Java tutorial
/* * Original code from Android MultiSelectListPreference * Modified to add a drag and drop behavior * * Copyright (C) 2010 The Android Open Source Project * * 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 android.preference; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Set; import org.apache.commons.lang3.ArrayUtils; import org.apache.commons.lang3.StringUtils; import android.app.AlertDialog.Builder; import android.content.Context; import android.content.SharedPreferences; import android.content.res.TypedArray; import android.os.Parcel; import android.os.Parcelable; import android.util.AttributeSet; import android.util.SparseBooleanArray; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ArrayAdapter; import android.widget.ListView; import com.abewy.android.apps.klyph.R; import com.mobeta.android.dslv.DragSortController; import com.mobeta.android.dslv.DragSortListView; /** * A {@link Preference} that displays a list of entries as * a dialog. * <p> * This preference will store a set of strings into the SharedPreferences. This * set will contain one or more values from the * {@link #setEntryValues(CharSequence[])} array. * * @attr ref R.styleable#MultiSelectDragListPreference_entries * @attr ref R.styleable#MultiSelectDragListPreference_entryValues */ public class MultiSelectDragListPreference extends DialogPreference { private CharSequence[] mEntries; private CharSequence[] mEntryValues; private List<String> mValues = new ArrayList<String>(); private List<String> mNewValues = new ArrayList<String>(); private boolean mPreferenceChanged; private DragSortListView listView; public MultiSelectDragListPreference(Context context, AttributeSet attrs) { super(context, attrs); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MultiSelectDragListPreference, 0, 0); mEntries = a.getTextArray(R.styleable.MultiSelectDragListPreference_entries); mEntryValues = a.getTextArray(R.styleable.MultiSelectDragListPreference_entryValues); a.recycle(); } public MultiSelectDragListPreference(Context context) { this(context, null); } /** * Sets the human-readable entries to be shown in the list. This will be * shown in subsequent dialogs. * <p> * Each entry must have a corresponding index in * {@link #setEntryValues(CharSequence[])}. * * @param entries The entries. * @see #setEntryValues(CharSequence[]) */ public void setEntries(CharSequence[] entries) { mEntries = entries; } /** * @see #setEntries(CharSequence[]) * @param entriesResId The entries array as a resource. */ public void setEntries(int entriesResId) { setEntries(getContext().getResources().getTextArray(entriesResId)); } /** * The list of entries to be shown in the list in subsequent dialogs. * * @return The list as an array. */ public CharSequence[] getEntries() { return mEntries; } /** * The array to find the value to save for a preference when an entry from * entries is selected. If a user clicks on the second item in entries, the * second item in this array will be saved to the preference. * * @param entryValues The array to be used as values to save for the * preference. */ public void setEntryValues(CharSequence[] entryValues) { mEntryValues = entryValues; } /** * @see #setEntryValues(CharSequence[]) * @param entryValuesResId The entry values array as a resource. */ public void setEntryValues(int entryValuesResId) { setEntryValues(getContext().getResources().getTextArray(entryValuesResId)); } /** * Returns the array of values to be saved for the preference. * * @return The array of values. */ public CharSequence[] getEntryValues() { return mEntryValues; } /** * Sets the value of the key. This should contain entries in * {@link #getEntryValues()}. * * @param values The values to set for the key. */ public void setValues(List<String> values) { mValues.clear(); mValues.addAll(values); persistStringSet(values); } /** * Attempts to persist a set of Strings to the * {@link android.content.SharedPreferences}. * <p> * This will check if this Preference is persistent, get an editor from the * {@link PreferenceManager}, put in the strings, and check if we should * commit (and commit if so). * * @param values The values to persist. * @return True if the Preference is persistent. (This is not whether the * value was persisted, since we may not necessarily commit if there * will be a batch commit later.) * @see #getPersistedString(Set) * * @hide Pending API approval */ protected boolean persistStringSet(List<String> values) { if (shouldPersist()) { // Shouldn't store null if (values.equals(getPersistedStringSet(""))) { // It's already there, so the same as persisting return true; } SharedPreferences.Editor editor = mPreferenceManager.getSharedPreferences().edit(); editor.putString(getKey(), StringUtils.join(values, ",")); editor.commit(); return true; } return false; } /** * Checks whether, at the given time this method is called, * this Preference should store/restore its value(s) into the * {@link SharedPreferences}. This, at minimum, checks whether this * Preference is persistent and it currently has a key. Before you * save/restore from the {@link SharedPreferences}, check this first. * * @return True if it should persist the value. */ protected boolean shouldPersist() { return mPreferenceManager != null && isPersistent() && hasKey(); } /** * Retrieves the current value of the key. */ public List<String> getValues() { return mValues; } /** * Returns the index of the given value (in the entry values array). * * @param value The value whose index should be returned. * @return The index of the value, or -1 if not found. */ public int findIndexOfValue(String value) { if (value != null && mEntryValues != null) { for (int i = mEntryValues.length - 1; i >= 0; i--) { if (mEntryValues[i].equals(value)) { return i; } } } return -1; } private DragSortListView getListView() { return listView; } @Override protected void onPrepareDialogBuilder(Builder builder) { super.onPrepareDialogBuilder(builder); if (mEntries == null || mEntryValues == null) { throw new IllegalStateException( "MultiSelectListPreference requires an entries array and " + "an entryValues array."); } String[] entries = new String[mEntries.length]; for (int i = 0; i < mEntries.length; i++) { entries[i] = mEntries[i].toString(); } boolean[] selectedItems = getSelectedItems(); ArrayList<String> orderedList = new ArrayList<String>(); int n = selectedItems.length; for (String value : mValues) { int index = ArrayUtils.indexOf(mEntryValues, value); orderedList.add(mEntries[index].toString()); } for (int i = 0; i < mEntries.length; i++) { if (!mValues.contains(mEntryValues[i])) orderedList.add(mEntries[i].toString()); } adapter = new ArrayAdapter<String>(getContext(), R.layout.item_list_preference_multi_drag, R.id.text, orderedList); listView = new DragSortListView(getContext(), null); listView.setAdapter(adapter); listView.setDropListener(onDrop); listView.setDragEnabled(true); listView.setFloatAlpha(0.8f); DragSortController controller = new DragSortController(listView); controller.setDragHandleId(R.id.drag_handle); controller.setRemoveEnabled(false); controller.setSortEnabled(true); controller.setBackgroundColor(0xFFFFFF); controller.setDragInitMode(DragSortController.ON_DOWN); listView.setFloatViewManager(controller); listView.setOnTouchListener(controller); builder.setView(listView); listView.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { mPreferenceChanged = true; refreshNewValues(); } }); listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE); for (int i = 0; i < n; i++) { listView.setItemChecked(i, i < mValues.size()); } /* * boolean [] checkedItems = getSelectedItems(); * builder.setMultiChoiceItems(mEntries, checkedItems, * new DialogInterface.OnMultiChoiceClickListener() { * public void onClick(DialogInterface dialog, int which, boolean * isChecked) { * if (isChecked) { * mPreferenceChanged |= mNewValues.add(mEntryValues[which].toString()); * } else { * mPreferenceChanged |= * mNewValues.remove(mEntryValues[which].toString()); * } * } * }); */ mNewValues.clear(); mNewValues.addAll(mValues); } private ArrayAdapter<String> adapter; private DragSortListView.DropListener onDrop = new DragSortListView.DropListener() { @Override public void drop(int from, int to) { if (from != to) { DragSortListView list = getListView(); String item = adapter.getItem(from); adapter.remove(item); adapter.insert(item, to); list.moveCheckState(from, to); mPreferenceChanged = true; refreshNewValues(); } } }; private void refreshNewValues() { mNewValues.clear(); int n = adapter.getCount(); SparseBooleanArray checkedPositions = listView.getCheckedItemPositions(); for (int i = 0; i < n; i++) { if (checkedPositions.get(i) == true) { mNewValues.add((String) mEntryValues[ArrayUtils.indexOf(mEntries, adapter.getItem(i))]); } } } private boolean[] getSelectedItems() { final CharSequence[] entries = mEntryValues; final int entryCount = entries.length; final List<String> values = mValues; boolean[] result = new boolean[entryCount]; for (int i = 0; i < entryCount; i++) { result[i] = values.contains(entries[i].toString()); } return result; } @Override protected void onDialogClosed(boolean positiveResult) { super.onDialogClosed(positiveResult); if (positiveResult && mPreferenceChanged) { refreshNewValues(); final List<String> values = mNewValues; if (callChangeListener(values) && values.size() > 0) { setValues(values); } } mPreferenceChanged = false; } @Override protected Object onGetDefaultValue(TypedArray a, int index) { final CharSequence[] defaultValues = a.getTextArray(index); final int valueCount = defaultValues.length; final List<String> result = new ArrayList<String>(); for (int i = 0; i < valueCount; i++) { result.add(defaultValues[i].toString()); } return result; } @SuppressWarnings("unchecked") @Override protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { List<String> v = (List<String>) defaultValue; String defValue = PreferenceManager.getDefaultSharedPreferences(getContext()).getString(getKey(), StringUtils.join(v.toArray(), ",")); setValues(restoreValue ? getPersistedStringSet(StringUtils.join(mValues)) : Arrays.asList(defValue.split(","))); } PreferenceManager mPreferenceManager; protected List<String> getPersistedStringSet(String defaultReturnValue) { if (!shouldPersist()) { return Arrays.asList(defaultReturnValue.split(",")); } return Arrays.asList( mPreferenceManager.getSharedPreferences().getString(getKey(), defaultReturnValue).split(",")); } protected void onAttachedToHierarchy(PreferenceManager preferenceManager) { super.onAttachedToHierarchy(preferenceManager); mPreferenceManager = preferenceManager; } @Override protected Parcelable onSaveInstanceState() { final Parcelable superState = super.onSaveInstanceState(); if (isPersistent()) { // No need to save instance state return superState; } final SavedState myState = new SavedState(superState); myState.values = StringUtils.join(getValues(), ","); return myState; } private static class SavedState extends BaseSavedState { String values; public SavedState(Parcel source) { super(source); values = source.readString(); } public SavedState(Parcelable superState) { super(superState); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeString(values); } public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; } }