I have a main activity (FragmentDemoActivity) which creates 2 tabs. Fragment A and Fragment B.
I have another class called CategoryList which loads a customlist from an sqlite database.
I am using this example which works great for the TAB parts.
I want to load the CategoryList into the Fragment A.
My CategoryList class is as follows
// All the imports
public class CategoryList extends BaseActivity{
ImageView imgFeedback;
ImageView imgAbout;
ListView listCategories;
ProgressBar prgLoading;
TextView txtAlert;
AdView ads;
static String[] CategoryName ;
ListAdapter la;
static int[] id;
List<String> catList;
static DBHelper dbhelper;
class ListAdapter extends BaseAdapter {
private LayoutInflater inflater;
#SuppressWarnings("unused")
private Context ctx;
public ListAdapter(Context context) {
inflater = LayoutInflater.from(context);
ctx = context;
}
#Override
public int getCount() {
return CategoryName.length;
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if(convertView == null){
convertView = inflater.inflate(R.layout.row, null);
holder = new ViewHolder();
holder.imgPreview = (ImageView) convertView.findViewById(R.id.imgPreview);
holder.txtRecipeName = (TextView) convertView.findViewById(R.id.txtRecipeName);
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
}
holder.imgPreview.setImageResource(getResources().
getIdentifier(CategoryName[position], "drawable", getPackageName()));
String categoryName = CategoryName[position];
categoryName = categoryName.toLowerCase();
categoryName = Character.toString(categoryName.charAt(0)).toUpperCase()+categoryName.substring(1);
holder.txtRecipeName.setText(categoryName);
return convertView;
}
class ViewHolder {
ImageView imgPreview;
TextView txtRecipeName;
}
}
final Context context = this ;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.categories_list);
AppRater.displayAsk2Rate(this, 1, 1, false);
getSupportActionBar().setHomeButtonEnabled(true);
dbhelper = new DBHelper(this);
try {
dbhelper.createDataBase();
}catch(IOException ioe){
throw new Error("Unable to create database");
}
/** then, the database will be open to use */
try{
dbhelper.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
CategoryName = dbhelper.getAllCategories();
dbhelper.close();
catList = Arrays.asList(CategoryName);
/* imgAbout = (ImageView) findViewById(R.id.imgAbout);
imgAbout.setOnClickListener(new ButtonListner(CategoryList.this));
imgFeedback = (ImageView) findViewById(R.id.imgFeedback);
imgFeedback.setOnClickListener(new ButtonListner(CategoryList.this));*/
listCategories = (ListView) findViewById(R.id.listCategories);
la = new ListAdapter(CategoryList.this);
listCategories.setAdapter(la);
txtAlert = (TextView) findViewById(R.id.txtAlert);
ads = (AdView) findViewById(R.id.ads);
Ads.loadAds(ads);
listCategories.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapter, View view, int position, long id) {
String category = catList.get(position);
Intent i = new Intent(CategoryList.this, RecipesList.class);
i.putExtra("Category_Name", category);
startActivity(i);
}
});
}
}
My FragmentA is as follows
public class FragmentA extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saved)
{
View view = inflater.inflate(R.layout.categories_list, container, false);
ListView listCategories = (ListView) getActivity().findViewById(R.id.listCategories);
ListAdapter lav = new ListAdapter(CategoryList.this);
listCategories.setAdapter(lav);
return view;
}
#Override
public void onActivityCreated (Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
}
}
Any pointers ?
Related
I'm working on a project that has a list view should update automatically with database changes, I'm working on it for a long time and find a solution that using ViewHolder pattern, and I tried this way and it's work really! but now I try manyyyy solution to do it again, it's not working!! pls help me or tell me if there is a tip in using this pattern.
Thanks really!
public class DownloadItem_ViewHolder {
private boolean hasInited = false;
public DownloadItem_ViewHolder() {
}
public DownloadItem_ViewHolder(View convertView) {
if (convertView != null) {
App_icon = (ImageView) convertView
.findViewById(R.id.Download_app_icon);
App_name = (TextView) convertView
.findViewById(R.id.Downlaod_app_name);
Downloaded_percent = (TextView) convertView
.findViewById(R.id.Downloaded_app_percent);
Downloaded_progress = (ProgressBar) convertView
.findViewById(R.id.Downloaded_app_progress);
Pause_btn = (ImageView) convertView
.findViewById(R.id.Download_pause_btn);
Resume_btn = (ImageView) convertView
.findViewById(R.id.Download_Resume_btn);
hasInited = true;
}
}
public void setPorgress(int progress) {
Downloaded_progress.setProgress(progress);
// Downloaded_percent.setText(String.valueOf(progress) + "%");
}
public void setData(DownloadManagerItem_Cls dlItem) {
if (hasInited) {
// this.App_icon.setBackground(newDownloadManager.getDownloadItemApp(
// dlItem.getItemID()).getAppIcon());
// App_name.setText(newDownloadManager.getDownloadItemApp(
// dlItem.getItemID()).getAppName()
// + "-->" + dlItem.getItemID());
this.Downloaded_progress
.setProgress(dlItem.getDownloadPercentage());
// this.Downloaded_percent.setText(String.valueOf(dlItem
// .getDownloadPercentage()) + "%");
// DownloadStatus downloadItemStatus = dlItem.getDownloadStatus();
// // PAUSE
// if (downloadItemStatus.equals(DownloadStatus.Pause)) {
// // Resume
// Resume_btn.setVisibility(View.VISIBLE);
// // Pause
// Pause_btn.setVisibility(View.GONE);
// } else if (downloadItemStatus.equals(DownloadStatus.Downloading))
// {// Resume
// Resume_btn.setVisibility(View.GONE);
// // Pause
// Pause_btn.setVisibility(View.VISIBLE);
// } else if (downloadItemStatus.equals(DownloadStatus.Complete)) {
// // Resume
// Resume_btn.setVisibility(View.GONE);
// // Pause
// Pause_btn.setVisibility(View.GONE);
// // Install or Run
// }
}
}
ImageView App_icon;
public TextView App_name;
ProgressBar Downloaded_progress;
TextView Downloaded_percent;
public ImageView Resume_btn;
public ImageView Pause_btn;
}
public class DownloadItemAdpater extends ArrayAdapter<DownloadManagerItem_Cls> {
int _rowResourceID;
public DownloadItemAdpater(Context context, int rowResourceID,
List<DownloadManagerItem_Cls> DownloadedItems) {
super(context, rowResourceID, DownloadedItems);
_rowResourceID = rowResourceID;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
// final int AppID = DownloadManager.DownloadedList.get(position).ApkID;
if (convertView == null) {
LayoutInflater vi = (LayoutInflater) getContext().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.download_history_item, null);
// store the holder with the view.
// convertView.setTag(1, viewHolder);
}
convertView.setTag(getItem(position).getItemID());
DownloadItem_ViewHolder viewHolder = new DownloadItem_ViewHolder(
convertView);
viewHolder.setData(getItem(position));
viewHolder.App_name.setText(String.valueOf(getItem(position)
.getItemID()));
// set data
// viewHolder.Pause_btn.setOnClickListener(new DownloadBtnListener(
// position, viewHolder));
// viewHolder.Resume_btn.setOnClickListener(new DownloadBtnListener(
// position, viewHolder));
return convertView;
}
public class DownloadManager_Act extends ListActivity {
DownloadItemAdpater dlAdapter;
ArrayList<DownloadManagerItem_Cls> listHistory;
// #Override
// protected void onDestroy() {
// unregisterReceiver(mReceiver);
// super.onDestroy();
// }
MyReceiver mReceiver;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dl_manager);
listHistory = CP_Connector.GDM_QueueTable_Connector.getDownloadList();
dlAdapter = new DownloadItemAdpater(getApplicationContext(),
R.layout.download_history_item, listHistory);
setListAdapter(dlAdapter);
mReceiver = new MyReceiver();
IntentFilter filter = new IntentFilter();
filter.addAction("com.glx.appscenter.dlmanager");
registerReceiver(mReceiver, filter);
}
public class MyReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent != null
&& intent.getAction()
.equals("com.glx.appscenter.dlmanager")) {
try {
int dlItemID = Integer.valueOf(intent
.getStringExtra("itemID"));
if (dlItemID >= 0) {
DownloadManagerItem_Cls dlTempItem = CP_Connector.GDM_QueueTable_Connector
.getDownloadItemByID(dlItemID);
View v = getListView().findViewWithTag(
dlTempItem.getItemID());
TextView tv = (TextView) v
.findViewById(R.id.Downlaod_app_name);
Utility.appUtility.ShowToast(String.valueOf(tv
.getText() + ":" + dlItemID));
DownloadItem_ViewHolder viewHolder = new DownloadItem_ViewHolder(
v);
viewHolder.setPorgress(dlTempItem
.getDownloadPercentage());
dlAdapter.notifyDataSetChanged();
}
} catch (Exception e) {
}
}
}
}
}
if you want to set adapter then follow this code.
adapter=new AuctionListAdapter(getActivity(), listAuctionBeans,progressBar,1);
setListAdapter(adapter);
if you wan to refresh list with new data change follow this
adapter.addData(getActivity(), listAuctionBeans);
adapter.notifyDataSetChanged();
and adapter is you your d1Adapter.
I have an imageView in a fragment. On imageView click I want to start an activity. Below is my code showing null pointer exception.
public static class DemoObjectFragment extends Fragment {
// public static final String ARG_OBJECT = "object";
Context con=getActivity();
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_collection_object, container, false);
Bundle args = getArguments();
ImageView shadow_img=(ImageView) rootView.findViewById(R.id.shadow_img);
ImageView img=(ImageView)rootView.findViewById(R.id.img);
img.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(getActivity(), Article.class);
getActivity().startActivity(intent);
}
});
shadow_img.setImageResource(R.drawable.featured_shadow);
new ImageLoadTask(args.getString("img_url"),(ImageView)rootView.findViewById(R.id.img),con).execute(null, null);
return rootView;
}
}
This code run fine, try litlle changes.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ViewGroup rootView = null;
rootView = (ViewGroup) inflater.inflate(R.layout.layname, container, false);
Button btnSec = (Button)rootView.findViewById(R.id.btnSec);
btnSec.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
Intent iz = new Intent(getActivity(), SecondActivity.class);
startActivity(iz)
I want to hide the title bar when i scrolling the items in the ListView and i want to show the title bar after scrolling. Suggest any ideas to solve this issue.
First add the Xml View into ActionBar like this:
LayoutInflater inflater = (LayoutInflater) getActionBar()
.getThemedContext().getSystemService(LAYOUT_INFLATER_SERVICE);
View customActionBarView = inflater.inflate(R.layout.main, null);
final ActionBar actionBar = getActionBar();
actionBar.setDisplayOptions(
ActionBar.DISPLAY_SHOW_TITLE | ActionBar.DISPLAY_SHOW_HOME);
actionBar.setCustomView(customActionBarView,
new ActionBar.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
setContentView(R.layout.main);
Then do the changes in onScrollStateChanged() method:
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
switch (scrollState) {
case SCROLL_STATE_IDLE:
actionBar.show();
break;
case SCROLL_STATE_TOUCH_SCROLL:
actionBar.hide();
break;
}
}
//declare this two globally
public static int ch = 0, cht = 1;
int myLastVisiblePos;
//Then add onScrollListener to your ListView
list.setOnScrollListener(new OnScrollListener() {
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
int currentFirstVisPos = view.getFirstVisiblePosition();
if (currentFirstVisPos > myLastVisiblePos) {
if (ch == 1) {
ch++;
cht = 1;
getActionBar().hide();
} else if (ch == 0) {
getActionBar().show();
ch++;
}
}
if (currentFirstVisPos < myLastVisiblePos)
if (cht == 1)
getActionBar().show();
myLastVisiblePos = currentFirstVisPos;
}
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
}
});
This solution worked for me very good:
// mLastFirstVisibleItem defined globally
quranTextList.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
/**
* Hide actionbar when scroll down
*/
if (mLastFirstVisibleItem < firstVisibleItem)
if (getSupportActionBar().isShowing())
getSupportActionBar().hide();
if (mLastFirstVisibleItem > firstVisibleItem)
if (!getSupportActionBar().isShowing())
getSupportActionBar().show();
mLastFirstVisibleItem = firstVisibleItem;
}
});
Source: Android ActionBar hide/show when scrolling list view
I've been reading about ViewHolder Pattern and it's effects on ListView scrolling performance lately.
For a smooth scrolling, fast ListView should i avoid using OnClickListener registerations inside adapter getView() method such as:
#Override
public View getView(final int position, View convertView, ViewGroup parent)
{
ViewHolder holder;
if (convertView == null)
{
holder = new ViewHolder();
LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(mResourceId, null);
holder.btn1 = (TextView) convertView.findViewById(R.id.btn1);
holder.img1 = (TextView) convertView.findViewById(R.id.img1);
convertView.setTag(holder);
} else { holder = (ViewHolder) convertView.getTag(); }
final Items item = getItem(position);
holder.btn1.setText(item.btnText);
holder.img1.setBackgroundResource(item.imgSource);
holder.img1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) { /* .. my code block USING POSITION ARG .. */ }
}
holder.btn1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) { /* .. My Code Block USING POSITION ARG .. */ }
}
return convertView;
}
If so, is registering a OnItemClickListener to ListView instance as following sample does a good practice:
myListView.setOnItemClickListener(new OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> arg0, View view, int position, long id) {
if (view.getId() == R.id.btn1)
{
// my code block USING POSITION ARG
}
else if (view.getId() == R.id.img1)
{
// my code block USING POSITION ARG
}
}
});
It's better to use a Wrapper to access to your View and to define your OnClickListener earlier (and outside the adapter for a better usability).
The following sample show how to handle 2 clickable View on one single item of the ListView with good performance:
public class ItemAdapter extends BaseAdapter {
private List<Item> items;
private ItemWrapper wrapper = null;
private OnClickListener onMyItemClickListener1;
private OnClickListener onMyItemClickListener2;
public ItemAdapter(Context context, List<Item> items, OnClickListener onMyItemClickListener1, OnClickListener onMyItemClickListener2) {
this.inflater = LayoutInflater.from(context);
this.items = items;
this.onMyItemClickListener1 = onMyItemClickListener1;
this.onMyItemClickListener2 = onMyItemClickListener2;
}
#Override
public int getCount() {
return items.size();
}
#Override
public Object getItem(int position) {
return items.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public synchronized View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
if (row == null) {
row = inflater.inflate( R.layout.item, null);
wrapper = new ItemWrapper(row);
row.setTag(wrapper);
} else {
wrapper = (ItemWrapper)row.getTag();
}
Item item = getItem(position);
wrapper.getClickView1().setOnClickListener(onMyItemClickListener1);
wrapper.getClickView2().setOnClickListener(onMyItemClickListener2);
return(row);
}
}
public class ItemWrapper {
private View baseView;
private View clickView1;
private View clickView2;
public ItemWrapper(View baseView) {
this.baseView = baseView;
}
public View getClickView1() {
if ( clickView1 == null) {
clickView1 = (View)baseView.findViewById(R.id.clickView1);
}
return(clickView1);
}
public View getClickView2() {
if ( clickView2 == null) {
clickView2 = (View)baseView.findViewById(R.id.clickView2);
}
return(clickView2);
}
}
I have some custom listview adapter, in adapter I use ViewHolder pattern,it is work correctly for anything but not for Bitmaps.
That code is work but plase that work with bitmap don't use viewholder. I commented it for test, so now I see that, viewholder not work with bitmaps.
If someone know why or have any idea please told me how to fix.
There is my code:
public class FrontListAdapter extends ArrayAdapter<GoodObject> {
private Context context;
private AdapterLoadNotifier notifier;
private List<GoodObject> list;
public HashMap<String, Bitmap> avatars = new HashMap<String, Bitmap>();
public FrontListAdapter(MainActivity activity, List<GoodObject> objects) {
super(activity, R.layout.row_front_layout, objects);
this.context = activity;
this.list = objects;
this.notifier = activity;
}
static class ViewHolder {
static TextView shopTitle;
static TextView time;
static TextView description;
static ImageView goodsImage;
static ProgressBar loadingGoodsImageDialogue;
static ImageView shopAvatar;
static ImageView loadingAvatarHolder;
static ProgressBar loadingAvatarDialogue;
static TextView commentAuthor;
static TextView commentText;
static Button likeButton;
static Button commentButton;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
LayoutInflater inflater = LayoutInflater.from(context);
convertView = inflater.inflate(R.layout.row_front_layout, null);
viewHolder = new ViewHolder();
viewHolder.shopTitle = (TextView) convertView.findViewById(R.id.row_front_layout_shop_title);
viewHolder.time = (TextView) convertView.findViewById(R.id.row_front_layout_time);
viewHolder.description= (TextView) convertView.findViewById(R.id.row_front_layout_description_label);
viewHolder.goodsImage = (ImageView) convertView.findViewById(R.id.row_front_layout_good_image);
viewHolder.loadingGoodsImageDialogue = (ProgressBar) convertView.findViewById(R.id.row_front_layout_good_image_progress);
viewHolder.shopAvatar = (ImageView) convertView.findViewById(R.id.row_front_layout_logo);
viewHolder.loadingAvatarDialogue = (ProgressBar) convertView.findViewById(R.id.row_front_layout_avatar_image_progress);
viewHolder.loadingAvatarHolder = (ImageView) convertView.findViewById(R.id.row_front_layout_logo_back);
viewHolder.commentAuthor = (TextView) convertView.findViewById(R.id.row_front_layout_first_comment_author);
viewHolder.commentText = (TextView) convertView.findViewById(R.id.row_front_layout_first_comment_text);
viewHolder.likeButton = (Button) convertView.findViewById(R.id.row_front_layout_like_button);
viewHolder.commentButton = (Button) convertView.findViewById(R.id.row_front_layout_comment_button);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
GoodObject goodObject = list.get(position);
String shopTitle = goodObject.getShopTitle();
Bitmap avatar = goodObject.getAvatar();
Bitmap image = goodObject.getGoods_logo();
viewHolder.shopTitle.setText(shopTitle);
viewHolder.time.setText(goodObject.getTime());
viewHolder.description.setText(goodObject.getDescription());
if (image != null) {
//viewHolder.goodsImage.setImageBitmap(image);
//viewHolder.loadingGoodsImageDialogue.setVisibility(View.GONE);
((ImageView) convertView.findViewById(R.id.row_front_layout_good_image)).setImageBitmap(image);
convertView.findViewById(R.id.row_front_layout_good_image_progress).setVisibility(View.GONE);
}
if (avatar != null) {
convertView.findViewById(R.id.row_front_layout_avatar_image_progress).setVisibility(View.GONE);
convertView.findViewById(R.id.row_front_layout_logo_back).setVisibility(View.GONE);
//viewHolder.loadingAvatarDialogue.setVisibility(View.GONE);
//viewHolder.loadingAvatarHolder.setVisibility(View.GONE);
}
((ImageView) convertView.findViewById(R.id.row_front_layout_logo)).setImageBitmap(avatars.get(shopTitle));
//viewHolder.shopAvatar.setImageBitmap(avatars.get(shopTitle));
viewHolder.commentAuthor.setText(goodObject.getLast_comment().getUser() + ":");
viewHolder.commentText.setText(goodObject.getLast_comment().getComment());
viewHolder.likeButton.setText(Integer.toString(goodObject.getLikesAmount()));
viewHolder.commentButton.setText(Integer.toString(goodObject.getCommentsAmount()));
if (position == list.size() - 2 && !notifier.isEnded()) {
notifier.loadNextPage();
}
return convertView;
}
}
For fix bug the fields in the ViewHolder class musn't be static:
static class ViewHolder {
TextView shopTitle;
TextView time;
TextView description;
ImageView goodsImage;
ProgressBar loadingGoodsImageDialogue;
ImageView shopAvatar;
ImageView loadingAvatarHolder;
ProgressBar loadingAvatarDialogue;
TextView commentAuthor;
TextView commentText;
Button likeButton;
Button commentButton;
}
In that case all work great and correctly.