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

package org.eclipse.dltk.ui.preferences;

import java.util.Collection;
import java.util.List;

import org.eclipse.core.resources.IProject;
import org.eclipse.dltk.compiler.task.ITodoTaskPreferences;
import org.eclipse.dltk.compiler.task.TaskTagUtils;
import org.eclipse.dltk.compiler.task.TodoTask;
import org.eclipse.dltk.compiler.util.Util;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.DialogField;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.IDialogFieldListener;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.IListAdapter;
import org.eclipse.dltk.internal.ui.wizards.dialogfields.ListDialogField;
import org.eclipse.dltk.ui.util.IStatusChangeListener;
import org.eclipse.dltk.ui.util.PixelConverter;
import org.eclipse.dltk.ui.util.SWTFactory;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
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.ui.preferences.IWorkbenchPreferenceContainer;

/**
 * Abstract options block that can be used by an
 * {@link AbstractConfigurationBlockPropertyAndPreferencePage} implementation to
 * create a preferences/property page for task tags.
 *
 * <p>
 * It is recommended to instantiate {@link TodoTaskOptionsBlock} instead.
 * </p>
 */
public abstract class AbstractTodoTaskOptionsBlock
		extends AbstractOptionsBlock {

	private static class TodoTaskLabelProvider extends LabelProvider
			implements ITableLabelProvider {

		@Override
		public Image getImage(Object element) {
			return null;
		}

		@Override
		public String getText(Object element) {
			return getColumnText(element, 0);
		}

		@Override
		public Image getColumnImage(Object element, int columnIndex) {
			return null;
		}

		@Override
		public String getColumnText(Object element, int columnIndex) {
			final TodoTask task = (TodoTask) element;
			if (columnIndex == 0) {
				return task.name;
			}

			if (TodoTask.PRIORITY_HIGH.equals(task.priority)) {
				return PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_high_priority;
			}

			if (TodoTask.PRIORITY_NORMAL.equals(task.priority)) {
				return PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_normal_priority;
			}

			if (TodoTask.PRIORITY_LOW.equals(task.priority)) {
				return PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_low_priority;
			}

			return Util.EMPTY_STRING;
		}

	}

	private static class TodoTaskSorter extends ViewerComparator {
		@Override
		public int compare(Viewer viewer, Object e1, Object e2) {
			return getComparator().compare(((TodoTask) e1).name,
					((TodoTask) e2).name);
		}
	}

	public class TaskTagAdapter implements IListAdapter, IDialogFieldListener {

		private boolean canEdit(List<?> selectedElements) {
			return selectedElements.size() == 1;
		}

		@Override
		public void customButtonPressed(ListDialogField field, int index) {
			doTodoButtonPressed(index);
		}

		@Override
		public void selectionChanged(ListDialogField field) {
			List<?> selectedElements = field.getSelectedElements();
			field.enableButton(IDX_EDIT, canEdit(selectedElements));
		}

		@Override
		public void doubleClicked(ListDialogField field) {
			if (canEdit(field.getSelectedElements())) {
				doTodoButtonPressed(IDX_EDIT);
			}
		}

		@Override
		public void dialogFieldChanged(DialogField field) {
			updateModel(field);
		}

	}

	private static final int IDX_ADD = 0;
	private static final int IDX_EDIT = 1;
	private static final int IDX_REMOVE = 2;

	private ListDialogField fTodoTasksList;
	private Button fCaseSensitiveCheckbox;

	public AbstractTodoTaskOptionsBlock(IStatusChangeListener context,
			IProject project, PreferenceKey[] allKeys,
			IWorkbenchPreferenceContainer container) {
		super(context, project, allKeys, container);
	}

	@Override
	public void performDefaults() {
		super.performDefaults();
		initialize();
	}

	/**
	 * Creates a 'case sensitive' preference key
	 */
	public static PreferenceKey createCaseSensitiveKey(String pluginId) {
		return new PreferenceKey(pluginId, ITodoTaskPreferences.CASE_SENSITIVE);
	}

	/**
	 * Creates an 'enabled' preference key
	 */
	public static PreferenceKey createEnabledKey(String pluginId) {
		return new PreferenceKey(pluginId, ITodoTaskPreferences.ENABLED);
	}

	/**
	 * Creates a 'tags' preference key
	 */
	public static PreferenceKey createTagKey(String pluginId) {
		return new PreferenceKey(pluginId, ITodoTaskPreferences.TAGS);
	}

	@Override
	protected Control createOptionsBlock(Composite parent) {
		final TaskTagAdapter adapter = new TaskTagAdapter();
		final String[] buttons = new String[] {
				PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_add_button,
				PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_edit_button,
				PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_remove_button };
		fTodoTasksList = new ListDialogField(adapter, buttons,
				new TodoTaskLabelProvider());
		fTodoTasksList.setDialogFieldListener(adapter);
		fTodoTasksList.setRemoveButtonIndex(IDX_REMOVE);

		final String[] columnsHeaders = new String[] {
				PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_name_column,
				PreferencesMessages.TodoTaskConfigurationBlock_markers_tasks_priority_column, };
		fTodoTasksList.setTableColumns(
				new ListDialogField.ColumnsDescription(columnsHeaders, true));
		fTodoTasksList.setViewerComparator(new TodoTaskSorter());

		final GridLayout layout = new GridLayout();
		layout.marginHeight = 0;
		layout.marginWidth = 0;
		layout.numColumns = 2;

		final PixelConverter conv = new PixelConverter(parent);

		final Composite markersComposite = new Composite(parent, SWT.NULL);
		markersComposite.setLayout(layout);
		markersComposite.setFont(parent.getFont());

		final Button enableCheckbox = SWTFactory.createCheckButton(
				markersComposite,
				PreferencesMessages.TodoTaskConfigurationBlock_enableTaskTags,
				null, false, 2);
		bindControl(enableCheckbox, getEnabledKey(), null);

		fCaseSensitiveCheckbox = SWTFactory.createCheckButton(markersComposite,
				PreferencesMessages.TodoTaskConfigurationBlock_casesensitive_label,
				null, false, 2);

		bindControl(fCaseSensitiveCheckbox, getCaseSensitiveKey(), null);

		final GridData data = new GridData(GridData.FILL_BOTH);
		data.widthHint = conv.convertWidthInCharsToPixels(50);
		fTodoTasksList.getListControl(markersComposite).setLayoutData(data);

		fTodoTasksList.getButtonBox(markersComposite)
				.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL
						| GridData.VERTICAL_ALIGN_BEGINNING));

		enableCheckbox.addSelectionListener(new SelectionAdapter() {

			@Override
			public void widgetSelected(SelectionEvent e) {
				final boolean enabled = ((Button) e.widget).getSelection();
				updateEnableState(enabled);
			}

		});

		return markersComposite;
	}

	/**
	 * Returns the preference key that will be used to store the 'case
	 * sensitive' preference
	 *
	 * @see #createCaseSensitiveKey(String)
	 */
	protected abstract PreferenceKey getCaseSensitiveKey();

	/**
	 * Returns the preference key that will be used to store the 'enabled'
	 * preference
	 *
	 * @see #createEnabledKey(String)
	 */
	protected abstract PreferenceKey getEnabledKey();

	/**
	 * Returns the preference key that will be used to store the task tags
	 *
	 * @see #createTagKey(String)
	 */
	protected abstract PreferenceKey getTags();

	@Override
	protected void initialize() {
		super.initialize();

		String tags = getValue(getTags());

		fTodoTasksList.setElements(TaskTagUtils.decodeTaskTags(tags));
		if (fTodoTasksList.getSize() > 0) {
			fTodoTasksList.selectFirstElement();
		} else {
			fTodoTasksList.enableButton(IDX_EDIT, false);
		}

	}

	protected void updateEnableState(boolean enabled) {
		fTodoTasksList.setEnabled(enabled);
		fCaseSensitiveCheckbox.setEnabled(enabled);
	}

	@SuppressWarnings("unchecked")
	protected final void updateModel(DialogField field) {
		setValue(getTags(),
				TaskTagUtils.encodeTaskTags(fTodoTasksList.getElements()));
	}

	@Override
	protected IPreferenceChangeRebuildPrompt getPreferenceChangeRebuildPrompt(
			boolean workspaceSettings,
			Collection<PreferenceKey> changedOptions) {
		return PreferenceChangeRebuildPrompt.create(workspaceSettings,
				PreferencesMessages.TodoTaskConfigurationBlock_needsbuild_title,
				PreferencesMessages.TodoTaskConfigurationBlock_needsbuild_message);
	}

	private void doTodoButtonPressed(int index) {
		TodoTask edited = null;
		if (index != IDX_ADD) {
			edited = (TodoTask) fTodoTasksList.getSelectedElements().get(0);
		}
		if (index == IDX_ADD || index == IDX_EDIT) {
			TodoTaskInputDialog dialog = new TodoTaskInputDialog(getShell(),
					edited, fTodoTasksList.getElements());
			if (dialog.open() == Window.OK) {
				if (edited != null) {
					fTodoTasksList.replaceElement(edited, dialog.getResult());
				} else {
					fTodoTasksList.addElement(dialog.getResult());
				}
			}
		}
	}
}