/*******************************************************************************
 * Copyright (c) 2000, 2005 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
 *     Sebastian Davids <sdavids@gmx.de> - Fix for bug 19346 - Dialog font should be
 *     activated and used by other components.
 *******************************************************************************/
package org.eclipse.ui.internal.ide.misc;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.IContentProvider;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
import org.eclipse.ui.internal.ide.dialogs.WizardStep;
import org.eclipse.ui.model.WorkbenchContentProvider;

/**
 * A group of controls used to view the list of
 * wizard steps to be done.
 */
public class WizardStepGroup {
	
	 private Image doneImage;

    private Image currentImage;

    private WizardStep currentStep;

    private Composite parentComposite;

    private TableViewer stepViewer;

    private ISelectionChangedListener selectionListener;

    /**
     * Creates a new instance of the <code>WizardStepGroup</code>
     */
    public WizardStepGroup() {
        super();
    }

    /**
     * Create the contents of this group. The basic layout is a table
     * with a label above it.
     */
    public Control createContents(Composite parent) {
        Font font = parent.getFont();
        parentComposite = parent;

        // Create a composite to hold everything together
        Composite composite = new Composite(parent, SWT.NULL);
        composite.setLayout(new GridLayout());
        composite.setLayoutData(new GridData(GridData.FILL_VERTICAL));
        composite.setFont(font);
        composite.addDisposeListener(new DisposeListener() {
            public void widgetDisposed(DisposeEvent e) {
                if (doneImage != null) {
                    doneImage.dispose();
                    doneImage = null;
                }
                if (currentImage != null) {
                    currentImage.dispose();
                    currentImage = null;
                }
            }
        });

        // Add a label to identify the step list field
        Label label = new Label(composite, SWT.LEFT);
        label.setText(IDEWorkbenchMessages.WizardStepGroup_stepsLabel);
        GridData data = new GridData();
        data.verticalAlignment = SWT.TOP;
        label.setLayoutData(data);
        label.setFont(font);

        // Table viewer of all the steps
        stepViewer = new TableViewer(composite, SWT.SINGLE | SWT.V_SCROLL
                | SWT.BORDER | SWT.FULL_SELECTION);
        data = new GridData(GridData.FILL_BOTH);
        stepViewer.getTable().setLayoutData(data);
        stepViewer.getTable().setFont(font);
        stepViewer.setContentProvider(getStepProvider());
        stepViewer.setLabelProvider(new StepLabelProvider());

        if (selectionListener != null)
            stepViewer.addSelectionChangedListener(selectionListener);

        return composite;
    }

    /**
     * Creates an image descriptor.
     */
    private Image createImage(String iconFileName) {
        ImageDescriptor desc = 
			IDEWorkbenchPlugin.getIDEImageDescriptor(iconFileName);
       
        return desc.createImage();
    }

    /**
     * Return the image indicating a step is current
     */
    private Image getCurrentImage() {
        if (currentImage == null) {
            currentImage = createImage("elcl16/step_current.gif"); //$NON-NLS-1$
        }
        return currentImage;
    }

    /**
     * Return the image indicating a step is done
     */
    private Image getDoneImage() {
        if (doneImage == null) {
            doneImage = createImage("elcl16/step_done.gif"); //$NON-NLS-1$
        }
        return doneImage;
    }

    /**
     * Returns the content provider for the step viewer
     */
    private IContentProvider getStepProvider() {
        return new WorkbenchContentProvider() {
            public Object[] getChildren(Object parentElement) {
                if (parentElement instanceof StepRoot)
                    return ((StepRoot) parentElement).getSteps();
                else
                    return null;
            }

        };
    }

    /**
     * Returns the steps.
     */
    public WizardStep[] getSteps() {
        if (stepViewer != null) {
            StepRoot root = (StepRoot) stepViewer.getInput();
            if (root != null)
                return root.getSteps();
        }

        return new WizardStep[0];
    }

    /**
     * Marks the current step as being done
     */
    public void markStepAsDone() {
        if (currentStep != null)
            currentStep.markAsDone();
    }

    /**
     * Sets the current step being worked on. Assumes
     * the step provided exist in the steps within the
     * group's viewer.
     * 
     * @param step the wizard step being worked on
     */
    public void setCurrentStep(WizardStep step) {
        WizardStep oldStep = currentStep;
        currentStep = step;
        if (stepViewer != null) {
            if (oldStep != null)
                stepViewer.update(oldStep, null);
            if (currentStep != null)
                stepViewer.update(currentStep, null);

            // Update the layout so that there is enough
            // room for the icon now.
            if (oldStep == null && currentStep != null)
                parentComposite.layout(true);
        }
    }

    /**
     * Set the current listener interested when the selection
     * state changes.
     * 
     * @param listener The selection listener to set
     */
    public void setSelectionListener(ISelectionChangedListener listener) {
        if (selectionListener != null && stepViewer != null)
            stepViewer.removeSelectionChangedListener(selectionListener);
        selectionListener = listener;
        if (selectionListener != null && stepViewer != null)
            stepViewer.addSelectionChangedListener(selectionListener);
    }

    /**
     * Sets the steps to be displayed. Ignored is the
     * method createContents has not been called yet.
     * 
     * @param steps the collection of steps
     */
    public void setSteps(WizardStep[] steps) {
        if (stepViewer != null) {
            stepViewer.setInput(new StepRoot(steps));
            parentComposite.layout(true);
        }
    }

    /**
     * Holder of all the steps within the viewer
     */
    private class StepRoot {
        private WizardStep[] steps;

        public StepRoot(WizardStep[] steps) {
            super();
            this.steps = steps;
        }

        public WizardStep[] getSteps() {
            if (steps == null)
                return new WizardStep[0];
            else
                return steps;
        }
    }

    /**
     * Label provider for step table viewer
     */
    private class StepLabelProvider extends LabelProvider {
        public String getText(Object element) {
            if (element instanceof WizardStep) {
                WizardStep step = (WizardStep) element;
                return String.valueOf(step.getNumber())
                        + ". " + step.getLabel(); //$NON-NLS-1$
            }

            return ""; //$NON-NLS-1$
        }

        public Image getImage(Object element) {
            if (element instanceof WizardStep) {
                WizardStep step = (WizardStep) element;
                if (step.isDone())
                    return getDoneImage();
                if (step == currentStep)
                    return getCurrentImage();
            }

            return null;
        }
    }
}