource to update ActionBar text
        private String selected = getActivity().getString(
                R.string.library_selected);

        @Override
        public boolean onCreateActionMode(ActionMode mode, Menu menu)
        {
            actionMode = mode;
            return true;
        }

        @Override
        public boolean onPrepareActionMode(ActionMode mode, Menu menu)
        {
            // remove previous items
            menu.clear();
            final int checked = list.getCheckedItemCount();
            // update title with number of checked items
            mode.setTitle(checked + this.selected);
            switch (checked) {
            case 0:
                // if nothing checked - exit action mode
                mode.finish();
                return true;
            case 1:
                // all items - rename + delete
                getSherlockActivity().getSupportMenuInflater().inflate(
                        R.menu.library_context, menu);
                return true;
            default:
                getSherlockActivity().getSupportMenuInflater().inflate(
                        R.menu.library_context, menu);
                // remove rename option - because we have more than one selected
                menu.removeItem(R.id.library_context_rename);
                return true;
            }
        }

        @Override
        public boolean onActionItemClicked(ActionMode mode,
                com.actionbarsherlock.view.MenuItem item)
        {
            SparseBooleanArray checked;
            switch (item.getItemId()) {
            case R.id.library_context_rename:
                // the rename action is present only when only one item is selected. 
                // so when the first checked item found, show the dialog and break
                checked = list.getCheckedItemPositions();
                for (int i = 0; i < checked.size(); i++) {
                    final int index = checked.keyAt(i);
                    if (checked.get(index)) {
                        final DialogFragment d = RenameDialog.instantiate(adapter.getItem(index).getFile(), LibraryFragment.this);
                        d.show(getActivity().getSupportFragmentManager(), "dialog");
                        break;
                    }
                }
                return true;

            case R.id.library_context_delete:
                // delete every checked item
                checked = list.getCheckedItemPositions();
                for (int i = 0; i < checked.size(); i++) {
                    final int index = checked.keyAt(i);
                    if (checked.get(index)) {
                        adapter.getItem(index).getFile().delete();
                    }
                }
                updateData();
                return true;
            default:
                return false;
            }
        }

        @Override
        public void onDestroyActionMode(ActionMode mode)
        {
            list.clearChoices();

            //workaround for some items not being unchecked.
            //see http://stackoverflow.com/a/10542628/1366471
            for (int i = 0; i < list.getChildCount(); i++) {
                (list.getChildAt(i).getBackground()).setState(new int[] { 0 });
            }

            list.setChoiceMode(AbsListView.CHOICE_MODE_NONE);
            actionMode = null;
        }

    }