Add LAN discovery and instance picker

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

4 files changed, 452 insertions, 1 deletions

diff --git a/app/src/main/java/mygram/droid/Discovery.java b/app/src/main/java/mygram/droid/Discovery.java
index 1d3e0be..56777f3 100644
--- a/app/src/main/java/mygram/droid/Discovery.java
+++ b/app/src/main/java/mygram/droid/Discovery.java
@@ -12,14 +12,33 @@
  * for more details.
  */
 
-
 package mygram.droid;
 
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.LinkAddress;
+import android.net.LinkProperties;
+
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import java.io.IOException;
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.URI;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
 /** Finds Foldergram instances on the LAN. */
+// ponytail: probes only the TV's /24 on the default port; manual URL entry covers proxies and other ports.
 final class Discovery {
+	static final int PORT = 4141;
+
 	private Discovery() {
 	}
 
@@ -32,4 +51,49 @@ final class Discovery {
 			return false;
 		}
 	}
+
+	/** The TV's own IPv4 address, or null when offline. */
+	static String localIpv4(Context c) {
+		ConnectivityManager cm = c.getSystemService(ConnectivityManager.class);
+		LinkProperties lp = cm.getLinkProperties(cm.getActiveNetwork());
+		if (lp != null)
+			for (LinkAddress a : lp.getLinkAddresses())
+				if (a.getAddress() instanceof Inet4Address)
+					return a.getAddress().getHostAddress();
+		return null;
+	}
+
+	/** Base URLs of instances answering on the /24 around self. Blocks a few seconds. */
+	static List<String> scan(String self) throws InterruptedException {
+		String prefix = self.substring(0, self.lastIndexOf('.') + 1);
+		ExecutorService pool = Executors.newFixedThreadPool(64);
+		List<String> found = Collections.synchronizedList(new ArrayList<>());
+		for (int i = 1; i < 255; i++) {
+			String base = "http://" + prefix + i + ":" + PORT;
+			pool.execute(() -> {
+				try {
+					if (isFoldergram(Api.request(base, "GET", "/health", null, 800)))
+						found.add(base);
+				} catch (IOException e) {
+					// nothing listening there
+				}
+			});
+		}
+		pool.shutdown();
+		pool.awaitTermination(20, TimeUnit.SECONDS);
+		List<String> out = new ArrayList<>(found);
+		Collections.sort(out);
+		return out;
+	}
+
+	/** Reverse-DNS name plus IP when there is a name, else the IP. */
+	static String label(String base) {
+		String ip = URI.create(base).getHost();
+		try {
+			String name = InetAddress.getByName(ip).getCanonicalHostName();
+			return name.equals(ip) ? ip : name + "  " + ip;
+		} catch (UnknownHostException e) {
+			return ip;
+		}
+	}
 }
diff --git a/app/src/main/java/mygram/droid/SetupActivity.java b/app/src/main/java/mygram/droid/SetupActivity.java
index ef1f68c..106ec9c 100644
--- a/app/src/main/java/mygram/droid/SetupActivity.java
+++ b/app/src/main/java/mygram/droid/SetupActivity.java
@@ -15,6 +15,112 @@
 package mygram.droid;
 
 import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+import android.text.InputType;
+import android.widget.EditText;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+import android.widget.Toast;
 
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/** Instance picker: LAN scan, manual URL, then the password when the instance asks for one. */
 public final class SetupActivity extends Activity {
+	private LinearLayout box;
+
+	@Override
+	protected void onCreate(Bundle state) {
+		super.onCreate(state);
+		box = Ui.column(this);
+		setContentView(box);
+		scan();
+	}
+
+	private void scan() {
+		reset("Searching the network for Foldergram…");
+		Api.async(() -> {
+			Map<String, String> found = new LinkedHashMap<>();
+			String self = Discovery.localIpv4(this);
+			if (self != null)
+				for (String base : Discovery.scan(self))
+					found.put(base, Discovery.label(base));
+			return found;
+		}, this::found, e -> {
+			reset("Scan failed: " + e.getMessage());
+			actions();
+		});
+	}
+
+	private void found(Map<String, String> instances) {
+		reset(instances.isEmpty() ? "No Foldergram found on port " + Discovery.PORT : "Choose an instance");
+		for (Map.Entry<String, String> e : instances.entrySet()) {
+			TextView t = Ui.text(this, e.getValue(), 20);
+			int p = Ui.dp(this, 12);
+			t.setPadding(p * 2, p, p * 2, p);
+			Ui.focusable(t);
+			t.setOnClickListener(v -> choose(e.getKey()));
+			box.addView(t);
+		}
+		actions();
+		box.getChildAt(1).requestFocus();
+	}
+
+	private void actions() {
+		LinearLayout row = Ui.row(this);
+		row.addView(Ui.iconButton(this, R.drawable.ic_refresh, "Rescan", v -> scan()));
+		row.addView(Ui.iconButton(this, R.drawable.ic_edit, "Enter URL", v -> manual()));
+		box.addView(row);
+	}
+
+	private void manual() {
+		reset("Instance URL");
+		EditText url = Ui.field(this, "http://host:" + Discovery.PORT,
+				InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_URI);
+		box.addView(url);
+		box.addView(Ui.iconButton(this, R.drawable.ic_check, "Connect",
+				v -> choose(Api.normalize(url.getText().toString()))));
+		url.requestFocus();
+	}
+
+	private void choose(String base) {
+		reset("Connecting to " + base + "…");
+		Api.async(() -> Api.authStatus(base), status -> {
+			if ("public".equals(status.optString("accessMode")))
+				save(base, "");
+			else
+				password(base);
+		}, e -> {
+			reset("Cannot reach " + base + ": " + e.getMessage());
+			actions();
+		});
+	}
+
+	private void password(String base) {
+		reset("Viewer password for " + base);
+		EditText pw = Ui.field(this, "Password", Ui.password());
+		box.addView(pw);
+		box.addView(Ui.iconButton(this, R.drawable.ic_check, "Log in", v -> {
+			String s = pw.getText().toString();
+			Api.async(() -> {
+				Api.login(base, s);
+				return true;
+			}, ok -> save(base, s), e -> Toast.makeText(this,
+					e instanceof Api.HttpError && ((Api.HttpError) e).code == 401 ? "Wrong password" : e.getMessage(),
+					Toast.LENGTH_LONG).show());
+		}));
+		pw.requestFocus();
+	}
+
+	private void save(String base, String password) {
+		Prefs.setServer(base, password);
+		startActivity(new Intent(this, MainActivity.class)
+				.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK));
+	}
+
+	private void reset(String title) {
+		box.removeAllViews();
+		box.addView(Ui.text(this, title, 24));
+	}
 }
diff --git a/app/src/main/java/mygram/droid/TileAdapter.java b/app/src/main/java/mygram/droid/TileAdapter.java
new file mode 100644
index 0000000..ee954b6
--- /dev/null
+++ b/app/src/main/java/mygram/droid/TileAdapter.java
@@ -0,0 +1,126 @@
+/*
+ * mygram-droid: Android TV client for Foldergram.
+ * Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+package mygram.droid;
+
+import android.content.Context;
+import android.graphics.Color;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.bumptech.glide.Glide;
+
+import java.util.List;
+
+/** Thumbnail tiles for rows and grids: posts, folders and the Continue tile. */
+final class TileAdapter extends RecyclerView.Adapter<TileAdapter.Holder> {
+	static final class Tile {
+		final String image, label;
+		final int icon, postId;
+		final Runnable click;
+
+		/** image or icon is shown; postId is -1 for tiles that are not posts. */
+		Tile(String image, String label, int icon, int postId, Runnable click) {
+			this.image = image;
+			this.label = label;
+			this.icon = icon;
+			this.postId = postId;
+			this.click = click;
+		}
+	}
+
+	static Tile post(Post p, Runnable click) {
+		return new Tile(p.media.get(0).thumbnailUrl, null, 0, p.id, click);
+	}
+
+	static final class Holder extends RecyclerView.ViewHolder {
+		final ImageView image, heart;
+		final TextView label;
+
+		Holder(View v, ImageView image, TextView label, ImageView heart) {
+			super(v);
+			this.image = image;
+			this.label = label;
+			this.heart = heart;
+		}
+	}
+
+	private final List<Tile> tiles;
+	private final int widthDp, heightDp;
+
+	TileAdapter(List<Tile> tiles, int widthDp, int heightDp) {
+		this.tiles = tiles;
+		this.widthDp = widthDp;
+		this.heightDp = heightDp;
+	}
+
+	@Override
+	public Holder onCreateViewHolder(ViewGroup parent, int type) {
+		Context c = parent.getContext();
+		FrameLayout frame = new FrameLayout(c);
+		RecyclerView.LayoutParams lp = new RecyclerView.LayoutParams(Ui.dp(c, widthDp), Ui.dp(c, heightDp));
+		int m = Ui.dp(c, 12);
+		lp.setMargins(m, m, m, m);
+		frame.setLayoutParams(lp);
+		frame.setBackgroundColor(0xFF222222);
+		ImageView image = new ImageView(c);
+		frame.addView(image, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
+				ViewGroup.LayoutParams.MATCH_PARENT));
+		TextView label = Ui.text(c, "", 14);
+		label.setShadowLayer(6, 0, 0, Color.BLACK);
+		int p = Ui.dp(c, 8);
+		label.setPadding(p, p, p, p);
+		frame.addView(label, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
+				ViewGroup.LayoutParams.WRAP_CONTENT, Gravity.BOTTOM));
+		ImageView heart = new ImageView(c);
+		heart.setImageResource(R.drawable.ic_favorite);
+		heart.setColorFilter(Ui.RED);
+		heart.setContentDescription("Liked");
+		int s = Ui.dp(c, 22);
+		FrameLayout.LayoutParams hp = new FrameLayout.LayoutParams(s, s, Gravity.TOP | Gravity.END);
+		hp.setMargins(p, p, p, p);
+		frame.addView(heart, hp);
+		Ui.focusable(frame);
+		return new Holder(frame, image, label, heart);
+	}
+
+	@Override
+	public void onBindViewHolder(Holder h, int position) {
+		Tile t = tiles.get(position);
+		if (t.image != null) {
+			h.image.setScaleType(ImageView.ScaleType.CENTER_CROP);
+			Glide.with(h.image).load(t.image).into(h.image);
+		} else {
+			Glide.with(h.image).clear(h.image);
+			h.image.setScaleType(ImageView.ScaleType.CENTER);
+			h.image.setImageResource(t.icon);
+		}
+		h.label.setText(t.label);
+		h.label.setVisibility(t.label == null ? View.GONE : View.VISIBLE);
+		h.heart.setVisibility(t.postId >= 0 && Likes.has(t.postId) ? View.VISIBLE : View.GONE);
+		h.itemView.setContentDescription(t.label != null ? t.label : "Post");
+		h.itemView.setOnClickListener(v -> t.click.run());
+	}
+
+	@Override
+	public int getItemCount() {
+		return tiles.size();
+	}
+}
diff --git a/app/src/main/java/mygram/droid/Ui.java b/app/src/main/java/mygram/droid/Ui.java
new file mode 100644
index 0000000..852fe54
--- /dev/null
+++ b/app/src/main/java/mygram/droid/Ui.java
@@ -0,0 +1,155 @@
+/*
+ * mygram-droid: Android TV client for Foldergram.
+ * Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+package mygram.droid;
+
+import android.content.Context;
+import android.graphics.Color;
+import android.graphics.RenderEffect;
+import android.graphics.Shader;
+import android.text.InputType;
+import android.view.Gravity;
+import android.view.View;
+import android.widget.EditText;
+import android.widget.ImageView;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+
+import androidx.recyclerview.widget.GridLayoutManager;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** View helpers. The UI is built in code, there are no layout files. */
+final class Ui {
+	static final int RED = 0xFFFF3B5C;
+	/** Post tiles: portrait, most media is 9:16. */
+	static final int POST_W = 128, POST_H = 228;
+
+	private Ui() {
+	}
+
+	static int dp(Context c, float v) {
+		return Math.round(v * c.getResources().getDisplayMetrics().density);
+	}
+
+	static TextView text(Context c, String s, int sp) {
+		TextView t = new TextView(c);
+		t.setText(s);
+		t.setTextSize(sp);
+		t.setTextColor(Color.WHITE);
+		return t;
+	}
+
+	static LinearLayout column(Context c) {
+		LinearLayout box = new LinearLayout(c);
+		box.setOrientation(LinearLayout.VERTICAL);
+		box.setGravity(Gravity.CENTER);
+		int p = dp(c, 32);
+		box.setPadding(p, p, p, p);
+		return box;
+	}
+
+	static LinearLayout row(Context c) {
+		LinearLayout row = new LinearLayout(c);
+		row.setGravity(Gravity.CENTER);
+		return row;
+	}
+
+	static EditText field(Context c, String hint, int inputType) {
+		EditText e = new EditText(c);
+		e.setHint(hint);
+		e.setInputType(inputType);
+		e.setTextColor(Color.WHITE);
+		e.setHintTextColor(Color.GRAY);
+		e.setMinWidth(dp(c, 400));
+		e.setSingleLine(true);
+		return e;
+	}
+
+	static int password() {
+		return InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD;
+	}
+
+	/** Focus ring and a small zoom: the only focus feedback on a TV. */
+	static void focusable(View v) {
+		v.setFocusable(true);
+		v.setForeground(v.getContext().getDrawable(R.drawable.focus_ring));
+		v.setOnFocusChangeListener((x, has) -> zoom(x, has));
+	}
+
+	private static void zoom(View v, boolean in) {
+		v.animate().scaleX(in ? 1.08f : 1f).scaleY(in ? 1.08f : 1f).setDuration(120).start();
+	}
+
+	/** Icon-only button; its label shows under it while it has focus. Child 0 is the ImageView. */
+	static LinearLayout iconButton(Context c, int icon, String label, View.OnClickListener click) {
+		LinearLayout box = new LinearLayout(c);
+		box.setOrientation(LinearLayout.VERTICAL);
+		box.setGravity(Gravity.CENTER_HORIZONTAL);
+		int p = dp(c, 10);
+		box.setPadding(p, p, p, p / 2);
+		ImageView image = new ImageView(c);
+		image.setImageResource(icon);
+		image.setContentDescription(label);
+		int s = dp(c, 36);
+		box.addView(image, new LinearLayout.LayoutParams(s, s));
+		TextView t = text(c, label, 12);
+		t.setVisibility(View.INVISIBLE);
+		box.addView(t);
+		box.setFocusable(true);
+		box.setForeground(c.getDrawable(R.drawable.focus_ring));
+		box.setOnFocusChangeListener((v, has) -> {
+			t.setVisibility(has ? View.VISIBLE : View.INVISIBLE);
+			zoom(v, has);
+		});
+		box.setOnClickListener(click);
+		return box;
+	}
+
+	static void blur(ImageView v, float radius) {
+		v.setRenderEffect(RenderEffect.createBlurEffect(radius, radius, Shader.TileMode.CLAMP));
+	}
+
+	static RecyclerView list(Context c, int orientation) {
+		RecyclerView rv = new RecyclerView(c);
+		rv.setLayoutManager(new LinearLayoutManager(c, orientation, false));
+		int p = dp(c, 24);
+		rv.setPadding(p, 0, p, 0);
+		rv.setClipToPadding(false);
+		return rv;
+	}
+
+	static RecyclerView grid(Context c, List<TileAdapter.Tile> tiles, int w, int h, int span) {
+		RecyclerView rv = new RecyclerView(c);
+		rv.setLayoutManager(new GridLayoutManager(c, span));
+		rv.setAdapter(new TileAdapter(tiles, w, h));
+		int p = dp(c, 24);
+		rv.setPadding(p, p, p, p);
+		rv.setClipToPadding(false);
+		return rv;
+	}
+
+	/** Tiles that open the viewer on posts, starting at the chosen one. */
+	static List<TileAdapter.Tile> postTiles(Context c, List<Post> posts) {
+		List<TileAdapter.Tile> tiles = new ArrayList<>();
+		for (int i = 0; i < posts.size(); i++) {
+			int start = i;
+			tiles.add(TileAdapter.post(posts.get(i), () -> Playlist.open(c, posts, start)));
+		}
+		return tiles;
+	}
+}