core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/preferences/PropertyAndPreferencePage.java

package org.eclipse.dltk.internal.ui.preferences;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.IScriptProject;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.internal.ui.dialogs.StatusUtil;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.IDialogFieldListener;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.LayoutUtil;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.SelectionButtonDialogField;
import org.eclipse.dltk.ui.dialogs.ProjectSelectionDialog;
import org.eclipse.dltk.ui.dialogs.StatusInfo;
import org.eclipse.dltk.ui.preferences.PreferencesMessages;
import org.eclipse.dltk.ui.util.IStatusChangeListener;
import org.eclipse.jface.dialogs.ControlEnableState;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.preference.PreferencePage;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Link;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPreferencePage;
import org.eclipse.ui.IWorkbenchPropertyPage;
import org.eclipse.ui.dialogs.PreferencesUtil;

/**
 * Direct port from the jdt ui, this class should not be extended by anyone but
 * the internal dltk ui.
 * 
 * @see org.eclipse.dltk.ui.preferences.AbstractConfigurationBlockPropertyAndPreferencePage
 */
public abstract class PropertyAndPreferencePage extends PreferencePage
		implements IWorkbenchPreferencePage, IWorkbenchPropertyPage {

	/*
	 * NOTE: this class was more or less a direct cut and paste from the jdt ui
	 * with some minor modifications to make it work for the dltk.
	 * 
	 * why something like this doesn't exist in the 'eclipse core' i am not
	 * sure, perhaps this one of the areas where it would make sense to join
	 * forces with the imp folks.
	 */

	private Control fConfigurationBlockControl;
	private ControlEnableState fBlockEnableState;
	private Link fChangeWorkspaceSettings;
	private SelectionButtonDialogField fUseProjectSettings;
	private IStatus fBlockStatus;
	private Composite fParentComposite;

	private IProject fProject; // project or null
	private Map fData; // page data

	public static final String DATA_NO_LINK = "PropertyAndPreferencePage.nolink"; //$NON-NLS-1$

	public PropertyAndPreferencePage() {
		fBlockStatus = new StatusInfo();
		fBlockEnableState = null;
		fProject = null;
		fData = null;
	}

	protected abstract Control createPreferenceContent(Composite composite);

	protected abstract boolean hasProjectSpecificOptions(IProject project);

	protected abstract String getPreferencePageId();

	protected abstract String getPropertyPageId();

	protected boolean supportsProjectSpecificOptions() {
		return getPropertyPageId() != null;
	}

	protected String getNatureId() {
		return null;
	}

	protected boolean offerLink() {
		return fData == null || !Boolean.TRUE.equals(fData.get(DATA_NO_LINK));
	}

	@Override
	protected Label createDescriptionLabel(Composite parent) {
		fParentComposite = parent;
		if (isProjectPreferencePage()) {
			Composite composite = new Composite(parent, SWT.NONE);
			composite.setFont(parent.getFont());
			GridLayout layout = new GridLayout();
			layout.marginHeight = 0;
			layout.marginWidth = 0;
			layout.numColumns = 2;
			composite.setLayout(layout);
			composite.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true,
					false));

			IDialogFieldListener listener = field -> enableProjectSpecificSettings(((SelectionButtonDialogField) field)
					.isSelected());

			fUseProjectSettings = new SelectionButtonDialogField(SWT.CHECK);
			fUseProjectSettings.setDialogFieldListener(listener);
			fUseProjectSettings
					.setLabelText(PreferencesMessages.PropertyAndPreferencePage_useprojectsettings_label);
			fUseProjectSettings.doFillIntoGrid(composite, 1);
			LayoutUtil.setHorizontalGrabbing(fUseProjectSettings
					.getSelectionButton(null));

			if (offerLink()) {
				fChangeWorkspaceSettings = createLink(
						composite,
						PreferencesMessages.PropertyAndPreferencePage_useworkspacesettings_change);
				fChangeWorkspaceSettings.setLayoutData(new GridData(SWT.END,
						SWT.CENTER, false, false));
			} else {
				LayoutUtil.setHorizontalSpan(fUseProjectSettings
						.getSelectionButton(null), 2);
			}

			Label horizontalLine = new Label(composite, SWT.SEPARATOR
					| SWT.HORIZONTAL);
			horizontalLine.setLayoutData(new GridData(GridData.FILL,
					GridData.FILL, true, false, 2, 1));
			horizontalLine.setFont(composite.getFont());
		} else if (supportsProjectSpecificOptions() && offerLink()) {
			fChangeWorkspaceSettings = createLink(
					parent,
					PreferencesMessages.PropertyAndPreferencePage_showprojectspecificsettings_label);
			fChangeWorkspaceSettings.setLayoutData(new GridData(SWT.END,
					SWT.CENTER, true, false));
		}

		return super.createDescriptionLabel(parent);
	}

	@Override
	protected Control createContents(Composite parent) {
		Composite composite = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.marginHeight = 0;
		layout.marginWidth = 0;
		composite.setLayout(layout);
		composite.setFont(parent.getFont());

		GridData data = new GridData(GridData.FILL, GridData.FILL, true, true);

		fConfigurationBlockControl = createPreferenceContent(composite);
		fConfigurationBlockControl.setLayoutData(data);

		if (isProjectPreferencePage()) {
			boolean useProjectSettings = hasProjectSpecificOptions(getProject());
			enableProjectSpecificSettings(useProjectSettings);
		}

		Dialog.applyDialogFont(composite);
		return composite;
	}

	private Link createLink(Composite composite, String text) {
		Link link = new Link(composite, SWT.NONE);
		link.setFont(composite.getFont());
		link.setText("<A>" + text + "</A>"); //$NON-NLS-1$//$NON-NLS-2$
		link.addSelectionListener(new SelectionListener() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				doLinkActivated((Link) e.widget);
			}

			@Override
			public void widgetDefaultSelected(SelectionEvent e) {
				doLinkActivated((Link) e.widget);
			}
		});
		return link;
	}

	protected boolean useProjectSettings() {
		return isProjectPreferencePage() && fUseProjectSettings != null
				&& fUseProjectSettings.isSelected();
	}

	protected boolean isProjectPreferencePage() {
		return fProject != null;
	}

	protected IProject getProject() {
		return fProject;
	}

	final void doLinkActivated(Link link) {
		Map data = new HashMap();
		data.put(DATA_NO_LINK, Boolean.TRUE);

		if (isProjectPreferencePage()) {
			openWorkspacePreferences(data);
		} else {
			HashSet projectsWithSpecifics = new HashSet();
			try {
				IScriptProject[] projects = DLTKCore.create(
						ResourcesPlugin.getWorkspace().getRoot())
						.getScriptProjects();
				for (int i = 0; i < projects.length; i++) {
					IScriptProject curr = projects[i];
					if (hasProjectSpecificOptions(curr.getProject())) {
						projectsWithSpecifics.add(curr);
					}
				}
			} catch (ModelException e) {
				// ignore
			}
			ProjectSelectionDialog dialog = new ProjectSelectionDialog(
					getShell(), projectsWithSpecifics, getNatureId());
			if (dialog.open() == Window.OK) {
				IScriptProject res = (IScriptProject) dialog.getFirstResult();
				openProjectProperties(res.getProject(), data);
			}
		}
	}

	protected final void openWorkspacePreferences(Object data) {
		String id = getPreferencePageId();
		PreferencesUtil.createPreferenceDialogOn(getShell(), id,
				new String[] { id }, data).open();
	}

	protected final void openProjectProperties(IProject project, Object data) {
		String id = getPropertyPageId();
		if (id != null) {
			PreferencesUtil.createPropertyDialogOn(getShell(), project, id,
					new String[] { id }, data).open();
		}
	}

	protected void enableProjectSpecificSettings(
			boolean useProjectSpecificSettings) {
		fUseProjectSettings.setSelection(useProjectSpecificSettings);
		enablePreferenceContent(useProjectSpecificSettings);
		updateLinkVisibility();
		doStatusChanged();
	}

	private void updateLinkVisibility() {
		if (fChangeWorkspaceSettings == null
				|| fChangeWorkspaceSettings.isDisposed()) {
			return;
		}

		if (isProjectPreferencePage()) {
			fChangeWorkspaceSettings.setEnabled(!useProjectSettings());
		}
	}

	protected void setPreferenceContentStatus(IStatus status) {
		fBlockStatus = status;
		doStatusChanged();
	}

	/**
	 * Returns a new status change listener that calls
	 * {@link #setPreferenceContentStatus(IStatus)} when the status has changed
	 * 
	 * @return The new listener
	 */
	protected IStatusChangeListener getNewStatusChangedListener() {
		return status -> setPreferenceContentStatus(status);
	}

	protected IStatus getPreferenceContentStatus() {
		return fBlockStatus;
	}

	protected void doStatusChanged() {
		if (!isProjectPreferencePage() || useProjectSettings()) {
			updateStatus(fBlockStatus);
		} else {
			updateStatus(new StatusInfo());
		}
	}

	protected void enablePreferenceContent(boolean enable) {
		if (enable) {
			if (fBlockEnableState != null) {
				fBlockEnableState.restore();
				fBlockEnableState = null;
			}
		} else {
			if (fBlockEnableState == null) {
				fBlockEnableState = ControlEnableState
						.disable(fConfigurationBlockControl);
			}
		}
	}

	@Override
	protected void performDefaults() {
		if (useProjectSettings()) {
			enableProjectSpecificSettings(false);
		}
		super.performDefaults();
	}

	private void updateStatus(IStatus status) {
		setValid(!status.matches(IStatus.ERROR));
		StatusUtil.applyToStatusLine(this, status);
	}

	@Override
	public void init(IWorkbench workbench) {
	}

	@Override
	public IAdaptable getElement() {
		return fProject;
	}

	@Override
	public void setElement(IAdaptable element) {
		fProject = (IProject) element.getAdapter(IResource.class);
	}

	@Override
	public void applyData(Object data) {
		if (data instanceof Map) {
			fData = (Map) data;
		}
		if (fChangeWorkspaceSettings != null) {
			if (!offerLink()) {
				fChangeWorkspaceSettings.dispose();
				fParentComposite.layout(true, true);
			}
		}
	}

	protected Map getData() {
		return fData;
	}

}