protocols: add hyprland_focus_grab_v1 implementation (#5850)

* protocols: add hyprland_focus_grab_v1 implementation

* protocols/focus_grab: fix keyboard focus staying on unlisted windows

When creating a focus grab with layershell surfaces, the last active
toplevel kept keyboard focus.

* protocols/focus_grab: fix formatting

* protocols/focus_grab: try to pick surface for keyboard focus

* focus_grab: update keyboard focus to match spec

* Revert "protocols/focus_grab: try to pick surface for keyboard focus"

This reverts commit 090358d0d19cc65208641eaefa0a905e99145730.

* protocols/focus_grab: fix issues and match new spec

* kde-server-decoration: move to new impl

* protocols/focus_grab: review fixup

* Update hyprland-protocols

---------

Co-authored-by: Vaxry <[email protected]>

7 files changed, 409 insertions, 3 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a4e400d1..cdf72fe0 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -266,6 +266,7 @@ protocolNew("protocols/wlr-virtual-pointer-unstable-v1.xml" "wlr-virtual-pointer
 protocolNew("protocols/input-method-unstable-v2.xml" "input-method-unstable-v2" true)
 protocolNew("protocols/wlr-output-management-unstable-v1.xml" "wlr-output-management-unstable-v1" true)
 protocolNew("protocols/kde-server-decoration.xml" "kde-server-decoration" true)
+protocolNew("subprojects/hyprland-protocols/protocols/hyprland-focus-grab-v1.xml" "hyprland-focus-grab-v1" true)
 protocolNew("staging/tearing-control/tearing-control-v1.xml" "tearing-control-v1" false)
 protocolNew("staging/fractional-scale/fractional-scale-v1.xml" "fractional-scale-v1" false)
 protocolNew("unstable/xdg-output/xdg-output-unstable-v1.xml" "xdg-output-unstable-v1" false)
diff --git a/flake.lock b/flake.lock
index 2e8ccf87..4dc48dc9 100644
--- a/flake.lock
+++ b/flake.lock
@@ -36,11 +36,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1691753796,
-        "narHash": "sha256-zOEwiWoXk3j3+EoF3ySUJmberFewWlagvewDRuWYAso=",
+        "lastModified": 1714869498,
+        "narHash": "sha256-vbLVOWvQqo4n1yvkg/Q70VTlPbMmTiCQfNTgcWDCfJM=",
         "owner": "hyprwm",
         "repo": "hyprland-protocols",
-        "rev": "0c2ce70625cb30aef199cb388f99e19a61a6ce03",
+        "rev": "e06482e0e611130cd1929f75e8c1cf679e57d161",
         "type": "github"
       },
       "original": {
diff --git a/protocols/meson.build b/protocols/meson.build
index 1c9013f0..f6c54d4d 100644
--- a/protocols/meson.build
+++ b/protocols/meson.build
@@ -43,6 +43,7 @@ new_protocols = [
   ['wlr-virtual-pointer-unstable-v1.xml'],
   ['wlr-output-management-unstable-v1.xml'],
   ['kde-server-decoration.xml'],
+  [hl_protocol_dir, 'protocols/hyprland-focus-grab-v1.xml'],
   [wl_protocol_dir, 'staging/tearing-control/tearing-control-v1.xml'],
   [wl_protocol_dir, 'staging/fractional-scale/fractional-scale-v1.xml'],
   [wl_protocol_dir, 'unstable/xdg-output/xdg-output-unstable-v1.xml'],
diff --git a/src/managers/ProtocolManager.cpp b/src/managers/ProtocolManager.cpp
index 47372d01..ee27d35d 100644
--- a/src/managers/ProtocolManager.cpp
+++ b/src/managers/ProtocolManager.cpp
@@ -24,6 +24,7 @@
 #include "../protocols/VirtualPointer.hpp"
 #include "../protocols/OutputManagement.hpp"
 #include "../protocols/ServerDecorationKDE.hpp"
+#include "../protocols/FocusGrab.hpp"
 
 CProtocolManager::CProtocolManager() {
 
@@ -51,6 +52,7 @@ CProtocolManager::CProtocolManager() {
     PROTO::virtualPointer      = std::make_unique<CVirtualPointerProtocol>(&zwlr_virtual_pointer_manager_v1_interface, 2, "VirtualPointer");
     PROTO::outputManagement    = std::make_unique<COutputManagementProtocol>(&zwlr_output_manager_v1_interface, 4, "OutputManagement");
     PROTO::serverDecorationKDE = std::make_unique<CServerDecorationKDEProtocol>(&org_kde_kwin_server_decoration_manager_interface, 1, "ServerDecorationKDE");
+    PROTO::focusGrab           = std::make_unique<CFocusGrabProtocol>(&hyprland_focus_grab_manager_v1_interface, 1, "FocusGrab");
 
     // Old protocol implementations.
     // TODO: rewrite them to use hyprwayland-scanner.
diff --git a/src/protocols/FocusGrab.cpp b/src/protocols/FocusGrab.cpp
new file mode 100644
index 00000000..61c17573
--- /dev/null
+++ b/src/protocols/FocusGrab.cpp
@@ -0,0 +1,325 @@
+#include "FocusGrab.hpp"
+#include "Compositor.hpp"
+#include <hyprland-focus-grab-v1.hpp>
+#include <managers/input/InputManager.hpp>
+#include <cstdint>
+#include <memory>
+#include <wayland-server.h>
+
+static void focus_grab_pointer_enter(wlr_seat_pointer_grab* grab, wlr_surface* surface, double sx, double sy) {
+    if (static_cast<CFocusGrab*>(grab->data)->isSurfaceComitted(surface))
+        wlr_seat_pointer_enter(grab->seat, surface, sx, sy);
+    else
+        wlr_seat_pointer_clear_focus(grab->seat);
+}
+
+static void focus_grab_pointer_clear_focus(wlr_seat_pointer_grab* grab) {
+    wlr_seat_pointer_clear_focus(grab->seat);
+}
+
+static void focus_grab_pointer_motion(wlr_seat_pointer_grab* grab, uint32_t time, double sx, double sy) {
+    wlr_seat_pointer_send_motion(grab->seat, time, sx, sy);
+}
+
+static uint32_t focus_grab_pointer_button(wlr_seat_pointer_grab* grab, uint32_t time, uint32_t button, wl_pointer_button_state state) {
+    uint32_t serial = wlr_seat_pointer_send_button(grab->seat, time, button, state);
+
+    if (serial)
+        return serial;
+    else {
+        static_cast<CFocusGrab*>(grab->data)->finish(true);
+        return 0;
+    }
+}
+
+static void focus_grab_pointer_axis(wlr_seat_pointer_grab* grab, uint32_t time, enum wl_pointer_axis orientation, double value, int32_t value_discrete,
+                                    enum wl_pointer_axis_source source, enum wl_pointer_axis_relative_direction relative_direction) {
+    wlr_seat_pointer_send_axis(grab->seat, time, orientation, value, value_discrete, source, relative_direction);
+}
+
+static void focus_grab_pointer_frame(wlr_seat_pointer_grab* grab) {
+    wlr_seat_pointer_send_frame(grab->seat);
+}
+
+static void focus_grab_pointer_cancel(wlr_seat_pointer_grab* grab) {
+    static_cast<CFocusGrab*>(grab->data)->finish(true);
+}
+
+static const wlr_pointer_grab_interface focus_grab_pointer_impl = {
+    .enter       = focus_grab_pointer_enter,
+    .clear_focus = focus_grab_pointer_clear_focus,
+    .motion      = focus_grab_pointer_motion,
+    .button      = focus_grab_pointer_button,
+    .axis        = focus_grab_pointer_axis,
+    .frame       = focus_grab_pointer_frame,
+    .cancel      = focus_grab_pointer_cancel,
+};
+
+static void focus_grab_keyboard_enter(wlr_seat_keyboard_grab* grab, wlr_surface* surface, const uint32_t keycodes[], size_t num_keycodes, const wlr_keyboard_modifiers* modifiers) {
+    if (static_cast<CFocusGrab*>(grab->data)->isSurfaceComitted(surface))
+        wlr_seat_keyboard_enter(grab->seat, surface, keycodes, num_keycodes, modifiers);
+
+    // otherwise the last grabbed window should retain keyboard focus.
+}
+
+static void focus_grab_keyboard_clear_focus(wlr_seat_keyboard_grab* grab) {
+    static_cast<CFocusGrab*>(grab->data)->finish(true);
+}
+
+static void focus_grab_keyboard_key(wlr_seat_keyboard_grab* grab, uint32_t time, uint32_t key, uint32_t state) {
+    wlr_seat_keyboard_send_key(grab->seat, time, key, state);
+}
+
+static void focus_grab_keyboard_modifiers(wlr_seat_keyboard_grab* grab, const wlr_keyboard_modifiers* modifiers) {
+    wlr_seat_keyboard_send_modifiers(grab->seat, modifiers);
+}
+
+static void focus_grab_keyboard_cancel(wlr_seat_keyboard_grab* grab) {
+    static_cast<CFocusGrab*>(grab->data)->finish(true);
+}
+
+static const wlr_keyboard_grab_interface focus_grab_keyboard_impl = {
+    .enter       = focus_grab_keyboard_enter,
+    .clear_focus = focus_grab_keyboard_clear_focus,
+    .key         = focus_grab_keyboard_key,
+    .modifiers   = focus_grab_keyboard_modifiers,
+    .cancel      = focus_grab_keyboard_cancel,
+};
+
+static uint32_t focus_grab_touch_down(wlr_seat_touch_grab* grab, uint32_t time, wlr_touch_point* point) {
+    if (!static_cast<CFocusGrab*>(grab->data)->isSurfaceComitted(point->surface))
+        return 0;
+
+    return wlr_seat_touch_send_down(grab->seat, point->surface, time, point->touch_id, point->sx, point->sy);
+}
+
+static void focus_grab_touch_up(wlr_seat_touch_grab* grab, uint32_t time, wlr_touch_point* point) {
+    wlr_seat_touch_send_up(grab->seat, time, point->touch_id);
+}
+
+static void focus_grab_touch_motion(wlr_seat_touch_grab* grab, uint32_t time, wlr_touch_point* point) {
+    wlr_seat_touch_send_motion(grab->seat, time, point->touch_id, point->sx, point->sy);
+}
+
+static void focus_grab_touch_enter(wlr_seat_touch_grab* grab, uint32_t time, wlr_touch_point* point) {}
+
+static void focus_grab_touch_frame(wlr_seat_touch_grab* grab) {
+    wlr_seat_touch_send_frame(grab->seat);
+}
+
+static void focus_grab_touch_cancel(wlr_seat_touch_grab* grab) {
+    static_cast<CFocusGrab*>(grab->data)->finish(true);
+}
+
+static const wlr_touch_grab_interface focus_grab_touch_impl = {
+    .down   = focus_grab_touch_down,
+    .up     = focus_grab_touch_up,
+    .motion = focus_grab_touch_motion,
+    .enter  = focus_grab_touch_enter,
+    .frame  = focus_grab_touch_frame,
+    .cancel = focus_grab_touch_cancel,
+};
+
+CFocusGrabSurfaceState::CFocusGrabSurfaceState(CFocusGrab* grab, wlr_surface* surface) {
+    hyprListener_surfaceDestroy.initCallback(
+        &surface->events.destroy, [=](void*, void*) { grab->eraseSurface(surface); }, this, "CFocusGrab");
+}
+
+CFocusGrabSurfaceState::~CFocusGrabSurfaceState() {
+    hyprListener_surfaceDestroy.removeCallback();
+}
+
+CFocusGrab::CFocusGrab(SP<CHyprlandFocusGrabV1> resource_) : resource(resource_) {
+    if (!resource->resource())
+        return;
+
+    m_sPointerGrab.interface = &focus_grab_pointer_impl;
+    m_sPointerGrab.data      = this;
+
+    m_sKeyboardGrab.interface = &focus_grab_keyboard_impl;
+    m_sKeyboardGrab.data      = this;
+
+    m_sTouchGrab.interface = &focus_grab_touch_impl;
+    m_sTouchGrab.data      = this;
+
+    resource->setDestroy([this](CHyprlandFocusGrabV1* pMgr) { PROTO::focusGrab->destroyGrab(this); });
+    resource->setOnDestroy([this](CHyprlandFocusGrabV1* pMgr) { PROTO::focusGrab->destroyGrab(this); });
+    resource->setAddSurface([this](CHyprlandFocusGrabV1* pMgr, wl_resource* surface) { addSurface(wlr_surface_from_resource(surface)); });
+    resource->setRemoveSurface([this](CHyprlandFocusGrabV1* pMgr, wl_resource* surface) { removeSurface(wlr_surface_from_resource(surface)); });
+    resource->setCommit([this](CHyprlandFocusGrabV1* pMgr) { commit(); });
+}
+
+CFocusGrab::~CFocusGrab() {
+    finish(false);
+}
+
+bool CFocusGrab::good() {
+    return resource->resource();
+}
+
+bool CFocusGrab::isSurfaceComitted(wlr_surface* surface) {
+    auto iter = m_mSurfaces.find(surface);
+    if (iter == m_mSurfaces.end())
+        return false;
+
+    return iter->second->state == CFocusGrabSurfaceState::Comitted;
+}
+
+void CFocusGrab::start() {
+    if (!m_bGrabActive) {
+        wlr_seat_pointer_start_grab(g_pCompositor->m_sSeat.seat, &m_sPointerGrab);
+        wlr_seat_keyboard_start_grab(g_pCompositor->m_sSeat.seat, &m_sKeyboardGrab);
+        wlr_seat_touch_start_grab(g_pCompositor->m_sSeat.seat, &m_sTouchGrab);
+        m_bGrabActive = true;
+
+        // Ensure the grab ends if another grab begins, including from xdg_popup::grab.
+
+        hyprListener_pointerGrabStarted.initCallback(
+            &g_pCompositor->m_sSeat.seat->events.pointer_grab_begin, [this](void*, void*) { finish(true); }, this, "CFocusGrab");
+
+        hyprListener_keyboardGrabStarted.initCallback(
+            &g_pCompositor->m_sSeat.seat->events.keyboard_grab_begin, [this](void*, void*) { finish(true); }, this, "CFocusGrab");
+
+        hyprListener_touchGrabStarted.initCallback(
+            &g_pCompositor->m_sSeat.seat->events.touch_grab_begin, [this](void*, void*) { finish(true); }, this, "CFocusGrab");
+    }
+
+    // Ensure new surfaces are focused if under the mouse when comitted.
+    g_pInputManager->simulateMouseMovement();
+    refocusKeyboard();
+}
+
+void CFocusGrab::finish(bool sendCleared) {
+    if (m_bGrabActive) {
+        m_bGrabActive = false;
+        hyprListener_pointerGrabStarted.removeCallback();
+        hyprListener_keyboardGrabStarted.removeCallback();
+        hyprListener_touchGrabStarted.removeCallback();
+
+        // Only clear grabs that belong to this focus grab. When superseded by another grab
+        // or xdg_popup grab we might not own the current grab.
+
+        bool hadGrab = false;
+        if (g_pCompositor->m_sSeat.seat->pointer_state.grab == &m_sPointerGrab) {
+            wlr_seat_pointer_end_grab(g_pCompositor->m_sSeat.seat);
+            hadGrab = true;
+        }
+
+        if (g_pCompositor->m_sSeat.seat->keyboard_state.grab == &m_sKeyboardGrab) {
+            wlr_seat_keyboard_end_grab(g_pCompositor->m_sSeat.seat);
+            hadGrab = true;
+        }
+
+        if (g_pCompositor->m_sSeat.seat->touch_state.grab == &m_sTouchGrab) {
+            wlr_seat_touch_end_grab(g_pCompositor->m_sSeat.seat);
+            hadGrab = true;
+        }
+
+        m_mSurfaces.clear();
+
+        if (sendCleared)
+            resource->sendCleared();
+
+        // Ensure surfaces under the mouse when the grab ends get focus.
+        if (hadGrab)
+            g_pInputManager->refocus();
+    }
+}
+
+void CFocusGrab::addSurface(wlr_surface* surface) {
+    auto iter = m_mSurfaces.find(surface);
+    if (iter == m_mSurfaces.end())
+        m_mSurfaces.emplace(surface, std::make_unique<CFocusGrabSurfaceState>(this, surface));
+}
+
+void CFocusGrab::removeSurface(wlr_surface* surface) {
+    auto iter = m_mSurfaces.find(surface);
+    if (iter != m_mSurfaces.end()) {
+        if (iter->second->state == CFocusGrabSurfaceState::PendingAddition)
+            m_mSurfaces.erase(iter);
+        else
+            iter->second->state = CFocusGrabSurfaceState::PendingRemoval;
+    }
+}
+
+void CFocusGrab::eraseSurface(wlr_surface* surface) {
+    removeSurface(surface);
+    commit();
+}
+
+void CFocusGrab::refocusKeyboard() {
+    auto keyboardSurface = g_pCompositor->m_sSeat.seat->keyboard_state.focused_surface;
+    if (keyboardSurface != nullptr && isSurfaceComitted(keyboardSurface))
+        return;
+
+    wlr_surface* surface = nullptr;
+    for (auto& [surf, state] : m_mSurfaces) {
+        if (state->state == CFocusGrabSurfaceState::Comitted) {
+            surface = surf;
+            break;
+        }
+    }
+
+    if (surface)
+        g_pCompositor->focusSurface(surface);
+    else
+        Debug::log(ERR, "CFocusGrab::refocusKeyboard called with no committed surfaces. This should never happen.");
+}
+
+void CFocusGrab::commit() {
+    auto surfacesChanged = false;
+    auto anyComitted     = false;
+    for (auto iter = m_mSurfaces.begin(); iter != m_mSurfaces.end();) {
+        switch (iter->second->state) {
+            case CFocusGrabSurfaceState::PendingRemoval:
+                iter            = m_mSurfaces.erase(iter);
+                surfacesChanged = true;
+                continue;
+            case CFocusGrabSurfaceState::PendingAddition:
+                iter->second->state = CFocusGrabSurfaceState::Comitted;
+                surfacesChanged     = true;
+                anyComitted         = true;
+                break;
+            case CFocusGrabSurfaceState::Comitted: anyComitted = true; break;
+        }
+
+        iter++;
+    }
+
+    if (surfacesChanged) {
+        if (anyComitted)
+            start();
+        else
+            finish(true);
+    }
+}
+
+CFocusGrabProtocol::CFocusGrabProtocol(const wl_interface* iface, const int& ver, const std::string& name) : IWaylandProtocol(iface, ver, name) {
+    ;
+}
+
+void CFocusGrabProtocol::bindManager(wl_client* client, void* data, uint32_t ver, uint32_t id) {
+    const auto RESOURCE = m_vManagers.emplace_back(std::make_unique<CHyprlandFocusGrabManagerV1>(client, ver, id)).get();
+    RESOURCE->setOnDestroy([this](CHyprlandFocusGrabManagerV1* p) { onManagerResourceDestroy(p->resource()); });
+
+    RESOURCE->setDestroy([this](CHyprlandFocusGrabManagerV1* p) { onManagerResourceDestroy(p->resource()); });
+    RESOURCE->setCreateGrab([this](CHyprlandFocusGrabManagerV1* pMgr, uint32_t id) { onCreateGrab(pMgr, id); });
+}
+
+void CFocusGrabProtocol::onManagerResourceDestroy(wl_resource* res) {
+    std::erase_if(m_vManagers, [&](const auto& other) { return other->resource() == res; });
+}
+
+void CFocusGrabProtocol::destroyGrab(CFocusGrab* grab) {
+    std::erase_if(m_vGrabs, [&](const auto& other) { return other.get() == grab; });
+}
+
+void CFocusGrabProtocol::onCreateGrab(CHyprlandFocusGrabManagerV1* pMgr, uint32_t id) {
+    m_vGrabs.push_back(std::make_unique<CFocusGrab>(std::make_shared<CHyprlandFocusGrabV1>(pMgr->client(), pMgr->version(), id)));
+    const auto RESOURCE = m_vGrabs.back().get();
+
+    if (!RESOURCE->good()) {
+        pMgr->noMemory();
+        m_vGrabs.pop_back();
+    }
+}
diff --git a/src/protocols/FocusGrab.hpp b/src/protocols/FocusGrab.hpp
new file mode 100644
index 00000000..11c26774
--- /dev/null
+++ b/src/protocols/FocusGrab.hpp
@@ -0,0 +1,77 @@
+#pragma once
+
+#include "WaylandProtocol.hpp"
+#include "hyprland-focus-grab-v1.hpp"
+#include "macros.hpp"
+#include <cstdint>
+#include <unordered_map>
+#include <vector>
+
+class CFocusGrab;
+
+class CFocusGrabSurfaceState {
+  public:
+    CFocusGrabSurfaceState(CFocusGrab* grab, wlr_surface* surface);
+    ~CFocusGrabSurfaceState();
+
+    enum State {
+        PendingAddition,
+        PendingRemoval,
+        Comitted,
+    } state = PendingAddition;
+
+  private:
+    DYNLISTENER(surfaceDestroy);
+};
+
+class CFocusGrab {
+  public:
+    CFocusGrab(SP<CHyprlandFocusGrabV1> resource_);
+    ~CFocusGrab();
+
+    bool good();
+    bool isSurfaceComitted(wlr_surface* surface);
+
+    void start();
+    void finish(bool sendCleared);
+
+  private:
+    void                                                         addSurface(wlr_surface* surface);
+    void                                                         removeSurface(wlr_surface* surface);
+    void                                                         eraseSurface(wlr_surface* surface);
+    void                                                         refocusKeyboard();
+    void                                                         commit();
+
+    SP<CHyprlandFocusGrabV1>                                     resource;
+    std::unordered_map<wlr_surface*, UP<CFocusGrabSurfaceState>> m_mSurfaces;
+    wlr_seat_pointer_grab                                        m_sPointerGrab;
+    wlr_seat_keyboard_grab                                       m_sKeyboardGrab;
+    wlr_seat_touch_grab                                          m_sTouchGrab;
+    bool                                                         m_bGrabActive = false;
+
+    DYNLISTENER(pointerGrabStarted);
+    DYNLISTENER(keyboardGrabStarted);
+    DYNLISTENER(touchGrabStarted);
+    friend class CFocusGrabSurfaceState;
+};
+
+class CFocusGrabProtocol : public IWaylandProtocol {
+  public:
+    CFocusGrabProtocol(const wl_interface* iface, const int& var, const std::string& name);
+
+    virtual void bindManager(wl_client* client, void* data, uint32_t ver, uint32_t id);
+
+  private:
+    void                                         onManagerResourceDestroy(wl_resource* res);
+    void                                         destroyGrab(CFocusGrab* grab);
+    void                                         onCreateGrab(CHyprlandFocusGrabManagerV1* pMgr, uint32_t id);
+
+    std::vector<UP<CHyprlandFocusGrabManagerV1>> m_vManagers;
+    std::vector<UP<CFocusGrab>>                  m_vGrabs;
+
+    friend class CFocusGrab;
+};
+
+namespace PROTO {
+    inline UP<CFocusGrabProtocol> focusGrab;
+}
diff --git a/subprojects/hyprland-protocols b/subprojects/hyprland-protocols
-Subproject 0c2ce70625cb30aef199cb388f99e19a61a6ce0
+Subproject e06482e0e611130cd1929f75e8c1cf679e57d16