de.jcup.egradle.codecompletion.UserHomeBasedXMLProposalDataModelProvider.java Source code

Introduction

Here is the source code for de.jcup.egradle.codecompletion.UserHomeBasedXMLProposalDataModelProvider.java

Source

/*
 * Copyright 2016 Albert Tregnaghi
 *
 * 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 de.jcup.egradle.codecompletion;

import java.io.File;
import java.io.FileFilter;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

import org.apache.commons.lang3.StringUtils;

import de.jcup.egradle.core.api.ErrorHandler;
import de.jcup.egradle.core.api.FileHelper;

/**
 * Data model provider which simply reads all xml files from
 * user.home/.egradle/codeCompletion.
 * 
 * @author albert
 *
 */
public class UserHomeBasedXMLProposalDataModelProvider implements XMLProposalDataModelProvider {

    public static final UserHomeBasedXMLProposalDataModelProvider INSTANCE = new UserHomeBasedXMLProposalDataModelProvider();

    private CodeCompletionFileFilter fileFilter = new CodeCompletionFileFilter();
    private List<XMLProposalDataModel> cachedDataModels = new ArrayList<>();
    private Object monitor = new Object();
    private boolean loaded;
    private ErrorHandler errorHandler;

    public void setErrorHandler(ErrorHandler errorHandler) {
        this.errorHandler = errorHandler;
    }

    public void reload() {
        synchronized (monitor) {
            loaded = true;
            cachedDataModels.clear();

            Set<File> files = findCodeCompletionFilesInUserHome();
            if (files == null || files.size() == 0) {
                return;
            }
            JAXBContext jc;
            try {
                jc = JAXBContext.newInstance(XMLProposalDataModel.class);
                Unmarshaller unmarshaller = jc.createUnmarshaller();
                for (File file : files) {
                    try {
                        XMLProposalDataModel loadedModel = (XMLProposalDataModel) unmarshaller
                                .unmarshal(new FileInputStream(file));
                        cachedDataModels.add(loadedModel);
                    } catch (IOException e) {
                        if (errorHandler != null) {
                            errorHandler.handleError(
                                    "Was not able to create xml code completion model for file:" + file, e);
                        }
                    }
                }
            } catch (JAXBException e) {
                if (errorHandler != null) {
                    errorHandler.handleError(
                            "Was not able to create JAXB context - so no xml code completion from user home base by xmls possible!",
                            e);
                }
                return;
            }
        }
    }

    private Set<File> findCodeCompletionFilesInUserHome() {
        Set<File> fileSet = new HashSet<>();
        /*
         * FIXME albert,06.01.2017: what about change this to changeable
         * preference value instead of always using user.home?!?!?
         */
        File defaultsSubDir = ensureDefaultsTargetDirectory();
        File customSubDir = ensureTargetDirectory("custom");

        File[] defaultFiles = defaultsSubDir.listFiles(fileFilter);
        if (defaultFiles == null || defaultFiles.length == 0) {
            installDefaultFiles(defaultsSubDir);
            defaultFiles = defaultsSubDir.listFiles(fileFilter);
        }
        File[] customFiles = customSubDir.listFiles(fileFilter);
        addFiles(defaultFiles, fileSet);
        addFiles(customFiles, fileSet);
        return fileSet;
    }

    private File ensureDefaultsTargetDirectory() {
        return ensureTargetDirectory("defaults/" + getVersion());
    }

    private void addFiles(File[] files, Set<File> fileSet) {
        if (files == null) {
            return;
        }
        for (File file : files) {
            if (file == null) {
                continue;
            }
            fileSet.add(file);
        }
    }

    public String getVersion() {
        return "1.3";
    }

    private File ensureTargetDirectory(String subDirName) {
        String userHome = System.getProperty("user.home");
        File file = new File(userHome);
        File subDir = new File(file, ".egradle/codeCompletion/" + subDirName);
        if (!subDir.exists()) {
            subDir.mkdirs();
        }
        return subDir;
    }

    public void restoreDefaults() {
        File dir = ensureDefaultsTargetDirectory();
        deleteOldDefaultFiles(dir);
        installDefaultFiles(dir);
        reload();
    }

    private void deleteOldDefaultFiles(File dir) {
        File[] files = dir.listFiles(fileFilter);
        for (File file : files) {
            if (!file.delete()) {
                if (errorHandler != null) {
                    errorHandler.handleError("Cannot delete old default file:" + file);
                }
            }
        }
    }

    private void installDefaultFiles(File dir) {
        installNewDefaultFiles("/codecompletion/defaults/core.xml", dir, "core.xml");
    }

    private void installNewDefaultFiles(String resPath, File dir, String fileName) {
        FileHelper helper = getFileHelper();
        InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resPath);
        try {
            StringBuffer sb = helper.read(new InputStreamReader(in));

            getFileHelper().createTextFile(dir, fileName, sb.toString());
        } catch (IOException e) {
            if (errorHandler != null) {
                errorHandler.handleError(e);
            }
        }
    }

    private FileHelper getFileHelper() {
        return FileHelper.DEFAULT;
    }

    private class CodeCompletionFileFilter implements FileFilter {

        @Override
        public boolean accept(File file) {
            if (file == null) {
                return false;
            }
            String name = file.getName();
            if (StringUtils.isEmpty(name)) {
                return false;
            }
            if (name.endsWith(".xml")) {
                return true;
            }
            return false;
        }

    }

    @Override
    public List<XMLProposalDataModel> getDataModels() {
        synchronized (monitor) {
            if (!loaded) {
                reload();
            }
            return cachedDataModels;
        }
    }

}