Updated layout for two columns in landscape.

app/build.gradle

@@ -1,15 +1,15 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.2"
+    compileSdkVersion 25
+    buildToolsVersion "23.0.3"
 
     defaultConfig {
         applicationId "cz.jiriskorpil.amixerwebui"
         minSdkVersion 15
-        targetSdkVersion 23
-        versionCode 1
-        versionName "0.1"
+        targetSdkVersion 25
+        versionCode 2
+        versionName "0.1.1"
     }
     buildTypes {
         release {
@@ -19,11 +19,13 @@ android {
     }
 }
 
+ext.supportLibraryVersion = '25.0.+'
 dependencies {
     compile fileTree(include: ['*.jar'], dir: 'libs')
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:appcompat-v7:23.2.1'
-    compile 'com.android.support:design:23.2.1'
-    compile 'com.android.support:support-v4:23.2.1'
-    compile 'com.android.support:cardview-v7:23.2.1'
+    compile "com.android.support:appcompat-v7:$supportLibraryVersion"
+    compile "com.android.support:design:$supportLibraryVersion"
+    compile "com.android.support:support-v4:$supportLibraryVersion"
+    compile "com.android.support:cardview-v7:$supportLibraryVersion"
+    compile "com.android.support:recyclerview-v7:$supportLibraryVersion"
 }

app/src/main/AndroidManifest.xml

@@ -12,6 +12,7 @@
         android:theme="@style/AppTheme">
         <activity
             android:name=".activity.MainActivity"
+            android:configChanges="orientation"
             android:label="@string/app_name"
             android:theme="@style/AppTheme.NoActionBar">
             <intent-filter>

app/src/main/java/cz/jiriskorpil/amixerwebui/activity/DataHandler.java

@@ -2,10 +2,12 @@
 
 import android.content.Context;
 import android.content.SharedPreferences;
+import android.content.res.Configuration;
 import android.preference.PreferenceManager;
 import android.support.v4.widget.SwipeRefreshLayout;
+import android.support.v7.widget.GridLayoutManager;
+import android.support.v7.widget.RecyclerView;
 import android.util.Log;
-import android.widget.ListView;
 
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -28,23 +30,27 @@
  */
 public class DataHandler
 {
-	Context context;
-	OnFailListener mOnFailListener;
+	private Context context;
+	private OnFailListener mOnFailListener;
 
 	/* GUI components */
-	ListView listView;
-	SwipeRefreshLayout swipeRefreshLayout;
-	List<ControlContainer> controls;
+	private RecyclerView listView;
+	private SwipeRefreshLayout swipeRefreshLayout;
+	private List<ControlContainer> controls;
 
 	/**
 	 * @param context            The context to use. Usually {@link android.app.Activity} object.
 	 * @param resultListView     ListView for results
 	 * @param swipeRefreshLayout layout for results
 	 */
-	public DataHandler(Context context, ListView resultListView, SwipeRefreshLayout swipeRefreshLayout)
+	public DataHandler(Context context, RecyclerView resultListView, SwipeRefreshLayout swipeRefreshLayout)
 	{
 		this.context = context;
+
 		this.listView = resultListView;
+		this.listView.setHasFixedSize(true);
+		this.listView.setLayoutManager(new GridLayoutManager(context, context.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE ? 2 : 1, GridLayoutManager.VERTICAL, false));
+
 		this.swipeRefreshLayout = swipeRefreshLayout;
 		this.swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener()
 		{
@@ -108,8 +114,7 @@ public void displayData(JSONArray jsonArray)
 			controls = parseControls(jsonArray);
 		}
 
-		ControlContainerAdapter adapter = new ControlContainerAdapter(context, R.layout.control_row, controls);
-		listView.setAdapter(adapter);
+		listView.setAdapter(new ControlContainerAdapter(context, controls));
 		swipeRefreshLayout.setRefreshing(false);
 	}
 

app/src/main/java/cz/jiriskorpil/amixerwebui/activity/MainActivity.java

@@ -1,16 +1,18 @@
 package cz.jiriskorpil.amixerwebui.activity;
 
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.os.Bundle;
 import android.support.design.widget.Snackbar;
 import android.support.v4.content.ContextCompat;
 import android.support.v4.widget.SwipeRefreshLayout;
 import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.GridLayoutManager;
+import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.Toolbar;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
-import android.widget.ListView;
 
 import cz.jiriskorpil.amixerwebui.R;
 
@@ -31,7 +33,7 @@ protected void onCreate(Bundle savedInstanceState)
 		setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
 
 		dataHandler = (new DataHandler(this,
-					(ListView) findViewById(R.id.controls_list),
+					(RecyclerView) findViewById(R.id.controls_list),
 					(SwipeRefreshLayout) findViewById(R.id.swipe_container)))
 				.setOnFailListener(new DataHandler.OnFailListener()
 				{
@@ -57,6 +59,18 @@ public void onClick(View v)
 		lastUrl = dataHandler.getBaseUrl();
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void onConfigurationChanged(Configuration newConfig)
+	{
+		super.onConfigurationChanged(newConfig);
+
+		GridLayoutManager manager = (GridLayoutManager) ((RecyclerView) findViewById(R.id.controls_list)).getLayoutManager();
+		manager.setSpanCount(newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE ? 2 : 1);
+	}
+
 	/**
 	 * {@inheritDoc}
 	 */

app/src/main/java/cz/jiriskorpil/amixerwebui/control/ControlContainerAdapter.java

@@ -2,10 +2,10 @@
 
 import android.app.Activity;
 import android.content.Context;
+import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.ArrayAdapter;
 import android.widget.CheckBox;
 import android.widget.LinearLayout;
 import android.widget.RadioButton;
@@ -26,71 +26,61 @@
 /**
  * List adapter for control container.
  */
-public class ControlContainerAdapter extends ArrayAdapter<ControlContainer>
+public class ControlContainerAdapter extends RecyclerView.Adapter<ControlContainerAdapter.ControlContainerHolder>
 {
-	Context context;
-	int layoutResourceId;
-	List<ControlContainer> data = null;
+	private Context context;
+	private List<ControlContainer> data = null;
 
 	private static final float FULL_VISIBILITY = 1;
 	private static final float LOW_VISIBILITY = (float) 0.4;
 
 	/**
 	 *
 	 * @param context          The context to use. Usually {@link android.app.Activity} object.
-	 * @param layoutResourceId GUI element for rendering
 	 * @param data             list of controls
 	 */
-	public ControlContainerAdapter(Context context, int layoutResourceId, List<ControlContainer> data)
+	public ControlContainerAdapter(Context context, List<ControlContainer> data)
 	{
-		super(context, layoutResourceId, data);
 		this.context = context;
-		this.layoutResourceId = layoutResourceId;
 		this.data = data;
 	}
 
 	@Override
-	public View getView(int position, View convertView, ViewGroup parent)
+	public int getItemCount()
 	{
-		View row = convertView;
-		ControlContainerHolder holder;
-
-		if (row == null)
-		{
-			LayoutInflater inflater = ((Activity) context).getLayoutInflater();
-			row = inflater.inflate(layoutResourceId, parent, false);
-
-			holder = new ControlContainerHolder();
-			holder.enabled = (Switch) row.findViewById(R.id.enabled);
-			holder.name = (TextView) row.findViewById(R.id.name);
-			holder.bind_sliders = (CheckBox) row.findViewById(R.id.bind_sliders);
-			holder.source_list = (RadioGroup) row.findViewById(R.id.source_list);
-			holder.channels_list = (LinearLayout) row.findViewById(R.id.channels_list);
+		return data.size();
+	}
 
-			row.setTag(holder);
+	@Override
+	public void onBindViewHolder(ControlContainerHolder holder, int i)
+	{
+		ControlContainer container = data.get(i);
 
-		} else {
-			holder = (ControlContainerHolder) row.getTag();
-		}
+		setupCard(container, holder);
+	}
 
-		setupCard(data.get(position), holder, row);
+	@Override
+	public ControlContainerHolder onCreateViewHolder(ViewGroup viewGroup, int i)
+	{
+		View itemView = LayoutInflater
+							.from(viewGroup.getContext())
+							.inflate(R.layout.control_row, viewGroup, false);
 
-		return row;
+		return new ControlContainerHolder(itemView);
 	}
 
 	/**
 	 * Setups control card.
 	 *
 	 * @param container control container
 	 * @param holder    control container holder
-	 * @param row       GUI row View
 	 */
-	private void setupCard(ControlContainer container, ControlContainerHolder holder, View row)
+	private void setupCard(ControlContainer container, ControlContainerHolder holder)
 	{
 		setupCardHeader(container, holder);
 
 		setupCardBodySource(container, holder);
-		setupCardBodyChannels(container, holder, row);
+		setupCardBodyChannels(container, holder);
 
 		setCardBodyAlpha(container, holder);
 	}
@@ -127,7 +117,7 @@ private void toggleControl(final ControlContainer container, final ControlContai
 	{
 		container.getSwitch().setChecked(isChecked);
 		setCardBodyAlpha(container, holder);
-		new ToggleControlHttpRequestTask(getContext(), ((MainActivity) getContext()).getDataHandler().getBaseUrl())
+		new ToggleControlHttpRequestTask(holder.getView().getContext(), ((MainActivity) holder.getView().getContext()).getDataHandler().getBaseUrl())
 				.execute(String.valueOf(container.getSwitch().getId()), container.getSwitch().isChecked() ? "1" : "0");
 	}
 
@@ -174,8 +164,8 @@ public void onClick(View v)
 				@Override
 				public boolean onLongClick(View v)
 				{
-					Toast.makeText(getContext(),
-							getContext().getResources().getString(holder.bind_sliders.isChecked() ? R.string.bound_sliders : R.string.unbounded_sliders),
+					Toast.makeText(holder.getView().getContext(),
+							holder.getView().getContext().getResources().getString(holder.bind_sliders.isChecked() ? R.string.bound_sliders : R.string.unbounded_sliders),
 							Toast.LENGTH_LONG).show();
 					return true;
 				}
@@ -200,22 +190,22 @@ private void setupCardBodySource(final ControlContainer container, final Control
 			holder.source_list.check(0);
 			for (int i = 0; i < container.getSource().getItems().length; i++)
 			{
-				final RadioButton button = new RadioButton(getContext());
-				button.setId(i);
+				final RadioButton button = new RadioButton(holder.getView().getContext());
+				button.setId(i + 1);
 				button.setText(container.getSource().getItems()[i]);
 				button.setOnClickListener(new View.OnClickListener()
 				{
 					@Override
 					public void onClick(View v)
 					{
 						container.getSource().setValue(holder.source_list.getCheckedRadioButtonId());
-						new ChangeSourceHttpRequestTask(getContext(), ((MainActivity) getContext()).getDataHandler().getBaseUrl())
+						new ChangeSourceHttpRequestTask(holder.getView().getContext(), ((MainActivity) holder.getView().getContext()).getDataHandler().getBaseUrl())
 								.execute(String.valueOf(container.getSource().getId()), String.valueOf(button.getId()));
 					}
 				});
 				holder.source_list.addView(button);
 			}
-			holder.source_list.check(container.getSource().getValue());
+			holder.source_list.check(container.getSource().getValue() + 1);
 		} else {
 			holder.source_list.setVisibility(View.INVISIBLE);
 		}
@@ -226,16 +216,15 @@ public void onClick(View v)
 	 *
 	 * @param container control container
 	 * @param holder    control container holder
-	 * @param row       GUI row View
 	 */
-	private void setupCardBodyChannels(final ControlContainer container, final ControlContainerHolder holder, View row)
+	private void setupCardBodyChannels(final ControlContainer container, final ControlContainerHolder holder)
 	{
 		holder.channels_list.removeAllViews();
 		if (container.hasVolumeControl())
 		{
 			for (int i = 0; i < container.getVolume().getChannels().length; i++)
 			{
-				LinearLayout channelLayout = (LinearLayout) row.findViewById(R.id.control_channel);
+				LinearLayout channelLayout = (LinearLayout) holder.getView().findViewById(R.id.control_channel);
 				View channelView = ((Activity) context).getLayoutInflater().inflate(R.layout.control_channel, channelLayout, false);
 				holder.channels_list.addView(channelView, i);
 
@@ -248,14 +237,14 @@ private void setupCardBodyChannels(final ControlContainer container, final Contr
 				channel_name.setText(channel.getName());
 				channel_volume_seek_bar.setMax(channel.getControl().getMax());
 				channel_volume_seek_bar.setProgress(channel.getValue());
-				channel_volume.setText(getContext().getString(R.string.channel_value, Math.round(100 * (double) channel.getValue() / channel.getControl().getMax())));
+				channel_volume.setText(holder.getView().getContext().getString(R.string.channel_value, Math.round(100 * (double) channel.getValue() / channel.getControl().getMax())));
 
 				channel_volume_seek_bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener()
 				{
 					@Override
 					public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
 					{
-						String progressMsg = getContext().getString(R.string.channel_value, Math.round(100 * progress / seekBar.getMax()));
+						String progressMsg = holder.getView().getContext().getString(R.string.channel_value, Math.round(100 * progress / seekBar.getMax()));
 						if (fromUser && holder.bind_sliders.isChecked()) {
 							for (int i = 0; i < container.getVolume().getChannels().length; i++) {
 								if (!holder.channels_list.getChildAt(i).equals(seekBar))
@@ -292,7 +281,7 @@ public void onStopTrackingTouch(SeekBar seekBar)
 							}
 							volumes += String.valueOf(container.getVolume().getChannels()[i].getValue());
 						}
-						new ChangeVolumeHttpRequestTask(getContext(), ((MainActivity) getContext()).getDataHandler().getBaseUrl())
+						new ChangeVolumeHttpRequestTask(holder.getView().getContext(), ((MainActivity) holder.getView().getContext()).getDataHandler().getBaseUrl())
 								.execute(String.valueOf(container.getVolume().getId()), volumes);
 					}
 				});
@@ -303,12 +292,31 @@ public void onStopTrackingTouch(SeekBar seekBar)
 	/**
 	 * Holds ControlContainer GUI controls.
 	 */
-	static class ControlContainerHolder
+	static class ControlContainerHolder extends RecyclerView.ViewHolder
 	{
+		View v;
+
 		Switch enabled;
 		TextView name;
 		CheckBox bind_sliders;
 		RadioGroup source_list;
 		LinearLayout channels_list;
+
+		ControlContainerHolder(View v)
+		{
+			super(v);
+			this.v = v;
+			enabled = (Switch) v.findViewById(R.id.enabled);
+			name = (TextView) v.findViewById(R.id.name);
+			bind_sliders = (CheckBox) v.findViewById(R.id.bind_sliders);
+			source_list = (RadioGroup) v.findViewById(R.id.source_list);
+			channels_list = (LinearLayout) v.findViewById(R.id.channels_list);
+		}
+
+
+		public View getView()
+		{
+			return v;
+		}
 	}
 }

app/src/main/res/layout/content_main.xml

@@ -10,11 +10,11 @@
 	tools:context=".activity.MainActivity"
 	tools:showIn="@layout/activity_main">
 
-	<ListView
+	<android.support.v7.widget.RecyclerView
 		android:id="@+id/controls_list"
 		android:layout_width="match_parent"
 		android:layout_height="match_parent"
-		android:paddingBottom="8dp"
+		android:padding="@dimen/controlCardMargin"
 		android:clipToPadding="false"
 		android:scrollbarStyle="outsideOverlay"
 		android:divider="@android:color/transparent"