Java tutorial
/* * Copyright (c) 2015 Data Harmonisation Panel * * All rights reserved. This program and the accompanying materials are made * available under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation, either version 3 of the License, * or (at your option) any later version. * * You should have received a copy of the GNU Lesser General Public License * along with this distribution. If not, see <http://www.gnu.org/licenses/>. * * Contributors: * HUMBOLDT EU Integrated Project #030962 * Data Harmonisation Panel <http://www.dhpanel.eu> */ package eu.esdihumboldt.hale.io.wfs.ui.capabilities; import java.io.InputStream; import java.net.URI; import java.net.URL; import java.util.List; import java.util.Timer; import java.util.TimerTask; import javax.annotation.Nullable; import org.apache.http.NameValuePair; import org.apache.http.client.utils.URIBuilder; import org.eclipse.jface.dialogs.DialogPage; import org.eclipse.jface.preference.FieldEditor; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.BusyIndicator; import org.eclipse.swt.events.ModifyEvent; import org.eclipse.swt.events.ModifyListener; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.widgets.Combo; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Display; import eu.esdihumboldt.hale.io.wfs.WFSVersion; import eu.esdihumboldt.hale.io.wfs.capabilities.CapabilitiesHelper; import eu.esdihumboldt.hale.io.wfs.capabilities.WFSCapabilities; import eu.esdihumboldt.hale.io.wfs.ui.WFSPreferences; /** * WFS location field editor * * @author Simon Templer */ public class WFSCapabilitiesFieldEditor extends FieldEditor { /** * Delay for validating on modification in milliseconds */ private static final int MODIFY_VALIDATE_DELAY = 1200; private Combo combo; private boolean valid; private Timer timer; private WFSCapabilities capabilities; private URL usedUrl; /** * @see FieldEditor#FieldEditor(String, String, Composite) */ public WFSCapabilitiesFieldEditor(String name, String labelText, Composite parent) { super(name, labelText, parent); } /** * @see FieldEditor#adjustForNumColumns(int) */ @Override protected void adjustForNumColumns(int numColumns) { GridData gd = (GridData) combo.getLayoutData(); gd.horizontalSpan = numColumns - 1; // We only grab excess space if we have to // If another field editor has more columns then // we assume it is setting the width. gd.grabExcessHorizontalSpace = gd.horizontalSpan == 1; } /** * @see FieldEditor#doFillIntoGrid(Composite, int) */ @Override protected void doFillIntoGrid(Composite parent, int numColumns) { getLabelControl(parent); combo = new Combo(parent, SWT.BORDER | SWT.DROP_DOWN); GridData layoutData = new GridData(SWT.FILL, SWT.CENTER, true, false, numColumns - 1, 1); combo.setLayoutData(layoutData); loadRecent(); refreshValidState(); combo.addModifyListener(new ModifyListener() { @Override public void modifyText(ModifyEvent e) { scheduleValidation(); // refreshValidState(); } }); } /** * Schedule the validation */ protected void scheduleValidation() { final Display display = Display.getCurrent(); synchronized (this) { if (timer != null) { timer.cancel(); } // invalidate invalidate(); // schedule validation timer = new Timer(); timer.schedule(new TimerTask() { @Override public void run() { display.syncExec(new Runnable() { @Override public void run() { BusyIndicator.showWhile(display, new Runnable() { @Override public void run() { refreshValidState(); } }); } }); } }, MODIFY_VALIDATE_DELAY); } } /** * Load the recently used WFSes */ protected void loadRecent() { List<String> recent = WFSPreferences.getRecent(); combo.setItems(recent.toArray(new String[recent.size()])); if (!recent.isEmpty() && (combo.getText() == null || combo.getText().isEmpty())) { combo.setText(recent.get(0)); } } /** * Update the recently used WFSes */ public void updateRecent() { String value = combo.getText(); if (value != null && !value.isEmpty()) { List<String> recent = WFSPreferences.getRecent(); recent.remove(value); recent.add(0, value); WFSPreferences.setRecent(recent); } } /** * @see FieldEditor#doLoad() */ @Override protected void doLoad() { String value = getPreferenceStore().getString(getPreferenceName()); combo.setText((value == null) ? ("") : (value)); //$NON-NLS-1$ } /** * @see FieldEditor#doLoadDefault() */ @Override protected void doLoadDefault() { String value = getPreferenceStore().getDefaultString(getPreferenceName()); combo.setText((value == null) ? ("") : (value)); //$NON-NLS-1$ } /** * @see FieldEditor#doStore() */ @Override protected void doStore() { getPreferenceStore().setValue(getPreferenceName(), combo.getText()); } /** * @see FieldEditor#getNumberOfControls() */ @Override public int getNumberOfControls() { return 2; } /** * Get the value * * @return the value */ public String getValue() { return combo.getText(); } /** * @return the capabilities */ public WFSCapabilities getCapabilities() { return capabilities; } /** * Set the value * * @param value the value to set */ public void setValue(String value) { combo.setText((value == null) ? ("") : (value)); //$NON-NLS-1$ refreshValidState(); } /** * @see FieldEditor#isValid() */ @Override public boolean isValid() { return valid; } /** * @see FieldEditor#refreshValidState() */ @Override protected void refreshValidState() { boolean newValid = getValidState(); if (valid != newValid) { valid = newValid; fireStateChanged(IS_VALID, !valid, valid); } } /** * Revalidate the capabilities. */ public void revalidate() { invalidate(); refreshValidState(); } /** * Invalidate the editor */ protected void invalidate() { if (valid) { capabilities = null; valid = false; fireStateChanged(IS_VALID, !valid, valid); } } private boolean getValidState() { String value = getValue(); DialogPage page = getPage(); // try to create a URL try { new URI(value); } catch (Exception e) { if (page != null) { page.setErrorMessage(e.getLocalizedMessage()); } return false; } // try to get capabilities try { URIBuilder builder = new URIBuilder(value); // add fixed parameters boolean requestPresent = false; boolean servicePresent = false; String versionParam = null; for (NameValuePair param : builder.getQueryParams()) { String name = param.getName().toLowerCase(); if (name.equals("request")) requestPresent = true; if (name.equals("service")) servicePresent = true; if (name.equals("version")) versionParam = param.getName(); } if (!requestPresent) { builder.addParameter("REQUEST", "GetCapabilities"); } if (!servicePresent) { builder.addParameter("SERVICE", "WFS"); } WFSVersion version = getWFSVersion(); if (version != null) { if (versionParam == null) { versionParam = "VERSION"; } builder.setParameter(versionParam, version.toString()); } usedUrl = builder.build().toURL(); try (InputStream in = usedUrl.openStream()) { capabilities = CapabilitiesHelper.loadCapabilities(in); } } catch (Exception e) { if (page != null) { page.setErrorMessage(e.getLocalizedMessage()); } return false; } // passed all tests if (page != null) { page.setErrorMessage(null); } return true; } /** * @return the WFS version to use, <code>null</code> to use the server * default or the version provided in the base URI */ @Nullable protected WFSVersion getWFSVersion() { return null; } /** * @return the URL used for retrieving the capabilities */ @Nullable public URL getUsedUrl() { return usedUrl; } }