core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/ui/preferences/FoldingConfigurationBlock.java

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 *******************************************************************************/
package org.eclipse.dltk.ui.preferences;

import java.util.ArrayList;

import org.eclipse.core.runtime.Assert;
import org.eclipse.dltk.internal.ui.text.folding.FoldingMessages;
import org.eclipse.dltk.ui.PreferenceConstants;
import org.eclipse.dltk.ui.text.folding.IFoldingPreferenceBlock;
import org.eclipse.dltk.ui.util.PixelConverter;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.preference.PreferencePage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StackLayout;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.FillLayout;
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.Label;

/**
 * Configures Script Editor folding preferences.
 */
public abstract class FoldingConfigurationBlock
		implements IPreferenceConfigurationBlock {

	private static class ErrorPreferences implements IFoldingPreferenceBlock {
		private String fMessage;

		protected ErrorPreferences(String message) {
			fMessage = message;
		}

		@Override
		public Control createControl(Composite composite) {
			Composite inner = new Composite(composite, SWT.NONE);
			inner.setLayout(new FillLayout(SWT.VERTICAL));

			Label label = new Label(inner, SWT.CENTER);
			label.setText(fMessage);

			return inner;
		}

		@Override
		public void initialize() {
		}

		@Override
		public void performOk() {
		}

		@Override
		public void performDefaults() {
		}

		@Override
		public void dispose() {
		}

	}

	/** The overlay preference store. */
	protected final OverlayPreferenceStore fStore;

	/* The controls */
	private Button fFoldingCheckbox;
	private Button fCommentsFoldingCheckbox;
	private Composite fGroup;
	private StackLayout fStackLayout;
	PreferencePage fMainPage;

	/* the model */
	private Control fProviderControl;

	private IFoldingPreferenceBlock fPreferenceBlock;

	public FoldingConfigurationBlock(OverlayPreferenceStore store,
			PreferencePage prefPage) {
		Assert.isNotNull(store);
		fMainPage = prefPage;
		fStore = store;
		fStore.addKeys(createOverlayStoreKeys());
		fPreferenceBlock = createFoldingPreferenceBlock();
		fProviderControl = null;
	}

	protected PreferencePage getPreferencePage() {
		return fMainPage;
	}

	protected abstract IFoldingPreferenceBlock createFoldingPreferenceBlock();

	private OverlayPreferenceStore.OverlayKey[] createOverlayStoreKeys() {

		ArrayList<OverlayPreferenceStore.OverlayKey> overlayKeys = new ArrayList<>();

		overlayKeys.add(new OverlayPreferenceStore.OverlayKey(
				OverlayPreferenceStore.BOOLEAN,
				PreferenceConstants.EDITOR_FOLDING_ENABLED));
		overlayKeys.add(new OverlayPreferenceStore.OverlayKey(
				OverlayPreferenceStore.BOOLEAN,
				PreferenceConstants.EDITOR_COMMENTS_FOLDING_ENABLED));

		OverlayPreferenceStore.OverlayKey[] keys = new OverlayPreferenceStore.OverlayKey[overlayKeys
				.size()];
		overlayKeys.toArray(keys);
		return keys;
	}

	/**
	 * Creates page for folding preferences.
	 *
	 * @param parent
	 *            the parent composite
	 * @return the control for the preference page
	 */
	@Override
	public Control createControl(Composite parent) {

		Composite composite = new Composite(parent, SWT.NULL);
		// assume parent page uses griddata
		GridData gd = new GridData(GridData.HORIZONTAL_ALIGN_BEGINNING);
		composite.setLayoutData(gd);
		GridLayout layout = new GridLayout();
		layout.numColumns = 1;
		PixelConverter pc = new PixelConverter(composite);
		layout.verticalSpacing = pc.convertHeightInCharsToPixels(1) / 2;
		composite.setLayout(layout);

		/* check box for new editors */
		fFoldingCheckbox = new Button(composite, SWT.CHECK);
		fFoldingCheckbox
				.setText(PreferencesMessages.FoldingConfigurationBlock_enable);
		gd = new GridData(GridData.HORIZONTAL_ALIGN_BEGINNING);
		fFoldingCheckbox.setLayoutData(gd);
		fFoldingCheckbox.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				boolean enabled = fFoldingCheckbox.getSelection();
				fStore.setValue(PreferenceConstants.EDITOR_FOLDING_ENABLED,
						enabled);
				updateCheckboxDependencies();
			}
		});

		createCommentsFoldingCheckbox(composite);

		// Label label = new Label(composite, SWT.CENTER);
		// gd = new GridData(GridData.FILL_HORIZONTAL
		// | GridData.VERTICAL_ALIGN_BEGINNING);
		// label.setLayoutData(gd);

		Composite groupComp = new Composite(composite, SWT.NONE);
		gd = new GridData(GridData.FILL_BOTH);
		gd.horizontalSpan = 1;
		groupComp.setLayoutData(gd);
		GridLayout gridLayout = new GridLayout(1, false);
		gridLayout.marginWidth = 0;
		groupComp.setLayout(gridLayout);

		Label label = new Label(groupComp, SWT.LEFT);
		label.setText(FoldingMessages.DefaultFoldingPreferenceBlock_title);

		/* contributed provider preferences. */
		fGroup = new Composite(groupComp, SWT.NONE);
		gd = new GridData(GridData.HORIZONTAL_ALIGN_BEGINNING
				| GridData.VERTICAL_ALIGN_BEGINNING | GridData.FILL_HORIZONTAL);
		fGroup.setLayoutData(gd);
		fStackLayout = new StackLayout();
		fGroup.setLayout(fStackLayout);

		return composite;
	}

	protected void createCommentsFoldingCheckbox(Composite composite) {
		fCommentsFoldingCheckbox = new Button(composite, SWT.CHECK);
		fCommentsFoldingCheckbox.setText(
				PreferencesMessages.FoldingConfigurationBlock_commentsEnable);
		GridData gd = new GridData(GridData.HORIZONTAL_ALIGN_BEGINNING);
		fCommentsFoldingCheckbox.setLayoutData(gd);
		fCommentsFoldingCheckbox.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				boolean enabled = fCommentsFoldingCheckbox.getSelection();
				fStore.setValue(
						PreferenceConstants.EDITOR_COMMENTS_FOLDING_ENABLED,
						enabled);
				updateCheckboxDependencies();
			}
		});
	}

	private void updateCheckboxDependencies() {
		if (fCommentsFoldingCheckbox != null) {
			fCommentsFoldingCheckbox
					.setEnabled(fFoldingCheckbox.getSelection());
		}
	}

	IFoldingPreferenceBlock getPreferenceBlock() {
		return fPreferenceBlock;
	}

	void updateListDependencies() {
		IFoldingPreferenceBlock prefs;

		prefs = getPreferenceBlock();
		if (prefs == null) {
			prefs = new ErrorPreferences(
					PreferencesMessages.FoldingConfigurationBlock_noFoldingPreferenceBlock);
		}

		Control control = fProviderControl;
		if (control == null) {
			control = prefs.createControl(fGroup);
			if (control == null) {
				String message = PreferencesMessages.FoldingConfigurationBlock_info_no_preferences;
				control = new ErrorPreferences(message).createControl(fGroup);
			} else {
				fProviderControl = control;
			}
		}
		Dialog.applyDialogFont(control);
		fStackLayout.topControl = control;
		control.pack();
		fGroup.layout();
		fGroup.getParent().layout();

		prefs.initialize();
	}

	@Override
	public void initialize() {
		restoreFromPreferences();
	}

	@Override
	public void performOk() {
		IFoldingPreferenceBlock prefs = getPreferenceBlock();
		prefs.performOk();
	}

	@Override
	public void performDefaults() {
		restoreFromPreferences();
		IFoldingPreferenceBlock prefs = getPreferenceBlock();
		prefs.performDefaults();
	}

	@Override
	public void dispose() {
		IFoldingPreferenceBlock prefs = getPreferenceBlock();
		prefs.dispose();
	}

	private void restoreFromPreferences() {
		boolean enabled = fStore
				.getBoolean(PreferenceConstants.EDITOR_FOLDING_ENABLED);
		fFoldingCheckbox.setSelection(enabled);
		boolean commentsEnabled = fStore.getBoolean(
				PreferenceConstants.EDITOR_COMMENTS_FOLDING_ENABLED);
		if (fCommentsFoldingCheckbox != null) {
			fCommentsFoldingCheckbox.setSelection(commentsEnabled);
		}
		updateCheckboxDependencies();
		updateListDependencies();
	}
}