I don't know what's wrong with my code, that it always returns null when I use getParseObject().
I'm using parse.com to save my data, and in one table I used one file as a pointer. I have a Game class that has ImgName as a Pointer<Gallery> to a gallery class.
Now I want to retrieve the ImgName value, so this is what I did:
public Adapter(Context context) {
super(context, new ParseQueryAdapter.QueryFactory<ParseObject>() {
public ParseQuery create() {
ParseQuery query = new ParseQuery("Game");
query.include("ImgName");
return query;
}
});
}
// Customize the layout by overriding getItemView
#Override
public View getItemView(final ParseObject object, View v, ViewGroup parent) {
if (v == null) {
v = View.inflate(getContext(), R.layout.list_item_landing_cards, null);
}
ParseObject gallery = object.getParseObject("ImgName");
String name=gallery.getString("name");
TextView nameTextView = (TextView) v.findViewById(R.id.text);
nameTextView.setText(name);
But I'm getting null all the time.
Any suggestions?
Use this for the re-use issue:
ParseObject gallery = object.getParseObject("ImgName");
if (gallery != null) {
String name=gallery.getString("name");
TextView nameTextView = (TextView) v.findViewById(R.id.text);
nameTextView.setText(name);
} else {
nameTextView.setText(""); // or any other default value you want to set
}
NOTE:
The cell re-use issue is not on Parse. Cell re-use is a general concept used by the ListView. The cells are recycled for performance by Android. We just have to protect it from re-using old values.
Related
I am working on a project where I have a let's say 5x5 grid of TextViews and I want to check if an entire row or column has equal elements. I am using an Adapter class to inflate my gridview with simply one textview element. Here is the code that I have tried but I cannot seem to make it work:
final int size = gridView.getCount(); //25
int temp = 0;
for (int i = 0; i < size; i++) {
ViewGroup gridChild = (ViewGroup) gridView.getChildAt(i);
childSize = gridChild.getChildCount();
for (int j = 0; j < childSize; j++) {
if (gridChild.getChildAt(j) instanceof TextView &&
((TextView) gridChild.getChildAt(j)).getText().toString().equals("x")) {
temp++;
}
The thing is when i tried to debug, debugger showed null values for childSize variable and could not properly get the value from getChildAt. Basically, what I am trying to do is get inside the if statement. Also this is the first time I am working with ViewGroup calss, and the methods that I call. Any help would be appreciated.
Edit:I am looking for a way to do this outside the getView method in the adapter class and not in a onClick method as well. (Code sample answers would be highly appreciated). Also, the getChildAt method call returns null so the code I have shown would not work because I am assigning a null value to the gridChild.
This is the onClick that I use for the TextViews:
`
public void numberFill(View view) {
if (((TextView) view).getText().toString().isEmpty()) {
((TextView) view).setText(String.valueOf(numbCounter + 1));
numbCounter++;
}
else if (!((TextView) view).getText().toString().isEmpty() && numbCounter >= 16) {
((TextView) view).setText("x");
}
}
This is my adapter class:
public class GridAdapter extends BaseAdapter {
private final Context mContext;
private String[] numbers;
public GridAdapter(Context context, String[] numbers) {
this.mContext = context;
this.numbers = numbers;
}
#Override
public int getCount() {
return numbers.length;
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public Object getItem(int position) {
return numbers[position];
//return null;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater)
mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View gridView;
if (convertView == null) {
gridView = new View(mContext);
gridView = inflater.inflate(R.layout.textview_layout, null);
TextView textView = (TextView) gridView.findViewById(R.id.cell);
textView.setText(numbers[position]);
} else {
gridView = (View) convertView;
}
return gridView;
}
}
numberFill reworked:
public void numberFill(View view) {
int index = (Integer) view.getTag();
if (numbers[index].toString().isEmpty()) {
numbers[index] = String.valueOf(numbCounter + 1);
numbCounter++;
}
else if (!numbers[index].toString().isEmpty() && numbCounter >= 25) {
numbers[index] = "x";
}
gridAdapter.notifyDataSetChanged();
}
`
When using an AdapterView – such as your GridView – you generally don't want to directly access and manipulate its child Views outside of its Adapter. Instead, the dataset backing the Adapter should be updated, and the GridView then refreshed.
In your case, you presumably have a setup similar to this in your Activity:
private GridAdapter gridAdapter;
private String[] numbers;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
numbers = new String[25];
gridAdapter = new GridAdapter(this, numbers);
}
Here, the numbers array is what you want to directly modify, rather than the text on the GridView's child TextViews. That array is then easily iterated over to do your row and column value checks.
Since the array will be modified in the Activity, we need a way to pass the clicked TextView's position in the Adapter to the Activity's click method, as we'll need it to access the correct array element. For this, we can utilize the tag property available on all View's, via the setTag() and getTag() methods. For example, in GridAdapter's getView() method:
...
TextView textView = (TextView) gridView.findViewById(R.id.cell);
textView.setText(numbers[position]);
textView.setTag(position);
...
In the click method, the position can be easily retrieved with getTag(), and used as the index to get the clicked TextView's text from the numbers array. You can then do the necessary processing or calculation with that text, set the modified value back to the array element, and trigger a refresh on the Adapter.
public void numberFill(View view) {
int index = (Integer) view.getTag();
// Do your processing with numbers[index]
numbers[index] = "new value";
gridAdapter.notifyDataSetChanged();
}
The notifyDataSetChanged() call will cause the GridView to update its children, and your new value will be set in the appropriate TextView. The numbers array now also has the current values, and is readily available in the Activity to perform the necessary checks there.
I created the following CursorAdapter which shows messages from my SQL database, everything is added well until I scroll the list, I know that the objects are recycled, but in a wrong way. Here is my CursorAdapter class:
public class ChatAdapter extends CursorAdapter {
public ChatAdapter(Context context, Cursor cursor, int flags) {
super(context, cursor, 0);
}
#Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return LayoutInflater.from(context).inflate(R.layout.chat_item, parent,
false);
}
#Override
public void bindView(View view, Context context, Cursor cursor) {
// Find fields to populate in inflated template
TextView left = (TextView) view.findViewById(R.id.lefttext);
TextView right = (TextView) view.findViewById(R.id.righttext);
LinearLayout rightBubble = (LinearLayout) view
.findViewById(R.id.right_bubble);
LinearLayout leftBubble = (LinearLayout) view
.findViewById(R.id.left_bubble);
TextView leftDate = (TextView) view.findViewById(R.id.leftdate);
TextView rightDate = (TextView) view.findViewById(R.id.rightdate);
// Extract properties from cursor
String from = cursor.getString(cursor.getColumnIndexOrThrow("from"));
String txt = cursor.getString(cursor.getColumnIndexOrThrow("message"));
String date = cursor.getString(cursor.getColumnIndexOrThrow("t"));
String id = cursor.getString(cursor.getColumnIndexOrThrow("id"));
// Parse time
long datevalue = Long.valueOf(date) * 1000;
Date dateformat = new java.util.Date(datevalue);
String convert = new SimpleDateFormat("HH:mm").format(dateformat);
// Populate fields with extracted properties
if (from.equals("me")) {
right.setText(txt);
left.setText("");
rightBubble
.setBackgroundResource(R.drawable.balloon_outgoing_normal);
leftBubble.setBackgroundDrawable(null);
rightDate.setText(convert);
leftDate.setVisibility(View.GONE);
}
else {
left.setText(txt);
right.setText("");
leftBubble
.setBackgroundResource(R.drawable.balloon_incoming_normal);
rightBubble.setBackgroundDrawable(null);
leftDate.setText(convert);
rightDate.setVisibility(View.GONE);
}
}
}
Unfortenately, after scrolling the list, dates from the rightDate and leftDate dissapears after moving back. I think it't due the .setVisibility(View.GONE)
Any suggestions to fix this?
when the view is recycled, it is in the previous state, android did not clear the status for you.
To fix your problem, you have to set the view in question to VISIBLE when needed
Edit:
like this, add the 2 lines
if (from.equals("me")) {
// your original code
rightDate.setVisibility(View.VISIBLE); //add this
}
else {
// your original code
leftDate.setVisibility(View.VISIBLE); //add this
}
I've searched all the posts I can find, and none seem to help with my situation. I have an android project that uses web services to pull down hourly weather data and populate a listView with the results.
The weird problem I'm having is that when I debug the project on my android phone, the main activity is blank and the listView isn't populated. If I run the project from android studio with my phone locked, and then unlock my phone the app opens on my phone with all of the listView properly formatted and populated.
I feel like it's a race condition issue between the asynctask and the adapter, but I can't seem to resolve it. I tried making my asyncTask an inner private class and calling notifyDataSetChanged on the adapter inside the onPostExecute method, but to no avail. I feel it must be something simple, but I'm relatively new to Android dev, so I'm stuck.
I have three classes that I'll post the pertinent code from
MainActivity.java (onCreate)
public class MainActivity extends ActionBarActivity {
ArrayList<Weather> w = new ArrayList<Weather>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DownloadWeatherTask myTask = new DownloadWeatherTask(w);
WeatherAdapter myAdapter = new WeatherAdapter(this,w);
ListView l = (ListView) findViewById(R.id.weatherList);
l.setAdapter(myAdapter);
myTask.execute();
}
}
WeatherAdapter.java
public class WeatherAdapter extends ArrayAdapter<Weather>{
public WeatherAdapter(Context context, ArrayList<Weather> weather) {
super(context, R.layout.item_weather, weather);
}
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
Weather forecast = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_weather, parent, false);
}
// Lookup view for data population
TextView tvTime = (TextView) convertView.findViewById(R.id.listTime);
TextView tvDescr = (TextView) convertView.findViewById(R.id.listDescr);
TextView tvTemp = (TextView) convertView.findViewById(R.id.listTemp);
TextView tvHumid = (TextView) convertView.findViewById(R.id.listHumid);
ImageView ivWeather = (ImageView) convertView.findViewById(R.id.weatherImg);
// Populate the data into the template view using the data object
tvTime.setText(forecast.time);
tvDescr.setText(forecast.description);
tvTemp.setText(forecast.temperature+"°(F)");
tvHumid.setText(forecast.humidity+"% humidity");
ivWeather.setImageBitmap(forecast.weatherImg);
// Return the completed view to render on screen
return convertView;
}
}
DownloadWeatherTask.java
public class DownloadWeatherTask extends AsyncTask<Void,Void,Void>{
ArrayList<Weather> data;
public DownloadWeatherTask(ArrayList<Weather> a){
data = a;
}
public ArrayList<Weather> getData() {
return data;
}
protected Void doInBackground(Void...params) {
try {
String website = "http://api.wunderground.com/api/1111111111111/geolookup/q/autoip.json";
URL site = new URL(website);
HttpURLConnection weatherUnderground = (HttpURLConnection) site.openConnection();
weatherUnderground.connect();
JsonParser weatherParser = new com.google.gson.JsonParser();
JsonElement weatherJson = weatherParser.parse(new InputStreamReader((InputStream) weatherUnderground.getContent()));
JsonObject weatherObj = weatherJson.getAsJsonObject();
String zip = weatherObj.get("location").getAsJsonObject().get("zip").getAsString();
String city = weatherObj.get("location").getAsJsonObject().get("city").getAsString();
String state = weatherObj.get("location").getAsJsonObject().get("state").getAsString();
String hourly = "http://api.wunderground.com/api/111111111111/hourly/q/" + state + "/" + city + ".json";
URL hourlySite = new URL(hourly);
HttpURLConnection hourlyConnection = (HttpURLConnection) hourlySite.openConnection();
hourlyConnection.connect();
com.google.gson.JsonParser hourlyParser = new com.google.gson.JsonParser();
JsonElement hourlyWeatherJson = weatherParser.parse(new InputStreamReader((InputStream) hourlyConnection.getContent()));
JsonArray weatherArr = hourlyWeatherJson.getAsJsonObject().get("hourly_forecast").getAsJsonArray();
int l = weatherArr.size();
for (int i = 0; i < l; i++) {
String date = weatherArr.get(i).getAsJsonObject().get("FCTTIME").getAsJsonObject().get("pretty").getAsString();
String temp = weatherArr.get(i).getAsJsonObject().get("temp").getAsJsonObject().get("english").getAsString();
String condition = weatherArr.get(i).getAsJsonObject().get("condition").getAsString();
String humidity = weatherArr.get(i).getAsJsonObject().get("humidity").getAsString();
String iconUrl = weatherArr.get(i).getAsJsonObject().get("icon_url").getAsString();
Bitmap icon = getBitmapFromURL(iconUrl);
data.add(new Weather(date, condition, temp, humidity, icon));
}
} catch (IOException e) {
Log.e("Error: ",e.toString());
}
return null;
}
protected void onPostExecute(Void...params){
}
}
Below are links to my screenshots showing the app not populating the listView, and the app working properly when the program is run while the phone is initially locked.
Any help would be greatly appreciated!!
Thanks
In postExecute(), you need to update the adapter's List and then invoke its notifyDataSetChanged method. I suspect that you were forgetting to update the adapter's data.
The other option is to create a new adapter with the new data, and set the new adapter on the ListView.
I figured out what the issue was! I hadn't added #Override to my onPostExecute() method so it was never being called.
I added the notifyDataSetChanged to my onPostExecute as suggested, which worked once I added the #override to my method.
I am new to android. I have implemented custom ArrayAdapter in my Android Application using view holder.
The getView() function of my ArrayAdapter is as follows for reference:
#Override
public View getView(int position, View convertView, final ViewGroup parent) {
View row = convertView;
MyClassViewHolder myClassViewHolder;
MyClass myClass;
if(row == null) {
LayoutInflater inflater = ((Activity)mContext).getLayoutInflater();
row = inflater.inflate(resourceId, parent, false);
if(resourceId == R.layout.my_row_item) {
myClassViewHolder = new MyClassViewHolder();
myClassViewHolder.title = (EditText) row.findViewById(R.id.title);
myClassViewHolder.switch = (Switch) row.findViewById(R.id.switch);
}
} else {
myViewHolder = (MyViewHolder) row.getTag();
}
if(resourceId == R.layout.my_row_item) {
myClass = (MyClass) myClassList.get(position); //myClassList sent as parameter to constructor of adapter
if(myClassViewHolder != null && myClass != null) {
myClassViewHolder.title.setText(myClass.getTitle());
myClassViewHolder.switch.setChecked(myClass.isEnabled());
myClassViewholder.id = myClass.getId();
myClassViewHolder.switch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
//GET ID OF THE ROW ITEM HERE
}
});
}
}
}
First of all I want to associate an id which is from database to
every row item to perform actions on them. So please confirm if the
way I have done is is right or wrong.
Secondly in the above code I have a String as title and a Switch in every row
item. I want to set an onClickListener on each switch. On toggling
the switch i want to get the id of the row item which is associated as per point 1.
Thanks in advance. Please let me know if I haven't described my problem properly.
Yes your code looks fine as for second part you should make a listener on switch and then get the id form the row and do switch from one id to another.
You may need to set a tag for each row item and thus you can identify each row. Here is an example -
row.setTag(1);
and to retrive the tag -
row.getTag();
is it possible to create a View which is driven by a SimpleCursorAdapter. The content from this view is ever time a entry from DB.
The View (dataView) looks like:
txtData1
txtData2
txtData3
btnPrev btnNext
I read around and tryd to setup this behavior. Hope its make sens:
public class mActivity extends Activity {
public Context me = this;
public SimpleCursorAdapter mAdapter = null;
public Cursor mCursor = null;
private OnClickListener btnStart_onClick = new OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.dataView);
mCursor = mDB.rawQuery("SELECT * FROM Data", null);
startManagingCursor(mCursor);
mAdapter = new SimpleCursorAdapter(
me,
R.layout.dataView,
mCursor,
new String[] {"Data1", "Data2", "Data3"},
new int[] {R.id.txtData1 , R.id.txtData2, R.id.txtData3});
mAdapter.setViewBinder(VIEW_BINDER);
mCursor.moveToFirst();
}
};
static final ViewBinder VIEW_BINDER = new ViewBinder() {
public boolean setViewValue(View view, Cursor cursor, int columnIndex)
{
switch (view.getId())
{
case R.id.txtData1:
TextView txt = (TextView) view;
if (txt != null)
{
int index = cursor.getColumnIndex("Data1");
txt.setText(cursor.getString(index));
}
return true;
case R.id.txtData2:
TextView txt = (TextView) view;
if (txt != null)
{
int index = cursor.getColumnIndex("Data2");
txt.setText(cursor.getString(index));
}
return true;
case R.id.txtData3:
TextView txt = (TextView) view;
if (txt != null)
{
int index = cursor.getColumnIndex("Data3");
txt.setText(cursor.getString(index));
}
return true;
default:
return false;
}
}
};
}
When I run from the btnStart_onClick I dont get Data in my Textboxes :-(
Can somebody help? Can it work like this?
Next question: how can I use the Prev or Next Buttons? Possible this is the only thing I miss to "load" the first data...
EDIT: I extended my example with the global mCursor and the call to mCursor.moveToFirst()
On my app I also tested with the next / prev buttons and the function mCursor.moveToNext() and mCursor.moveToPrevious()
But its not change :-(
As far as I can tell, there are a lot of what I think are conceptual/organizational/syntactical problems with your code. First of all, an adapter is usually exploited by a view such as ListView or Spinner, that gets populated with the data retrieved by the adapter via the cursor (or whatever data structure is backing it). However, I don't see this pattern in your code, and I'm left wondering what use an adapter would have in your case.
Second, you perform a whole SELECT * query in your click listener, i.e. you retrieve all your 1000 records for each click on... well, on what, exactly? You define the click listener, but never set it onto anything - just as you define the adapter, but you don't bind it to anything. The code that sets up the adapter, with the database query and the binder should really be placed outside the listener.
Last, I believe you mocked variable names a bit before posting the code, because in the following snippet:
TextView txt = (TextView) view;
if (txt != null)
{
int index = cursor.getColumnIndex("Data1");
String txt = cursor.getString(index);
txt.setText(txt);
}
I could hardly see how the compiler is intended to distinguish the two txt variables on the last line of the if body.