ProcessesListViewImpl.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.command.toolbar.processes;

import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.Widget;
import com.google.inject.Singleton;

import org.eclipse.che.ide.command.CommandResources;
import org.eclipse.che.ide.command.toolbar.ToolbarMessages;
import org.eclipse.che.ide.ui.dropdown.BaseListItem;
import org.eclipse.che.ide.ui.dropdown.DropdownList;
import org.eclipse.che.ide.ui.dropdown.StringItemRenderer;

import javax.inject.Inject;
import java.util.HashMap;
import java.util.Map;

/** Implementation of {@link ProcessesListView} that displays processes in a dropdown list. */
@Singleton
public class ProcessesListViewImpl implements ProcessesListView {


    private final Map<Process, BaseListItem<Process>> listItems;
    private final Map<Process, ProcessItemRenderer>   renderers;
    private final FlowPanel                           rootPanel;
    private final DropdownList                        dropdownList;
    private final EmptyListWidget                     emptyListWidget;
    private final ToolbarMessages                     messages;
    private final CreateCommandItem                   createCommandItem;
    private final CreateCommandItemRenderer           createCommandItemRenderer;

    private ActionDelegate delegate;

    @Inject
    public ProcessesListViewImpl(CommandResources resources, EmptyListWidget emptyListWidget, ToolbarMessages messages) {
        this.emptyListWidget = emptyListWidget;
        this.messages = messages;

        listItems = new HashMap<>();
        renderers = new HashMap<>();

        final Label label = new Label("EXEC");
        label.addStyleName(resources.commandToolbarCss().processesListLabel());

        dropdownList = new DropdownList(emptyListWidget, true);
        dropdownList.setWidth("100%");
        dropdownList.ensureDebugId("dropdown-processes");
        dropdownList.setSelectionHandler(item -> {
            if (item instanceof CreateCommandItem) {
                delegate.onCreateCommand();
            } else {
                listItems.entrySet()
                         .stream()
                         .filter(entry -> item.equals(entry.getValue()))
                         .forEach(entry -> delegate.onProcessChosen(entry.getKey()));
            }
        });

        rootPanel = new FlowPanel();
        rootPanel.add(label);
        rootPanel.add(dropdownList);

        createCommandItem = new CreateCommandItem();
        createCommandItemRenderer = new CreateCommandItemRenderer();
        checkCreateCommandItem();
    }

    /** Ensures that item for creating command added to the empty list or removed from non empty list. */
    private void checkCreateCommandItem() {
        if (listItems.isEmpty()) {
            dropdownList.addItem(createCommandItem, createCommandItemRenderer);
        } else {
            dropdownList.removeItem(createCommandItem);
        }
    }

    @Override
    public void setDelegate(ActionDelegate delegate) {
        this.delegate = delegate;
    }

    @Override
    public Widget asWidget() {
        return rootPanel;
    }

    @Override
    public void clearList() {
        dropdownList.clear();

        checkCreateCommandItem();
    }

    @Override
    public void processStopped(Process process) {
        final ProcessItemRenderer renderer = renderers.get(process);

        if (renderer != null) {
            renderer.notifyProcessStopped();
        }
    }

    @Override
    public void addProcess(Process process) {
        final BaseListItem<Process> listItem = new BaseListItem<>(process);
        final ProcessItemRenderer renderer = new ProcessItemRenderer(listItem,
                                                                     p -> delegate.onStopProcess(p),
                                                                     p -> delegate.onReRunProcess(p));

        listItems.put(process, listItem);
        renderers.put(process, renderer);

        dropdownList.addItem(listItem, renderer);

        checkCreateCommandItem();
    }

    @Override
    public void removeProcess(Process process) {
        final BaseListItem<Process> listItem = listItems.get(process);

        if (listItem != null) {
            listItems.remove(process);
            renderers.remove(process);

            dropdownList.removeItem(listItem);

            checkCreateCommandItem();
        }
    }

    private class CreateCommandItem extends BaseListItem<String> {
        CreateCommandItem() {
            super(messages.guideItemLabel("new"));
        }
    }

    private class CreateCommandItemRenderer extends StringItemRenderer {
        CreateCommandItemRenderer() {
            super(createCommandItem);
        }

        @Override
        public Widget renderHeaderWidget() {
            return emptyListWidget;
        }
    }
}