RecyclerView - recycle at specific position - Java for Android App Development

I have a recyclerview in which I can remove items. When I remove an item, a new one replaces it, but this happens at the end/bottom of the recyclerview, whereas I would like the new item to replace the deleted item at its very position. I hope this makes sense!
Do you guys have any ideas as to how I can implement that?
This is my delete method:
Code:
public void deleteItem(int position) {
mProvider.removeItem(position);
notifyItemRemoved(position);
}

StrangerWeather said:
I have a recyclerview in which I can remove items. When I remove an item, a new one replaces it, but this happens at the end/bottom of the recyclerview, whereas I would like the new item to replace the deleted item at its very position. I hope this makes sense!
Do you guys have any ideas as to how I can implement that?
This is my delete method:
Code:
public void deleteItem(int position) {
mProvider.removeItem(position);
notifyItemRemoved(position);
}
Click to expand...
Click to collapse
Ok, I've worked it out. The idea is simply to first remove the item and then to swap it for the last item (here, item 25):
Code:
public void deleteItem(int position) {
mProvider.removeItem(getItemCount());
mProvider.swapItem(25, position);
notifyItemRemoved(position);
}

StrangerWeather said:
Ok, I've worked it out. The idea is simply to first remove the item and then to swap it for the last item (here, item 25):
Click to expand...
Click to collapse
Here is my solution in my RecylcerViewAdapter with an ArrayList:
Code:
public boolean removeAt(int position) {
if(position >= 0 && position < data.size()) {
data.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, data.size());
return true;
}
return false;
}

Related

WebView - Handle JavaScript Pop Up ?

Hi,
I am new to Android Development. I am making an application with a WebView object. This loads a URL with some elements. However, I cannot get JavaScript PopUp to show up when the button is pressed.
My WebView has JavaScript enabled, but all other properties are disabled.
What is the property to enable WebView popups to show??
I had to do this. Override the onJSAlert() method in the WebChromeClient class:
Code:
public class MyWebChromeClient extends WebChromeClient {
@Override
public boolean onJsAlert(WebView view, String url, String message, JsResult result)
{
final JsResult finalRes = result;
new AlertDialog.Builder(view.getContext())
.setMessage(message)
.setPositiveButton(android.R.string.ok,
new AlertDialog.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which) {
finalRes.confirm();
}
})
.setCancelable(false)
.create()
.show();
return true;
}
}
Then add it to your webview:
Code:
MyWebChromeClient myWebChromeClient = new MyWebChromeClient();
webView.setWebChromeClient(myWebChromeClient);
Thanks. That did work!
One small thing, how do you set a Title for the pop-ups. Currently it shows the url in the Title.
I found a better example that sets the title:
http://lexandera.com/2009/01/adding-alert-support-to-a-webview/
footboydog said:
I found a better example that sets the title:
http://lexandera.com/2009/01/adding-alert-support-to-a-webview/
Click to expand...
Click to collapse
I tried that, but the Title is only displayed when the alert has one button/option. When there are multiple options, the Title shows the URL.
Sorry not sure how to fix that
footboydog said:
Sorry not sure how to fix that
Click to expand...
Click to collapse
Ok, I think I'll have to live with "file:///" showing as the Title for now...
you can convert to toast

[Q] DatePickerDialog cancelclick

Hi there!
I have been trying to catch the Cancel click of a DatePickerDialog, because I want to do some additional stuff, when the user clicks on the Cancel Button.
I tried it like described in the second answer from esilver from this Question:
http://stackoverflow.com/questions/...erner-of-datepicker-dialog?tab=active#tab-top
But I can't get it to work like that. When do I have to call this onClick method?
Would be great if someone could help me with that!
Thanks!
cTrox said:
Hi there!
I have been trying to catch the Cancel click of a DatePickerDialog, because I want to do some additional stuff, when the user clicks on the Cancel Button.
I tried it like described in the second answer from esilver from this Question:
http://stackoverflow.com/questions/...erner-of-datepicker-dialog?tab=active#tab-top
But I can't get it to work like that. When do I have to call this onClick method?
Would be great if someone could help me with that!
Thanks!
Click to expand...
Click to collapse
the "checked" solution in that example seems wrong to me. but the second one people voted up seems correct.
You can also set the onDissmissListener which will catch if the user backs out with the back key ( recommended for user friendliness )
have a look here:
http://developer.android.com/refere...id.content.DialogInterface.OnDismissListener)
Also, since DatePickerDialog is a subclass of AlertDialog, you can set the buttons the same way:
http://developer.android.com/guide/topics/ui/dialogs.html#AlertDialog
That should get you started but feel free to post back if you get stuck again. And post the code you are using.
Also, one other thing, it might be useful to keep a private reference to your dialog in your activity class.
All those examples (in the API docs and tutorials) always show a new dialog created when "onCreateDialog(int ID)" is called by the OS on your activity and they never save any sort of reference to it. They give you just enough code to hang yourself
Anyways, while this is a perfectly normal way to do things, it doesnt give you a chance to follow what is actually happening with the dialog. It also makes it harder to reference your dialog from elsewhere in the activity.
Keeping a reference, and exploring the onPrepareDialog(int ID) method are good for learning what the OS is doing with your dialog. (IMHO)
hth
Thanks a lot for your answers. But I still can't figure out how to do it.
Here's my current Code:
Code:
private DatePickerDialog.OnDateSetListener mDateSetListener = new DatePickerDialog.OnDateSetListener() {
public void onDateSet(DatePicker datePicker, int year, int monthOfYear,
int dayOfMonth) {
mYear = year;
mMonth = monthOfYear;
mDay = dayOfMonth;
// do some more stuff...
}
};
Code:
protected Dialog onCreateDialog(int id) {
Calendar cDate = Calendar.getInstance();
int cyear = cDate.get(Calendar.YEAR);
int cmonth = cDate.get(Calendar.MONTH);
int cday = cDate.get(Calendar.DAY_OF_MONTH);
switch(id){
case DATE_DIALOG_ID:
return new DatePickerDialog(this, mDateSetListener, cyear, cmonth, cday);
}
return null;
}
With that I can just call showDialog(DATE_DIALOG_ID); and I get the dialog. Now, where do I have to implement this OnDismissListener and how?
Thanks!
there are lots of ways to do this but I broke it out into several parts so hopefully it seems more obvious what is happening.
Code:
//here's our field reference we could use later or reuse or whatever
private DatePickerDialog dateDialog = null;
protected Dialog onCreateDialog(int id)
{
//your calendar code here... just removed to save space
switch(id)
{
case DATE_DIALOG_ID:
dateDialog = new DatePickerDialog(this, mDateSetListener, cyear, cmonth, cday);
dateDialog.setButton ( DialogInterface.BUTTON_NEGATIVE, android.R.string.cancel, cancelBtnListener );
dateDialog.setOnDismissListener ( listener );
break;
}
return dateDialog;
}
//our dismiss listener
protected DialogInterface.OnDismissListener dismissListener = new OnDismissListener( )
{
@Override
public void onDismiss ( DialogInterface dialog )
{
// do your thang here
}
};
//our click listener
protected DialogInterface.OnClickListener cancelBtnListener = new OnClickListener( )
{
@Override
public void onClick ( DialogInterface dialog, int which )
{
dialog.dismiss ( );
// since we dismiss here, the next listener to get called
// is the dismiss listener. now we'll have consistent behavoir
}
};
Ah thank you very much! I was always confused, where to set the Button and the OnDismissListener.
It works perfectly like that!

[Q] Using Split Action in android

Hi!
My self Raj, i have a problem when using the split action in my application.
i am doing an E-Menu for an restaurant. i list out all available category in major listview if the user click on the item of major list it should display all available minor items of its in behind of the Major listview.
I found one solution in Google it is possible by using split action.
Can anyone guide me / give some sample i may know about it..,
I am waiting for your guide.,
Have A Happy Day..,
Thanks to all..,
Simply add the following line to your <activity> or <application> tag in your AndroidManifest :
Code:
uiOptions="splitActionBarWhenNarrow"
EDIT : As a side note, it seems you want the split actionbar to be displayed only after the user clicked something, in that use case, the Contextual ActionBar seems more suited.
To use it, simply define your actionbar items in a menu.xml just like the normal actionbar, then in your java code use something like :
Code:
private ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_item1:
//do something
mode.finish();
return true;
case R.id.menu_item2:
// do something else
mode.finish();
return true;
case R.id.menu_item3:
// etc....
mode.finish();
return true;
default:
return false;
}
}
@Override
public void onDestroyActionMode(ActionMode mode) {
mActionMode = null;
}
And in the onClickListener() of the component that triggers the contextual ActionBar, call it like that :
Code:
if (mActionMode != null)
// Do nothing
else
mActionMode = startActionMode(mActionModeCallback);
You might want to use the ActionBarSherlock Library in order to keep compatibility with gingerbread/froyo

[Q]Content Provider - Huge Data

Hi,
Im using a content provider to query data, the following code was working good until I test it in another device(low end) with a larger data(~3000). With a larger data app became unusable, what can I do for improve this?
Code:
public void ContentSearch(String uriS,String id)
{
Uri uri = Uri.parse(uriS);
Cursor cur = getContentResolver().query(uri, NULL,
"_id = " + id, null, null);
cur.moveToFirst();
do {
//Do Things
} while (cur.moveToNext());
cur.close();
}
try to put it in a thread:
Code:
new Thread(new Runnable() {
[user=439709]@override[/user]
public void run() {
//CODE GOES HERE
}
}).start();
You do this for anything that might take the system a long time to execute and isn't directly needed for the UI.
If it is needed by the UI try an AsyncTask:
Code:
AsyncTask<Params,Progress,Result>() {
[user=439709]@override[/user]
protected Result doInBackground(Params params) {
}
protected void onProgressUpdate(Progress progress) {
}
protected void onPostExecute(Result result) {
}
}.execute();
I never used Content Providers so I'm not sure what you would put in for each thing on the Async but here is the Android Docs perhaps you can figure it out
Im filling an array to inflate in listview, my approach is load 25 items then break, and when the list reaches the end load more 25 and so on, but it seems that the cursor is in the same overloaded.
I need it for the UI so I dont have sure if the thread solve the problem, but I will try it anyway.
avlisF said:
Im filling an array to inflate in listview, my approach is load 25 items then break, and when the list reaches the end load more 25 and so on, but it seems that the cursor is in the same overloaded.
I need it for the UI so I dont have sure if the thread solve the problem, but I will try it anyway.
Click to expand...
Click to collapse
You fill the array then you fill the list? This might be what's causing our crash as the list is trying to setup before the array is done.
You could just use the async to do the lookup and set the list item info in the list adapter and as the async finishes each lookup it will enter each item in the list
Sent from my Nexus 7 using XDA Premium HD app

PreferenceFragment and Tabs

Hi,
currently I am developing a App.
I use the NavigationDrawer to set up a Menu (with the "Burger-Button") on the left side.
Wenn I choose a menu item, for example a PreferenceFragment i displayed.
My problem: I want to display a Tab-Layout with a PreferenceFragment in each Tab.
But I don´t know how...
In my MainActitivty-Class (AppCompatActivity) I change the content of my App (after the user clicked on a menu item) like this:
Code:
@Override
public boolean onNavigationItemSelected(MenuItem item) {
FragmentTransaction fragmentTransaction = this.getFragmentManager().beginTransaction();
int id = item.getItemId();
// Globale Eistellungen
if (id == R.id.nav_main_settings) {
fragmentTransaction.replace(R.id.containerView, new MainPreferenceMenu());
fragmentTransaction.commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
Whereby "MainPreferenceMenu" is a PreferenceFragment.
I tried it with this tutorial: https://guides.codepath.com/android/google-play-style-tabs-using-tablayout
First Problem: I can´t set my PreferenceFragment here:
Code:
@Override
public Fragment getItem(int position) {
return PageFragment.newInstance(position + 1);
}
Because "PreferenceFragment" is the wring Class.
Also I don´t know how to set the "ViewPager" like in the Tutorial (MainActivity).
Can anybody help me?
I hope my Problem is clear.
Using view pager for tabs is the best option as it behaves as per material guide lines.

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