Gtk: change title prompt (#5905)

This PR implements the title change functionality for the GTK app and
closes https://github.com/ghostty-org/ghostty/issues/5769

Demo:


https://github.com/user-attachments/assets/cad611b3-b7bf-40ac-8d0f-11d2095fe525

For now I came up with a basic UI that i believe is sufficient, but I'm
open to feedback and happy to iterate on it further.

https://github.com/ghostty-org/ghostty/issues/5769#issuecomment-2660341107
- Regarding Mitchell's comment I checked Gnome Console and I could not
find a similar feature.

snap/snapcraft.yaml

@@ -70,8 +70,10 @@ parts:
     plugin: nil
     build-attributes: [enable-patchelf]
     build-packages:
+      - blueprint-compiler
       - libgtk-4-dev
       - libadwaita-1-dev
+      - libxml2-utils
       - git
       - patchelf
     override-build: |

src/apprt/gtk/App.zig

@@ -495,6 +495,7 @@ pub fn performAction(
         .toggle_split_zoom => self.toggleSplitZoom(target),
         .toggle_window_decorations => self.toggleWindowDecorations(target),
         .quit_timer => self.quitTimer(value),
+        .prompt_title => try self.promptTitle(target),
 
         // Unimplemented
         .close_all_windows,
@@ -506,7 +507,6 @@ pub fn performAction(
         .render_inspector,
         .renderer_health,
         .color_change,
-        .prompt_title,
         => {
             log.warn("unimplemented action={}", .{action});
             return false;
@@ -770,6 +770,15 @@ fn quitTimer(self: *App, mode: apprt.action.QuitTimer) void {
     }
 }
 
+fn promptTitle(_: *App, target: apprt.Target) !void {
+    switch (target) {
+        .app => {},
+        .surface => |v| {
+            try v.rt_surface.promptTitle();
+        },
+    }
+}
+
 fn setTitle(
     _: *App,
     target: apprt.Target,
@@ -777,7 +786,7 @@ fn setTitle(
 ) !void {
     switch (target) {
         .app => {},
-        .surface => |v| try v.rt_surface.setTitle(title.title),
+        .surface => |v| try v.rt_surface.setTitle(title.title, .terminal),
     }
 }
 
@@ -1016,6 +1025,7 @@ fn syncActionAccelerators(self: *App) !void {
     try self.syncActionAccelerator("win.paste", .{ .paste_from_clipboard = {} });
     try self.syncActionAccelerator("win.reset", .{ .reset = {} });
     try self.syncActionAccelerator("win.clear", .{ .clear_screen = {} });
+    try self.syncActionAccelerator("win.prompt-title", .{ .prompt_surface_title = {} });
 }
 
 fn syncActionAccelerator(

src/apprt/gtk/Builder.zig

@@ -25,7 +25,7 @@ pub fn init(comptime name: []const u8, comptime kind: enum { blp, ui }) Builder
                 // GResource.
                 const gresource = @import("gresource.zig");
                 for (gresource.blueprint_files) |blueprint_file| {
-                    if (std.mem.eql(u8, blueprint_file, name)) break;
+                    if (std.mem.eql(u8, blueprint_file.name, name)) break;
                 } else @compileError("missing blueprint file '" ++ name ++ "' in gresource.zig");
             },
             .ui => {

src/apprt/gtk/Surface.zig

@@ -4,6 +4,10 @@
 const Surface = @This();
 
 const std = @import("std");
+const adw = @import("adw");
+const gtk = @import("gtk");
+const gio = @import("gio");
+const gobject = @import("gobject");
 const Allocator = std.mem.Allocator;
 const build_config = @import("../../build_config.zig");
 const build_options = @import("build_options");
@@ -26,6 +30,8 @@ const ResizeOverlay = @import("ResizeOverlay.zig");
 const inspector = @import("inspector.zig");
 const gtk_key = @import("key.zig");
 const c = @import("c.zig").c;
+const Builder = @import("Builder.zig");
+const adwaita = @import("adwaita.zig");
 
 const log = std.log.scoped(.gtk_surface);
 
@@ -347,6 +353,12 @@ cursor: ?*c.GdkCursor = null,
 /// pass it to GTK.
 title_text: ?[:0]const u8 = null,
 
+/// The title of the surface as reported by the terminal. If it is null, the
+/// title reported by the terminal is currently being used. If the title was
+/// manually overridden by the user, this will be set to a non-null value
+/// representing the default terminal title.
+title_from_terminal: ?[:0]const u8 = null,
+
 /// Our current working directory. We use this value for setting tooltips in
 /// the headerbar subtitle if we have focus. When set, the text in this buf
 /// will be null-terminated because we need to pass it to GTK.
@@ -663,6 +675,7 @@ fn realize(self: *Surface) !void {
 pub fn deinit(self: *Surface) void {
     self.init_config.deinit(self.app.core_app.alloc);
     if (self.title_text) |title| self.app.core_app.alloc.free(title);
+    if (self.title_from_terminal) |title| self.app.core_app.alloc.free(title);
     if (self.pwd) |pwd| self.app.core_app.alloc.free(pwd);
 
     // We don't allocate anything if we aren't realized.
@@ -940,8 +953,9 @@ fn updateTitleLabels(self: *Surface) void {
 }
 
 const zoom_title_prefix = "🔍 ";
+pub const SetTitleSource = enum { user, terminal };
 
-pub fn setTitle(self: *Surface, slice: [:0]const u8) !void {
+pub fn setTitle(self: *Surface, slice: [:0]const u8, source: SetTitleSource) !void {
     const alloc = self.app.core_app.alloc;
 
     // Always allocate with the "🔍 " at the beginning and slice accordingly
@@ -954,6 +968,14 @@ pub fn setTitle(self: *Surface, slice: [:0]const u8) !void {
     };
     errdefer alloc.free(copy);
 
+    // The user has overridden the title
+    // We only want to update the terminal provided title so that it can be restored to the most recent state.
+    if (self.title_from_terminal != null and source == .terminal) {
+        alloc.free(self.title_from_terminal.?);
+        self.title_from_terminal = copy;
+        return;
+    }
+
     if (self.title_text) |old| alloc.free(old);
     self.title_text = copy;
 
@@ -978,15 +1000,41 @@ fn updateTitleTimerExpired(ctx: ?*anyopaque) callconv(.C) c.gboolean {
 
 pub fn getTitle(self: *Surface) ?[:0]const u8 {
     if (self.title_text) |title_text| {
-        return if (self.zoomed_in)
-            title_text
-        else
-            title_text[zoom_title_prefix.len..];
+        return self.resolveTitle(title_text);
     }
 
     return null;
 }
 
+pub fn getTerminalTitle(self: *Surface) ?[:0]const u8 {
+    if (self.title_from_terminal) |title_text| {
+        return self.resolveTitle(title_text);
+    }
+
+    return null;
+}
+
+fn resolveTitle(self: *Surface, title: [:0]const u8) [:0]const u8 {
+    return if (self.zoomed_in)
+        title
+    else
+        title[zoom_title_prefix.len..];
+}
+
+pub fn promptTitle(self: *Surface) !void {
+    if (!adwaita.versionAtLeast(1, 5, 0)) return;
+    const window = self.container.window() orelse return;
+
+    var builder = Builder.init("prompt-title-dialog", .blp);
+    defer builder.deinit();
+
+    const entry = builder.getObject(gtk.Entry, "title_entry").?;
+    entry.getBuffer().setText(self.getTitle() orelse "", -1);
+
+    const dialog = builder.getObject(adw.AlertDialog, "prompt_title_dialog").?;
+    dialog.choose(@ptrCast(window.window), null, gtkPromptTitleResponse, self);
+}
+
 /// Set the current working directory of the surface.
 ///
 /// In addition, update the tab's tooltip text, and if we are the focused child,
@@ -2273,3 +2321,40 @@ fn g_value_holds(value_: ?*c.GValue, g_type: c.GType) bool {
     }
     return false;
 }
+
+fn gtkPromptTitleResponse(source_object: ?*gobject.Object, result: *gio.AsyncResult, ud: ?*anyopaque) callconv(.C) void {
+    if (!adwaita.versionAtLeast(1, 5, 0)) return;
+    const dialog = gobject.ext.cast(adw.AlertDialog, source_object.?).?;
+    const self = userdataSelf(ud orelse return);
+
+    const response = dialog.chooseFinish(result);
+    if (std.mem.orderZ(u8, "ok", response) == .eq) {
+        const title_entry = gobject.ext.cast(gtk.Entry, dialog.getExtraChild().?).?;
+        const title = std.mem.span(title_entry.getBuffer().getText());
+
+        // if the new title is empty and the user has set the title previously, restore the terminal provided title
+        if (title.len == 0) {
+            if (self.getTerminalTitle()) |terminal_title| {
+                self.setTitle(terminal_title, .user) catch |err| {
+                    log.err("failed to set title={}", .{err});
+                };
+                self.app.core_app.alloc.free(self.title_from_terminal.?);
+                self.title_from_terminal = null;
+            }
+        } else if (title.len > 0) {
+            // if this is the first time the user is setting the title, save the current terminal provided title
+            if (self.title_from_terminal == null and self.title_text != null) {
+                self.title_from_terminal = self.app.core_app.alloc.dupeZ(u8, self.title_text.?) catch |err| switch (err) {
+                    error.OutOfMemory => {
+                        log.err("failed to allocate memory for title={}", .{err});
+                        return;
+                    },
+                };
+            }
+
+            self.setTitle(title, .user) catch |err| {
+                log.err("failed to set title={}", .{err});
+            };
+        }
+    }
+}

src/apprt/gtk/Window.zig

@@ -478,6 +478,7 @@ fn initActions(self: *Window) void {
         .{ "paste", &gtkActionPaste },
         .{ "reset", &gtkActionReset },
         .{ "clear", &gtkActionClear },
+        .{ "prompt_title", &gtkActionPromptTitle },
     };
 
     inline for (actions) |entry| {
@@ -1071,6 +1072,19 @@ fn gtkActionClear(
     };
 }
 
+fn gtkActionPromptTitle(
+    _: *c.GSimpleAction,
+    _: *c.GVariant,
+    ud: ?*anyopaque,
+) callconv(.C) void {
+    const self: *Window = @ptrCast(@alignCast(ud orelse return));
+    const surface = self.actionSurface() orelse return;
+    _ = surface.performBindingAction(.{ .prompt_surface_title = {} }) catch |err| {
+        log.warn("error performing binding action error={}", .{err});
+        return;
+    };
+}
+
 /// Returns the surface to use for an action.
 pub fn actionSurface(self: *Window) ?*CoreSurface {
     const tab = self.notebook.currentTab() orelse return null;

src/apprt/gtk/blueprint_compiler.zig

@@ -0,0 +1,57 @@
+const std = @import("std");
+
+pub const c = @cImport({
+    @cInclude("adwaita.h");
+});
+
+pub fn main() !void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    const alloc = gpa.allocator();
+
+    var it = try std.process.argsWithAllocator(alloc);
+    defer it.deinit();
+
+    _ = it.next();
+
+    const major = try std.fmt.parseUnsigned(u8, it.next() orelse return error.NoMajorVersion, 10);
+    const minor = try std.fmt.parseUnsigned(u8, it.next() orelse return error.NoMinorVersion, 10);
+    const micro = try std.fmt.parseUnsigned(u8, it.next() orelse return error.NoMicroVersion, 10);
+    const output = it.next() orelse return error.NoOutput;
+    const input = it.next() orelse return error.NoInput;
+
+    if (c.ADW_MAJOR_VERSION < major or
+        (c.ADW_MAJOR_VERSION == major and c.ADW_MINOR_VERSION < minor) or
+        (c.ADW_MAJOR_VERSION == major and c.ADW_MINOR_VERSION == minor and c.ADW_MICRO_VERSION < micro))
+    {
+        // If the Adwaita version is too old, generate an "empty" file.
+        const file = try std.fs.createFileAbsolute(output, .{
+            .truncate = true,
+        });
+        try file.writeAll(
+            \\<?xml version="1.0" encoding="UTF-8"?>
+            \\<interface domain="com.mitchellh.ghostty"/>
+        );
+        defer file.close();
+
+        return;
+    }
+
+    var compiler = std.process.Child.init(
+        &.{
+            "blueprint-compiler",
+            "compile",
+            "--output",
+            output,
+            input,
+        },
+        alloc,
+    );
+
+    const term = try compiler.spawnAndWait();
+    switch (term) {
+        .Exited => |rc| {
+            if (rc != 0) std.posix.exit(1);
+        },
+        else => std.posix.exit(1),
+    }
+}

src/apprt/gtk/gresource.zig

@@ -57,7 +57,17 @@ pub const ui_files = [_][]const u8{
     "menu-window-titlebar_menu",
     "menu-surface-context_menu",
 };
-pub const blueprint_files = [_][]const u8{};
+
+pub const VersionedBlueprint = struct {
+    major: u16,
+    minor: u16,
+    micro: u16,
+    name: []const u8,
+};
+
+pub const blueprint_files = [_]VersionedBlueprint{
+    .{ .major = 1, .minor = 5, .micro = 0, .name = "prompt-title-dialog" },
+};
 
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
@@ -72,9 +82,9 @@ pub fn main() !void {
     var it = try std.process.argsWithAllocator(alloc);
     defer it.deinit();
 
-    while (it.next()) |filename| {
-        if (std.mem.eql(u8, std.fs.path.extension(filename), ".ui")) {
-            try extra_ui_files.append(try alloc.dupe(u8, filename));
+    while (it.next()) |argument| {
+        if (std.mem.eql(u8, std.fs.path.extension(argument), ".ui")) {
+            try extra_ui_files.append(try alloc.dupe(u8, argument));
         }
     }
 
@@ -144,7 +154,7 @@ pub const dependencies = deps: {
         index += 1;
     }
     for (blueprint_files) |blueprint_file| {
-        deps[index] = std.fmt.comptimePrint("src/apprt/gtk/ui/{s}.blp", .{blueprint_file});
+        deps[index] = std.fmt.comptimePrint("src/apprt/gtk/ui/{s}.blp", .{blueprint_file.name});
         index += 1;
     }
     break :deps deps;

src/apprt/gtk/ui/prompt-title-dialog.blp

@@ -0,0 +1,16 @@
+using Gtk 4.0;
+using Adw 1;
+
+Adw.AlertDialog prompt_title_dialog {
+  heading: _("Change Terminal Title");
+  body: _("Leave blank to restore the default title.");
+
+  responses [
+    cancel: _("Cancel") suggested,
+    ok: _("OK") destructive
+  ]
+
+  focus-widget: title_entry;
+
+  extra-child: Entry title_entry {};
+}

src/build/SharedDeps.zig

@@ -443,6 +443,7 @@ pub fn add(
                     .{ "glib", "glib2" },
                     .{ "gtk", "gtk4" },
                     .{ "gdk", "gdk4" },
+                    .{ "adw", "adw1" },
                 };
                 inline for (gobject_imports) |import| {
                     const name, const module = import;
@@ -451,7 +452,6 @@ pub fn add(
 
                 step.linkSystemLibrary2("gtk4", dynamic_link_opts);
                 step.linkSystemLibrary2("libadwaita-1", dynamic_link_opts);
-                step.root_module.addImport("adw", gobject.module("adw1"));
 
                 if (self.config.x11) {
                     step.linkSystemLibrary2("X11", dynamic_link_opts);
@@ -500,14 +500,24 @@ pub fn add(
 
                         const generate = b.addRunArtifact(generate_gresource_xml);
 
+                        const gtk_blueprint_compiler = b.addExecutable(.{
+                            .name = "gtk_blueprint_compiler",
+                            .root_source_file = b.path("src/apprt/gtk/blueprint_compiler.zig"),
+                            .target = b.host,
+                        });
+                        gtk_blueprint_compiler.linkSystemLibrary2("gtk4", dynamic_link_opts);
+                        gtk_blueprint_compiler.linkSystemLibrary2("libadwaita-1", dynamic_link_opts);
+                        gtk_blueprint_compiler.linkLibC();
+
                         for (gresource.blueprint_files) |blueprint_file| {
-                            const blueprint_compiler = b.addSystemCommand(&.{
-                                "blueprint-compiler",
-                                "compile",
-                                "--output",
+                            const blueprint_compiler = b.addRunArtifact(gtk_blueprint_compiler);
+                            blueprint_compiler.addArgs(&.{
+                                b.fmt("{d}", .{blueprint_file.major}),
+                                b.fmt("{d}", .{blueprint_file.minor}),
+                                b.fmt("{d}", .{blueprint_file.micro}),
                             });
-                            const ui_file = blueprint_compiler.addOutputFileArg(b.fmt("{s}.ui", .{blueprint_file}));
-                            blueprint_compiler.addFileArg(b.path(b.fmt("src/apprt/gtk/ui/{s}.blp", .{blueprint_file})));
+                            const ui_file = blueprint_compiler.addOutputFileArg(b.fmt("{s}.ui", .{blueprint_file.name}));
+                            blueprint_compiler.addFileArg(b.path(b.fmt("src/apprt/gtk/ui/{s}.blp", .{blueprint_file.name})));
                             generate.addFileArg(ui_file);
                         }
 

src/build/docker/debian/Dockerfile

@@ -5,9 +5,11 @@ FROM docker.io/library/debian:${DISTRO_VERSION}
 RUN DEBIAN_FRONTEND="noninteractive" apt-get -qq update && \
     apt-get -qq -y --no-install-recommends install \
     # Build Tools
+    blueprint-compiler \
     build-essential \
     libbz2-dev \
     libonig-dev \
+    libxml2-utils \
     lintian \
     lsb-release \
     libxml2-utils \

src/input/Binding.zig

@@ -349,7 +349,6 @@ pub const Action = union(enum) {
     toggle_tab_overview: void,
 
     /// Change the title of the current focused surface via a prompt.
-    /// This only works on macOS currently.
     prompt_surface_title: void,
 
     /// Create a new split in the given direction.