com.google.dart.tools.ui.callhierarchy.CallHierarchyLabelDecorator.java Source code

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Here is the source code for com.google.dart.tools.ui.callhierarchy.CallHierarchyLabelDecorator.java

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/*
 * Copyright (c) 2012, the Dart project authors.
 * 
 * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
 * 
 * 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 com.google.dart.tools.ui.callhierarchy;

import com.google.dart.tools.ui.DartToolsPlugin;
import com.google.dart.tools.ui.internal.callhierarchy.MethodWrapper;
import com.google.dart.tools.ui.internal.viewsupport.ImageImageDescriptor;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.ILabelDecorator;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;

/**
 * Label decorator that decorates an method's image with recursion overlays. The viewer using this
 * decorator is responsible for updating the images on element changes.
 */
public class CallHierarchyLabelDecorator implements ILabelDecorator {

    /**
     * Creates a decorator. The decorator creates an own image registry to cache images.
     */
    public CallHierarchyLabelDecorator() {
        // Do nothing
    }

    @Override
    public void addListener(ILabelProviderListener listener) {
        // Do nothing
    }

    @Override
    public Image decorateImage(Image image, Object element) {
        if (image == null) {
            return null;
        }

        int adornmentFlags = computeAdornmentFlags(element);
        if (adornmentFlags != 0) {
            ImageDescriptor baseImage = new ImageImageDescriptor(image);
            Rectangle bounds = image.getBounds();
            return DartToolsPlugin.getImageDescriptorRegistry().get(new CallHierarchyImageDescriptor(baseImage,
                    adornmentFlags, new Point(bounds.width, bounds.height)));
        }
        return image;
    }

    @Override
    public String decorateText(String text, Object element) {
        return text;
    }

    @Override
    public void dispose() {
        // Nothing to dispose
    }

    @Override
    public boolean isLabelProperty(Object element, String property) {
        return true;
    }

    @Override
    public void removeListener(ILabelProviderListener listener) {
        // Do nothing
    }

    /**
     * Note: This method is for internal use only. Clients should not call this method.
     * 
     * @param element the element for which to compute the flags
     * @return the flags
     */
    private int computeAdornmentFlags(Object element) {
        int flags = 0;
        if (element instanceof MethodWrapper) {
            MethodWrapper methodWrapper = (MethodWrapper) element;
            if (methodWrapper.isRecursive()) {
                flags = CallHierarchyImageDescriptor.RECURSIVE;
            }
            if (isMaxCallDepthExceeded(methodWrapper)) {
                flags |= CallHierarchyImageDescriptor.MAX_LEVEL;
            }
        }
        return flags;
    }

    private boolean isMaxCallDepthExceeded(MethodWrapper methodWrapper) {
        return methodWrapper.getLevel() > CallHierarchyUI.getDefault().getMaxCallDepth();
    }
}