/******************************************************************************* 
 * 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 
 *   Sebastian Davids <sdavids@gmx.de> - Fix for bug 19346 - Dialog
 * 	 	font should be activated and used by other components.
************************************************************************/

package org.eclipse.ui.dialogs;

import java.io.File;

import org.eclipse.core.resources.*;
import org.eclipse.core.runtime.*;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.help.WorkbenchHelp;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
import org.eclipse.ui.internal.ide.IHelpContextIds;
import org.eclipse.ui.internal.ide.dialogs.PathVariableSelectionDialog;

/**
 * Standard resource link page for a wizard that creates a file or 
 * folder resource.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * @since 2.1
 */
public class WizardNewLinkPage extends WizardPage {	
	private String initialLinkTarget;
	private int type;
	private boolean createLink = false;
	private IContainer container;

	// widgets
	private Text linkTargetField;
	private Button browseButton;
	private Button variablesButton;
 
/**
 * Creates a new resource link wizard page. 
 *
 * @param pageName the name of the page
 * @param type specifies the type of resource to link to. 
 * 	<code>IResource.FILE</code> or <code>IResource.FOLDER</code>
 */
public WizardNewLinkPage(String pageName, int type) {
	super(pageName);
	this.type = type;
	setPageComplete(true);
}
/* (non-Javadoc)
 * Method declared on IDialogPage.
 */
public void createControl(Composite parent) {
	Font font = parent.getFont();
	initializeDialogUnits(parent);
	// top level group
	Composite topLevel = new Composite(parent,SWT.NONE);
	GridLayout layout = new GridLayout();
	layout.numColumns = 3;
	topLevel.setLayout(layout);
	topLevel.setLayoutData(new GridData(
		GridData.VERTICAL_ALIGN_FILL | GridData.HORIZONTAL_ALIGN_FILL));
	topLevel.setFont(font);
	WorkbenchHelp.setHelp(topLevel, IHelpContextIds.NEW_LINK_WIZARD_PAGE);

	final Button createLinkButton = new Button(topLevel, SWT.CHECK);
	if (type == IResource.FILE)
		createLinkButton.setText(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkFileButton")); //$NON-NLS-1$
	else
		createLinkButton.setText(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkFolderButton")); //$NON-NLS-1$
	createLinkButton.setSelection(createLink);
	GridData data = new GridData();
	data.horizontalSpan = 3;
	createLinkButton.setLayoutData(data);
	createLinkButton.setFont(font);
	SelectionListener listener = new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			createLink = createLinkButton.getSelection();
			browseButton.setEnabled(createLink);
			variablesButton.setEnabled(createLink);
			linkTargetField.setEnabled(createLink);
			setPageComplete(validatePage());	
		}
	};
	createLinkButton.addSelectionListener(listener);

	createLinkLocationGroup(topLevel, createLink);
	validatePage();

	setErrorMessage(null);
	setMessage(null);
	setControl(topLevel);
}
/**
 * Creates the link target location widgets.
 *
 * @param locationGroup the parent composite
 * @param enabled sets the initial enabled state of the widgets
 */
private void createLinkLocationGroup(Composite locationGroup, boolean enabled) {
	Font font = locationGroup.getFont();
	Label fill = new Label(locationGroup, SWT.NONE);
	GridData data = new GridData();
	Button button = new Button(locationGroup, SWT.CHECK);
	data.widthHint = button.computeSize(SWT.DEFAULT, SWT.DEFAULT).x;
	button.dispose();
	fill.setLayoutData(data);
		
	// link target location entry field
	linkTargetField = new Text(locationGroup, SWT.BORDER);
	data = new GridData(GridData.FILL_HORIZONTAL);
	linkTargetField.setLayoutData(data);
	linkTargetField.setFont(font);
	linkTargetField.setEnabled(enabled);
	linkTargetField.addModifyListener(new ModifyListener() {
		public void modifyText(ModifyEvent e) {
			setPageComplete(validatePage());
		}
	});
	if (initialLinkTarget != null) {
		linkTargetField.setText(initialLinkTarget);
	}

	// browse button
	browseButton = new Button(locationGroup, SWT.PUSH);
	setButtonLayoutData(browseButton);
	browseButton.setFont(font);
	browseButton.setText(IDEWorkbenchMessages.getString("WizardNewLinkPage.browseButton")); //$NON-NLS-1$
	browseButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent event) {
			handleLinkTargetBrowseButtonPressed();
		}
	});
	browseButton.setEnabled(enabled);

	fill = new Label(locationGroup, SWT.NONE);
	data = new GridData();
	data.horizontalSpan = 2;
	fill.setLayoutData(data);

	// variables button
	variablesButton = new Button(locationGroup, SWT.PUSH);
	setButtonLayoutData(variablesButton);
	variablesButton.setFont(font);
	variablesButton.setText(IDEWorkbenchMessages.getString("WizardNewLinkPage.variablesButton")); //$NON-NLS-1$
	variablesButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent event) {
			handleVariablesButtonPressed();
		}
	});
	variablesButton.setEnabled(enabled);
}
/**
 * Returns the link target location entered by the user. 
 *
 * @return the link target location entered by the user. null if the user
 * 	choose not to create a link.
 */
public String getLinkTarget() {
	if (createLink && linkTargetField != null && linkTargetField.isDisposed() == false) {
		return linkTargetField.getText();
	}
	return null;
}
/**
 * Opens a file or directory browser depending on the link type.
 */
private void handleLinkTargetBrowseButtonPressed() {
	String linkTargetName = linkTargetField.getText();
	File file = null;
	String selection = null;
	
	if ("".equals(linkTargetName) == false) {	//$NON-NLS-1$
		file = new File(linkTargetName);
		if (file.exists() == false) {
			file = null;
		}
	}
	if (type == IResource.FILE) {
		FileDialog dialog = new FileDialog(getShell());
		if (file != null) {
			if (file.isFile()) {
				dialog.setFileName(linkTargetName);
			}
			else {
				dialog.setFilterPath(linkTargetName);
			}
		}
		selection = dialog.open();		
	}
	else {
		DirectoryDialog dialog = new DirectoryDialog(getShell());
		if (file != null) {
			if (file.isFile()) {
				linkTargetName = file.getParent();
			}
			if (linkTargetName != null) {
				dialog.setFilterPath(linkTargetName);
			}
		}
		dialog.setMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.targetSelectionLabel")); //$NON-NLS-1$
		selection = dialog.open();
	}					
	if (selection != null) {
		linkTargetField.setText(selection);
	}
}
/**
 * Opens a path variable selection dialog
 */
private void handleVariablesButtonPressed() {
	PathVariableSelectionDialog dialog = 
		new PathVariableSelectionDialog(getShell(), type);
	
	if (dialog.open() == IDialogConstants.OK_ID) {
		String[] variableNames = (String[]) dialog.getResult();
				
		if (variableNames != null) {
			IPathVariableManager pathVariableManager = ResourcesPlugin.getWorkspace().getPathVariableManager();
			IPath path = pathVariableManager.getValue(variableNames[0]);
		
			if (path != null) {
				linkTargetField.setText(path.toOSString());
			}
		}
	}
}
/**
 * Sets the container to use for link validation.
 * This should be the parent of the new resource that is being 
 * linked.
 *
 * @param container the container to use for link validation.
 */
public void setContainer(IContainer container) {
	this.container = container;
}
/**
 * Sets the value of the link target field
 * 
 * @param target the value of the link target field
 */
public void setLinkTarget(String target) {
	initialLinkTarget = target;
	if (linkTargetField != null && linkTargetField.isDisposed() == false) {
		linkTargetField.setText(target);
	}
}
/**
 * Validates the type of the given file against the link type specified
 * during page creation.
 * 
 * @param linkTargetFile file to validate
 * @return boolean <code>true</code> if the link target type is valid
 * 	and <code>false</code> otherwise.
 */
private boolean validateFileType(File linkTargetFile) {
	boolean valid = true;
	
	if (type == IResource.FILE && linkTargetFile.isFile() == false) {
		setErrorMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkTargetNotFile")); //$NON-NLS-1$
		valid = false;
	}
	else
	if (type == IResource.FOLDER && linkTargetFile.isDirectory() == false) {
		setErrorMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkTargetNotFolder")); //$NON-NLS-1$
		valid = false;
	}
	return valid;
}
/**
 * Validates the name of the link target
 *
 * @param linkTargetName link target name to validate
 * @return boolean <code>true</code> if the link target name is valid
 * 	and <code>false</code> otherwise.
 */
private boolean validateLinkTargetName(String linkTargetName) {
	boolean valid = true;

	if ("".equals(linkTargetName)) {//$NON-NLS-1$
		setErrorMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkTargetEmpty")); //$NON-NLS-1$
		valid = false;
	}
	else {
		IPath path = new Path("");//$NON-NLS-1$
		if (path.isValidPath(linkTargetName) == false) {
			setErrorMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkTargetInvalid")); //$NON-NLS-1$
			valid = false;
		}
	}
	return valid;
}
/**
 * Returns whether this page's controls currently all contain valid 
 * values.
 *
 * @return <code>true</code> if all controls are valid, and
 *   <code>false</code> if at least one is invalid
 */
private boolean validatePage() {
	boolean valid = true;
	IWorkspace workspace = IDEWorkbenchPlugin.getPluginWorkspace();
	
	if (createLink) {
		String linkTargetName = linkTargetField.getText();

		valid = validateLinkTargetName(linkTargetName); 
		if (valid) {
			File linkTargetFile = new Path(linkTargetName).toFile();
			if (linkTargetFile.exists() == false) {
				setErrorMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkTargetNonExistent")); //$NON-NLS-1$
				valid = false;
			}
			else {
				IStatus locationStatus = workspace.validateLinkLocation(
					container,
					new Path(linkTargetName));

				if (locationStatus.isOK() == false) {
					setErrorMessage(IDEWorkbenchMessages.getString("WizardNewLinkPage.linkTargetLocationInvalid")); //$NON-NLS-1$
					valid = false;
				}
				else {
					valid = validateFileType(linkTargetFile);
				}
			}
		}
	}	
	// Avoid draw flicker by clearing error message
	// if all is valid.
	if (valid) {
		setMessage(null);
		setErrorMessage(null);
	}
	return valid;
}
}