Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2011 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.ui; import org.eclipse.core.runtime.IAdaptable; import org.eclipse.core.runtime.IPath; import org.eclipse.core.resources.IContainer; import org.eclipse.core.resources.IFile; import org.eclipse.core.resources.IProject; import org.eclipse.core.resources.IResource; import org.eclipse.core.resources.IStorage; import org.eclipse.jface.viewers.ContentViewer; import org.eclipse.jface.viewers.IBaseLabelProvider; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.Viewer; import org.eclipse.jface.viewers.ViewerComparator; import org.eclipse.ui.model.IWorkbenchAdapter; import org.eclipse.jdt.core.Flags; import org.eclipse.jdt.core.IField; import org.eclipse.jdt.core.IInitializer; import org.eclipse.jdt.core.IJarEntryResource; import org.eclipse.jdt.core.IJavaElement; import org.eclipse.jdt.core.IJavaProject; import org.eclipse.jdt.core.IMember; import org.eclipse.jdt.core.IMethod; import org.eclipse.jdt.core.IPackageFragment; import org.eclipse.jdt.core.IPackageFragmentRoot; import org.eclipse.jdt.core.IType; import org.eclipse.jdt.core.JavaModelException; import org.eclipse.jdt.core.Signature; import org.eclipse.jdt.internal.corext.util.JavaModelUtil; import org.eclipse.jdt.internal.corext.util.JdtFlags; import org.eclipse.jdt.internal.ui.JavaPlugin; import org.eclipse.jdt.internal.ui.packageview.PackageFragmentRootContainer; import org.eclipse.jdt.internal.ui.preferences.MembersOrderPreferenceCache; /** * Viewer comparator for Java elements. Ordered by element category, then by element name. * Package fragment roots are sorted as ordered on the classpath. * * <p> * This class may be instantiated; it is not intended to be subclassed. * </p> * * @since 3.3 * * @noextend This class is not intended to be subclassed by clients. */ public class JavaElementComparator extends ViewerComparator { private static final int PROJECTS = 1; private static final int PACKAGEFRAGMENTROOTS = 2; private static final int PACKAGEFRAGMENT = 3; private static final int COMPILATIONUNITS = 4; private static final int CLASSFILES = 5; private static final int RESOURCEFOLDERS = 7; private static final int RESOURCES = 8; private static final int PACKAGE_DECL = 10; private static final int IMPORT_CONTAINER = 11; private static final int IMPORT_DECLARATION = 12; // Includes all categories ordered using the OutlineSortOrderPage: // types, initializers, methods & fields private static final int MEMBERSOFFSET = 15; private static final int JAVAELEMENTS = 50; private static final int OTHERS = 51; private MembersOrderPreferenceCache fMemberOrderCache; /** * Constructor. */ public JavaElementComparator() { super(null); // delay initialization of collator fMemberOrderCache = JavaPlugin.getDefault().getMemberOrderPreferenceCache(); } /* (non-Javadoc) * @see org.eclipse.jface.viewers.ViewerComparator#category(java.lang.Object) */ @Override public int category(Object element) { if (element instanceof IJavaElement) { try { IJavaElement je = (IJavaElement) element; switch (je.getElementType()) { case IJavaElement.METHOD: { IMethod method = (IMethod) je; if (method.isConstructor()) { return getMemberCategory(MembersOrderPreferenceCache.CONSTRUCTORS_INDEX); } int flags = method.getFlags(); if (Flags.isStatic(flags)) return getMemberCategory(MembersOrderPreferenceCache.STATIC_METHODS_INDEX); else return getMemberCategory(MembersOrderPreferenceCache.METHOD_INDEX); } case IJavaElement.FIELD: { int flags = ((IField) je).getFlags(); if (Flags.isEnum(flags)) { return getMemberCategory(MembersOrderPreferenceCache.ENUM_CONSTANTS_INDEX); } if (Flags.isStatic(flags)) return getMemberCategory(MembersOrderPreferenceCache.STATIC_FIELDS_INDEX); else return getMemberCategory(MembersOrderPreferenceCache.FIELDS_INDEX); } case IJavaElement.INITIALIZER: { int flags = ((IInitializer) je).getFlags(); if (Flags.isStatic(flags)) return getMemberCategory(MembersOrderPreferenceCache.STATIC_INIT_INDEX); else return getMemberCategory(MembersOrderPreferenceCache.INIT_INDEX); } case IJavaElement.TYPE: return getMemberCategory(MembersOrderPreferenceCache.TYPE_INDEX); case IJavaElement.PACKAGE_DECLARATION: return PACKAGE_DECL; case IJavaElement.IMPORT_CONTAINER: return IMPORT_CONTAINER; case IJavaElement.IMPORT_DECLARATION: return IMPORT_DECLARATION; case IJavaElement.PACKAGE_FRAGMENT: return PACKAGEFRAGMENT; case IJavaElement.PACKAGE_FRAGMENT_ROOT: return PACKAGEFRAGMENTROOTS; case IJavaElement.JAVA_PROJECT: return PROJECTS; case IJavaElement.CLASS_FILE: return CLASSFILES; case IJavaElement.COMPILATION_UNIT: return COMPILATIONUNITS; } } catch (JavaModelException e) { if (!e.isDoesNotExist()) JavaPlugin.log(e); } return JAVAELEMENTS; } else if (element instanceof IFile) { return RESOURCES; } else if (element instanceof IProject) { return PROJECTS; } else if (element instanceof IContainer) { return RESOURCEFOLDERS; } else if (element instanceof IJarEntryResource) { if (((IJarEntryResource) element).isFile()) { return RESOURCES; } return RESOURCEFOLDERS; } else if (element instanceof PackageFragmentRootContainer) { return PACKAGEFRAGMENTROOTS; } return OTHERS; } private int getMemberCategory(int kind) { int offset = fMemberOrderCache.getCategoryIndex(kind); return offset + MEMBERSOFFSET; } /* (non-Javadoc) * @see org.eclipse.jface.viewers.ViewerComparator#compare(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object) */ @Override public int compare(Viewer viewer, Object e1, Object e2) { int cat1 = category(e1); int cat2 = category(e2); if (needsClasspathComparision(e1, cat1, e2, cat2)) { IPackageFragmentRoot root1 = getPackageFragmentRoot(e1); IPackageFragmentRoot root2 = getPackageFragmentRoot(e2); if (root1 == null) { if (root2 == null) { return 0; } else { return 1; } } else if (root2 == null) { return -1; } // check if not same to avoid expensive class path access if (!root1.getPath().equals(root2.getPath())) { int p1 = getClassPathIndex(root1); int p2 = getClassPathIndex(root2); if (p1 != p2) { return p1 - p2; } } } if (cat1 != cat2) return cat1 - cat2; if (cat1 == PROJECTS || cat1 == RESOURCES || cat1 == RESOURCEFOLDERS || cat1 == OTHERS) { String name1 = getNonJavaElementLabel(viewer, e1); String name2 = getNonJavaElementLabel(viewer, e2); if (name1 != null && name2 != null) { return getComparator().compare(name1, name2); } return 0; // can't compare } // only java elements from this point if (e1 instanceof IMember) { if (fMemberOrderCache.isSortByVisibility()) { try { int flags1 = JdtFlags.getVisibilityCode((IMember) e1); int flags2 = JdtFlags.getVisibilityCode((IMember) e2); int vis = fMemberOrderCache.getVisibilityIndex(flags1) - fMemberOrderCache.getVisibilityIndex(flags2); if (vis != 0) { return vis; } } catch (JavaModelException ignore) { } } } String name1 = getElementName(e1); String name2 = getElementName(e2); if (e1 instanceof IType) { // handle anonymous types if (name1.length() == 0) { if (name2.length() == 0) { try { return getComparator().compare(((IType) e1).getSuperclassName(), ((IType) e2).getSuperclassName()); } catch (JavaModelException e) { return 0; } } else { return 1; } } else if (name2.length() == 0) { return -1; } } int cmp = getComparator().compare(name1, name2); if (cmp != 0) { return cmp; } if (e1 instanceof IMethod) { String[] params1 = ((IMethod) e1).getParameterTypes(); String[] params2 = ((IMethod) e2).getParameterTypes(); int len = Math.min(params1.length, params2.length); for (int i = 0; i < len; i++) { cmp = getComparator().compare(Signature.toString(params1[i]), Signature.toString(params2[i])); if (cmp != 0) { return cmp; } } return params1.length - params2.length; } return 0; } private IPackageFragmentRoot getPackageFragmentRoot(Object element) { if (element instanceof PackageFragmentRootContainer) { // return first package fragment root from the container PackageFragmentRootContainer cp = (PackageFragmentRootContainer) element; Object[] roots = cp.getPackageFragmentRoots(); if (roots.length > 0) return (IPackageFragmentRoot) roots[0]; // non resolvable - return null return null; } return JavaModelUtil.getPackageFragmentRoot((IJavaElement) element); } private String getNonJavaElementLabel(Viewer viewer, Object element) { // try to use the workbench adapter for non - java resources or if not available, use the viewers label provider if (element instanceof IResource) { return ((IResource) element).getName(); } if (element instanceof IStorage) { return ((IStorage) element).getName(); } if (element instanceof IAdaptable) { IWorkbenchAdapter adapter = (IWorkbenchAdapter) ((IAdaptable) element) .getAdapter(IWorkbenchAdapter.class); if (adapter != null) { return adapter.getLabel(element); } } if (viewer instanceof ContentViewer) { IBaseLabelProvider prov = ((ContentViewer) viewer).getLabelProvider(); if (prov instanceof ILabelProvider) { return ((ILabelProvider) prov).getText(element); } } return null; } private int getClassPathIndex(IPackageFragmentRoot root) { try { IPath rootPath = root.getPath(); IPackageFragmentRoot[] roots = root.getJavaProject().getPackageFragmentRoots(); for (int i = 0; i < roots.length; i++) { if (roots[i].getPath().equals(rootPath)) { return i; } } } catch (JavaModelException e) { } return Integer.MAX_VALUE; } private boolean needsClasspathComparision(Object e1, int cat1, Object e2, int cat2) { if ((cat1 == PACKAGEFRAGMENTROOTS && cat2 == PACKAGEFRAGMENTROOTS) || (cat1 == PACKAGEFRAGMENT && ((IPackageFragment) e1).getParent().getResource() instanceof IProject && cat2 == PACKAGEFRAGMENTROOTS) || (cat1 == PACKAGEFRAGMENTROOTS && cat2 == PACKAGEFRAGMENT && ((IPackageFragment) e2).getParent().getResource() instanceof IProject)) { IJavaProject p1 = getJavaProject(e1); return p1 != null && p1.equals(getJavaProject(e2)); } return false; } private IJavaProject getJavaProject(Object element) { if (element instanceof IJavaElement) { return ((IJavaElement) element).getJavaProject(); } else if (element instanceof PackageFragmentRootContainer) { return ((PackageFragmentRootContainer) element).getJavaProject(); } return null; } private String getElementName(Object element) { if (element instanceof IJavaElement) { return ((IJavaElement) element).getElementName(); } else if (element instanceof PackageFragmentRootContainer) { return ((PackageFragmentRootContainer) element).getLabel(); } else { return element.toString(); } } }