/*******************************************************************************
 * Copyright (c) 2006, 2008 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *     Matthew Hall - bug 206839
 *     Matthew Hall - bug 124684
 *******************************************************************************/

module org.eclipse.jface.databinding.viewers.ViewersObservables;

import java.lang.all;

import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.jface.internal.databinding.viewers.CheckableCheckedElementsObservableSet;
import org.eclipse.jface.internal.databinding.viewers.CheckboxViewerCheckedElementsObservableSet;
import org.eclipse.jface.internal.databinding.viewers.SelectionProviderMultipleSelectionObservableList;
import org.eclipse.jface.internal.databinding.viewers.SelectionProviderSingleSelectionObservableValue;
import org.eclipse.jface.internal.databinding.viewers.ViewerInputObservableValue;
import org.eclipse.jface.internal.databinding.viewers.ViewerMultipleSelectionObservableList;
import org.eclipse.jface.internal.databinding.viewers.ViewerSingleSelectionObservableValue;
import org.eclipse.jface.viewers.CheckboxTableViewer;
import org.eclipse.jface.viewers.CheckboxTreeViewer;
import org.eclipse.jface.viewers.ICheckable;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.widgets.Display;

/**
 * Factory methods for creating observables for JFace viewers
 * 
 * @since 1.1
 */
public class ViewersObservables {

    /**
     * Returns an observable value that tracks the current selection of the
     * given selection provider. If the selection provider provides selections
     * of type {@link IStructuredSelection}, the observable value will be the
     * first element of the structured selection as returned by
     * {@link IStructuredSelection#getFirstElement()}.
     * 
     * @param selectionProvider
     * @return the observable value tracking the (single) selection of the given
     *         selection provider
     */
    public static IObservableValue observeSingleSelection(
            ISelectionProvider selectionProvider) {
        if (null !is cast(Viewer)selectionProvider) {
            return observeSingleSelection(cast(Viewer) selectionProvider);
        }
        return new SelectionProviderSingleSelectionObservableValue(
                SWTObservables.getRealm(Display.getDefault()),
                selectionProvider);
    }

    /**
     * Returns an observable list that tracks the current selection of the
     * given selection provider. Assumes that the selection provider provides
     * selections of type {@link IStructuredSelection}. Note that the
     * observable list will not honor the full contract of
     * <code>java.util.List</code> in that it may delete or reorder elements
     * based on what the selection provider returns from
     * {@link ISelectionProvider#getSelection()} after having called
     * {@link ISelectionProvider#setSelection(org.eclipse.jface.viewers.ISelection)}
     * based on the requested change to the observable list. The affected
     * methods are <code>add</code>, <code>addAll</code>, and
     * <code>set</code>.
     * 
     * @param selectionProvider
     * @return the observable value tracking the (multi) selection of the given
     *         selection provider
     * 
     * @since 1.2
     */
    public static IObservableList observeMultiSelection(
            ISelectionProvider selectionProvider) {
        if (null !is cast(Viewer)selectionProvider) {
            return observeMultiSelection(cast(Viewer) selectionProvider);
        }
        return new SelectionProviderMultipleSelectionObservableList(
                SWTObservables.getRealm(Display.getDefault()),
                selectionProvider, Object.classinfo);
    }

    /**
     * Returns an observable value that tracks the current selection of the
     * given viewer. If the viewer provides selections of type
     * {@link IStructuredSelection}, the observable value will be the first
     * element of the structured selection as returned by
     * {@link IStructuredSelection#getFirstElement()}.
     * 
     * @param viewer
     *            the viewer
     * @return the observable value tracking the (single) selection of the given
     *         viewer
     * @since 1.2
     */
    public static IViewerObservableValue observeSingleSelection(Viewer viewer) {
        return new ViewerSingleSelectionObservableValue(
                SWTObservables.getRealm(Display.getDefault()),
                viewer);
    }
    
    /**
     * Returns an observable list that tracks the current selection of the
     * given viewer. Assumes that the viewer provides
     * selections of type {@link IStructuredSelection}. Note that the
     * observable list will not honor the full contract of
     * <code>java.util.List</code> in that it may delete or reorder elements
     * based on what the viewer returns from
     * {@link ISelectionProvider#getSelection()} after having called
     * {@link ISelectionProvider#setSelection(org.eclipse.jface.viewers.ISelection)}
     * based on the requested change to the observable list. The affected
     * methods are <code>add</code>, <code>addAll</code>, and
     * <code>set</code>.
     * 
     * @param viewer
     * @return the observable value tracking the (multi) selection of the given
     *         selection provider
     * 
     * @since 1.2
     */
    public static IViewerObservableList observeMultiSelection(
            Viewer viewer) {
        return new ViewerMultipleSelectionObservableList(
                SWTObservables.getRealm(Display.getDefault()),
                viewer, Object.classinfo);
    }
    
    /**
     * Returns an observable value that tracks the input of the given viewer.
     * <p>
     * The returned observer is blind to changes in the viewer's input unless
     * its {@link IObservableValue#setValue(Object)} method is called directly.
     * 
     * @param viewer
     *            the viewer to observe
     * @return an observable value tracking the input of the given viewer
     * @since 1.2
     */
    public static IObservableValue observeInput(Viewer viewer) {
        return new ViewerInputObservableValue(SWTObservables.getRealm(viewer
                .getControl().getDisplay()), viewer);
    }

    /**
     * Returns an observable set that tracks the checked elements of the given
     * <code>ICheckable</code>.
     * 
     * @param checkable
     *            {@link ICheckable} containing the checked elements to track
     * @param elementType
     *            element type of the returned set
     * @return an observable set tracking the checked elements of the given
     *         checkable.
     * @since 1.2
     */
    public static IObservableSet observeCheckedElements(ICheckable checkable,
            Object elementType) {
        if (null !is cast(CheckboxTableViewer)checkable) {
            return observeCheckedElements(cast(CheckboxTableViewer) checkable,
                    elementType);
        }
        if (null !is cast(CheckboxTreeViewer)checkable) {
            return observeCheckedElements(cast(CheckboxTreeViewer) checkable,
                    elementType);
        }
        return new CheckableCheckedElementsObservableSet(SWTObservables
                .getRealm(Display.getDefault()), checkable, elementType);
    }

    /**
     * Returns an observable set that tracks the checked elements of the given
     * viewer. Assumes that the viewer implements {@link ICheckable}.
     * 
     * @param viewer
     *            {@link CheckboxTableViewer} containing the checked elements to
     *            track.
     * @param elementType
     *            element type of the returned set
     * @return an observable set that tracks the checked elements of the given
     *         viewer.
     * @since 1.2
     */
    public static IViewerObservableSet observeCheckedElements(
            CheckboxTableViewer viewer, Object elementType) {
        return new CheckboxViewerCheckedElementsObservableSet(SWTObservables
                .getRealm(viewer.getControl().getDisplay()), viewer,
                elementType);
    }

    /**
     * Returns an observable set that tracks the checked elements of the given
     * viewer. Assumes that the viewer implements {@link ICheckable}.
     * 
     * @param viewer
     *            {@link CheckboxTreeViewer} containing the checked elements to
     *            track.
     * @param elementType
     *            element type of the returned set
     * @return an observable set that tracks the checked elements of the given
     *         viewer.
     * @since 1.2
     */
    public static IViewerObservableSet observeCheckedElements(
            CheckboxTreeViewer viewer, Object elementType) {
        return new CheckboxViewerCheckedElementsObservableSet(SWTObservables
                .getRealm(viewer.getControl().getDisplay()), viewer,
                elementType);
    }
}