Tag: ListView

这个组件与Mark Murphy 的书《The Busy Coder’s Guide to Advanced Android Development》有一些不同，这个SectionedAdapter是通过干坏事，反编译Vending.apk得到的。还有一个是AggregatedAdapter，合起来实现market单个软件信息显示的效果。

不过AggregatedAdapter比较难反编译出来，没关系，加上cwac-merge这个组件，就可以实现同样的效果。不同分段的Adapter，继承SectionedAdapter，实现自己的东西，该干啥就干啥，然后merge起来。

SectionAdapter.java

/*
 * Copyright (C) 2010 lytsing.org
 *
 * 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 org.lytsing.adapters;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

/**
 * abstract SectionAdapter, difference from
 * cw-advandroid/ListView/Sections/src/com/commonsware/android/listview/SectionedAdapter.java
 * just decompile from Vending.apk :-)
 *
 */
abstract public class SectionAdapter extends BaseAdapter {
    protected int mCount;
    protected boolean mDeactivated;
    protected View mSectionHeaderView;

    /**
     * Constructor
     * 
     * @param sectionTitleId The resource ID for a layout file containing a layout to use when
     *                  instantiating views.
     * @param context The current context.
     * @param parent The parent that this view will eventually be attached to
     */
    public SectionAdapter(int sectionTitleId, Context context, ViewGroup parent) {
        this(Util.inflateView(R.layout.section_header, context, parent));
        ((TextView)mSectionHeaderView).setText(sectionTitleId);
    }

    /**
     * Constructor
     * 
     * @param sectionHeaderView The header view
     */
    public SectionAdapter(View sectionHeaderView) {
        mSectionHeaderView = sectionHeaderView;
        mDeactivated = false;
        mCount = 0;
    }

    public void activate() {
        if (mDeactivated) {
            mDeactivated = false;
            notifyDataSetChanged();
        }
    }

    /**
     * Are all items in this SectionAdapter enable?
     * If yes it means all items are selectable and clickable.
     */
    public boolean areAllItemsEnabled() {
        return false;
    }

    public void deactivate() {
        if (mDeactivated == false) {
            mDeactivated = true;
            notifyDataSetChanged();
        }
    }

    /**
     * How many items are in the data set represented by this
     * Adapter.
     */
    public int getCount() {
        if (mDeactivated) {
            return 0;
        } else {
            return mCount + 1; // add one for header
        }
    }

    /**
     * Get the data item associated with the specified
     * position in the data set.
     * 
     * @param position Position of the item whose data we want
     */
    public Object getItem(int position) {
        if (position == 0) {
            return mSectionHeaderView;
        }
        
        return null;
    }

    /**
     * Get the row id associated with the specified position
     * in the list.
     * 
     * @param position Position of the item whose data we want
     */
    public long getItemId(int position) {
        if (position == 0) {
            return mSectionHeaderView.getId();
        } 
        
        return 0;
    }

    /**
     * Get a View that displays the data at the specified
     * position in the data set.
     * 
     * @param position Position of the item whose data we want
     * @param convertView View to recycle, if not null
     * @param parent ViewGroup containing the returned View
     */
    public View getView(int position, View convertView, ViewGroup parent) {

        return position == 0 ? mSectionHeaderView : null;
    }

    /**
     * Returns true if the item at the specified position is not a separator
     * (A separator is a non-selectable, non-clickable item).
     * 
     * @param position Index of the item
     * @return True if the item is not a separator
     */
    public boolean isEnabled(int position) {
        return false;
    }
}

Util.java

/*
 * Copyright (C) 2010 lytsing.org
 *
 * 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 org.lytsing.adapters;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

/**
 * Util 
 *
 */
public class Util {

    private Util() {
    }
    
    /**
     * Inflate a new view hierarchy from the specified XML resource.
     * 
     * @param resource ID for an XML layout resource to load 
     * @param context The current context.
     * @return The root View of the inflated XML file.
     */
    public static View inflateView(int resource, Context context) {

        return inflateView(resource, context, null);
    }

    /**
     * Inflate a new view hierarchy from the specified xml resource.
     * 
     * @param resourceID for an XML layout resource to load (e.g.,
     * @param context The current context.
     * @param parent simply an object that provides a set of LayoutParams
     *        values for root of the returned hierarchy
     * @return The root View of the inflated XML file.
     */
    public static View inflateView(int resource, Context context, ViewGroup parent) {
        LayoutInflater vi = (LayoutInflater)context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        return  vi.inflate(resource, parent, false);
    }
}

res/layout/section_header.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textStyle="bold"
    android:gravity="center_vertical"
    android:background="@android:drawable/dark_header"
    android:paddingLeft="8.0dip"
    android:layout_width="fill_parent"
    android:layout_height="26.0dip"
    >
</TextView>

代码下载; https://github.com/lytsing/SectionedAdapter
参考阅读：
Jeff Sharkey’s blog : Separating Lists with Headers in Android 0.9
androidguys: CWAC’d Up: Alternative Adapters
本博客文章: 千万不要把Listview放在ScrollView里