/*******************************************************************************
 * Copyright (c) 2009 Wind River Systems and others.
 * 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:
 *     Wind River Systems - initial API and implementation
 *******************************************************************************/
package org.eclipse.debug.internal.ui.viewers.model;

import org.eclipse.debug.internal.ui.viewers.model.provisional.IModelChangedListener;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IModelDelta;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IStateUpdateListener;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdateListener;
import org.eclipse.debug.internal.ui.viewers.model.provisional.ModelDelta;
import org.eclipse.debug.internal.ui.viewers.model.provisional.TreeModelViewer;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.ColumnLabelProvider;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.jface.viewers.ViewerLabel;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;

/**
 * Specialized tree viewer which displays only sub-tree of a full model. 
 * 
 * @since 3.5
 */
public class SubTreeModelViewer extends TreeModelViewer {

    /**
     * The tree path in the model to the root element of this viewer.
     */
    private TreePath fRootPath = TreePath.EMPTY;

    /**
     * Viewer delegate that content and label providers refer to for viewer data.
     */
    private DelegatingTreeModelViewer fDelegatingViewer;
    
    /**
     * Returns the root element's model tree path. 
     */
    public TreePath getRootPath() {
        return fRootPath;
    }

    public SubTreeModelViewer(Composite parent, int style, IPresentationContext context) {
        super(parent, style, context);
    }

    /**
     * Sets the viewer's input and root element's path
     * 
     * @param input New viewer input.
     * @param rootPath New root element path.
     */
    public void setInput(Object input, TreePath rootPath) {
        fRootPath = rootPath;
        super.setInput(input);
    }
    
    /**
     * A proxy for the sub tree viewer which is given to the content and 
     * label providers.  It translates the sub-tree paths in the viewer to the 
     * full model paths that the providers expect.
     */
    public class DelegatingTreeModelViewer extends Viewer 
        implements ITreeModelLabelProviderTarget, ITreeModelContentProviderTarget 
    {
        public void reveal(TreePath path, int index) {
            if (path.startsWith(fRootPath, null)) {
                SubTreeModelViewer.this.reveal(createSubPath(path), index);
            }
        }
        
        public void replace(Object parentOrTreePath, int index, Object element) {
            if (parentOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)parentOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.replace(createSubPath(path), index, element);
                }
            } else {
                SubTreeModelViewer.this.replace(parentOrTreePath, index, element);
            }
        }
        
        public void setChildCount(Object elementOrTreePath, int count) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.setChildCount(createSubPath(path), count);
                }
            } else {
                SubTreeModelViewer.this.setChildCount(elementOrTreePath, count);
            }
        }
        
        public void setHasChildren(Object elementOrTreePath, boolean hasChildren) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.setHasChildren(createSubPath(path), hasChildren);
                }
            } else {
                SubTreeModelViewer.this.setHasChildren(elementOrTreePath, hasChildren);
            }
        }

        public void autoExpand(TreePath elementPath) {
            // not supported
        }

        public void setExpandedState(Object elementOrTreePath, boolean expanded) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.setExpandedState(createSubPath(path), expanded);
                }
            } else {
                SubTreeModelViewer.this.setExpandedState(elementOrTreePath, expanded);
            }
        }
        
        public void expandToLevel(Object elementOrTreePath, int level) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.expandToLevel(createSubPath(path), level);
                }
            } else {
                SubTreeModelViewer.this.expandToLevel(elementOrTreePath, level);
            }
        }

        public void remove(Object elementOrTreePath) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.remove(createSubPath(path));
                }
            } else {
                SubTreeModelViewer.this.remove(elementOrTreePath);
            }
        }

        public void remove(Object parentOrTreePath, final int index) {
            if (parentOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)parentOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.remove(createSubPath(path), index);
                }
            } else {
                SubTreeModelViewer.this.remove(parentOrTreePath, index);
            }
        }

        public void insert(Object parentOrTreePath, Object element, int position) {
            if (parentOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)parentOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    SubTreeModelViewer.this.insert(createSubPath(path), element, position);
                }
            } else {
                SubTreeModelViewer.this.insert(parentOrTreePath, element, position);
            }
        }

        public boolean getExpandedState(Object elementOrTreePath) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    return SubTreeModelViewer.this.getExpandedState(createSubPath(path));
                }
            } else {
                return SubTreeModelViewer.this.getExpandedState(elementOrTreePath);
            }
            return false;
        }
        
        public int getChildCount(TreePath path) {
            if (path.startsWith(fRootPath, null)) {
                return SubTreeModelViewer.this.getChildCount(createSubPath(path));
            }        
            return -1;
        }

        public boolean getHasChildren(Object elementOrTreePath) {
            if (elementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)elementOrTreePath;
                if (path.startsWith(fRootPath, null)) {
                    return SubTreeModelViewer.this.getHasChildren(createSubPath(path));
                }
            } else {
                return SubTreeModelViewer.this.getHasChildren(elementOrTreePath);
            }
            return false;
        }

        public Object getChildElement(TreePath path, int index) {
            if (path.startsWith(fRootPath, null)) {
                return SubTreeModelViewer.this.getChildElement(createSubPath(path), index);
            }        
            return null;
        }
        
        public TreePath getTopElementPath() {
            return createFullPath(SubTreeModelViewer.this.getTopElementPath());
        }
        
        public int findElementIndex(TreePath parentPath, Object element) {
            if (parentPath.startsWith(fRootPath, null)) {
                return SubTreeModelViewer.this.findElementIndex(createSubPath(parentPath), element);
            }        
            return -1;
        }

        public boolean getElementChildrenRealized(TreePath parentPath) {
            if (parentPath.startsWith(fRootPath, null)) {
                return SubTreeModelViewer.this.getElementChildrenRealized(createSubPath(parentPath));
            }        
            return true;
        }
        
        public void setElementData(TreePath path, int numColumns, String[] labels, ImageDescriptor[] images, FontData[] fontDatas, RGB[] foregrounds, RGB[] backgrounds) {
            if (path.startsWith(fRootPath, null)) {
                SubTreeModelViewer.this.setElementData(createSubPath(path), numColumns, labels, images, fontDatas, foregrounds, backgrounds);
            }        
        }

        public Control getControl() {
            return SubTreeModelViewer.this.getControl();
        }

        public Object getInput() {
            return SubTreeModelViewer.this.getInput();
        }

        public ISelection getSelection() {
            return SubTreeModelViewer.this.getSelection();
        }

        public void refresh() {
            SubTreeModelViewer.this.refresh();
        }

        public void setInput(Object input) {
            SubTreeModelViewer.this.setInput(input);
        }

        public void setSelection(ISelection selection, boolean reveal) {
            SubTreeModelViewer.this.setSelection(selection, reveal);
        }

        public String[] getVisibleColumns() {
             return SubTreeModelViewer.this.getVisibleColumns();
        }

        public void addLabelUpdateListener(ILabelUpdateListener listener) {
            SubTreeModelViewer.this.addLabelUpdateListener(listener);
        }

        public void addModelChangedListener(IModelChangedListener listener) {
            SubTreeModelViewer.this.addModelChangedListener(listener);
        }

        public void addStateUpdateListener(IStateUpdateListener listener) {
            SubTreeModelViewer.this.addStateUpdateListener(listener);
        }

        public void addViewerUpdateListener(IViewerUpdateListener listener) {
            SubTreeModelViewer.this.addViewerUpdateListener(listener);
        }

        public int getAutoExpandLevel() {
            return SubTreeModelViewer.this.getAutoExpandLevel();
        }

        public Display getDisplay() {
            return SubTreeModelViewer.this.getDisplay();
        }

        public ViewerLabel getElementLabel(TreePath path, String columnId) {
            return SubTreeModelViewer.this.getElementLabel(path, columnId);
        }

        public IPresentationContext getPresentationContext() {
            return SubTreeModelViewer.this.getPresentationContext();
        }

        public void removeLabelUpdateListener(ILabelUpdateListener listener) {
            SubTreeModelViewer.this.removeLabelUpdateListener(listener);
        }

        public void removeModelChangedListener(IModelChangedListener listener) {
            SubTreeModelViewer.this.removeModelChangedListener(listener);
        }

        public void removeStateUpdateListener(IStateUpdateListener listener) {
            SubTreeModelViewer.this.removeStateUpdateListener(listener);
        }

        public void removeViewerUpdateListener(IViewerUpdateListener listener) {
            SubTreeModelViewer.this.removeViewerUpdateListener(listener);
        }

        public void saveElementState(TreePath path, ModelDelta delta, int deltaFlags) {
            SubTreeModelViewer.this.saveElementState(path, delta, deltaFlags);
        }

        public void setAutoExpandLevel(int level) {
            SubTreeModelViewer.this.setAutoExpandLevel(level);
        }

        public void setSelection(ISelection selection, boolean reveal, boolean force) {
            SubTreeModelViewer.this.setSelection(selection, reveal, force);
        }

        public void updateViewer(IModelDelta delta) {
            SubTreeModelViewer.this.updateViewer(delta);
        }

        public ViewerFilter[] getFilters() {
            return SubTreeModelViewer.this.getFilters();
        }

        public boolean overrideSelection(ISelection current, ISelection candidate) {
            return SubTreeModelViewer.this.overrideSelection(current, candidate);
        }

        public void refresh(Object element) {
            SubTreeModelViewer.this.refresh(element);
        }

        public void update(Object element) {
            SubTreeModelViewer.this.update(element);
        }
    }

    
    /**
     * Delegating content provider.  It translates all the calls to the 
     * underlying content provider to use full model tree paths.
     */
    private class SubTreeModelContentProvider implements ITreeModelContentProvider {
        
        private TreeModelContentProvider fBaseProvider;
        
        public SubTreeModelContentProvider() {
            fBaseProvider = new TreeModelContentProvider();
        }
        
        public void updateHasChildren(TreePath path) {
            fBaseProvider.updateHasChildren(createFullPath(path));
        }
        
        public void updateChildCount(TreePath path, int currentChildCount) {
            fBaseProvider.updateChildCount(createFullPath(path), currentChildCount);
        }

        public void updateElement(TreePath parentPath, int viewIndex) {
            fBaseProvider.updateElement(createFullPath(parentPath), viewIndex);
        }
        
        public int viewToModelCount(TreePath parentPath, int count) {
            return fBaseProvider.viewToModelCount(createFullPath(parentPath), count);
        }
        
        public int viewToModelIndex(TreePath parentPath, int index) {
            return fBaseProvider.viewToModelIndex(createFullPath(parentPath), index);
        }

        public void addModelChangedListener(IModelChangedListener listener) {
            fBaseProvider.addModelChangedListener(listener);
        }

        public void addStateUpdateListener(IStateUpdateListener listener) {
            fBaseProvider.addStateUpdateListener(listener);
        }

        public void addViewerUpdateListener(IViewerUpdateListener listener) {
            fBaseProvider.addViewerUpdateListener(listener);
        }

        public int getModelDeltaMask() {
            return fBaseProvider.getModelDeltaMask();
        }

        public int modelToViewChildCount(TreePath parentPath, int count) {
            return fBaseProvider.modelToViewChildCount(createFullPath(parentPath), count);
        }

        public int modelToViewIndex(TreePath parentPath, int index) {
            return fBaseProvider.modelToViewIndex(createFullPath(parentPath), index);
        }

        public void removeModelChangedListener(IModelChangedListener listener) {
            fBaseProvider.removeModelChangedListener(listener);
        }

        public void removeStateUpdateListener(IStateUpdateListener listener) {
            fBaseProvider.removeStateUpdateListener(listener);
        }

        public void removeViewerUpdateListener(IViewerUpdateListener listener) {
            fBaseProvider.removeViewerUpdateListener(listener);
        }

        public void setModelDeltaMask(int mask) {
            fBaseProvider.setModelDeltaMask(mask);
        }

        public boolean shouldFilter(Object parentElementOrTreePath, Object element) {
            if (parentElementOrTreePath instanceof TreePath) {
                TreePath path = (TreePath)parentElementOrTreePath;
                return fBaseProvider.shouldFilter(createFullPath(path), element);
            } else {
                return fBaseProvider.shouldFilter(parentElementOrTreePath, element);
            }
            
        }

        public void unmapPath(TreePath path) {
            fBaseProvider.unmapPath(createFullPath(path));
        }

        public void updateModel(IModelDelta delta, int mask) {
            fBaseProvider.updateModel(delta, mask);
        }

        public TreePath[] getParents(Object element) {
            // Not used
            return null;
        }

        public void dispose() {
            fBaseProvider.dispose();
        }

        public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
            fBaseProvider.inputChanged(fDelegatingViewer, oldInput, newInput);
        }
    }

    /**
     * Delegating label provider.  It translates all the calls to the 
     * underlying label provider to use full model tree paths.
     */
    private class SubTreeModelLabelProvider extends ColumnLabelProvider
        implements ITreeModelLabelProvider 
    {

        private TreeModelLabelProvider fBaseProvider;
        
        public SubTreeModelLabelProvider(ITreeModelLabelProviderTarget viewer) {
            fBaseProvider = new TreeModelLabelProvider(viewer);
        }
        
        public boolean update(TreePath elementPath) {
            return fBaseProvider.update( createFullPath(elementPath) );
        }

        public void addLabelUpdateListener(ILabelUpdateListener listener) {
            fBaseProvider.addLabelUpdateListener(listener);
        }

        public Color getColor(RGB rgb) {
            return fBaseProvider.getColor(rgb);
        }

        public Font getFont(FontData fontData) {
            return fBaseProvider.getFont(fontData);
        }

        public Image getImage(ImageDescriptor descriptor) {
            return fBaseProvider.getImage(descriptor);
        }

        public void removeLabelUpdateListener(ILabelUpdateListener listener) {
            fBaseProvider.removeLabelUpdateListener(listener);
        }

        public void addListener(ILabelProviderListener listener) {
            fBaseProvider.addListener(listener);
        }

        public void dispose() {
            fBaseProvider.dispose();
            super.dispose();
        }

        public boolean isLabelProperty(Object element, String property) {
            return fBaseProvider.isLabelProperty(element, property);
        }

        public void removeListener(ILabelProviderListener listener) {
            fBaseProvider.removeListener(listener);
        }
    }
        
    private TreePath createFullPath(TreePath subPath) {
        Object[] segments = new Object[fRootPath.getSegmentCount() + subPath.getSegmentCount()];
        for (int i = 0; i < fRootPath.getSegmentCount(); i++) {
            segments[i] = fRootPath.getSegment(i);
        }
        for (int i = 0; i < subPath.getSegmentCount(); i++) {
            segments[i + fRootPath.getSegmentCount()] = subPath.getSegment(i);
        }
        return new TreePath(segments);
    }
    
    private TreePath createSubPath(TreePath fullPath) {
        if (fullPath.getSegmentCount() <= fRootPath.getSegmentCount()) {
            return TreePath.EMPTY;
        }
        Object[] segments = new Object[fullPath.getSegmentCount() - fRootPath.getSegmentCount()];
        for (int i = 0; i < segments.length; i++) {
            segments[i] = fullPath.getSegment(i + fRootPath.getSegmentCount());
        }
        return new TreePath(segments);
    }
    
    private DelegatingTreeModelViewer getDelegatingViewer() {
    	if (fDelegatingViewer == null) {
    		fDelegatingViewer = new DelegatingTreeModelViewer();
    	}
    	return fDelegatingViewer;
    }
    
    protected ITreeModelContentProvider createContentProvider() {
        return new SubTreeModelContentProvider();
    }
    
    protected ITreeModelLabelProvider createLabelProvider() {
        return new SubTreeModelLabelProvider(getDelegatingViewer());
    }
    

}