adapter - w3toppers.com

Remove all items from RecyclerView

This works great for me: public void clear() { int size = data.size(); if (size > 0) { for (int i = 0; i < size; i++) { data.remove(0); } notifyItemRangeRemoved(0, size); } } Source: https://github.com/mikepenz/LollipopShowcase/blob/master/app/src/main/java/com/mikepenz/lollipopshowcase/adapter/ApplicationAdapter.java or: public void clear() { int size = data.size(); data.clear(); notifyItemRangeRemoved(0, size); } For you: @Override protected void onRestart() … Read more

adapter-Any real example of Adapter Pattern [closed]

Many examples of Adapter are trivial or unrealistic (Rectangle vs. LegacyRectangle, Ratchet vs. Socket, SquarePeg vs RoundPeg, Duck vs. Turkey). Worse, many don’t show multiple Adapters for different Adaptees (someone cited Java’s Arrays.asList as an example of the adapter pattern). Adapting an interface of only one class to work with another seems a weak example … Read more

android attaching multiple adapters to one adapter

You can use MergeAdapter for your ListView. This is my modified and fully tested version. /** * Adapter that merges multiple child adapters and views into a single * contiguous whole. * * Adapters used as pieces within MergeAdapter must have view type IDs * monotonically increasing from 0. Ideally, adapters also have distinct ranges … Read more

Difference between Bridge pattern and Adapter pattern

“Adapter makes things work after they’re designed; Bridge makes them work before they are. [GoF, p219]” Effectively, the Adapter pattern is useful when you have existing code, be it third party, or in-house, but out of your control, or otherwise not changeable to quite meet the interface you need it to. For instance, we have … Read more

ListView Viewholder checkbox state

Here’s how I made it work: First, you need a separate array for your checked state. It has to be the same size as your adapter’s getCount(). Then on your getView, your checkbox’s setOnCheckedChangedListener MUST PRECEED your checkbox.setChecked statements. example: holder.checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { isChecked[position] = isChecked; } … Read more

What’s the purpose of item-id’s in Android ListView Adapter?

Imagine this structure: You have db table Notes with such 3 records: +—-+————————–+ | ID | Note Text | +—-+————————–+ | 43 | Note text blah blah | | 67 | Note text blah blah blah | | 85 | Last note | +—-+————————–+ and you implement an adapter to serve this data. Now let’s … Read more

How to show installed app list in a listview without Checkbox getting unchecked when listview is scrolled?

Activity import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.pm.PackageInfo; import android.os.Bundle; import android.widget.ListView; public class AppScreen extends Activity { private ListView list; ArrayList<Datamodel> res; MyAdapter _adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.app_screen); list = (ListView) findViewById(R.id.list); List<PackageInfo> _myapps = getPackageManager().getInstalledPackages(0); res = new ArrayList<Datamodel>(); for (int i = 0; i < _myapps.size(); i++) … Read more

GetView Vs. BindView in a custom CursorAdapter?

CursorAdapter has an implementation of getView() that delegates to newView() and bindView(), in such a way as enforces the row recycling pattern. Hence, you do not need to do anything special with a CursorAdapter for row recycling if you are overriding newView() and bindView().

Finding SSID of a wireless network with Java

You can’t access this low-level details of the network in Java. You can get some details of the network interface with the NetworkInterface class but if you see at the provided methods, no one is related to Wifi networks nor any way to get the SSID is provided. As pointed below, you should use some … Read more

Android: notifyDataSetChanged(); not working

One of the main reasons notifyDataSetChanged() won’t work for you – is, Your adapter loses reference to your list. When you first initialize the Adapter it takes a reference of your arrayList and passes it to its superclass. But if you reinitialize your existing arrayList it loses the reference, and hence, the communication channel with … Read more