Java tutorial
/* * Copyright (C) 2009 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.gesture; import android.annotation.RawRes; import android.util.Log; import static android.gesture.GestureConstants.*; import android.content.Context; import java.io.File; import java.io.FileOutputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.FileInputStream; import java.io.InputStream; import java.lang.ref.WeakReference; public final class GestureLibraries { private GestureLibraries() { } public static GestureLibrary fromFile(String path) { return fromFile(new File(path)); } public static GestureLibrary fromFile(File path) { return new FileGestureLibrary(path); } public static GestureLibrary fromPrivateFile(Context context, String name) { return fromFile(context.getFileStreamPath(name)); } public static GestureLibrary fromRawResource(Context context, @RawRes int resourceId) { return new ResourceGestureLibrary(context, resourceId); } private static class FileGestureLibrary extends GestureLibrary { private final File mPath; public FileGestureLibrary(File path) { mPath = path; } @Override public boolean isReadOnly() { return !mPath.canWrite(); } public boolean save() { if (!mStore.hasChanged()) return true; final File file = mPath; final File parentFile = file.getParentFile(); if (!parentFile.exists()) { if (!parentFile.mkdirs()) { return false; } } boolean result = false; try { //noinspection ResultOfMethodCallIgnored file.createNewFile(); mStore.save(new FileOutputStream(file), true); result = true; } catch (FileNotFoundException e) { Log.d(LOG_TAG, "Could not save the gesture library in " + mPath, e); } catch (IOException e) { Log.d(LOG_TAG, "Could not save the gesture library in " + mPath, e); } return result; } public boolean load() { boolean result = false; final File file = mPath; if (file.exists() && file.canRead()) { try { mStore.load(new FileInputStream(file), true); result = true; } catch (FileNotFoundException e) { Log.d(LOG_TAG, "Could not load the gesture library from " + mPath, e); } catch (IOException e) { Log.d(LOG_TAG, "Could not load the gesture library from " + mPath, e); } } return result; } } private static class ResourceGestureLibrary extends GestureLibrary { private final WeakReference<Context> mContext; private final int mResourceId; public ResourceGestureLibrary(Context context, int resourceId) { mContext = new WeakReference<Context>(context); mResourceId = resourceId; } @Override public boolean isReadOnly() { return true; } public boolean save() { return false; } public boolean load() { boolean result = false; final Context context = mContext.get(); if (context != null) { final InputStream in = context.getResources().openRawResource(mResourceId); try { mStore.load(in, true); result = true; } catch (IOException e) { Log.d(LOG_TAG, "Could not load the gesture library from raw resource " + context.getResources().getResourceName(mResourceId), e); } } return result; } } }