TreeNavigator.java

/*
 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * 
 *      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 org.kie.workbench.common.screens.explorer.client.widgets.navigator;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.annotation.PostConstruct;
import javax.enterprise.context.Dependent;
import javax.inject.Inject;

import com.google.gwt.dom.client.Style;
import com.google.gwt.event.logical.shared.OpenEvent;
import com.google.gwt.event.logical.shared.OpenHandler;
import com.google.gwt.event.logical.shared.SelectionEvent;
import com.google.gwt.event.logical.shared.SelectionHandler;
import com.google.gwt.user.client.ui.Composite;
import org.guvnor.structure.client.resources.NavigatorResources;
import org.kie.workbench.common.screens.explorer.client.resources.i18n.ProjectExplorerConstants;
import org.kie.workbench.common.screens.explorer.client.widgets.BaseViewPresenter;
import org.kie.workbench.common.screens.explorer.model.FolderItem;
import org.kie.workbench.common.screens.explorer.model.FolderItemType;
import org.kie.workbench.common.screens.explorer.model.FolderListing;
import org.uberfire.backend.vfs.Path;
import org.uberfire.ext.widgets.core.client.tree.Tree;
import org.uberfire.ext.widgets.core.client.tree.TreeItem;
import org.uberfire.workbench.type.DotResourceTypeDefinition;

import static org.uberfire.commons.validation.PortablePreconditions.*;

@Dependent
public class TreeNavigator extends Composite implements Navigator {

    private static final String LAZY_LOAD = ProjectExplorerConstants.INSTANCE.LoadingDotDotDot();

    @Inject
    private DotResourceTypeDefinition hiddenTypeDef;

    private NavigatorOptions options = new NavigatorOptions();

    private final Tree tree = new Tree();
    private BaseViewPresenter presenter;

    private FolderListing activeContent;

    @PostConstruct
    public void init() {
        tree.addStyleName( NavigatorResources.INSTANCE.css().treeNav() );
        initWidget( tree );

        tree.addOpenHandler( new OpenHandler<TreeItem>() {
            @Override
            public void onOpen( final OpenEvent<TreeItem> event ) {
                if ( needsLoading( event.getTarget() ) ) {
                    presenter.loadContent( (FolderItem) event.getTarget().getUserObject() );
                }
            }
        } );

        tree.addSelectionHandler( new SelectionHandler<TreeItem>() {
            @Override
            public void onSelection( SelectionEvent<TreeItem> event ) {
                if ( event.getSelectedItem().getUserObject() != null && event.getSelectedItem().getUserObject() instanceof FolderItem ) {
                    presenter.onItemSelected( ( FolderItem ) event.getSelectedItem().getUserObject() );
                }
            }
        } );
    }

    @Override
    public void setOptions( final NavigatorOptions options ) {
        this.options = options;
    }

    @Override
    public void loadContent( final FolderListing content ) {
        loadContent( content,
                     new HashMap<FolderItem, List<FolderItem>>() );
    }

    @Override
    public void loadContent( final FolderListing content,
                             final Map<FolderItem, List<FolderItem>> siblings ) {
        if ( content == null || content.getItem() == null ) {
            clear();
            return;
        }
        if ( content.equals( activeContent ) ) {
            if ( tree.getSelectedItem() != null ) {
                tree.getSelectedItem().setState( TreeItem.State.OPEN,
                                                 true,
                                                 false );
            }
            return;
        }

        this.activeContent = content;

        TreeItem item = null;
        if ( !tree.isEmpty() ) {
            item = findItemInTree( content.getItem() );
        }

        if ( item == null ) {
            if ( content.getSegments().isEmpty() ) {
                final FolderItem rootItem = content.getItem();
                item = new TreeItem( TreeItem.Type.FOLDER,
                                     rootItem.getFileName().replaceAll( " ",
                                                                        "\u00a0" ) );
                tree.addItem( item );
                item.setUserObject( rootItem );
            } else {
                final TreeItem parent = loadRoots( content.getSegments(),
                                                   siblings );
                if ( parent != null ) {
                    item = loadSiblings( content.getItem(),
                                         new TreeNavigatorItemImpl( parent ),
                                         siblings );
                    if ( item != null ) {
                        item.setUserObject( content.getItem() );
                    }
                }
            }
        }
        if ( item != null ) {
            item.setState( TreeItem.State.OPEN,
                           true,
                           false );
            tree.setSelectedItem( item );

            item.removeItems();

            loadContent( new TreeNavigatorItemImpl( item ),
                         content );
        }
    }

    private TreeItem findItemInTree( final FolderItem xxx ) {
        TreeItem item = null;
        for ( final TreeItem treeItem : tree.getItems() ) {
            if ( item != null ) {
                return item;
            }
            if ( xxx != null && xxx.equals( treeItem.getUserObject() ) ) {
                item = treeItem;
            } else {
                item = findItemInChildren( treeItem, xxx );
            }
        }
        return item;
    }

    private TreeItem loadRoots( final List<FolderItem> segments,
                                final Map<FolderItem, List<FolderItem>> siblings ) {
        TreeItem parent = null;
        for ( final FolderItem segment : segments ) {
            TreeItem item;
            if ( tree.isEmpty() ) {
                item = new TreeItem( TreeItem.Type.FOLDER,
                                     segment.getFileName().replaceAll( " ",
                                                                       "\u00a0" ) );
                item.setUserObject( segment );
                tree.addItem( item );
                parent = item;
            } else {
                if ( parent == null ) {
                    parent = findItemInTree( segment );
                } else {
                    item = findItemInTree( segment );
                    if ( item == null ) {
                        item = loadSiblings( segment,
                                             new TreeNavigatorItemImpl( parent ),
                                             siblings );
                        if ( item != null ) {
                            item.setUserObject( segment );
                        }
                    } else if ( needsLoading( item ) ) {
                        item.getChild( 0 ).getElement().getStyle().setDisplay( Style.Display.NONE );
                    }
                    parent = item;
                }
            }
        }
        return parent;
    }

    private TreeItem loadSiblings( final FolderItem item,
                                   final TreeNavigatorItemImpl parent,
                                   final Map<FolderItem, List<FolderItem>> siblings ) {
        final List<FolderItem> mySiblings = siblings.get( item );
        if ( mySiblings != null && !mySiblings.isEmpty() ) {
            for ( final FolderItem sibling : new ArrayList<FolderItem>( mySiblings ) ) {
                final TreeItem existingSibling = findItemInChildren( parent.parent,
                                                                     sibling );
                if ( existingSibling == null ) {
                    if ( sibling.getType().equals( FolderItemType.FOLDER ) ) {
                        parent.addDirectory( sibling );
                    } else {
                        parent.addFile( sibling );
                    }
                    mySiblings.remove( sibling );
                }
            }
            if ( mySiblings.isEmpty() ) {
                siblings.remove( item );
            }
        }
        return findItemInChildren( parent.parent,
                                   item );
    }

    private TreeItem findItemInChildren( final TreeItem item,
                                         final FolderItem target ) {
        TreeItem result = null;
        for ( final TreeItem treeItem : item.getChildren() ) {
            if ( result != null ) {
                break;
            }
            if ( target != null && target.equals( treeItem.getUserObject() ) ) {
                result = treeItem;
            } else {
                result = findItemInChildren( treeItem, target );
            }
        }

        return result;
    }

    @Override
    public void clear() {
        tree.clear();
        activeContent = null;
    }

    @Override
    public void setPresenter( final BaseViewPresenter presenter ) {
        this.presenter = presenter;
    }

    private void loadContent( final NavigatorItem parent,
                              final FolderListing content ) {
        if ( content != null ) {
            for ( final FolderItem folderItem : content.getContent() ) {
                if ( folderItem.getType().equals( FolderItemType.FOLDER ) ) {
                    if ( options.showDirectories() ) {
                        parent.addDirectory( folderItem );
                    }
                } else {
                    if ( options.showFiles() ) {
                        if ( !options.showHiddenFiles() && !isHidden( folderItem ) ) {
                            parent.addFile( folderItem );
                        } else {
                            parent.addFile( folderItem );
                        }
                    }
                }
            }
            parent.cleanup();
        }
    }

    private boolean isHidden( final FolderItem folderItem ) {
        return hiddenTypeDef.accept( new Path() {
            @Override
            public String getFileName() {
                return folderItem.getFileName();
            }

            @Override
            public String toURI() {
                return null;
            }

            @Override
            public int compareTo( final Path path ) {
                return 0;
            }
        } );
    }

    private boolean needsLoading( final TreeItem item ) {
        return item.getChildCount() == 1 && LAZY_LOAD.equals( item.getChild( 0 ).getText() );
    }

    private class TreeNavigatorItemImpl implements NavigatorItem {

        private final TreeItem parent;

        TreeNavigatorItemImpl( final TreeItem treeItem ) {
            this.parent = checkNotNull( "parent", treeItem );
        }

        public void addDirectory( final FolderItem child ) {
            checkCleanupLoading();

            for ( final TreeItem treeItem : parent.getChildren() ) {
                if ( treeItem.getUserObject() != null && treeItem.getUserObject().equals( child ) ) {
                    return;
                }
            }

            final TreeItem newDirectory = parent.addItem( TreeItem.Type.FOLDER, child.getFileName().replaceAll( " ", "\u00a0" ) );
            newDirectory.addItem( TreeItem.Type.LOADING, LAZY_LOAD );
            newDirectory.setUserObject( child );
        }

        public void addFile( final FolderItem child ) {
            checkCleanupLoading();

            for ( final TreeItem treeItem : parent.getChildren() ) {
                if ( treeItem.getUserObject() != null && treeItem.getUserObject().equals( child ) ) {
                    return;
                }
            }

            final TreeItem newFile = parent.addItem( TreeItem.Type.ITEM, child.getFileName().replaceAll( " ", "\u00a0" ) );
            newFile.setUserObject( child );
        }

        @Override
        public void cleanup() {
            checkCleanupLoading();
        }

        public void checkCleanupLoading() {
            if ( parent.getChild( 0 ) != null && parent.getChild( 0 ).getUserObject() == null ) {
                parent.getChild( 0 ).remove();
            }
        }

    }
}