/** * Copyright (C) 2014 Pau Picas Sans <[email protected]> * * 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 cat.ppicas.customtypeface; import android.app.Activity; import android.content.Context; import android.graphics.Typeface; import android.util.AttributeSet; import android.view.InflateException; import android.view.LayoutInflater; import android.view.View; import java.lang.reflect.Constructor; import java.util.HashMap; /** * An implementation of {@link LayoutInflater.Factory} that creates a {@link View} and applies * on it a custom {@link Typeface} calling {@link CustomTypeface#applyTypeface(View, AttributeSet)}. * * <p> * This class can also accept another {@code LayoutInflater.Factory} implementation to delegate * the view creation first. If the delegated {@code LayoutInflater.Factory} returns * {@code null} on the view creation, this class will then use the internal * {@code View} factory. Please use {@link #CustomTypefaceFactory(Context, CustomTypeface, * LayoutInflater.Factory)} if you want this class to use a delegate {@code LayoutInflater.Factory}. * </p> * * <p> * Please, take in account that {@link LayoutInflater} only accepts the * {@link LayoutInflater.Factory} to be set once. If you call {@link LayoutInflater#setFactory} * on a {@code LayoutInflater} that already has one, it will throw a {@code RuntimeException}. * This is why we recommend you to set the {@code Factory} before calling * super.{@link Activity#onCreate onCreate} when you are overriding {@code Activity.onCreate} * on your own {@code Activity}. Please, check the following example: * </p> * * <pre><code> * public class MainActivity extends Activity { * * // ... * * {@literal @Override} * protected void onCreate(Bundle savedInstanceState) { * getLayoutInflater().setFactory(new CustomTypefaceFactory( * this, CustomTypeface.getInstance())); * * super.onCreate(savedInstanceState); * setContentView(R.layout.activity_main); * } * * // ... * * } * </code></pre> * * <p> * For more info on how to use this class in combination with {@link CustomTypeface} please * check the {@link CustomTypeface documentation} of that class. * </p> * * @see CustomTypeface * @see LayoutInflater.Factory */ public class CustomTypefaceFactory implements LayoutInflater.Factory { private static final Class<?>[] CONSTRUCTOR_SIGNATURE = new Class[] { Context.class, AttributeSet.class}; private static final HashMap<String, Constructor<? extends View>> CONSTRUCTOR_MAP = new HashMap<String, Constructor<? extends View>>(); private final Object[] mConstructorArgs = new Object[2]; private final Context mContext; private final CustomTypeface mCustomTypeface; private LayoutInflater.Factory mFactory; public CustomTypefaceFactory(Context context, CustomTypeface customTypeface) { this(context, customTypeface, null); } public CustomTypefaceFactory(Context context, CustomTypeface customTypeface, LayoutInflater.Factory factory) { mContext = context; mCustomTypeface = customTypeface; mFactory = factory; } public LayoutInflater.Factory getFactory() { return mFactory; } public void setFactory(LayoutInflater.Factory factory) { mFactory = factory; } /** * Implements {@link LayoutInflater.Factory} interface. Inflate the {@link View} for the * specified tag name and apply custom {@link Typeface} if is required. This * method first will delegate to the {@code LayoutInflater.Factory} if it was specified on the * constructor. When the {@code View} is created, this method will call {@link * CustomTypeface#applyTypeface(View, AttributeSet)} on it. * * <p> * This method can be used to delegate the implementation of {@link * LayoutInflater.Factory#onCreateView} * or {@link LayoutInflater.Factory2#onCreateView}. * </p> * * @param name Tag name to be inflated. * @param context The context the view is being created in. * @param attrs Inflation attributes as specified in XML file. * @return Newly created view. * @see LayoutInflater.Factory * @see CustomTypeface#applyTypeface(View, AttributeSet) */ @Override public View onCreateView(String name, Context context, AttributeSet attrs) { String prefix = null; if (name.indexOf('.') == -1) { prefix = "android.widget."; } try { View view = null; if (mFactory != null) { view = mFactory.onCreateView(name, context, attrs); } if (view == null) { view = createView(name, prefix, context, attrs); } mCustomTypeface.applyTypeface(view, attrs); return view; } catch (ClassNotFoundException e) { return null; } } /** * Low-level function for instantiating a view by name. This attempts to * instantiate a view class of the given <var>name</var> found in this * LayoutInflater's ClassLoader. * * <p> * There are two things that can happen in an error case: either the * exception describing the error will be thrown, or a null will be * returned. You must deal with both possibilities -- the former will happen * the first time createView() is called for a class of a particular name, * the latter every time there-after for that class name. * * @param name The full name of the class to be instantiated. * @param context The Context in which this LayoutInflater will create its * Views; most importantly, this supplies the theme from which the default * values for their attributes are retrieved. * @param attrs The XML attributes supplied for this instance. * @return View The newly instantiated view, or null. */ private View createView(String name, String prefix, Context context, AttributeSet attrs) throws ClassNotFoundException, InflateException { Constructor<? extends View> constructor = CONSTRUCTOR_MAP.get(name); Class<? extends View> clazz = null; try { if (constructor == null) { // Class not found in the cache, see if it's real, and try to add it clazz = mContext.getClassLoader().loadClass( prefix != null ? (prefix + name) : name).asSubclass(View.class); constructor = clazz.getConstructor(CONSTRUCTOR_SIGNATURE); constructor.setAccessible(true); CONSTRUCTOR_MAP.put(name, constructor); } mConstructorArgs[0] = context; mConstructorArgs[1] = attrs; return constructor.newInstance(mConstructorArgs); } catch (NoSuchMethodException e) { InflateException ie = new InflateException(attrs.getPositionDescription() + ": Error inflating class " + (prefix != null ? (prefix + name) : name)); ie.initCause(e); throw ie; } catch (ClassCastException e) { // If loaded class is not a View subclass InflateException ie = new InflateException(attrs.getPositionDescription() + ": Class is not a View " + (prefix != null ? (prefix + name) : name)); ie.initCause(e); throw ie; } catch (ClassNotFoundException e) { // If loadClass fails, we should propagate the exception. throw e; } catch (Exception e) { InflateException ie = new InflateException(attrs.getPositionDescription() + ": Error inflating class " + (clazz == null ? "<unknown>" : clazz.getName())); ie.initCause(e); throw ie; } } }
