Replace heuristic reading with chat toggle

.gitea/workflows/android.yaml

@@ -16,13 +16,31 @@ jobs:
         run: |
           set -eu
 
+          install_packages() {
+            if command -v apt-get >/dev/null 2>&1; then
+              apt-get update
+              apt-get install -y "$@"
+            elif command -v apk >/dev/null 2>&1; then
+              apk add --no-cache "$@"
+            elif command -v dnf >/dev/null 2>&1; then
+              dnf install -y "$@"
+            else
+              echo "No supported package manager found." >&2
+              exit 1
+            fi
+          }
+
           if ! command -v git >/dev/null 2>&1 || ! command -v curl >/dev/null 2>&1 || ! command -v unzip >/dev/null 2>&1; then
-            apt-get update
-            apt-get install -y git curl unzip
+            install_packages git curl unzip
           fi
           if ! command -v java >/dev/null 2>&1; then
-            apt-get update
-            apt-get install -y openjdk-17-jdk-headless
+            if command -v apk >/dev/null 2>&1; then
+              install_packages openjdk17-jdk
+            elif command -v dnf >/dev/null 2>&1; then
+              install_packages java-17-openjdk-devel
+            else
+              install_packages openjdk-17-jdk-headless
+            fi
           fi
           java -version
 

app/src/main/java/com/neatstudio/tmuxandroid/AppEventSocketClient.java

@@ -4,6 +4,7 @@ import android.util.Base64;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
+import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
@@ -14,16 +15,22 @@ import java.util.Arrays;
 import javax.net.ssl.SSLSocketFactory;
 
 final class AppEventSocketClient {
+    private static final long HEARTBEAT_INTERVAL_MS = 15000L;
+    private static final int SOCKET_CONNECT_TIMEOUT_MS = 10000;
+    private static final int SOCKET_READ_TIMEOUT_MS = 45000;
+
     interface Listener {
         void onMessage(String text);
         void onClosed();
     }
 
     private final Listener listener;
+    private final Object writeLock = new Object();
     private Socket socket;
     private BufferedInputStream input;
     private BufferedOutputStream output;
     private volatile boolean closed;
+    private Thread heartbeatThread;
 
     AppEventSocketClient(Listener listener) {
         this.listener = listener;
@@ -40,12 +47,11 @@ final class AppEventSocketClient {
             sendFrame(8, new byte[0]);
         } catch (Exception ignored) {
         }
-        try {
-            if (socket != null) {
-                socket.close();
-            }
-        } catch (Exception ignored) {
-        }
+        closeSocketQuietly();
+    }
+
+    boolean isClosed() {
+        return closed;
     }
 
     private void run(String baseUrl) {
@@ -55,6 +61,7 @@ final class AppEventSocketClient {
             input = new BufferedInputStream(socket.getInputStream());
             output = new BufferedOutputStream(socket.getOutputStream());
             handshake(uri);
+            startHeartbeat();
             while (!closed) {
                 Frame frame = readFrame();
                 if (frame.opcode == 1) {
@@ -69,12 +76,7 @@ final class AppEventSocketClient {
         } finally {
             closed = true;
             listener.onClosed();
-            try {
-                if (socket != null) {
-                    socket.close();
-                }
-            } catch (Exception ignored) {
-            }
+            closeSocketQuietly();
         }
     }
 
@@ -91,10 +93,39 @@ final class AppEventSocketClient {
         if (port == -1) {
             port = "wss".equalsIgnoreCase(uri.getScheme()) ? 443 : 80;
         }
+        Socket raw = new Socket();
+        raw.connect(new InetSocketAddress(uri.getHost(), port), SOCKET_CONNECT_TIMEOUT_MS);
+        Socket connected;
         if ("wss".equalsIgnoreCase(uri.getScheme())) {
-            return SSLSocketFactory.getDefault().createSocket(uri.getHost(), port);
+            connected = ((SSLSocketFactory) SSLSocketFactory.getDefault())
+                    .createSocket(raw, uri.getHost(), port, true);
+        } else {
+            connected = raw;
         }
-        return new Socket(uri.getHost(), port);
+        connected.setKeepAlive(true);
+        connected.setTcpNoDelay(true);
+        connected.setSoTimeout(SOCKET_READ_TIMEOUT_MS);
+        return connected;
+    }
+
+    private void startHeartbeat() {
+        heartbeatThread = new Thread(() -> {
+            while (!closed) {
+                try {
+                    Thread.sleep(HEARTBEAT_INTERVAL_MS);
+                    if (!closed) {
+                        sendFrame(9, new byte[0]);
+                    }
+                } catch (InterruptedException ignored) {
+                    Thread.currentThread().interrupt();
+                    return;
+                } catch (Exception error) {
+                    closeSocketQuietly();
+                    return;
+                }
+            }
+        }, "app-events-ws-heartbeat");
+        heartbeatThread.start();
     }
 
     private void handshake(URI uri) throws Exception {
@@ -181,32 +212,47 @@ final class AppEventSocketClient {
     }
 
     private void sendFrame(int opcode, byte[] payload) throws Exception {
-        if (output == null) {
-            return;
-        }
-        output.write(0x80 | opcode);
-        byte[] mask = new byte[4];
-        new SecureRandom().nextBytes(mask);
-        int length = payload.length;
-        if (length < 126) {
-            output.write(0x80 | length);
-        } else if (length <= 0xffff) {
-            output.write(0x80 | 126);
-            output.write((length >>> 8) & 0xff);
-            output.write(length & 0xff);
-        } else {
-            output.write(0x80 | 127);
-            for (int i = 7; i >= 0; i--) {
-                output.write((length >>> (8 * i)) & 0xff);
+        synchronized (writeLock) {
+            if (output == null) {
+                return;
             }
+            output.write(0x80 | opcode);
+            byte[] mask = new byte[4];
+            new SecureRandom().nextBytes(mask);
+            int length = payload.length;
+            if (length < 126) {
+                output.write(0x80 | length);
+            } else if (length <= 0xffff) {
+                output.write(0x80 | 126);
+                output.write((length >>> 8) & 0xff);
+                output.write(length & 0xff);
+            } else {
+                output.write(0x80 | 127);
+                for (int i = 7; i >= 0; i--) {
+                    output.write((length >>> (8 * i)) & 0xff);
+                }
+            }
+            output.write(mask);
+            byte[] masked = Arrays.copyOf(payload, payload.length);
+            for (int i = 0; i < masked.length; i++) {
+                masked[i] = (byte) (masked[i] ^ mask[i % 4]);
+            }
+            output.write(masked);
+            output.flush();
         }
-        output.write(mask);
-        byte[] masked = Arrays.copyOf(payload, payload.length);
-        for (int i = 0; i < masked.length; i++) {
-            masked[i] = (byte) (masked[i] ^ mask[i % 4]);
+    }
+
+    private void closeSocketQuietly() {
+        if (heartbeatThread != null) {
+            heartbeatThread.interrupt();
+            heartbeatThread = null;
+        }
+        try {
+            if (socket != null) {
+                socket.close();
+            }
+        } catch (Exception ignored) {
         }
-        output.write(masked);
-        output.flush();
     }
 
     private static final class Frame {

app/src/main/java/com/neatstudio/tmuxandroid/ConversationMessage.java

@@ -0,0 +1,85 @@
+package com.neatstudio.tmuxandroid;
+
+import org.json.JSONObject;
+
+final class ConversationMessage {
+    final String messageId;
+    final String sessionName;
+    final String role;
+    final String contentType;
+    final String content;
+    final String status;
+    final String toolName;
+    final String parentMessageId;
+    final String createdAt;
+    final boolean local;
+
+    ConversationMessage(
+            String messageId,
+            String sessionName,
+            String role,
+            String contentType,
+            String content,
+            String status,
+            String toolName,
+            String parentMessageId,
+            String createdAt,
+            boolean local
+    ) {
+        this.messageId = messageId;
+        this.sessionName = sessionName;
+        this.role = role;
+        this.contentType = contentType;
+        this.content = content;
+        this.status = status;
+        this.toolName = toolName;
+        this.parentMessageId = parentMessageId;
+        this.createdAt = createdAt;
+        this.local = local;
+    }
+
+    static ConversationMessage fromJson(JSONObject object) {
+        return new ConversationMessage(
+                value(object, "messageId", object.optString("id", "")),
+                object.optString("sessionName", ""),
+                object.optString("role", "assistant"),
+                object.optString("contentType", "text"),
+                object.optString("content", ""),
+                object.optString("status", "complete"),
+                object.optString("toolName", ""),
+                value(object, "parentMessageId", ""),
+                object.optString("createdAt", ""),
+                false
+        );
+    }
+
+    static ConversationMessage localUser(String sessionName, String content) {
+        long now = System.currentTimeMillis();
+        return new ConversationMessage(
+                "local-" + now,
+                sessionName,
+                "user",
+                "text",
+                content,
+                "sending",
+                "",
+                "",
+                "~" + now,
+                true
+        );
+    }
+
+    boolean isTool() {
+        return "tool".equals(role)
+                || "tool".equals(contentType)
+                || "command".equals(contentType)
+                || "code".equals(contentType);
+    }
+
+    private static String value(JSONObject object, String key, String fallback) {
+        if (!object.has(key) || object.isNull(key)) {
+            return fallback;
+        }
+        return object.optString(key, fallback);
+    }
+}

app/src/main/java/com/neatstudio/tmuxandroid/TerminalScreenBuffer.java

@@ -4,16 +4,22 @@ import android.graphics.Color;
 import android.graphics.Typeface;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
+import android.text.TextPaint;
 import android.text.style.BackgroundColorSpan;
+import android.text.style.ClickableSpan;
 import android.text.style.ForegroundColorSpan;
 import android.text.style.StyleSpan;
+import android.view.View;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
+import java.util.Set;
 
 final class TerminalScreenBuffer {
     private static final int DEFAULT_FG = 0xffe6ebf2;
     private static final int DEFAULT_BG = Color.TRANSPARENT;
+    private static final int TERMINAL_BG = 0xff0b0e13;
 
     private int cols;
     private int rows;
@@ -27,6 +33,11 @@ final class TerminalScreenBuffer {
     private int fg = DEFAULT_FG;
     private int bg = DEFAULT_BG;
     private boolean bold;
+    private boolean dim;
+
+    interface FocusToggle {
+        void toggle(String key);
+    }
 
     TerminalScreenBuffer(int cols, int rows) {
         resize(cols, rows);
@@ -35,9 +46,6 @@ final class TerminalScreenBuffer {
     void resize(int nextCols, int nextRows) {
         nextCols = Math.max(1, nextCols);
         nextRows = Math.max(1, nextRows);
-        Cell[][] previous = cells;
-        int previousRows = rows;
-        int previousCols = cols;
         cols = nextCols;
         rows = nextRows;
         cells = new Cell[rows][cols];
@@ -46,21 +54,11 @@ final class TerminalScreenBuffer {
                 cells[row][col] = new Cell();
             }
         }
-        if (previous != null) {
-            int copyRows = Math.min(previousRows, rows);
-            int copyCols = Math.min(previousCols, cols);
-            int previousStart = Math.max(0, previousRows - copyRows);
-            int nextStart = Math.max(0, rows - copyRows);
-            for (int row = 0; row < copyRows; row++) {
-                for (int col = 0; col < copyCols; col++) {
-                    cells[nextStart + row][col].copyFrom(previous[previousStart + row][col]);
-                }
-            }
-        }
-        cursorRow = clamp(cursorRow, 0, rows - 1);
-        cursorCol = clamp(cursorCol, 0, cols - 1);
-        savedRow = clamp(savedRow, 0, rows - 1);
-        savedCol = clamp(savedCol, 0, cols - 1);
+        cursorRow = 0;
+        cursorCol = 0;
+        savedRow = 0;
+        savedCol = 0;
+        wrapPending = false;
     }
 
     void clear() {
@@ -74,6 +72,7 @@ final class TerminalScreenBuffer {
         fg = DEFAULT_FG;
         bg = DEFAULT_BG;
         bold = false;
+        dim = false;
     }
 
     void write(String text) {
@@ -131,6 +130,120 @@ final class TerminalScreenBuffer {
         return output;
     }
 
+    String renderTail(int maxRows) {
+        List<String> visible = new ArrayList<>();
+        for (int row = rows - 1; row >= 0 && visible.size() < maxRows; row--) {
+            String text = rowText(row).trim();
+            if (!text.isEmpty()) {
+                visible.add(0, text);
+            }
+        }
+        if (visible.isEmpty()) {
+            return "Waiting for terminal output";
+        }
+        return String.join("\n", visible);
+    }
+
+    CharSequence renderFocused(Set<String> expandedBlocks, FocusToggle toggle) {
+        SpannableStringBuilder output = new SpannableStringBuilder();
+        List<String> hiddenRows = new ArrayList<>();
+        int hiddenStart = -1;
+        for (int row = 0; row < rows; row++) {
+            String text = rowText(row).trim();
+            if (containsHan(text)) {
+                if (!hiddenRows.isEmpty()) {
+                    appendFocusBlock(output, hiddenRows, hiddenStart, row - 1, expandedBlocks, toggle);
+                    hiddenRows.clear();
+                    hiddenStart = -1;
+                }
+                appendLine(output, text);
+            } else if (!text.isEmpty()) {
+                if (hiddenStart < 0) {
+                    hiddenStart = row;
+                }
+                hiddenRows.add(text);
+            }
+        }
+        if (!hiddenRows.isEmpty()) {
+            appendFocusBlock(output, hiddenRows, hiddenStart, rows - 1, expandedBlocks, toggle);
+        }
+        if (output.length() == 0) {
+            output.append("暂无可读内容");
+        }
+        return output;
+    }
+
+    private void appendFocusBlock(
+            SpannableStringBuilder output,
+            List<String> lines,
+            int startRow,
+            int endRow,
+            Set<String> expandedBlocks,
+            FocusToggle toggle
+    ) {
+        String key = startRow + ":" + endRow;
+        boolean expanded = expandedBlocks.contains(key);
+        String summary = focusSummary(lines);
+        int actionStart = output.length();
+        appendLine(output, (expanded ? "▼ " : "▶ ") + summary);
+        int actionEnd = output.length();
+        output.setSpan(new ClickableSpan() {
+            @Override
+            public void onClick(View widget) {
+                toggle.toggle(key);
+            }
+
+            @Override
+            public void updateDrawState(TextPaint paint) {
+                paint.setColor(0xff67da91);
+                paint.setUnderlineText(false);
+                paint.setFakeBoldText(true);
+            }
+        }, actionStart, actionEnd, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+        if (expanded) {
+            for (String line : lines) {
+                appendLine(output, "  " + line);
+            }
+        }
+    }
+
+    private String focusSummary(List<String> lines) {
+        String joined = String.join(" ", lines).toLowerCase(Locale.ROOT);
+        String type;
+        if (joined.contains("error") || joined.contains("failed") || joined.contains("exception")) {
+            type = "错误输出";
+        } else if (joined.contains("working") || joined.contains("running")
+                || joined.contains("waiting") || joined.contains("interrupt")) {
+            type = "运行状态";
+        } else if (joined.contains("test") || joined.contains("build") || joined.contains("compile")
+                || joined.contains("gradle") || joined.contains("webpack") || joined.contains("npm")) {
+            type = "构建/测试";
+        } else if (joined.contains("git ") || joined.contains("commit") || joined.contains("push")) {
+            type = "Git 操作";
+        } else if (lines.get(0).startsWith(">") || lines.get(0).startsWith("$")
+                || lines.get(0).startsWith("!")) {
+            type = "命令与输出";
+        } else {
+            type = "终端细节";
+        }
+        return type + " · " + lines.size() + " 行 · " + compactSummary(lines.get(0), 42);
+    }
+
+    private String compactSummary(String text, int maxChars) {
+        String compact = text.replaceAll("\\s+", " ").trim();
+        if (compact.length() <= maxChars) {
+            return compact;
+        }
+        return compact.substring(0, maxChars - 1) + "…";
+    }
+
+    private void appendLine(SpannableStringBuilder output, String text) {
+        if (output.length() > 0) {
+            output.append('\n');
+        }
+        output.append(text);
+    }
+
     private int handleEscape(String text, int index) {
         if (index + 1 >= text.length()) {
             return -1;
@@ -257,10 +370,14 @@ final class TerminalScreenBuffer {
                 fg = DEFAULT_FG;
                 bg = DEFAULT_BG;
                 bold = false;
+                dim = false;
             } else if (value == 1) {
                 bold = true;
+            } else if (value == 2) {
+                dim = true;
             } else if (value == 22) {
                 bold = false;
+                dim = false;
             } else if (value == 39) {
                 fg = DEFAULT_FG;
             } else if (value == 49) {
@@ -302,14 +419,34 @@ final class TerminalScreenBuffer {
             wrapPending = false;
             newLine();
         }
-        cells[cursorRow][cursorCol].set(value, fg, bg, bold);
-        if (cursorCol == cols - 1) {
+        int width = isWideCharacter(value) ? 2 : 1;
+        if (width == 2 && cursorCol == cols - 1) {
+            newLine();
+        }
+        cells[cursorRow][cursorCol].set(value, fg, bg, bold, dim);
+        if (width == 2) {
+            cells[cursorRow][cursorCol + 1].setContinuation(fg, bg, bold, dim);
+        }
+        if (cursorCol + width >= cols) {
+            cursorCol = cols - 1;
             wrapPending = true;
         } else {
-            cursorCol++;
+            cursorCol += width;
         }
     }
 
+    private boolean isWideCharacter(char value) {
+        return value >= '\u1100' && (value <= '\u115f'
+                || value == '\u2329' || value == '\u232a'
+                || (value >= '\u2e80' && value <= '\ua4cf' && value != '\u303f')
+                || (value >= '\uac00' && value <= '\ud7a3')
+                || (value >= '\uf900' && value <= '\ufaff')
+                || (value >= '\ufe10' && value <= '\ufe19')
+                || (value >= '\ufe30' && value <= '\ufe6f')
+                || (value >= '\uff00' && value <= '\uff60')
+                || (value >= '\uffe0' && value <= '\uffe6'));
+    }
+
     private void newLine() {
         wrapPending = false;
         cursorRow++;
@@ -453,15 +590,21 @@ final class TerminalScreenBuffer {
             int fgColor = first.fg;
             int bgColor = first.bg;
             boolean isBold = first.bold;
+            boolean isDim = first.dim;
             while (col < cols) {
                 Cell cell = cells[row][col];
-                if (cell.fg != fgColor || cell.bg != bgColor || cell.bold != isBold) {
+                if (cell.fg != fgColor || cell.bg != bgColor || cell.bold != isBold || cell.dim != isDim) {
                     break;
                 }
-                output.append(cell.value);
+                if (!cell.continuation) {
+                    output.append(cell.value);
+                }
                 col++;
             }
             int end = output.length();
+            if (isDim) {
+                fgColor = blendColor(fgColor, bgColor == DEFAULT_BG ? TERMINAL_BG : bgColor, 0.55f);
+            }
             output.setSpan(new ForegroundColorSpan(fgColor), start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
             if (bgColor != DEFAULT_BG) {
                 output.setSpan(new BackgroundColorSpan(bgColor), start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
@@ -472,6 +615,29 @@ final class TerminalScreenBuffer {
         }
     }
 
+    private String rowText(int row) {
+        StringBuilder text = new StringBuilder(cols);
+        for (int col = 0; col < cols; col++) {
+            Cell cell = cells[row][col];
+            if (!cell.continuation) {
+                text.append(cell.value);
+            }
+        }
+        return text.toString();
+    }
+
+    private boolean containsHan(String text) {
+        for (int index = 0; index < text.length(); index++) {
+            Character.UnicodeBlock block = Character.UnicodeBlock.of(text.charAt(index));
+            if (block == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS
+                    || block == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
+                    || block == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private void saveCursor() {
         savedRow = cursorRow;
         savedCol = cursorCol;
@@ -613,6 +779,15 @@ final class TerminalScreenBuffer {
         return value == 0 ? 0 : 55 + value * 40;
     }
 
+    private static int blendColor(int foreground, int background, float foregroundRatio) {
+        float backgroundRatio = 1f - foregroundRatio;
+        return Color.rgb(
+                Math.round(Color.red(foreground) * foregroundRatio + Color.red(background) * backgroundRatio),
+                Math.round(Color.green(foreground) * foregroundRatio + Color.green(background) * backgroundRatio),
+                Math.round(Color.blue(foreground) * foregroundRatio + Color.blue(background) * backgroundRatio)
+        );
+    }
+
     private static int clamp(int value, int min, int max) {
         return Math.max(min, Math.min(max, value));
     }
@@ -622,19 +797,34 @@ final class TerminalScreenBuffer {
         int fg = DEFAULT_FG;
         int bg = DEFAULT_BG;
         boolean bold;
+        boolean dim;
+        boolean continuation;
 
         void clear() {
             value = ' ';
             fg = DEFAULT_FG;
             bg = DEFAULT_BG;
             bold = false;
+            dim = false;
+            continuation = false;
         }
 
-        void set(char nextValue, int nextFg, int nextBg, boolean nextBold) {
+        void set(char nextValue, int nextFg, int nextBg, boolean nextBold, boolean nextDim) {
             value = nextValue;
             fg = nextFg;
             bg = nextBg;
             bold = nextBold;
+            dim = nextDim;
+            continuation = false;
+        }
+
+        void setContinuation(int nextFg, int nextBg, boolean nextBold, boolean nextDim) {
+            value = ' ';
+            fg = nextFg;
+            bg = nextBg;
+            bold = nextBold;
+            dim = nextDim;
+            continuation = true;
         }
 
         void copyFrom(Cell other) {
@@ -642,6 +832,8 @@ final class TerminalScreenBuffer {
             fg = other.fg;
             bg = other.bg;
             bold = other.bold;
+            dim = other.dim;
+            continuation = other.continuation;
         }
     }
 }

app/src/main/java/com/neatstudio/tmuxandroid/TerminalSocketClient.java

@@ -6,6 +6,7 @@ import org.json.JSONObject;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
+import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
@@ -19,6 +20,10 @@ import java.util.concurrent.RejectedExecutionException;
 import javax.net.ssl.SSLSocketFactory;
 
 final class TerminalSocketClient {
+    private static final long HEARTBEAT_INTERVAL_MS = 15000L;
+    private static final int SOCKET_CONNECT_TIMEOUT_MS = 10000;
+    private static final int SOCKET_READ_TIMEOUT_MS = 45000;
+
     interface Listener {
         void onConnected();
         void onOutput(String data);
@@ -35,6 +40,7 @@ final class TerminalSocketClient {
     private BufferedOutputStream output;
     private volatile boolean closed;
     private Thread thread;
+    private Thread heartbeatThread;
 
     TerminalSocketClient(Listener listener) {
         this.listener = listener;
@@ -97,6 +103,7 @@ final class TerminalSocketClient {
                     "rows", rows
             );
             listener.onConnected();
+            startHeartbeat();
             readLoop();
         } catch (Exception error) {
             if (!closed) {
@@ -123,10 +130,39 @@ final class TerminalSocketClient {
         if (port == -1) {
             port = "wss".equalsIgnoreCase(uri.getScheme()) ? 443 : 80;
         }
+        Socket raw = new Socket();
+        raw.connect(new InetSocketAddress(uri.getHost(), port), SOCKET_CONNECT_TIMEOUT_MS);
+        Socket connected;
         if ("wss".equalsIgnoreCase(uri.getScheme())) {
-            return SSLSocketFactory.getDefault().createSocket(uri.getHost(), port);
+            connected = ((SSLSocketFactory) SSLSocketFactory.getDefault())
+                    .createSocket(raw, uri.getHost(), port, true);
+        } else {
+            connected = raw;
         }
-        return new Socket(uri.getHost(), port);
+        connected.setKeepAlive(true);
+        connected.setTcpNoDelay(true);
+        connected.setSoTimeout(SOCKET_READ_TIMEOUT_MS);
+        return connected;
+    }
+
+    private void startHeartbeat() {
+        heartbeatThread = new Thread(() -> {
+            while (!closed) {
+                try {
+                    Thread.sleep(HEARTBEAT_INTERVAL_MS);
+                    if (!closed) {
+                        sendFrame(9, new byte[0]);
+                    }
+                } catch (InterruptedException ignored) {
+                    Thread.currentThread().interrupt();
+                    return;
+                } catch (Exception error) {
+                    closeSocketQuietly();
+                    return;
+                }
+            }
+        }, "terminal-ws-heartbeat");
+        heartbeatThread.start();
     }
 
     private void handshake(URI uri) throws Exception {
@@ -279,6 +315,10 @@ final class TerminalSocketClient {
     }
 
     private void closeSocketQuietly() {
+        if (heartbeatThread != null) {
+            heartbeatThread.interrupt();
+            heartbeatThread = null;
+        }
         try {
             if (socket != null) {
                 socket.close();