UpdateHelper.java

package com.nolanlawson.logcat.helper;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.preference.PreferenceManager;

import com.nolanlawson.logcat.R;
import com.nolanlawson.logcat.util.Callback;
import com.nolanlawson.logcat.util.Function;

/**
 * Helper for applying app-wide updates of persistent data.
 * @author nlawson
 *
 */
public class UpdateHelper {

    public static boolean areUpdatesNecessary(Context context) {
        for (Update update : Update.values()) {
            if (update.getIsNecessary().apply(context)) {
                return true;
            }
        }
        return false;
    }
    
    public static void runUpdatesIfNecessary(Context context) {
        for (Update update : Update.values()) {
            if (update.getIsNecessary().apply(context)) {
                update.getRunUpdate().onCallback(context);
            }
        }
    }
    
    private static enum Update {
        
        // update to change "all_combined" to a comma-separation of all three buffers
        Update1(new Function<Context, Boolean>(){

                @Override
                public Boolean apply(Context context) {
                    SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
                    String bufferPref = sharedPrefs.getString(
                            context.getString(R.string.pref_buffer), context.getString(R.string.pref_buffer_choice_main));
                    
                    return bufferPref.equals("all_combined");
                }
            }, new Callback<Context>(){

                @Override
                public void onCallback(Context context) {
                    SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
                    String bufferPref = sharedPrefs.getString(
                            context.getString(R.string.pref_buffer), context.getString(R.string.pref_buffer_choice_main));
                    
                    if (bufferPref.equals("all_combined")) {
                        Editor editor = sharedPrefs.edit();
                        editor.putString(context.getString(R.string.pref_buffer), "main,events,radio");
                        editor.commit();
                    }
                }
            }),
            
            // update to move saved logs from /sdcard/catlog_saved_logs to /sdcard/catlog/saved_logs
            Update2(new Function<Context, Boolean>(){

                    @Override
                    public Boolean apply(Context context) {
                        return SaveLogHelper.checkIfSdCardExists() && SaveLogHelper.legacySavedLogsDirExists();
                    }
                }, new Callback<Context>(){

                    @Override
                    public void onCallback(Context context) {
                        if (SaveLogHelper.checkIfSdCardExists()) {
                            SaveLogHelper.moveLogsFromLegacyDirIfNecessary();
                        }
                    }
                }),    
                
                // update to request superuser READ_LOGS permission on JellyBean
                Update3(new Function<Context, Boolean>(){

                        @Override
                        public Boolean apply(Context context) {
                        	
                        	boolean isJellyBean = VersionHelper.getVersionSdkIntCompat() >= VersionHelper.VERSION_JELLYBEAN;
                        	
                        	return isJellyBean && !PreferenceHelper.getJellybeanRootRan(context);
                        }
                    }, new Callback<Context>(){

                        @Override
                        public void onCallback(Context context) {
                            SuperUserHelper.requestRoot(context);
                        }
                    }),  
            
            
        ;
        
        private Function<Context, Boolean> isNecessary;
        private Callback<Context> runUpdate;
        
        private Update(Function<Context, Boolean> isNecessary, Callback<Context> runUpdate) {
            this.isNecessary = isNecessary;
            this.runUpdate = runUpdate;
        }
        public Function<Context, Boolean> getIsNecessary() {
            return isNecessary;
        }
        public Callback<Context> getRunUpdate() {
            return runUpdate;
        }
    }
}