A list view that demonstrates the use of setEmptyView This example alos uses a custom layout file that adds some extra buttons to the s
/* * Copyright (C) 2007 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 com.example.android.apis.view; import com.example.android.apis.R; import android.app.ListActivity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.ImageView; import android.widget.AbsListView; import java.util.ArrayList; /** * A list view that demonstrates the use of setEmptyView. This example alos uses * a custom layout file that adds some extra buttons to the screen. */ public class List8 extends ListActivity { PhotoAdapter mAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Use a custom layout file setContentView(R.layout.list_8);
// Tell the list view which view to display when the list is empty getListView().setEmptyView(findViewById(R.id.empty));
// Set up our adapter mAdapter = new PhotoAdapter(this); setListAdapter(mAdapter);
// Wire up the clear button to remove all photos Button clear = (Button) findViewById(R.id.clear); clear.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { mAdapter.clearPhotos(); } });
// Wire up the add button to add a new photo Button add = (Button) findViewById(R.id.add); add.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { mAdapter.addPhotos(); } }); } /** * A simple adapter which maintains an ArrayList of photo resource Ids. * Each photo is displayed as an image. This adapter supports clearing the * list of photos and adding a new photo. * */ public class PhotoAdapter extends BaseAdapter { private Integer[] mPhotoPool = { R.drawable.sample_thumb_0, R.drawable.sample_thumb_1, R.drawable.sample_thumb_2, R.drawable.sample_thumb_3, R.drawable.sample_thumb_4, R.drawable.sample_thumb_5, R.drawable.sample_thumb_6, R.drawable.sample_thumb_7}; private ArrayList mPhotos = new ArrayList();
public PhotoAdapter(Context c) { mContext = c; } public int getCount() { return mPhotos.size(); } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { // Make an ImageView to show a photo ImageView i = new ImageView(mContext); i.setImageResource(mPhotos.get(position)); i.setAdjustViewBounds(true); i.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); // Give it a nice background i.setBackgroundResource(R.drawable.picture_frame); return i; } private Context mContext; public void clearPhotos() { mPhotos.clear(); notifyDataSetChanged(); }
public void addPhotos() { int whichPhoto = (int)Math.round(Math.random() * (mPhotoPool.length - 1)); int newPhoto = mPhotoPool[whichPhoto]; mPhotos.add(newPhoto); notifyDataSetChanged(); } } } //list_8.xml