k-9/src/com/fsck/k9/preferences/Editor.java

package com.fsck.k9.preferences;

import android.util.Log;
import com.fsck.k9.K9;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class Editor implements android.content.SharedPreferences.Editor {
    private Storage storage;
    private Map<String, String> changes = new HashMap<String, String>();
    private List<String> removals = new ArrayList<String>();
    private boolean removeAll = false;

    Map<String, String> snapshot = new HashMap<String, String>();


    protected Editor(Storage storage) {
        this.storage = storage;
        snapshot.putAll(storage.getAll());
    }

    public void copy(android.content.SharedPreferences input) {
        Map < String, ? > oldVals = input.getAll();
        for (Entry < String, ? > entry : oldVals.entrySet()) {
            String key = entry.getKey();
            Object value = entry.getValue();
            if (key != null && value != null) {
                if (K9.DEBUG) {
                    Log.d(K9.LOG_TAG, "Copying key '" + key + "', value '" + value + "'");
                }
                changes.put(key, "" + value);
            } else {
                if (K9.DEBUG) {
                    Log.d(K9.LOG_TAG, "Skipping copying key '" + key + "', value '" + value + "'");
                }
            }
        }
    }

    //@Override
    public android.content.SharedPreferences.Editor clear() {
        removeAll = true;
        return this;
    }


    // TODO Android 2.3 provides a sexy new "apply" method we need to implement
    public void apply() {
        commit();
    }



    /* This method is poorly defined.  It should throw an Exception on failure */
    //@Override
    public boolean commit() {
        try {
            commitChanges();
            return true;
        } catch (Exception e) {
            Log.e(K9.LOG_TAG, "Failed to save preferences", e);
            return false;
        }
    }

    public void commitChanges() {
        long startTime = System.currentTimeMillis();
        Log.i(K9.LOG_TAG, "Committing preference changes");
        Runnable committer = new Runnable() {
            public void run() {
                if (removeAll) {
                    storage.removeAll();
                }
                for (String removeKey : removals) {
                    storage.remove(removeKey);
                }
                Map<String, String> insertables = new HashMap<String, String>();
                for (Entry<String, String> entry : changes.entrySet()) {
                    String key = entry.getKey();
                    String newValue = entry.getValue();
                    String oldValue = snapshot.get(key);
                    if (removeAll || removals.contains(key) || !newValue.equals(oldValue)) {
                        insertables.put(key, newValue);
                    }
                }
                storage.put(insertables);
            }
        };
        storage.doInTransaction(committer);
        long endTime = System.currentTimeMillis();
        Log.i(K9.LOG_TAG, "Preferences commit took " + (endTime - startTime) + "ms");

    }

    //@Override
    public android.content.SharedPreferences.Editor putBoolean(String key,
            boolean value) {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putFloat(String key,
            float value) {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putInt(String key, int value) {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putLong(String key, long value) {
        changes.put(key, "" + value);
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor putString(String key,
            String value) {
        if (value == null) {
            remove(key);
        } else {
            changes.put(key, value);
        }
        return this;
    }

    //@Override
    public android.content.SharedPreferences.Editor remove(String key) {
        removals.add(key);
        return this;
    }

    @Override
    public android.content.SharedPreferences.Editor putStringSet(String arg0, Set<String> arg1) {
        throw new RuntimeException("Not implemented");
    }

}