PreferenceGroupAdapter.java

package org.holoeverywhere.preference;

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

import org.holoeverywhere.preference.Preference.OnPreferenceChangeInternalListener;

import android.os.Handler;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.BaseAdapter;

class PreferenceGroupAdapter extends BaseAdapter implements
        OnPreferenceChangeInternalListener {
    private static class PreferenceLayout implements
            Comparable<PreferenceLayout> {
        private String name;
        private int resId;
        private int widgetResId;

        @Override
        public int compareTo(PreferenceLayout other) {
            int compareNames = name.compareTo(other.name);
            if (compareNames == 0) {
                if (resId == other.resId) {
                    if (widgetResId == other.widgetResId) {
                        return 0;
                    } else {
                        return widgetResId - other.widgetResId;
                    }
                } else {
                    return resId - other.resId;
                }
            } else {
                return compareNames;
            }
        }
    }

    private Handler mHandler = new Handler();
    private boolean mHasReturnedViewTypeCount = false;
    private volatile boolean mIsSyncing = false;
    private PreferenceGroup mPreferenceGroup;
    private List<PreferenceLayout> mPreferenceLayouts;
    private List<Preference> mPreferenceList;
    private Runnable mSyncRunnable = new Runnable() {
        @Override
        public void run() {
            syncMyPreferences();
        }
    };

    private PreferenceLayout mTempPreferenceLayout = new PreferenceLayout();

    public PreferenceGroupAdapter(PreferenceGroup preferenceGroup) {
        mPreferenceGroup = preferenceGroup;
        mPreferenceGroup.setOnPreferenceChangeInternalListener(this);
        int c = preferenceGroup.getPreferenceCount();
        mPreferenceList = new ArrayList<Preference>(c);
        mPreferenceLayouts = new ArrayList<PreferenceLayout>(c);
        syncMyPreferences();
    }

    private void addPreferenceClassName(Preference preference) {
        final PreferenceLayout pl = createPreferenceLayout(preference, null);
        int insertPos = Collections.binarySearch(mPreferenceLayouts, pl);
        if (insertPos < 0) {
            insertPos = insertPos * -1 - 1;
            mPreferenceLayouts.add(insertPos, pl);
        }
    }

    @Override
    public boolean areAllItemsEnabled() {
        return false;
    }

    private PreferenceLayout createPreferenceLayout(Preference preference,
            PreferenceLayout in) {
        PreferenceLayout pl = in != null ? in : new PreferenceLayout();
        pl.name = preference.getClass().getName();
        pl.resId = preference.getLayoutResource();
        pl.widgetResId = preference.getWidgetLayoutResource();
        return pl;
    }

    private void flattenPreferenceGroup(List<Preference> preferences,
            PreferenceGroup group) {
        group.sortPreferences();
        final int groupSize = group.getPreferenceCount();
        for (int i = 0; i < groupSize; i++) {
            final Preference preference = group.getPreference(i);
            preferences.add(preference);
            if (!mHasReturnedViewTypeCount && !preference.hasSpecifiedLayout()) {
                addPreferenceClassName(preference);
            }
            if (preference instanceof PreferenceGroup) {
                final PreferenceGroup preferenceAsGroup = (PreferenceGroup) preference;
                if (preferenceAsGroup.isOnSameScreenAsChildren()) {
                    flattenPreferenceGroup(preferences, preferenceAsGroup);
                }
            }
            preference.setOnPreferenceChangeInternalListener(this);
        }
    }

    @Override
    public int getCount() {
        return mPreferenceList.size();
    }

    @Override
    public Preference getItem(int position) {
        if (position < 0 || position >= getCount()) {
            return null;
        }
        return mPreferenceList.get(position);
    }

    @Override
    public long getItemId(int position) {
        if (position < 0 || position >= getCount()) {
            return AdapterView.INVALID_ROW_ID;
        }
        return getItem(position).getId();
    }

    @Override
    public int getItemViewType(int position) {
        if (!mHasReturnedViewTypeCount) {
            mHasReturnedViewTypeCount = true;
        }
        final Preference preference = getItem(position);
        if (!preference.hasSpecifiedLayout()) {
            return Adapter.IGNORE_ITEM_VIEW_TYPE;
        }
        mTempPreferenceLayout = createPreferenceLayout(preference,
                mTempPreferenceLayout);
        int viewType = Collections.binarySearch(mPreferenceLayouts,
                mTempPreferenceLayout);
        if (viewType < 0) {
            return Adapter.IGNORE_ITEM_VIEW_TYPE;
        } else {
            return viewType;
        }
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        final Preference preference = getItem(position);
        mTempPreferenceLayout = createPreferenceLayout(preference,
                mTempPreferenceLayout);
        if (Collections.binarySearch(mPreferenceLayouts, mTempPreferenceLayout) < 0) {
            convertView = null;
        }
        return preference.getView(convertView, parent);
    }

    @Override
    public int getViewTypeCount() {
        if (!mHasReturnedViewTypeCount) {
            mHasReturnedViewTypeCount = true;
        }
        return Math.max(1, mPreferenceLayouts.size());
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public boolean isEnabled(int position) {
        if (position < 0 || position >= getCount()) {
            return true;
        }
        return getItem(position).isSelectable();
    }

    @Override
    public void onPreferenceChange(Preference preference) {
        notifyDataSetChanged();
    }

    @Override
    public void onPreferenceHierarchyChange(Preference preference) {
        mHandler.removeCallbacks(mSyncRunnable);
        mHandler.post(mSyncRunnable);
    }

    private void syncMyPreferences() {
        synchronized (this) {
            if (mIsSyncing) {
                return;
            }
            mIsSyncing = true;
        }
        List<Preference> newPreferenceList = new ArrayList<Preference>(
                mPreferenceList.size());
        flattenPreferenceGroup(newPreferenceList, mPreferenceGroup);
        mPreferenceList = newPreferenceList;
        notifyDataSetChanged();
        synchronized (this) {
            mIsSyncing = false;
            notifyAll();
        }
    }
}