net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/core/DeleteElementsOperation.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.core;
  12
  13 import java.util.HashMap;
  14 import java.util.Iterator;
  15 import java.util.Map;
  16
  17 import net.sourceforge.phpdt.core.IBuffer;
  18 import net.sourceforge.phpdt.core.ICompilationUnit;
  19 import net.sourceforge.phpdt.core.IJavaElement;
  20 import net.sourceforge.phpdt.core.IJavaModelStatusConstants;
  21 import net.sourceforge.phpdt.core.IRegion;
  22 import net.sourceforge.phpdt.core.JavaModelException;
  23 import net.sourceforge.phpdt.core.compiler.CharOperation;
  24 import net.sourceforge.phpdt.core.jdom.DOMFactory;
  25 import net.sourceforge.phpdt.core.jdom.IDOMCompilationUnit;
  26 import net.sourceforge.phpdt.internal.core.jdom.DOMNode;
  27 import net.sourceforge.phpdt.internal.core.util.Util;
  28 import net.sourceforge.phpdt.internal.corext.Assert;
  29
  30 /**
  31  * This operation deletes a collection of elements (and all of their children).
  32  * If an element does not exist, it is ignored.
  33  *
  34  * <p>
  35  * NOTE: This operation only deletes elements contained within leaf resources -
  36  * that is, elements within compilation units. To delete a compilation unit or a
  37  * package, etc (which have an actual resource), a DeleteResourcesOperation
  38  * should be used.
  39  */
  40 public class DeleteElementsOperation extends MultiOperation {
  41         /**
  42          * The elements this operation processes grouped by compilation unit
  43          *
  44          * @see processElements(). Keys are compilation units, values are
  45          *      <code>IRegion</code>s of elements to be processed in each
  46          *      compilation unit.
  47          */
  48         protected Map fChildrenToRemove;
  49
  50         /**
  51          * The <code>DOMFactory</code> used to manipulate the source code of
  52          * <code>ICompilationUnit</code>s.
  53          */
  54         protected DOMFactory fFactory;
  55
  56         /**
  57          * When executed, this operation will delete the given elements. The
  58          * elements to delete cannot be <code>null</code> or empty, and must be
  59          * contained within a compilation unit.
  60          */
  61         public DeleteElementsOperation(IJavaElement[] elementsToDelete,
  62                         boolean force) {
  63                 super(elementsToDelete, force);
  64                 fFactory = new DOMFactory();
  65         }
  66
  67         /**
  68          * @see MultiOperation
  69          */
  70         protected String getMainTaskName() {
  71                 return Util.bind("operation.deleteElementProgress"); //$NON-NLS-1$
  72         }
  73
  74         /**
  75          * Groups the elements to be processed by their compilation unit. If
  76          * parent/child combinations are present, children are discarded (only the
  77          * parents are processed). Removes any duplicates specified in elements to
  78          * be processed.
  79          */
  80         protected void groupElements() throws JavaModelException {
  81                 fChildrenToRemove = new HashMap(1);
  82                 int uniqueCUs = 0;
  83                 for (int i = 0, length = fElementsToProcess.length; i < length; i++) {
  84                         IJavaElement e = fElementsToProcess[i];
  85                         ICompilationUnit cu = getCompilationUnitFor(e);
  86                         if (cu == null) {
  87                                 throw new JavaModelException(new JavaModelStatus(
  88                                                 JavaModelStatus.READ_ONLY, e));
  89                         } else {
  90                                 IRegion region = (IRegion) fChildrenToRemove.get(cu);
  91                                 if (region == null) {
  92                                         region = new Region();
  93                                         fChildrenToRemove.put(cu, region);
  94                                         uniqueCUs += 1;
  95                                 }
  96                                 region.add(e);
  97                         }
  98                 }
  99                 fElementsToProcess = new IJavaElement[uniqueCUs];
 100                 Iterator iter = fChildrenToRemove.keySet().iterator();
 101                 int i = 0;
 102                 while (iter.hasNext()) {
 103                         fElementsToProcess[i++] = (IJavaElement) iter.next();
 104                 }
 105         }
 106
 107         /**
 108          * Deletes this element from its compilation unit.
 109          *
 110          * @see MultiOperation
 111          */
 112         protected void processElement(IJavaElement element)
 113                         throws JavaModelException {
 114                 ICompilationUnit cu = (ICompilationUnit) element;
 115
 116                 // keep track of the import statements - if all are removed, delete
 117                 // the import container (and report it in the delta)
 118                 // int numberOfImports = cu.getImports().length;
 119
 120                 IBuffer buffer = cu.getBuffer();
 121                 if (buffer == null)
 122                         return;
 123                 JavaElementDelta delta = new JavaElementDelta(cu);
 124                 IJavaElement[] cuElements = ((IRegion) fChildrenToRemove.get(cu))
 125                                 .getElements();
 126                 for (int i = 0, length = cuElements.length; i < length; i++) {
 127                         IJavaElement e = cuElements[i];
 128                         if (e.exists()) {
 129                                 char[] contents = buffer.getCharacters();
 130                                 if (contents == null)
 131                                         continue;
 132                                 IDOMCompilationUnit cuDOM = fFactory.createCompilationUnit(
 133                                                 contents, cu.getElementName());
 134                                 DOMNode node = (DOMNode) ((JavaElement) e).findNode(cuDOM);
 135                                 if (node == null)
 136                                         Assert
 137                                                         .isTrue(
 138                                                                         false,
 139                                                                         "Failed to locate " + e.getElementName() + " in " + cuDOM.getName()); //$NON-NLS-1$//$NON-NLS-2$
 140
 141                                 int startPosition = node.getStartPosition();
 142                                 buffer.replace(startPosition, node.getEndPosition()
 143                                                 - startPosition + 1, CharOperation.NO_CHAR);
 144                                 delta.removed(e);
 145                                 // if (e.getElementType() == IJavaElement.IMPORT_DECLARATION) {
 146                                 // numberOfImports--;
 147                                 // if (numberOfImports == 0) {
 148                                 // delta.removed(cu.getImportContainer());
 149                                 // }
 150                                 // }
 151                         }
 152                 }
 153                 if (delta.getAffectedChildren().length > 0) {
 154                         cu.save(getSubProgressMonitor(1), force);
 155                         if (!cu.isWorkingCopy()) { // if unit is working copy, then save
 156                                                                                 // will have already fired the delta
 157                                 addDelta(delta);
 158                                 this.setAttribute(HAS_MODIFIED_RESOURCE_ATTR, TRUE);
 159                         }
 160                 }
 161         }
 162
 163         /**
 164          * @see MultiOperation This method first group the elements by
 165          *      <code>ICompilationUnit</code>, and then processes the
 166          *      <code>ICompilationUnit</code>.
 167          */
 168         protected void processElements() throws JavaModelException {
 169                 groupElements();
 170                 super.processElements();
 171         }
 172
 173         /**
 174          * @see MultiOperation
 175          */
 176         protected void verify(IJavaElement element) throws JavaModelException {
 177                 IJavaElement[] children = ((IRegion) fChildrenToRemove.get(element))
 178                                 .getElements();
 179                 for (int i = 0; i < children.length; i++) {
 180                         IJavaElement child = children[i];
 181                         if (child.getCorrespondingResource() != null)
 182                                 error(IJavaModelStatusConstants.INVALID_ELEMENT_TYPES, child);
 183                         if (child.isReadOnly())
 184                                 error(IJavaModelStatusConstants.READ_ONLY, child);
 185                 }
 186         }
 187 }