/*******************************************************************************
* Copyright (c) 2000, 2007 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.ui.examples.readmetool;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.PropertyPage;
/**
* This page will be added to the property page dialog
* when "Properties..." popup menu item is selected
* for Readme files.
*
* This page demonstrates conditional property pages which look
* different depending on the state of the element. In this example,
* the arbitrary condition chosen is whether the Readme file is
* greater than 256 bytes in length. If it is smaller than 256 bytes
* in length, this will be a placeholder page containing
* a simple message. If it is 256 bytes or larger, additional
* information will be provided. This information is determined at
* runtime.
*
* This class may be reused to implement a conditional property page.
* The getPageIndex() method tests the condition and returns the
* index of the page to create. The createPage*() methods are called
* upon to create the actual pages.
*/
public class ReadmeFilePropertyPage2 extends PropertyPage {
/**
* Utility method that creates a new composite and
* sets up its layout data.
*
* @param parent the parent of the composite
* @param numColumns the number of columns in the new composite
* @return the newly-created composite
*/
protected Composite createComposite(Composite parent, int numColumns) {
Composite composite = new Composite(parent, SWT.NULL);
GridLayout layout = new GridLayout();
layout.numColumns = numColumns;
composite.setLayout(layout);
GridData data = new GridData();
data.verticalAlignment = GridData.FILL;
data.horizontalAlignment = GridData.FILL;
composite.setLayoutData(data);
return composite;
}
@Override
public Control createContents(Composite parent) {
// ensure the page has no special buttons
noDefaultAndApplyButton();
Composite panel = createComposite(parent, 2);
PlatformUI.getWorkbench().getHelpSystem().setHelp(getControl(),
IReadmeConstants.PROPERTY_PAGE2_CONTEXT);
// layout the page
int page = getPageIndex();
switch (page) {
case 1:
createPageOne(panel);
break;
case 2:
createPageTwo(panel);
break;
default:
}
return new Canvas(panel, 0);
}
/**
* Utility method that creates a new label and sets up
* its layout data.
*
* @param parent the parent of the label
* @param text the text of the label
* @return the newly-created label
*/
protected Label createLabel(Composite parent, String text) {
Label label = new Label(parent, SWT.LEFT);
label.setText(text);
GridData data = new GridData();
data.horizontalAlignment = GridData.FILL;
label.setLayoutData(data);
return label;
}
/**
* Creates the first version of the page. This is a placeholder page which
* notified the user that the page is not available.
*
* @param panel the panel in which to create the page
*/
protected void createPageOne(Composite panel) {
Label l = createLabel(panel, MessageUtil
.getString("Additional_Readme_properties_not_available.")); //$NON-NLS-1$
GridData gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
l = createLabel(
panel,
MessageUtil
.getString("This_illustrates_a_property_page_that_is_dynamically_determined")); //$NON-NLS-1$
gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
l = createLabel(
panel,
MessageUtil
.getString("not_to_be_available_based_on_the_state_of_the_object.")); //$NON-NLS-1$
gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
}
/**
* Creates the second version of the page. This page might contain more information
* about the file or other information.
*
* @param panel the panel in which to create the page
*/
protected void createPageTwo(Composite panel) {
Label l = createLabel(
panel,
MessageUtil
.getString("The_size_of_the_Readme_file_is_at_least_256_bytes.")); //$NON-NLS-1$
GridData gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
l = createLabel(
panel,
MessageUtil
.getString("Had_it_been_less_than_256_bytes_this_page_would_be_a_placeholder_page.")); //$NON-NLS-1$
gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
l = createLabel(panel, MessageUtil.getString("Additional_information")); //$NON-NLS-1$
gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
l = createLabel(
panel,
MessageUtil
.getString("This_illustrates_a_property_page_that_is_dynamically_determined")); //$NON-NLS-1$
gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
l = createLabel(panel, MessageUtil
.getString("to_be_available_based_on_the_state_of_the_object.")); //$NON-NLS-1$
gd = (GridData) l.getLayoutData();
gd.horizontalSpan = 2;
gd.grabExcessHorizontalSpace = true;
}
/**
* Returns which page to display. This implementation
* answers 1 if the size of the Readme file is less than 256 bytes
* and 2 otherwise.
*
* @return the index of the page to display
*/
protected int getPageIndex() {
IResource resource = (IResource) getElement();
if (resource.getType() == IResource.FILE) {
InputStream contentStream = null;
int length = 0;
try {
IFile file = (IFile) resource;
contentStream = file.getContents();
Reader in = new InputStreamReader(contentStream);
int chunkSize = contentStream.available();
StringBuffer buffer = new StringBuffer(chunkSize);
char[] readBuffer = new char[chunkSize];
int n = in.read(readBuffer);
while (n > 0) {
buffer.append(readBuffer);
n = in.read(readBuffer);
}
contentStream.close();
length = buffer.length();
} catch (CoreException e) {
length = 0;
} catch (IOException e) {
// do nothing
} finally {
if (contentStream != null) {
try {
contentStream.close();
} catch (IOException e) {
// do nothing
}
}
}
if (length < 256)
return 1;
return 2;
}
return 0;
}
/** (non-Javadoc)
* Method declared on PreferencePage
*/
@Override
public boolean performOk() {
// nothing to do - read-only page
return true;
}
}