core/plugins/org.eclipse.dltk.ui/ui refactoring/org/eclipse/dltk/internal/ui/refactoring/reorg/ReorgUserInputPage.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.internal.ui.refactoring.reorg;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.internal.corext.refactoring.reorg.IReorgDestinationValidator;
import org.eclipse.dltk.internal.corext.util.Messages;
import org.eclipse.dltk.ui.DLTKUIPlugin;
import org.eclipse.dltk.ui.ModelElementLabelProvider;
import org.eclipse.dltk.ui.ModelElementSorter;
import org.eclipse.dltk.ui.ScriptElementLabels;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;
import org.eclipse.ltk.ui.refactoring.UserInputWizardPage;
import org.eclipse.swt.SWT;
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;

abstract class ReorgUserInputPage extends UserInputWizardPage {
	private static final long LABEL_FLAGS = ScriptElementLabels.ALL_DEFAULT
			| ScriptElementLabels.M_APP_RETURNTYPE
			| ScriptElementLabels.M_PARAMETER_NAMES
			| ScriptElementLabels.F_PRE_TYPE_SIGNATURE;
	private TreeViewer fViewer;

	public ReorgUserInputPage(String pageName) {
		super(pageName);
	}

	@Override
	public void createControl(Composite parent) {
		initializeDialogUnits(parent);
		Composite result = new Composite(parent, SWT.NONE);
		setControl(result);
		result.setLayout(new GridLayout());

		Object initialSelection = getInitiallySelectedElement();
		verifyDestination(initialSelection, true);

		addLabel(result);

		fViewer = createViewer(result);
		fViewer.setSelection(new StructuredSelection(initialSelection), true);
		fViewer.addSelectionChangedListener(
				event -> ReorgUserInputPage.this.viewerSelectionChanged(event));
		Dialog.applyDialogFont(result);
	}

	protected Control addLabel(Composite parent) {
		Label label = new Label(parent, SWT.NONE);
		String text;
		int resources = getResources().length;
		int modelElements = getScriptElements().length;

		if (resources == 0 && modelElements == 1) {
			text = Messages.format(
					ReorgMessages.ReorgUserInputPage_choose_destination_single,
					ScriptElementLabels.getDefault().getElementLabel(
							getScriptElements()[0], LABEL_FLAGS));
		} else if (resources == 1 && modelElements == 0) {
			text = Messages.format(
					ReorgMessages.ReorgUserInputPage_choose_destination_single,
					getResources()[0].getName());
		} else {
			text = Messages.format(
					ReorgMessages.ReorgUserInputPage_choose_destination_multi,
					String.valueOf(resources + modelElements));
		}

		label.setText(text);
		label.setLayoutData(new GridData(SWT.BEGINNING, SWT.END, false, false));
		return label;
	}

	private void viewerSelectionChanged(SelectionChangedEvent event) {
		ISelection selection = event.getSelection();
		if (!(selection instanceof IStructuredSelection))
			return;
		IStructuredSelection ss = (IStructuredSelection) selection;
		verifyDestination(ss.getFirstElement(), false);
	}

	protected abstract Object getInitiallySelectedElement();

	/** Set and verify destination */
	protected abstract RefactoringStatus verifyDestination(Object selected)
			throws ModelException;

	protected abstract IResource[] getResources();

	protected abstract IModelElement[] getScriptElements();

	protected abstract IReorgDestinationValidator getDestinationValidator();

	private final void verifyDestination(Object selected,
			boolean initialVerification) {
		try {
			RefactoringStatus status = verifyDestination(selected);
			if (initialVerification)
				setPageComplete(status.isOK());
			else
				setPageComplete(status);
		} catch (ModelException e) {
			DLTKUIPlugin.log(e);
			setPageComplete(false);
		}
	}

	private TreeViewer createViewer(Composite parent) {
		TreeViewer treeViewer = new TreeViewer(parent,
				SWT.SINGLE | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER);
		GridData gd = new GridData(GridData.FILL_BOTH);
		gd.widthHint = convertWidthInCharsToPixels(40);
		gd.heightHint = convertHeightInCharsToPixels(15);
		treeViewer.getTree().setLayoutData(gd);
		treeViewer.setLabelProvider(new ModelElementLabelProvider(
				ModelElementLabelProvider.SHOW_SMALL_ICONS));
		treeViewer.setContentProvider(
				new DestinationContentProvider(getDestinationValidator()));
		treeViewer.setComparator(new ModelElementSorter());
		treeViewer.setInput(
				DLTKCore.create(ResourcesPlugin.getWorkspace().getRoot()));
		return treeViewer;
	}

	protected TreeViewer getTreeViewer() {
		return fViewer;
	}
}