Implement xdg-dialog-v1 Wayland protocol

src/server/frontend_wayland/CMakeLists.txt

@@ -57,6 +57,7 @@ set(
   primary_selection_v1.cpp      primary_selection_v1.h
   session_lock_v1.cpp           session_lock_v1.h
   xdg_decoration_unstable_v1.cpp           xdg_decoration_unstable_v1.h
+  xdg_dialog_v1.cpp                        xdg_dialog_v1.h
   ${PROJECT_SOURCE_DIR}/src/include/server/mir/frontend/wayland.h
   ${CMAKE_CURRENT_BINARY_DIR}/wayland_frontend.tp.c
   ${CMAKE_CURRENT_BINARY_DIR}/wayland_frontend.tp.h

src/server/frontend_wayland/wayland_default_configuration.cpp

@@ -51,6 +51,7 @@
 #include "xdg_activation_v1.h"
 #include "xdg-decoration-unstable-v1_wrapper.h"
 #include "xdg_decoration_unstable_v1.h"
+#include "xdg_dialog_v1.h"
 #include "xdg_output_v1.h"
 #include "xdg_shell_stable.h"
 #include "xdg_shell_v6.h"
@@ -261,6 +262,10 @@ std::vector<ExtensionBuilder> const internal_extension_builders = {
         {
             return mf::create_xdg_decoration_unstable_v1(ctx.display, ctx.decoration_strategy);
         }),
+    make_extension_builder<mw::XdgWmDialogV1>([](auto const& ctx)
+        {
+            return mf::create_xdg_dialog_v1(ctx.display);
+        }),
     make_extension_builder<mw::FractionalScaleManagerV1>([](auto const& ctx)
         {
             return mf::create_fractional_scale_v1(ctx.display);
@@ -399,6 +404,7 @@ auto mf::get_standard_extensions() -> std::vector<std::string>
         mw::TextInputManagerV3::interface_name,
         mw::MirShellV1::interface_name,
         mw::XdgDecorationManagerV1::interface_name,
+        mw::XdgWmDialogV1::interface_name,
         mw::XdgActivationV1::interface_name,
         mw::FractionalScaleManagerV1::interface_name};
 }

src/server/frontend_wayland/xdg_dialog_v1.cpp

@@ -0,0 +1,154 @@
+/*
+ * Copyright © Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or 3 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "xdg_dialog_v1.h"
+
+#include <mir/wayland/protocol_error.h>
+
+#include "xdg-dialog-v1_wrapper.h"
+#include "xdg_shell_stable.h"
+
+#include <memory>
+#include <unordered_set>
+
+namespace mir
+{
+namespace frontend
+{
+class ToplevelsWithDialogs
+{
+public:
+    ToplevelsWithDialogs() = default;
+    ToplevelsWithDialogs(ToplevelsWithDialogs const&) = delete;
+    ToplevelsWithDialogs& operator=(ToplevelsWithDialogs const&) = delete;
+
+    /// \return true if no duplicates existed before insertion, false otherwise.
+    bool register_toplevel(wl_resource* toplevel)
+    {
+        auto [_, inserted] = toplevels_with_dialogs.insert(toplevel);
+        return inserted;
+    }
+
+    /// \return true if the toplevel was still registered, false otherwise.
+    bool unregister_toplevel(wl_resource* toplevel)
+    {
+        return toplevels_with_dialogs.erase(toplevel) > 0;
+    }
+
+private:
+    std::unordered_set<wl_resource*> toplevels_with_dialogs;
+};
+
+class XdgDialogV1 : public wayland::XdgDialogV1
+{
+public:
+    explicit XdgDialogV1(wl_resource* id);
+
+    void set_modal() override;
+    void unset_modal() override;
+};
+
+class XdgWmDialogV1 : public wayland::XdgWmDialogV1
+{
+public:
+    XdgWmDialogV1(wl_resource* resource);
+
+    class Global : public wayland::XdgWmDialogV1::Global
+    {
+    public:
+        Global(wl_display* display);
+
+    private:
+        void bind(wl_resource* new_xdg_wm_dialog_v1) override;
+    };
+
+private:
+    void get_xdg_dialog(wl_resource* id, wl_resource* toplevel) override;
+
+    std::shared_ptr<ToplevelsWithDialogs> const toplevels_with_dialogs;
+};
+} // namespace frontend
+} // namespace mir
+
+auto mir::frontend::create_xdg_dialog_v1(wl_display* display)
+    -> std::shared_ptr<mir::wayland::XdgWmDialogV1::Global>
+{
+    return std::make_shared<XdgWmDialogV1::Global>(display);
+}
+
+mir::frontend::XdgWmDialogV1::Global::Global(wl_display* display) :
+    wayland::XdgWmDialogV1::Global::Global{display, Version<1>{}}
+{
+}
+
+void mir::frontend::XdgWmDialogV1::Global::bind(wl_resource* new_xdg_wm_dialog_v1)
+{
+    new XdgWmDialogV1{new_xdg_wm_dialog_v1};
+}
+
+mir::frontend::XdgWmDialogV1::XdgWmDialogV1(wl_resource* resource) :
+    wayland::XdgWmDialogV1{resource, Version<1>{}},
+    toplevels_with_dialogs{std::make_shared<ToplevelsWithDialogs>()}
+{
+}
+
+void mir::frontend::XdgWmDialogV1::get_xdg_dialog(wl_resource* id, wl_resource* toplevel)
+{
+    auto* tl = XdgToplevelStable::from(toplevel);
+    if (!tl)
+    {
+        BOOST_THROW_EXCEPTION(std::runtime_error(
+            "Failed to obtain XdgToplevelStable from xdg_toplevel resource"));
+    }
+
+    if (!toplevels_with_dialogs->register_toplevel(toplevel))
+    {
+        BOOST_THROW_EXCEPTION(mir::wayland::ProtocolError(
+            resource, Error::already_used, "xdg_dialog_v1 already created for this toplevel"));
+    }
+
+    auto* dialog = new XdgDialogV1{id};
+    dialog->add_destroy_listener(
+        [toplevels_with_dialogs = this->toplevels_with_dialogs, toplevel]()
+        {
+            toplevels_with_dialogs->unregister_toplevel(toplevel);
+        });
+
+    tl->add_destroy_listener(
+        [toplevels_with_dialogs = this->toplevels_with_dialogs, toplevel]()
+        {
+            toplevels_with_dialogs->unregister_toplevel(toplevel);
+        });
+
+    tl->set_type(mir_window_type_dialog);
+}
+
+mir::frontend::XdgDialogV1::XdgDialogV1(wl_resource* id) :
+    wayland::XdgDialogV1{id, Version<1>{}}
+{
+}
+
+void mir::frontend::XdgDialogV1::set_modal()
+{
+    // In Mir, mir_window_type_dialog already represents a modal dialog.
+    // No additional state change is needed.
+}
+
+void mir::frontend::XdgDialogV1::unset_modal()
+{
+    // Mir does not distinguish between modal and non-modal dialogs at the
+    // window type level; the toplevel remains a dialog regardless.
+}

src/server/frontend_wayland/xdg_dialog_v1.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright © Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or 3 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MIR_FRONTEND_XDG_DIALOG_V1_H
+#define MIR_FRONTEND_XDG_DIALOG_V1_H
+
+#include "xdg-dialog-v1_wrapper.h"
+
+struct wl_display;
+
+namespace mir
+{
+namespace frontend
+{
+auto create_xdg_dialog_v1(struct wl_display* display) -> std::shared_ptr<wayland::XdgWmDialogV1::Global>;
+}
+}
+
+#endif // MIR_FRONTEND_XDG_DIALOG_V1_H

src/wayland/CMakeLists.txt

@@ -40,6 +40,7 @@ mir_generate_protocol_wrapper(mirwayland "z" xdg-decoration-unstable-v1.xml)
 mir_generate_protocol_wrapper(mirwayland "wp_" viewporter.xml)
 mir_generate_protocol_wrapper(mirwayland "wp_" fractional-scale-v1.xml)
 mir_generate_protocol_wrapper(mirwayland "z" xdg-activation-v1.xml)
+mir_generate_protocol_wrapper(mirwayland "" xdg-dialog-v1.xml)
 mir_generate_protocol_wrapper(mirwayland "wp_" linux-drm-syncobj-v1.xml)
 mir_generate_protocol_wrapper(mirwayland "ext_" ext-data-control-v1.xml)
 # We don't strip the "ext_" prefix here, because it would conflict

wayland-protocols/xdg-dialog-v1.xml

@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="xdg_dialog_v1">
+
+  <copyright>
+    Copyright © 2023 Carlos Garnacho
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <interface name="xdg_wm_dialog_v1" version="1">
+    <description summary="create dialogs related to other toplevels">
+      The xdg_wm_dialog_v1 interface is exposed as a global object allowing
+      to create xdg_dialog_v1 objects. These objects can be used to
+      coordinate the creation of dialogs relative to another toplevel.
+
+      Warning! The protocol described in this file is currently in the testing
+      phase. Backward compatible changes may be added together with the
+      corresponding interface version bump. Backward incompatible changes can
+      only be done by creating a new major version of the extension.
+    </description>
+
+    <enum name="error">
+      <description summary="error values for this object"/>
+      <entry name="already_used" value="0"
+             summary="the xdg_toplevel object has already been used to create a xdg_dialog_v1"/>
+    </enum>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the dialog manager object">
+        Destroys the xdg_wm_dialog_v1 object. This does not affect
+        the xdg_dialog_v1 objects created from it.
+      </description>
+    </request>
+
+    <request name="get_xdg_dialog">
+      <description summary="create a dialog object">
+        Create a new dialog object associated with the given toplevel, to
+        allow managing dialogs.
+
+        Only one xdg_dialog_v1 may exist for each xdg_toplevel. If an
+        xdg_dialog_v1 already exists for the given xdg_toplevel, the
+        already_used error is raised.
+      </description>
+      <arg name="id" type="new_id" interface="xdg_dialog_v1"/>
+      <arg name="toplevel" type="object" interface="xdg_toplevel"/>
+    </request>
+  </interface>
+
+  <interface name="xdg_dialog_v1" version="1">
+    <description summary="dialog object">
+      A dialog object is associated to a xdg_toplevel. It allows the
+      compositor to treat the toplevel as a dialog and apply dialog-specific
+      policies.
+
+      Compositors may treat dialogs differently from regular windows in many
+      ways, e.g. refusing to iconify or maximize them. The user can usually
+      dismiss a dialog by pressing a dedicated key (e.g. Escape).
+    </description>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the dialog object">
+        Destroys the xdg_dialog_v1 object. This does not affect
+        the dialog state on the associated xdg_toplevel.
+      </description>
+    </request>
+
+    <request name="set_modal">
+      <description summary="mark dialog as modal">
+        Hint that the dialog has modal behavior. See the description of
+        xdg_dialog_v1 for more details about what is expected from
+        modal dialogs.
+
+        This request does not take effect for an unmapped toplevel.
+      </description>
+    </request>
+
+    <request name="unset_modal">
+      <description summary="mark dialog as not modal">
+        Hint that the dialog does not have modal behavior. See the description
+        of xdg_dialog_v1 for more details.
+
+        This request does not take effect for an unmapped toplevel.
+      </description>
+    </request>
+  </interface>
+
+</protocol>