/*******************************************************************************
 * Copyright (c) 2000, 2009 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
 *******************************************************************************/
package org.eclipse.team.internal.ui.dialogs;

import org.eclipse.jface.dialogs.*;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.PlatformUI;

/**
 * A simple superclass for detail button dialogs.
 */
abstract public class DetailsDialog extends TrayDialog {
	/**
	 * The Details button.
	 */
	private Button detailsButton;

	/**
	 * The Ok button.
	 */
	private Button okButton;

	/**
	 * The title of the dialog.
	 */
	private String title;

	/**
	 * The error message
	 */
	private Label errorMessageLabel;

	/**
	 * The SWT list control that displays the error details.
	 */
	private Composite detailsComposite;

	/**
	 * Indicates whether the error details viewer is currently created.
	 */
	private boolean detailsCreated = false;

	/**
	 * The key for the image to be displayed (one of the image constants on Dialog)
	 */
	private String imageKey = null;

	/**
	 * Creates a details pane dialog.
	 * Note that the dialog will have no visual representation (no widgets)
	 * until it is told to open.
	 *
	 * @param parentShell the shell under which to create this dialog
	 * @param dialogTitle the title to use for this dialog
	 * @see org.eclipse.core.runtime.IStatus#matches
	 */
	public DetailsDialog(Shell parentShell, String dialogTitle) {
		super(parentShell);
		this.title = dialogTitle;
		initializeStyle();
	}

	protected void initializeStyle() {
		setShellStyle(SWT.DIALOG_TRIM | SWT.RESIZE | SWT.APPLICATION_MODAL);
	}

	/* (non-Javadoc)
	 * Method declared on Dialog.
	 * Handles the pressing of the Ok or Details button in this dialog.
	 * If the Ok button was pressed then close this dialog.  If the Details
	 * button was pressed then toggle the displaying of the error details area.
	 * Note that the Details button will only be visible if the error being
	 * displayed specifies child details.
	 */
	@Override
	protected void buttonPressed(int id) {
		if (id == IDialogConstants.DETAILS_ID) {  // was the details button pressed?
			toggleDetailsArea();
		} else {
			super.buttonPressed(id);
		}
	}

	/* (non-Javadoc)
	 * Method declared in Window.
	 */
	@Override
	protected void configureShell(Shell shell) {
		super.configureShell(shell);
		shell.setText(title);
        String helpContextId = getHelpContextId();
        if (helpContextId != null) {
            PlatformUI.getWorkbench().getHelpSystem().setHelp(shell, helpContextId);
        }
	}

	/* (non-Javadoc)
	 * Method declared on Dialog.
	 */
	@Override
	protected void createButtonsForButtonBar(Composite parent) {
		// create OK and Details buttons
		if(includeOkButton()) {
			okButton = createButton(parent, IDialogConstants.OK_ID, IDialogConstants.OK_LABEL, true);
		}
		if (includeCancelButton()) {
			createButton(parent, IDialogConstants.CANCEL_ID, IDialogConstants.CANCEL_LABEL, false);
		}
		if(includeDetailsButton()) {
			detailsButton = createButton(parent, IDialogConstants.DETAILS_ID, getDetailsButtonLabelShow(), false);
		}
		updateEnablements();
	}

	protected String getDetailsButtonLabelShow() {
		return IDialogConstants.SHOW_DETAILS_LABEL;
	}

	protected String getDetailsButtonLabelHide() {
		return IDialogConstants.HIDE_DETAILS_LABEL;
	}

	/* (non-Javadoc)
	 * Method declared on Dialog.
	 * Creates and returns the contents of the upper part
	 * of the dialog (above the button bar).
	 */
	@Override
	final protected Control createDialogArea(Composite parent) {

		applyDialogFont(parent);
		initializeDialogUnits(parent);

		// create composite
		Composite composite = (Composite)super.createDialogArea(parent);
		if (!isMainGrabVertical()) {
		    composite.setLayoutData(new GridData(SWT.FILL, SWT.TOP, true, false));
		}

        String helpContextId = getHelpContextId();
        if (helpContextId != null) {
            PlatformUI.getWorkbench().getHelpSystem().setHelp(composite, helpContextId);
        }

		// create image
		String key = getImageKey();
		Image image = null;
		if (key != null) {
			image = JFaceResources.getImageRegistry().get(key);
		}
		if (image != null) {
			// create a composite to split the dialog area in two
			Composite top = new Composite(composite, SWT.NONE);
			GridLayout layout = new GridLayout();
			layout.marginHeight = 0;
			layout.marginWidth = 0;
			layout.verticalSpacing = 0;
			layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING);
			layout.numColumns = 2;
			top.setLayout(layout);
			top.setLayoutData(new GridData(GridData.FILL_BOTH));

			// add the image to the left of the composite
			Label label = new Label(top, 0);
			image.setBackground(label.getBackground());
			label.setImage(image);
			label.setLayoutData(new GridData(
				GridData.HORIZONTAL_ALIGN_CENTER |
				GridData.VERTICAL_ALIGN_BEGINNING));

			// add a composite to the right to contain the custom components
			Composite right = new Composite(top, SWT.NONE);
			layout = new GridLayout();
			layout.marginHeight = 0;
			layout.marginWidth = 0;
			layout.verticalSpacing = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING);
			layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING);
			right.setLayout(layout);
			right.setLayoutData(new GridData(GridData.FILL_BOTH));
			createMainDialogArea(right);
		} else {
		    createMainDialogArea(composite);
		}

		if(includeErrorMessage()) {
			errorMessageLabel = new Label(composite, SWT.NONE);
			errorMessageLabel.setLayoutData(new GridData(
				GridData.GRAB_HORIZONTAL |
				GridData.HORIZONTAL_ALIGN_FILL));
			errorMessageLabel.setForeground(getShell().getDisplay().getSystemColor(SWT.COLOR_RED));
		}

        Dialog.applyDialogFont(parent);
		return composite;
	}

    /**
     * Return the help context id to be used for the dialog.
     * This context Id will be registered by this class.
     * By default, this method returns <code>null</code>.
     * @return the help context id to be used for the dialog.
     */
	protected String getHelpContextId() {
        return null;
    }

    /**
	 * Return whether the main area should grab excess vertical space.
	 * The default is <code>true</code> but subclasses can override
	 * in cases where the main is more or less fixed but the details
	 * needs to grab.
     * @return whether the main area should grab excess vertical space
     */
    protected boolean isMainGrabVertical() {
        return true;
    }

    /**
	 * Creates the dialog's top composite
	 *
	 * @param parent the parent composite
	 */
	abstract protected void createMainDialogArea(Composite parent);

	/**
	 * Create this dialog's drop-down list component.
	 *
	 * @param parent the parent composite
	 * @return the drop-down list component
	 */
	abstract protected Composite createDropDownDialogArea(Composite parent);

	/**
	 * Toggles the unfolding of the details area.  This is triggered by
	 * the user pressing the details button.
	 */
	private void toggleDetailsArea() {
		Point windowSize = getShell().getSize();
		Point oldSize = getContents().computeSize(SWT.DEFAULT, SWT.DEFAULT);

		if (detailsCreated) {
			detailsComposite.dispose();
			detailsCreated = false;
			detailsButton.setText(getDetailsButtonLabelShow());
		} else {
			detailsComposite = createDropDownDialogArea((Composite)getContents());
			detailsCreated = true;
			detailsButton.setText(getDetailsButtonLabelHide());
		}
        Dialog.applyDialogFont(getContents());
		Point newSize = getContents().computeSize(SWT.DEFAULT, SWT.DEFAULT);

		getShell().setSize(new Point(windowSize.x, windowSize.y + (newSize.y - oldSize.y)));
	}

	final protected void setErrorMessage(String error) {
		if(errorMessageLabel != null) {
			if(error == null || error.length() == 0) {
				errorMessageLabel.setText(""); //$NON-NLS-1$
			} else {
				errorMessageLabel.setText(error);
			}
			errorMessageLabel.update();
		}
	}

	final protected void setPageComplete(boolean complete) {
		if(okButton != null ) {
			okButton.setEnabled(complete);
		}
	}

	abstract protected void updateEnablements();

	protected boolean includeCancelButton() {
		return true;
	}

	protected boolean includeOkButton() {
		return true;
	}

	/**
	 * Returns the imageKey.
	 * @return String
	 */
	protected String getImageKey() {
		return imageKey;
	}


	/**
	 * Sets the imageKey.
	 * @param imageKey The imageKey to set
	 */
	protected void setImageKey(String imageKey) {
		this.imageKey = imageKey;
	}

	protected Label createWrappingLabel(Composite parent, String text) {
		Label label = new Label(parent, SWT.LEFT | SWT.WRAP);
		label.setText(text);
		GridData data = new GridData();
		data.horizontalSpan = 1;
		data.horizontalAlignment = GridData.FILL;
		data.horizontalIndent = 0;
		data.grabExcessHorizontalSpace = true;
		data.widthHint = convertHorizontalDLUsToPixels(IDialogConstants.MINIMUM_MESSAGE_AREA_WIDTH);
		label.setLayoutData(data);
		label.setFont(parent.getFont());
		return label;
	}

	protected Composite createComposite(Composite parent) {
		Composite composite = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		composite.setLayout(layout);
		composite.setLayoutData(new GridData(GridData.FILL_BOTH));
		composite.setFont(parent.getFont());
		return composite;
	}

	protected boolean isDetailsVisible() {
		return detailsCreated;
	}

	protected boolean includeErrorMessage() {
		return true;
	}

	protected boolean includeDetailsButton() {
		return true;
	}
}
