/gwt/plugins/in.cypal.studio.gwt.ui/src/in/cypal/studio/gwt/ui/preferences/GwtVersionsPreferencePage.java

package in.cypal.studio.gwt.ui.preferences;



import in.cypal.studio.gwt.core.common.Constants;

import in.cypal.studio.gwt.core.common.GwtRuntime;

import in.cypal.studio.gwt.ui.Activator;

import in.cypal.studio.gwt.ui.common.GwtLabelProvider;

import in.cypal.studio.gwt.ui.common.Util;



import java.io.File;

import java.lang.reflect.Field;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLClassLoader;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;



import org.eclipse.jface.dialogs.MessageDialog;

import org.eclipse.jface.preference.PreferencePage;

import org.eclipse.jface.viewers.ArrayContentProvider;

import org.eclipse.jface.viewers.CheckStateChangedEvent;

import org.eclipse.jface.viewers.CheckboxTableViewer;

import org.eclipse.jface.viewers.ICheckStateListener;

import org.eclipse.jface.viewers.ISelectionChangedListener;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.jface.viewers.SelectionChangedEvent;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.SelectionAdapter;

import org.eclipse.swt.events.SelectionEvent;

import org.eclipse.swt.layout.GridData;

import org.eclipse.swt.layout.GridLayout;

import org.eclipse.swt.widgets.Button;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Control;

import org.eclipse.swt.widgets.DirectoryDialog;

import org.eclipse.swt.widgets.Label;

import org.eclipse.ui.IWorkbench;

import org.eclipse.ui.IWorkbenchPreferencePage;



public class GwtVersionsPreferencePage extends PreferencePage implements IWorkbenchPreferencePage {



	private CheckboxTableViewer tableViewer;

	private Button addButton;

	private Button deleteButton;

	private IWorkbench workbench;

	List<GwtRuntime> runtimes;



	public GwtVersionsPreferencePage() {

		setPreferenceStore(Util.getPreferenceStore());

		setDescription("Add or Remove available GWT versions. The checked version is set as the default one.");

		runtimes = new ArrayList<GwtRuntime>();

		runtimes.addAll(Arrays.asList(Util.getRuntimes()));

	}



	public void init(IWorkbench workbench) {

		this.workbench = workbench;

	}



	@Override

	protected Control createContents(Composite parent) {

		Composite composite = new Composite(parent, SWT.NONE);

		composite.setLayout(new GridLayout(2, false));



		Label label = new Label(composite, SWT.NONE);

		label.setText("GWT Runtimes:");

		label.setLayoutData(new GridData(SWT.FILL, SWT.NONE, true, false, 2, 1));



		tableViewer = CheckboxTableViewer.newCheckList(composite, SWT.BORDER | SWT.SINGLE);

		tableViewer.setContentProvider(new ArrayContentProvider());

		tableViewer.setLabelProvider(new GwtLabelProvider());

		tableViewer.setInput(runtimes);

		GridData layoutData = new GridData(SWT.FILL, SWT.NONE, true, false, 1, 4);

		layoutData.heightHint = 100;

		tableViewer.getTable().setLayoutData(layoutData);



		addButton = new Button(composite, SWT.PUSH);

		addButton.setText("Add...");

		addButton.setLayoutData(new GridData(SWT.FILL, SWT.NONE, false, false));



		deleteButton = new Button(composite, SWT.PUSH);

		deleteButton.setText("Delete");

		deleteButton.setLayoutData(new GridData(SWT.FILL, SWT.NONE, false, false));

		deleteButton.setEnabled(false);



		addListeners();

		updateTable(null);



		return composite;

	}



	private void addListeners() {

		tableViewer.addSelectionChangedListener(new ISelectionChangedListener() {



			public void selectionChanged(SelectionChangedEvent event) {

				boolean isEmptySelection = event.getSelection().isEmpty();

				deleteButton.setEnabled(!isEmptySelection);

			}

		});



		tableViewer.addCheckStateListener(new ICheckStateListener() {

			public void checkStateChanged(CheckStateChangedEvent event) {

				if (event.getChecked()) {

					GwtRuntime defaultRuntime = (GwtRuntime) event.getElement();

					defaultRuntime.setWorkspaceDefault(true);

					updateTable(defaultRuntime);

				}



			}

		});



		addButton.addSelectionListener(new SelectionAdapter() {

			@Override

			public void widgetSelected(SelectionEvent e) {

				doAdd();

			}

		});



		deleteButton.addSelectionListener(new SelectionAdapter() {

			@Override

			public void widgetSelected(SelectionEvent e) {

				IStructuredSelection selection = (IStructuredSelection) tableViewer.getSelection();

				runtimes.remove(selection.getFirstElement());

				updateTable(null);

			}

		});

	}



	protected void doAdd() {

		DirectoryDialog dialog = new DirectoryDialog(getShell());

		dialog.setMessage("Browse for the GWT installation:");

		String location = dialog.open();

		if (location != null) {

			File file = new File(location + File.separatorChar + Util.getGwtDevLibJarName());

			if (!file.exists()) {

				MessageDialog.openError(getShell(), "Invalid directory", "The directory doesn't contain '" + Util.getGwtDevLibJarName() + "' file.");

			} else {

				try {

					URLClassLoader classLoader = new URLClassLoader(new URL[] { file.toURI().toURL() }, this.getClass().getClassLoader());

					@SuppressWarnings("unchecked")

					Class aboutClass = classLoader.loadClass(Constants.GWT_ABOUT_CLASS);

					Field versionField = aboutClass.getDeclaredField("GWT_VERSION");

					String version = (String) versionField.get(aboutClass);

					GwtRuntime gwtRuntime = new GwtRuntime();

					gwtRuntime.setName(version);

					gwtRuntime.setLocation(location);

					runtimes.add(gwtRuntime);

					updateTable(null);

				} catch (MalformedURLException e) {

					Activator.logException(e);

					MessageDialog.openError(getShell(), "Error Occured", "Could not determine the GWT version.");

				} catch (Exception e) {

					Activator.logException(e);

					MessageDialog.openError(getShell(), "Error Occured", "The '" + Util.getGwtDevLibJarName() + "' file seems to be corrupted");

				}

			}

		}

	}



	private void updateTable(GwtRuntime defaultRuntime) {

		

		if (defaultRuntime == null) {



			// first search in the list of runtimes

			for (GwtRuntime gwtRuntime : runtimes) {

				if (gwtRuntime.isWorkspaceDefault()) {

					defaultRuntime = gwtRuntime;

					break;

				}

			}



			// if nothing set, then set the first one

			if (defaultRuntime == null && runtimes.size() > 0) {

				defaultRuntime = runtimes.get(0);

				defaultRuntime.setWorkspaceDefault(true);

			}



		}



		tableViewer.refresh();



		if (defaultRuntime != null) {

			// unset others

			for (GwtRuntime gwtRuntime : runtimes) {

				if (gwtRuntime != defaultRuntime)

					gwtRuntime.setWorkspaceDefault(false);

			}

			tableViewer.setCheckedElements(new Object[] { defaultRuntime });

		}



	}



	@Override

	public boolean performOk() {

		Util.setRuntimes(runtimes.toArray(new GwtRuntime[runtimes.size()]));

		return true;

	}



	@Override

	protected void performDefaults() {

		super.performDefaults();

	}



}