Tab bar and stuff

mastodon/src/main/java/org/joinmastodon/android/ui/views/TabBar.java

@@ -0,0 +1,55 @@
+package org.joinmastodon.android.ui.views;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.LinearLayout;
+
+import org.joinmastodon.android.R;
+
+import java.util.function.IntConsumer;
+
+import androidx.annotation.IdRes;
+
+public class TabBar extends LinearLayout{
+	@IdRes
+	private int selectedTabID;
+	private IntConsumer listener;
+
+	public TabBar(Context context){
+		this(context, null);
+	}
+
+	public TabBar(Context context, AttributeSet attrs){
+		this(context, attrs, 0);
+	}
+
+	public TabBar(Context context, AttributeSet attrs, int defStyle){
+		super(context, attrs, defStyle);
+	}
+
+	@Override
+	public void onViewAdded(View child){
+		super.onViewAdded(child);
+		if(child.getId()!=0){
+			if(selectedTabID==0){
+				selectedTabID=child.getId();
+				child.setSelected(true);
+			}
+			child.setOnClickListener(this::onChildClick);
+		}
+	}
+
+	private void onChildClick(View v){
+		if(v.getId()==selectedTabID)
+			return;
+		findViewById(selectedTabID).setSelected(false);
+		v.setSelected(true);
+		selectedTabID=v.getId();
+		listener.accept(selectedTabID);
+	}
+
+	public void setListener(IntConsumer listener){
+		this.listener=listener;
+	}
+}