I was aiming for this:
.png "Android Custom Multi Choice Item 1")
.png "Android Custom Multi Choice Item 2")
.png)
So, here it is: activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<Button
android:onClick="onDialog"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Show Dialog" />
</LinearLayout>
And this is our array.xml file in resources that we will use for our list:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="items">
<item >Select all</item>
<item >First</item>
<item >Second</item>
<item >Third</item>
<item >Fourth</item>
</string-array>
</resources>
And finally, MainActivity.java in which the magic happens. Main things are AlertDialog.Builder.setMultiChoiceItems(R.array.items, null, null) and listView.setOnItemClickListener(...), because these two things combined give us a possibility to have a "Select All" option.
public class MainActivity extends Activity {
AlertDialog mDialog = null;
/**
* This becomes false when "Select All" is selected while deselecting some other item on list.
*/
boolean selectAll = true;
/**
* Number of items in array list and eventually in ListView
*/
int length;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
length = getResources().getStringArray(R.array.items).length;
}
public void onDialog (View v) {
mDialog = onCreateDialog(null);
mDialog.show();
// we get the ListView from already shown dialog
final ListView listView = mDialog.getListView();
// ListView Item Click Listener that enables "Select all" choice
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
boolean isChecked = listView.isItemChecked(position);
if (position == 0) {
if(selectAll) {
for (int i = 1; i < length; i++) { // we start with first element after "Select all" choice
if (isChecked && !listView.isItemChecked(i)
|| !isChecked && listView.isItemChecked(i)) {
listView.performItemClick(listView, i, 0);
}
}
}
} else {
if (!isChecked && listView.isItemChecked(0)) {
// if other item is unselected while "Select all" is selected, unselect "Select all"
// false, performItemClick, true is a must in order for this code to work
selectAll = false;
listView.performItemClick(listView, 0, 0);
selectAll = true;
}
}
}
});
}
public AlertDialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
// Set the dialog title
builder.setTitle(R.string.dialog)
// Specify the list array, the items to be selected by default (null for none),
// and the listener is null in order to "Select all" choice to work
.setMultiChoiceItems(R.array.items, null, null)
// Set the action buttons
.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int id) {
// User clicked OK, so save something here
}
})
.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int id) {}
});
return builder.create();
}
}
Hope you've enjoyed in this code example!
Cheers!
