Develop Reference

Select multiple items from recycler view list delete not working Properly

if (RFidList.size() >0){
for (String s: RFidList){
RFidTagValueList.remove(s);
}
}
mTimeAdapter.notifyDataSetChanged();
dialog.dismiss();
when choose multiple items in recyclerview checkbox not working / and am use private ArrayList<String> data = new ArrayList<>();

You can't move and delete from the list. The best option to do this is to have an array that will remember the state of the checkbox. Scrolling through your recycler view will always change the state of the checkbox and maybe won't remember it. The way to do this is to add an array of boolean
private boolean[] checkStates;
then inside your constructor of the adapter do this.
checkStates = new boolean[data.size()];
This way you'll create an array of boolean filled with FALSE value the same size your data array is. Now, inside your adapter when you are binding your view do this for the checkbox.
holder.checkbox.setChecked(checkStates[position]);
Also, don't use onCheckedChangeListener on checkbox inside adapter. This will be called even when you scroll and it will change whatever you are doing inside the function. What you can do is override onClick for the checkbox, but there is something tricky here. When you click the checkbox to check it, inside the onClick method the view will have the state as it is already checked so to follow this do it like this:
holder.checkbox.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Checkbox c = (CheckBox) v;
checkStates[position] = c.isChecked();
}
});
I wrote this from my head and maybe there are some mistakes but you'll get the point. The animation of the check state will be handled you just need to handle changes inside the checkStates array.
Now your checkbox will always have the state it had before. After this, you can create a function to delete items from your data.
public void removeItems() {
ArrayList<YOUR-MODEL> items_to_delete = new ArrayList<>();
for (int i = 0; i < checkStates.length(); ++i) {
if (checkStates[i]) items_to_delete.add(data.get(i]);
}
data.removeAll(items_to_delete);
notifyDataSetChanged();
checkStates = new boolean[data.size()];
}
This works if your data is a type of ArrayList. I think this is the best way to go.

How to get the count of Listview item selection in Android

I have a ListView which am setting that to my adapter. The ListView item contains two view elements which are chekbox and TextView.
I have given the setChoiceMode(ListView.CHOICE_MODE_MULTIPLE) for the ListView.
When i want to select one or more element, I want to get the count (based on selecting and deselecting).
I can't do this stuff in onItemClickListener of ListView.
So I have written the logic in BaseAdapter.
holder.check.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
count += 1;
}
});
But If i deselect the item then the value have to decrease. If iam having only one item in ListView then I can write
SparseBooleanArray checked = listView.getCheckedItemPositions();
and get the value in Fragment. Just I get confused. Could someone help me?

Use this.
SparseBooleanArray checkedItemPositions = getListView().getCheckedItemPositions();
int count = 0;
for (int i = 0, ei = checkedItemPositions.size(); i < ei; i++) {
if (checkedItemPositions.valueAt(i)) {
count++;
}
}
// use count as you wish
Make sure count is in a local (or block of the OnClickListener) scope so that every time you click a button or something, count gets reset and it recounts how many items are checked/unchecked.
Let me know if you have more question :)

Click all the list view elements while scrolling using robotium

I have a listView that contains lots of elements i.e. we have to scroll down to see all the elements. Now what i want to do is, click all the listView elements. How can I do that. Right now,I am using the following code but it doesn't scroll automatically. Please help.
ListView l = solo.getCurrentListViews().get(0);
assertNotNull("No list views!", l);
assertTrue("No items in list view!", l.getChildCount() > 0);
// Get the last list item
View v = l.getChildAt(l.getChildCount());
System.out.println("getChildCount: " + l.getChildCount());
int i = 1;
while (i <= l.getChildCount()) {
solo.clickInList(i);
solo.goBack();
i++;
}

I have previously used these helper functions in a slightly different state to handle most of what we need with listviews:
public View getViewAtIndex(final ListView listElement, final int indexInList, Instrumentation instrumentation) {
ListView parent = listElement;
if (parent != null) {
if (indexInList <= parent.getAdapter().getCount()) {
scrollListTo(parent, indexInList, instrumentation);
int indexToUse = indexInList - parent.getFirstVisiblePosition();
return parent.getChildAt(indexToUse);
}
}
return null;
}
public <T extends AbsListView> void scrollListTo(final T listView,
final int index, Instrumentation instrumentation) {
instrumentation.runOnMainSync(new Runnable() {
#Override
public void run() {
listView.setSelection(index);
}
});
instrumentation.waitForIdleSync();
}
With these your method would be:
ListView list = solo.getCurrentListViews().get(0);
for(int i=0; i < list.getAdapter().getCount(); i++){
solo.clickOnView(getViewAtIndex(list, i, getInstrumentation()))
}

It looks like your code, as currently implemented, is only considering the visibile list items when controlling the loop and handling the clicking. It's important to note the behavior of two things:
First, there's a concept called view recycling in Android that helps conserve memory when dealing with ListViews. Only the views that are currently on screen are created, and once they scroll off the screen they'll be repopulated with new data. Therefore, calling methods like getChildCount and getChildAt on a ListView will only perform these operations on the visible items. To find information about the data that populates the list, you can call methods such as getCount() or getItem() on the ListView's adapter.
Second, the clickInList() method is 1-indexed, relative to the current position of the list, and can only be used for visible items. As far as I know, it will never scroll your list automatically. This means that calling clickInList(2) when at the top of the list will click the second item, but then calling clickInList(2) again when the 30th item is at the top of the list will click the 32nd.
Knowing these two things, your solution will need to consider all of the list data and perhaps have a bit more precision when making clicks. Here's how I'd rewrite your while loop to ensure you'll be able to handle every item on the list, hope this helps:
ListAdapter adapter = l.getAdapter();
for(int i=0; i < adapter.getCount(); i++)
{
//Scroll down the list to make sure the current item is visible
solo.scrollListToLine(l, i);
//Here you need to figure out which view to click on.
//Perhaps using adapter.getItem() to get the data for the current list item, so you know the text it is displaying.
//Here you need to click the item!
//Even though you're in a list view, you can use methods such as clickOnText(), which might be easier based on how your adapter is set up
solo.goBack();
}

It should help you(not tested):
public void clickAllElementsOnListView(int index) {
ListView listView = solo.getCurrentListViews().get(index);
count = listView.getAdapter() != null ? listView.getAdapter().getCount() : 0;
for (int i = 0; i < count; i++) {
scrollListToLine(listView, i);
solo.clickInList(1, index);
solo.goBack();
}
}
protected void scrollListToLine(final ListView listView, final int line) {
getInstrumentation().runOnMainSync(new Runnable() {
public void run() {
listView.setSelection(line);
}
});
}

How to check a checkbox status inside a ListView on Android

I got on my code a listview with check boxes, but How can I check if the value of the checkbox?
I'm implementing a program with tabs, and one of the tabs has the ListView with checkboxes, the code is as follows:
spec = tabHost.newTabSpec(OPTS_TAB_TAG).setIndicator("Options",
res.getDrawable(R.drawable.ic_tab_options))
.setContent(new TabContentFactory()
{
public View createTabContent(String arg0)
{
DbAdapter databaseManager = new DbAdapter(BusTrackerBetaActivity.this);
databaseManager.open();
List<String> BusLinesList = new ArrayList<String>();
BusLinesList = databaseManager.toStringList(databaseManager.getAllBusLines(), 1);
String[] BusLinesArray = BusLinesList.toArray(new String[BusLinesList.size()]);
databaseManager.close();
ListView ls1 = new ListView(BusTrackerBetaActivity.this);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
BusTrackerBetaActivity.this,
android.R.layout.simple_list_item_multiple_choice,
BusLinesArray);
ls1.setAdapter(adapter);
ls1.setOnCreateContextMenuListener(BusTrackerBetaActivity.this);
ls1.setItemsCanFocus(false);
ls1.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
return ls1;
}
});
It's working fine, acctually I got this way of implementing the list from some examples, but my question is: How can I check the value (true or false) of each checkbox?

You can use ListView's getCheckedItemPositions function to accomplish this. It will return a SparseBooleanArray object containing the checked status of each item in the ListView. Loop through the SparseBooleanArray to determine which items are checked.
You will need to keep a reference to your ListView object somewhere so that you can easily access it later when you need to determine checked item status.
SparseBooleanArray checkedItems = ls1.getCheckedItemPositions();
if (checkedItems != null)
for (int i = 0; i < checkedItems.size(); i++)
{
if (checkedItems.valueAt(i))
{
String s = ls1.getAdapter().getItem(checkedItems.keyAt(i)).toString();
//s contains your checked item, checkedItems.keyAt(i) is the index of the checked item
}
}

Select All items of a ListView (custom row with checkbox in it)

What I have: I have a ListView with custom rows, having a CheckBox & two TextViews in each row. I have a button for "Select All".
What i want: I want that when I click the button, all the CheckBox in ListView get checked/unchecked.
What is the problem: In OnClick of the "Select All" button. i am doing this:
public void OnClickSelectAllButton(View view)
{
ListView l = getListView();
int count = l.getCount();
for(int i=0; i<count; ++i)
{
ViewGroup row = (ViewGroup)l.getChildAt(i);
CheckBox check = (CheckBox) row.findViewById(R.id.checkBoxID);
check.setChecked(true); // true for select all and false for unselect all etc..
}
}
Here l.getChildAt(i) is giving me the visible items only. And when the index goes out of visible items, the problem occurs. I want to check all the CheckBox in List, not just the visible ones.

It will occur, because ListView adapter reuses views. The way you are trying to do is incorrect. I don't think you ever should access listview rows through listview children.
Introduce a variable in your activity, that will hold the current state (boolean checkAll). When the user presses the button, it must set "checkAll" to true, and call notifyDataSetChanged() (for arrayadapter), or requery() (for cursoradapter) on your ListView's adapter. In adapter's getView() method introduce a check for this flag, so if (checkAll) {check the check box}

have you looked this Correct way to check all checkboxes in ListView?
int count = getListAdapter().getCount();

I think you should run this long-running task off the UI thread.
When you click button in OnClickListener:
new Thread(new Runnable() {
#Override
public void run() {
for (int i = 0; i < list.getAdapter().getCount(); i++) {
final int position = i;
mHandler.post(new Runnable() {
#Override
public void run() {
list.setItemChecked(pos, true);
}
});
}
}
}).start();
and in onCreate() :
this.mHandler = new Handler();
Each item in list view should be Checkable like CheckableRelativeLayout that implements Checkable interface.