com.amashchenko.eclipse.strutsclipse.java.JavaClassCompletion.java Source code

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Here is the source code for com.amashchenko.eclipse.strutsclipse.java.JavaClassCompletion.java

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/*
 * Copyright 2015-2016 Aleksandr Mashchenko.
 *
 * 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 com.amashchenko.eclipse.strutsclipse.java;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jdt.core.IBuffer;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.ui.text.java.IJavaCompletionProposal;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.contentassist.CompletionProposal;
import org.eclipse.jface.text.contentassist.ICompletionProposal;

import com.amashchenko.eclipse.strutsclipse.ProjectUtil;

public class JavaClassCompletion {
    private static final String CLASS_NAME = "_xxx";
    private static final String CLASS_SOURCE_END = "\n" + "    }\n" + "}";
    private static final String CLASS_SOURCE_START = "public class " + CLASS_NAME + " {\n"
            + "    public void main(String[] args) {\n" + "        ";

    private JavaClassCompletion() {
    }

    public static List<ICompletionProposal> getSimpleJavaProposals(String prefix, IDocument document,
            IRegion region) {
        final String sourceStart = CLASS_SOURCE_START + prefix;
        final String source = sourceStart + CLASS_SOURCE_END;

        return createProposals(source, sourceStart.length(), document, region, false);
    }

    public static List<ICompletionProposal> getActionMethodProposals(String prefix, String className,
            IDocument document, IRegion region) {
        final String sourceStart = CLASS_SOURCE_START + className + " a;a." + prefix;
        final String source = sourceStart + CLASS_SOURCE_END;

        return createProposals(source, sourceStart.length(), document, region, true);
    }

    private static List<ICompletionProposal> createProposals(String source, int completionOffset,
            IDocument document, IRegion region, boolean collectMethods) {
        List<ICompletionProposal> proposals = new ArrayList<ICompletionProposal>();
        try {
            ICompilationUnit unit = createSourceCompilationUnit(document);
            if (unit != null) {
                setCompilationUnitContents(unit, source);

                SimpleJavaProposalCollector collector = new SimpleJavaProposalCollector(unit, collectMethods);
                unit.codeComplete(completionOffset, collector);

                IJavaCompletionProposal[] props = collector.getJavaCompletionProposals();

                if (props != null) {
                    for (IJavaCompletionProposal p : props) {
                        if (p instanceof SimpleJavaCompletionProposal) {
                            SimpleJavaCompletionProposal sjp = (SimpleJavaCompletionProposal) p;

                            // ignore fake class proposals
                            if (!sjp.getReplacementString().endsWith(CLASS_NAME)) {
                                proposals.add(new CompletionProposal(sjp.getReplacementString(), region.getOffset(),
                                        region.getLength(), sjp.getReplacementString().length(), sjp.getImage(),
                                        sjp.getDisplayString(), sjp.getContextInformation(),
                                        sjp.getAdditionalProposalInfo()));
                            }
                        }
                    }
                }
            }
        } catch (JavaModelException e) {
            e.printStackTrace();
        }

        return proposals;
    }

    private static ICompilationUnit createSourceCompilationUnit(IDocument document) throws JavaModelException {
        ICompilationUnit unit = null;

        IJavaProject javaProject = ProjectUtil.getCurrentJavaProject(document);
        if (javaProject != null) {
            IPackageFragment packageFragment = javaProject.getPackageFragments()[0];
            if (packageFragment != null) {
                unit = packageFragment.getCompilationUnit(CLASS_NAME + ".java").getWorkingCopy(null);
            }
        }
        return unit;
    }

    private static void setCompilationUnitContents(ICompilationUnit cu, String source) {
        if (cu == null) {
            return;
        }

        synchronized (cu) {
            IBuffer buffer;
            try {
                buffer = cu.getBuffer();
            } catch (JavaModelException e) {
                buffer = null;
            }

            if (buffer != null) {
                buffer.setContents(source);
            }
        }
    }
}