adds Andreas' constraint-aware provider to the AF3 kernel

refs 2334

org.fortiss.tooling.kernel.ui/trunk/src/org/fortiss/tooling/kernel/ui/presentation/ConstraintViolationAwareLabelProviderBase.java

+/*--------------------------------------------------------------------------+
+$Id$
+|                                                                          |
+| Copyright 2015 ForTISS GmbH                     |
+|                                                                          |
+| Licensed under the Apache License, Version 2.0 (the "License");          |
+| you may not use this file except in compliance with the License.         |
+| You may obtain a copy of the License at                                  |
+|                                                                          |
+|    http://www.apache.org/licenses/LICENSE-2.0                            |
+|                                                                          |
+| Unless required by applicable law or agreed to in writing, software      |
+| distributed under the License is distributed on an "AS IS" BASIS,        |
+| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
+| See the License for the specific language governing permissions and      |
+| limitations under the License.                                           |
++--------------------------------------------------------------------------*/
+package org.fortiss.tooling.kernel.ui.presentation;
+
+import static org.eclipse.ui.ISharedImages.IMG_DEC_FIELD_ERROR;
+import static org.eclipse.ui.ISharedImages.IMG_DEC_FIELD_WARNING;
+import static org.eclipse.ui.PlatformUI.getWorkbench;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.apache.commons.lang.WordUtils;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.jface.resource.ImageDescriptor;
+import org.eclipse.jface.viewers.DecorationOverlayIcon;
+import org.eclipse.jface.viewers.LabelProvider;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.graphics.Point;
+import org.fortiss.tooling.kernel.extension.data.IConstraintViolation;
+import org.fortiss.tooling.kernel.extension.data.IConstraintViolation.ESeverity;
+import org.fortiss.tooling.kernel.ui.ToolingKernelUIActivator;
+import org.fortiss.tooling.kernel.ui.service.IMarkerService;
+
+/**
+ * {@link LabelProvider} for {@link EObject}s, that decorates the icon according to possibly
+ * existing {@link IConstraintViolation} for the element.
+ * 
+ * @author bayha
+ * @author $Author$
+ * @version $Rev$
+ * @ConQAT.Rating YELLOW Hash: C85CA550A48E319CEF8A6CAB10F55273
+ */
+public class ConstraintViolationAwareLabelProviderBase extends ModelElementLabelProvider {
+	/** Text with in characters, for tool tips. */
+	protected static final int TOOL_TIP_TEXT_WIDTH = 60;
+
+	/** Time in ms, tool tips (potentially with warnings are displayed). */
+	protected static final int TOOL_TIP_DISPLAY_TIME = 100000;
+
+	/** Constructor. */
+	public ConstraintViolationAwareLabelProviderBase() {
+		super();
+	}
+
+	/**
+	 * Retrieves all {@link IConstraintViolation}s for 'object', which have
+	 * 'object' as source.
+	 * Applies {@link #filterViolations(Collection, Object)}.
+	 * 
+	 * @param object
+	 *            object, which caused violation for 'object'.
+	 * @return A {@link List} of {@link IConstraintViolation}s.
+	 */
+	protected Collection<IConstraintViolation<?>> getViolationsForObject(Object object) {
+		Collection<IConstraintViolation<?>> violations =
+				IMarkerService.INSTANCE.getViolations((EObject)object);
+
+		return filterViolations(violations, object);
+	}
+
+	/**
+	 * Filters ConstraintViolations before they are taken into account for decorating the label.
+	 * 
+	 * This Method might be overwritten, if filtering is intended.
+	 * 
+	 * @param toFilter
+	 *            {@link Collection} of {@link IConstraintViolation}s to be filtered.
+	 * @param object
+	 *            {@link Object}, for which a label shall be provided.
+	 * @return Filtered {@link Collection} of {@link IConstraintViolation}s.
+	 */
+	protected Collection<IConstraintViolation<?>> filterViolations(
+			Collection<IConstraintViolation<?>> toFilter, Object object) {
+		return toFilter;
+	}
+
+	/**
+	 * Retrieves a standard image, to be displayed as icon.
+	 * 
+	 * @param element
+	 *            The {@link Object} to get an image for.
+	 * @return {@link ImageDescriptor} for fall back {@link Image}.
+	 */
+	protected ImageDescriptor getFallbackImage(Object element) {
+		return ToolingKernelUIActivator.getImageDescriptor("icons/transparent_icon.gif");
+	}
+
+	/**
+	 * Retrieves the base image for the icon, which is decorated then with error or warning markers.
+	 * 
+	 * @param element
+	 *            The {@link Object} to get an image for.
+	 * @return {@link Image} to be decorated and displayed.
+	 */
+	protected Image getBaseImage(Object element) {
+		Image image = super.getImage(element);
+
+		if(image == null) {
+			image = getFallbackImage(element).createImage();
+		}
+
+		return image;
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public Image getImage(Object element) {
+		Image image = getBaseImage(element);
+
+		ESeverity highestSeverity = ESeverity.INFO;
+
+		Collection<IConstraintViolation<?>> violationsForElementSelection =
+				getViolationsForObject(element);
+
+		// Find highest severity.
+		for(IConstraintViolation<? extends EObject> v : violationsForElementSelection) {
+			if(v.getSeverity().compareTo(highestSeverity) < 0) {
+				highestSeverity = v.getSeverity();
+			}
+		}
+
+		ImageDescriptor overlay;
+		switch(highestSeverity) {
+			case ERROR:
+				overlay = getWorkbench().getSharedImages().getImageDescriptor(IMG_DEC_FIELD_ERROR);
+				break;
+			case WARNING:
+				overlay =
+						getWorkbench().getSharedImages().getImageDescriptor(IMG_DEC_FIELD_WARNING);
+				break;
+			default:
+				return image;
+		}
+
+		DecorationOverlayIcon decorated =
+				new DecorationOverlayIcon(image, new ImageDescriptor[] {null, null, null, overlay,
+						null}, new Point(16, 16));
+
+		return decorated.createImage();
+	}
+
+	/** Wraps long lines after TOOL_TIP_TEXT_WIDTH characters. */
+	private String wrap(String s) {
+		StringBuilder buffer = new StringBuilder();
+
+		String delim = "";
+		for(String line : s.trim().split("\n")) {
+			buffer.append(delim);
+			delim = "\n";
+			buffer.append(WordUtils.wrap(line, TOOL_TIP_TEXT_WIDTH, "\n", true));
+		}
+
+		return buffer.toString();
+	}
+
+	/**
+	 * Get ToolTip text for the given 'element'.
+	 * 
+	 * This text will be displayed in the ToolTip, before the errors.
+	 * 
+	 * @param element
+	 *            The {@link Object} to get an explanation for.
+	 * @return A {@link String}, explaining 'element'.
+	 */
+	protected String getExplanatoryToolTipText(Object element) {
+		return "";
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public String getToolTipText(Object element) {
+		StringBuffer ttBuffer = new StringBuffer(getExplanatoryToolTipText(element));
+
+		Collection<IConstraintViolation<?>> violations = getViolationsForObject(element);
+
+		for(IConstraintViolation<?> v : violations) {
+			ttBuffer.append("\n\n");
+			ttBuffer.append(v.getSeverity());
+			ttBuffer.append(": ");
+			ttBuffer.append(v.getExplanation());
+		}
+		return wrap(ttBuffer.toString());
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	public int getToolTipTimeDisplayed(Object object) {
+		return TOOL_TIP_DISPLAY_TIME;
+	}
+}