Android Open Source - Todo Instance Creation Utils

From Project

Back to project page Todo.
License

The source code is released under:
GNU General Public License
If you think the Android project Todo listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.
Java Source Code

/*
 * Copyright 2013 Chris Banes// w ww . j  a va2s  .co  m
 *
 * 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 uk.co.senab.actionbarpulltorefresh.library;

import android.content.Context;
import android.util.Log;
import android.view.View;

import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import uk.co.senab.actionbarpulltorefresh.library.viewdelegates.AbsListViewDelegate;
import uk.co.senab.actionbarpulltorefresh.library.viewdelegates.ScrollYDelegate;
import uk.co.senab.actionbarpulltorefresh.library.viewdelegates.WebViewDelegate;

class InstanceCreationUtils {

    private static final String LOG_TAG = "InstanceCreationUtils";

    private static final Class<?>[] VIEW_DELEGATE_CONSTRUCTOR_SIGNATURE = new Class[]{};
    private static final Class<?>[] TRANSFORMER_CONSTRUCTOR_SIGNATURE = new Class[]{};

    private static final HashMap<Class, Class> BUILT_IN_DELEGATES;
    static {
        BUILT_IN_DELEGATES = new HashMap<Class, Class>();
        BUILT_IN_DELEGATES.put(AbsListViewDelegate.SUPPORTED_VIEW_CLASS, AbsListViewDelegate.class);
        BUILT_IN_DELEGATES.put(WebViewDelegate.SUPPORTED_VIEW_CLASS, WebViewDelegate.class);
    }

    static PullToRefreshAttacher.ViewDelegate getBuiltInViewDelegate(final View view) {
        final Set<Map.Entry<Class, Class>> entries = BUILT_IN_DELEGATES.entrySet();
        for (final Map.Entry<Class, Class> entry : entries) {
            if (entry.getKey().isInstance(view)) {
                return InstanceCreationUtils.newInstance(view.getContext(),
                        entry.getValue(), VIEW_DELEGATE_CONSTRUCTOR_SIGNATURE, null);
            }
        }

        // Default is the ScrollYDelegate
        return InstanceCreationUtils.newInstance(view.getContext(),
                ScrollYDelegate.class, VIEW_DELEGATE_CONSTRUCTOR_SIGNATURE, null);
    }

    static <T> T instantiateViewDelegate(Context context, String className, Object[] arguments) {
        try {
            Class<?> clazz = context.getClassLoader().loadClass(className);
            return newInstance(context, clazz, VIEW_DELEGATE_CONSTRUCTOR_SIGNATURE, arguments);
        } catch (Exception e) {
            Log.w(LOG_TAG, "Cannot instantiate class: " + className, e);
        }
        return null;
    }

    static <T> T instantiateTransformer(Context context, String className, Object[] arguments) {
        try {
            Class<?> clazz = context.getClassLoader().loadClass(className);
            return newInstance(context, clazz, TRANSFORMER_CONSTRUCTOR_SIGNATURE, arguments);
        } catch (Exception e) {
            Log.w(LOG_TAG, "Cannot instantiate class: " + className, e);
        }
        return null;
    }

    private static <T> T newInstance(Context context, Class clazz, Class[] constructorSig,
            Object[] arguments) {
        try {
            Constructor<?> constructor = clazz.getConstructor(constructorSig);
            return (T) constructor.newInstance(arguments);
        } catch (Exception e) {
            Log.w(LOG_TAG, "Cannot instantiate class: " + clazz.getName(), e);
        }
        return null;
    }

}
Java Source Code List
