/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ui.views.markers.internal;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuListener;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.IToolBarManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.jface.viewers.ColumnLayoutData;
import org.eclipse.jface.viewers.ColumnPixelData;
import org.eclipse.jface.viewers.IOpenListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.OpenEvent;
import org.eclipse.jface.viewers.TableLayout;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Scrollable;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.ui.IActionBars;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.IViewSite;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.part.ViewPart;

public abstract class TableView extends ViewPart {
	
	private static final String TAG_COLUMN_WIDTH = "columnWidth"; //$NON-NLS-1$
	private static final String TAG_VERTICAL_POSITION = "verticalPosition"; //$NON-NLS-1$
	private static final String TAG_HORIZONTAL_POSITION = "horizontalPosition"; //$NON-NLS-1$

	public static final String SORT_ACTION_ID = "sort"; //$NON-NLS-1$
	public static final String FILTERS_ACTION_ID = "filters"; //$NON-NLS-1$
	
	private TableViewer viewer;
	private IMemento memento;
	protected ColumnLayoutData[] columnLayouts;
	
	private Map actions = new HashMap();

	private TableSorter sorter;

	/* (non-Javadoc)
	 * Method declared on IViewPart.
	 */
	public void init(IViewSite site, IMemento memento) throws PartInitException {
		super.init(site, memento);
		this.memento = memento;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.part.WorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
	 */
	public void createPartControl(Composite parent) {
		viewer = new TableViewer(createTable(parent));
		restoreColumnWidths(memento);
		createColumns(viewer.getTable());
		getContentProvider().setFilter(getFilter());
		viewer.setContentProvider(new TableContentProvider(getSite(), getContentProvider()));
		viewer.setLabelProvider(new TableViewLabelProvider(getVisibleFields()));

		viewer.setSorter(getSorter());
		
		//create the actions before the input is set on the viewer but after the 
		//sorter and filter are set so the actions will be enabled correctly.
		createActions();

		viewer.setInput(getViewerInput());
		viewer.setSelection(restoreSelection(memento), true);
		Scrollable scrollable = (Scrollable) viewer.getControl();
		ScrollBar bar = scrollable.getVerticalBar();
		if (bar != null) {
			bar.setSelection(restoreVerticalScrollBarPosition(memento));
		}
		bar = scrollable.getHorizontalBar();
		if (bar != null) {
			bar.setSelection(restoreHorizontalScrollBarPosition(memento));
		}
		
		MenuManager mgr = initContextMenu();
		Menu menu = mgr.createContextMenu(viewer.getControl());
		viewer.getControl().setMenu(menu);
		getSite().registerContextMenu(mgr, viewer);
		initActionBars(getViewSite().getActionBars());
		registerGlobalActions(getViewSite().getActionBars());
		
		viewer.addOpenListener(new IOpenListener() {
			public void open(OpenEvent event) {
				handleOpenEvent(event);
			}
		});
		viewer.getControl().addKeyListener(new KeyAdapter() {
			public void keyPressed(KeyEvent e) {
				handleKeyPressed(e);
			}
		});
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkbenchPart#dispose()
	 */
	public void dispose() {
	}
	
	/**
	 * Creates the table control.
	 */
	protected Table createTable(Composite parent) {
		Table table = new Table(parent, SWT.H_SCROLL | SWT.V_SCROLL | SWT.MULTI | SWT.FULL_SELECTION);
		table.setLinesVisible(true);
		table.setFont(parent.getFont());
		return table;
	}
	
	protected void createColumns(final Table table) {
		SelectionListener headerListener = getHeaderListener();
		TableLayout layout = new TableLayout();
		table.setLayout(layout);
		table.setHeaderVisible(true);
		final IField[] fields = getVisibleFields();
		ColumnLayoutData[] columnWidths = columnLayouts;
		if (columnWidths == null) {
			columnWidths = getDefaultColumnLayouts();
		}
		for (int i = 0; i < fields.length; i++) {
			if (columnWidths == null || i >= columnWidths.length || columnWidths[i] == null) {
				layout.addColumnData(new ColumnPixelData(504 / fields.length, true));
			}
			else {
				layout.addColumnData(columnWidths[i]);
			}
			TableColumn tc = new TableColumn(table, SWT.NONE,i);
			tc.setText(fields[i].getColumnHeaderText());
			tc.setImage(fields[i].getColumnHeaderImage());
			tc.addSelectionListener(headerListener);
		}
	}
	
	protected void createActions() {
		if (getSortDialog() != null) {
			putAction(SORT_ACTION_ID, new TableSortAction(this, getSortDialog()));
		}
		if (getFiltersDialog() != null) {
			putAction(FILTERS_ACTION_ID, new FiltersAction(this, getFiltersDialog()));
		}
	}
	
	protected IAction getAction(String id) {
		return (IAction) actions.get(id);
	}
	
	protected void putAction(String id, IAction action) {
		actions.put(id, action);
	}
	
	protected MenuManager initContextMenu() {
		MenuManager mgr = new MenuManager();
		mgr.setRemoveAllWhenShown(true);
		mgr.addMenuListener(new IMenuListener() {
			public void menuAboutToShow(IMenuManager mgr) {
				getViewer().cancelEditing();
				fillContextMenu(mgr);
			}
		});
		return mgr;
	}
	
	protected abstract void initToolBar(IToolBarManager tbm);
	
	protected void initActionBars(IActionBars actionBars) {
		initMenu(actionBars.getMenuManager());
		initToolBar(actionBars.getToolBarManager());
	}
	
	protected void initMenu(IMenuManager menu) {
		IAction sortAction = getAction(SORT_ACTION_ID);
		if (sortAction != null)
			menu.add(sortAction);
		IAction filtersAction = getAction(FILTERS_ACTION_ID);
		if (filtersAction != null)
			menu.add(filtersAction);
	}

	protected abstract void registerGlobalActions(IActionBars actionBars);
	
	protected abstract void fillContextMenu(IMenuManager manager);
	
	/* (non-Javadoc)
	 * @see org.eclipse.ui.part.WorkbenchPart#setFocus()
	 */
	public void setFocus() {
		TableViewer viewer = getViewer();
		if (viewer != null && !viewer.getControl().isDisposed()) { 
			viewer.getControl().setFocus();
		}
	}
	
	protected abstract IFilter getFilter();

	protected TableSorter getSorter() {
		if (sorter == null) {
			int[] priorities = new int[getFields().length];
			int[] directions = new int[getFields().length];
			for (int i = 0; i < getFields().length; i++) {
				priorities[i] = i;
			}
			Arrays.fill(directions, TableSorter.ASCENDING);
			sorter = new TableSorter(getFields(), priorities, directions);
			sorter.restoreState(getDialogSettings());
		}
		return sorter;
	}
	
	protected abstract ITableViewContentProvider getContentProvider();
	
	protected IField[] getFields() {
		IField[] vProps = getVisibleFields();
		IField[] hProps = getHiddenFields();
		IField[] fields = new IField[vProps.length + hProps.length];
		System.arraycopy(vProps, 0, fields, 0, vProps.length);
		System.arraycopy(hProps, 0, fields, vProps.length, hProps.length);
		return fields;
	}
	
	protected abstract Object getViewerInput();
	
	protected abstract IField[] getVisibleFields();
	
	protected abstract IField[] getHiddenFields();

	protected abstract IDialogSettings getDialogSettings();
	
	protected TableViewer getViewer() {
		return viewer;
	}
	
	protected SelectionListener getHeaderListener() {
		return new SelectionAdapter() {
			/**
			 * Handles the case of user selecting the
			 * header area.
			 */
			public void widgetSelected(SelectionEvent e) {
				int column = getViewer().getTable().indexOf((TableColumn) e.widget);
				if (column == getSorter().getTopPriority())
					getSorter().reverseTopPriority();
				else {
					getSorter().setTopPriority(column);
				}
				viewer.refresh(false);
				getSorter().saveState(getDialogSettings());
			}
		};
	}
	
	protected abstract ColumnLayoutData[] getDefaultColumnLayouts();
	
	protected TableSortDialog getSortDialog() {
		if (getSorter() != null) {
			return new TableSortDialog(getSite().getShell(), getSorter());
		}
		return null;
	}
	
	protected abstract Dialog getFiltersDialog();
	
	protected void filtersChanged() {
		final TableViewer viewer = getViewer();
		if (viewer == null) {
			return;
		}
		getSite().getShell().getDisplay().asyncExec(new Runnable() {
			public void run() {
				viewer.getControl().setRedraw(false);
				viewer.refresh(false);
				viewer.getControl().setRedraw(true);
			}
		});
	}
	
	protected void sorterChanged() {
		final TableViewer viewer = getViewer();
		if (viewer == null) {
			return;
		}
		getSite().getShell().getDisplay().asyncExec(new Runnable() {
			public void run() {
				viewer.getControl().setRedraw(false);
				viewer.refresh(false);
				viewer.getControl().setRedraw(true);
			}
		});
	}
	
	protected abstract void handleKeyPressed(KeyEvent event);
	
	protected abstract void handleOpenEvent(OpenEvent event);
	
	/* (non-Javadoc)
	 * @see org.eclipse.ui.part.ViewPart#saveState(org.eclipse.ui.IMemento)
	 */
	public void saveState(IMemento memento) {
		super.saveState(memento);

		//save column widths
		TableColumn[] columns = viewer.getTable().getColumns();
		for (int i = 0; i < columns.length; i++) {
			memento.putInteger(TAG_COLUMN_WIDTH + i, columns[i].getWidth());
		}
		
		saveSelection(memento);
		
		//save vertical position
		Scrollable scrollable = (Scrollable) viewer.getControl();
		ScrollBar bar = scrollable.getVerticalBar();
		int position = (bar != null) ? bar.getSelection() : 0;
		memento.putInteger(TAG_VERTICAL_POSITION, position);
		//save horizontal position
		bar = scrollable.getHorizontalBar();
		position = (bar != null) ? bar.getSelection() : 0;
		memento.putInteger(TAG_HORIZONTAL_POSITION, position);
	}
	
	protected abstract void saveSelection(IMemento memento);

	private void restoreColumnWidths(IMemento memento) {
		if (memento == null) {
			return;
		}
		columnLayouts = new ColumnLayoutData[getFields().length];
		for (int i = 0; i < columnLayouts.length; i++) {
			Integer width = memento.getInteger(TAG_COLUMN_WIDTH + i);
			if (width == null) {
				columnLayouts = null;
				break;
			}
			else {
				columnLayouts[i] = new ColumnPixelData(width.intValue(), true);
			}
		}
	}
	
	protected abstract IStructuredSelection restoreSelection(IMemento memento);
	
	private int restoreVerticalScrollBarPosition(IMemento memento) {
		if (memento == null) {
			return 0;
		}
		Integer position = memento.getInteger(TAG_VERTICAL_POSITION);
		return (position == null) ? 0 : position.intValue();
	}
	
	private int restoreHorizontalScrollBarPosition(IMemento memento) {
		if (memento == null) {
			return 0;
		}
		Integer position = memento.getInteger(TAG_HORIZONTAL_POSITION);
		return (position == null) ? 0 : position.intValue();
	}

}