/*
* Copyright (C) 2006 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.widget;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.view.LayoutInflater;
import android.net.Uri;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
* 这是一个简单的适配器，可以将静态数据映射到XML文件中定义好的视图.
* 你可以将 Maps 的 ArrayList 指定为用于列表的数据.ArrayList 中的每一项对应列表中的一行.
* Maps 中包含用于一行的数据.你也可以指定 XML 文件，其中定义了用于显示行的视图，通过
* Map 的关键字映射到指定的视图.
* 绑定数据到视图分两个阶段.首先，如果 {@link android.widget.SimpleAdapter.ViewBinder} 是有效的，
* 则调用 {@link ViewBinder#setViewValue(android.view.View, Object, String)} 方法.
* 如果返回值为真，则执行绑定.如果返回值为假，则按以下顺序绑定视图：
* <ul>
* <li> 实现了 Checkable 的视图（例如 CheckBox），期望绑定值是布尔类型.
* <li> TextView，期望绑定值是字符串类型，通过调用 {@link #setViewText(TextView, String)} 绑定.
* <li> ImageView，期望绑定值是资源 ID 或者一个字符串，通过调用
* {@link #setViewImage(ImageView, int)} 或 {@link #setViewImage(ImageView, String)}绑定.
* </ul>
* 如果没有合适的绑定发生，将会抛出 {@link IllegalStateException} 异常.
* @author translate by 德罗德
* @author convert by cnmahj
*/
public class SimpleAdapter extends BaseAdapter implements Filterable {
private int[] mTo;
private String[] mFrom;
private ViewBinder mViewBinder;
private List<? extends Map<String, ?>> mData;
private int mResource;
private int mDropDownResource;
private LayoutInflater mInflater;
private SimpleFilter mFilter;
private ArrayList<Map<String, ?>> mUnfilteredData;
/**
* 构造函数
*
* @param context 与 SimpleAdapter 关联的运行着的视图的上下文.
* @param data Map 的列表.列表中的每个条目对应一行.Maps 中包含所有在 from 中指定的数据.
* @param resource 定义列表项目的视图布局的资源 ID.布局文件至少应该包含在 to 中定义了的名称.
* @param from 与 Map 中的项目建立关联的列名的列表.
* @param to 用于显示 from 中参数中的列的视图列表.这些视图应该都是 TextView 类型的.
* 该列表中的第 N 个视图显示从参数 from 中的第 N 列获取的值.
*/
public SimpleAdapter(Context context, List<? extends Map<String, ?>> data,
int resource, String[] from, int[] to) {
mData = data;
mResource = mDropDownResource = resource;
mFrom = from;
mTo = to;
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
/**
* @see android.widget.Adapter#getCount()
*/
public int getCount() {
return mData.size();
}
/**
* @see android.widget.Adapter#getItem(int)
*/
public Object getItem(int position) {
return mData.get(position);
}
/**
* @see android.widget.Adapter#getItemId(int)
*/
public long getItemId(int position) {
return position;
}
/**
* @see android.widget.Adapter#getView(int, View, ViewGroup)
*/
public View getView(int position, View convertView, ViewGroup parent) {
return createViewFromResource(position, convertView, parent, mResource);
}
private View createViewFromResource(int position, View convertView,
ViewGroup parent, int resource) {
View v;
if (convertView == null) {
v = mInflater.inflate(resource, parent, false);
} else {
v = convertView;
}
bindView(position, v);
return v;
}
/**
* <p>设置创建下拉列表视图的布局资源 ID.</p>
*
* @param resource 定义下拉列表视图的布局资源 ID.
* @see #getDropDownView(int, android.view.View, android.view.ViewGroup)
*/
public void setDropDownViewResource(int resource) {
this.mDropDownResource = resource;
}
@Override
public View getDropDownView(int position, View convertView, ViewGroup parent) {
return createViewFromResource(position, convertView, parent, mDropDownResource);
}
private void bindView(int position, View view) {
final Map dataSet = mData.get(position);
if (dataSet == null) {
return;
}
final ViewBinder binder = mViewBinder;
final String[] from = mFrom;
final int[] to = mTo;
final int count = to.length;
for (int i = 0; i < count; i++) {
final View v = view.findViewById(to[i]);
if (v != null) {
final Object data = dataSet.get(from[i]);
String text = data == null ? "" : data.toString();
if (text == null) {
text = "";
}
boolean bound = false;
if (binder != null) {
bound = binder.setViewValue(v, data, text);
}
if (!bound) {
if (v instanceof Checkable) {
if (data instanceof Boolean) {
((Checkable) v).setChecked((Boolean) data);
} else if (v instanceof TextView) {
// Note: keep the instanceof TextView check at the bottom of these
// ifs since a lot of views are TextViews (e.g. CheckBoxes).
setViewText((TextView) v, text);
} else {
throw new IllegalStateException(v.getClass().getName() +
" should be bound to a Boolean, not a " +
(data == null ? "<unknown type>" : data.getClass()));
}
} else if (v instanceof TextView) {
// Note: keep the instanceof TextView check at the bottom of these
// ifs since a lot of views are TextViews (e.g. CheckBoxes).
setViewText((TextView) v, text);
} else if (v instanceof ImageView) {
if (data instanceof Integer) {
setViewImage((ImageView) v, (Integer) data);
} else {
setViewImage((ImageView) v, text);
}
} else {
throw new IllegalStateException(v.getClass().getName() + " is not a " +
" view that can be bounds by this SimpleAdapter");
}
}
}
}
}
/**
* 返回用于将数据绑定到视图的 {@link ViewBinder}.
*
* @return ViewBinder，如果绑定器不存在则返回 null.
*
* @see #setViewBinder(android.widget.SimpleAdapter.ViewBinder)
*/
public ViewBinder getViewBinder() {
return mViewBinder;
}
/**
* 设置用于将数据绑定到视图的绑定器.
*
* @param viewBinder 用于将数据绑定到视图的绑定器.设置为 null，可以删除既存的绑定器.
*
* @see #getViewBinder()
*/
public void setViewBinder(ViewBinder viewBinder) {
mViewBinder = viewBinder;
}
/**
* 由 bindView() 方法调用，用于为 ImageView 设置图像.只在
* ViewBinder 不存在或者既存的 ViewBinder 无法处理 ImageView 的绑定时才调用.
*
* 如果调用 {@link #setViewImage(ImageView, String)} 方法时提供的
* value 参数可以转换为整数类型，则会自动调用本方法.
*
* @param v 接收图像的 ImageView.
* @param value 从数据集获取到的值
*
* @see #setViewImage(ImageView, String)
*/
public void setViewImage(ImageView v, int value) {
v.setImageResource(value);
}
/**
* 由 bindView() 方法调用，用于为 ImageView 设置图像.只在
* ViewBinder 不存在或者既存的 ViewBinder 无法处理 ImageView 的绑定时才调用.
*
* 本方法默认将 value 作为图像资源 ID 来对待；当 value
* 无法变换为整数类型时，才作为图像的 Uri 来使用.
*
* @param v 接收图像的 ImageView.
* @param value 从数据集获取到的值.
*
* @see #setViewImage(ImageView, int)
*/
public void setViewImage(ImageView v, String value) {
try {
v.setImageResource(Integer.parseInt(value));
} catch (NumberFormatException nfe) {
v.setImageURI(Uri.parse(value));
}
}
/**
* 由 bindView() 方法调用，用于为 TextView 设置文本.只在
* ViewBinder 不存在或者既存的 ViewBinder 无法处理 TextView 的绑定时才调用.
*
* @param v 接收文本的 TextView.
* @param text 设置到 TextView 的文本.
*/
public void setViewText(TextView v, String text) {
v.setText(text);
}
public Filter getFilter() {
if (mFilter == null) {
mFilter = new SimpleFilter();
}
return mFilter;
}
/**
* 该类用于 SimpleAdapter 的外部客户将适配器的值绑定到视图.
*
* 你可以使用此类将 SimpleAdapter 不支持的值绑定到视图，或者改变 SimpleAdapter
* 支持的视图的绑定方式.
*
* @see SimpleAdapter#setViewImage(ImageView, int)
* @see SimpleAdapter#setViewImage(ImageView, String)
* @see SimpleAdapter#setViewText(TextView, String)
*/
public static interface ViewBinder {
/**
* 绑定指定的数据到指定的视图.
*
* 当使用 ViewBinder 绑定了数据时，必须返回真.如果该方法返回假，
* SimpleAdapter 会用自己的方式去绑定数据.
*
* @param view 要绑定数据的视图
* @param data 绑定用的数据
* @param textRepresentation 代表所提供的数据的安全字符串：
* 或者是 data.toString()，或者是空串，不能为空.
*
* @return 如果将数据绑定到了视图，返回真；否则返回假.
*/
boolean setViewValue(View view, Object data, String textRepresentation);
}
/**
* <p>An array filters constrains the content of the array adapter with
* a prefix. Each item that does not start with the supplied prefix
* is removed from the list.</p>
*/
private class SimpleFilter extends Filter {
@Override
protected FilterResults performFiltering(CharSequence prefix) {
FilterResults results = new FilterResults();
if (mUnfilteredData == null) {
mUnfilteredData = new ArrayList<Map<String, ?>>(mData);
}
if (prefix == null || prefix.length() == 0) {
ArrayList<Map<String, ?>> list = mUnfilteredData;
results.values = list;
results.count = list.size();
} else {
String prefixString = prefix.toString().toLowerCase();
ArrayList<Map<String, ?>> unfilteredValues = mUnfilteredData;
int count = unfilteredValues.size();
ArrayList<Map<String, ?>> newValues = new ArrayList<Map<String, ?>>(count);
for (int i = 0; i < count; i++) {
Map<String, ?> h = unfilteredValues.get(i);
if (h != null) {
int len = mTo.length;
for (int j=0; j<len; j++) {
String str = (String)h.get(mFrom[j]);
String[] words = str.split(" ");
int wordCount = words.length;
for (int k = 0; k < wordCount; k++) {
String word = words[k];
if (word.toLowerCase().startsWith(prefixString)) {
newValues.add(h);
break;
}
}
}
}
}
results.values = newValues;
results.count = newValues.size();
}
return results;
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
//noinspection unchecked
mData = (List<Map<String, ?>>) results.values;
if (results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
}
}