feat(backend): 支持鼠标抓取功能

src/backend/x11/backend.c

@@ -522,6 +522,22 @@ backend_bind_key(backend_t *backend, const effect_bind_key_t *bind_key) {
   window_grab_keys(backend, root, bind_key->keys, bind_key->count);
 }
 
+static void backend_grab_button(
+  backend_t *backend,
+  const effect_grab_button_t *grab_button
+) {
+  auto conn   = backend->conn;
+  auto window = grab_button->window;
+  xcb_ungrab_button(conn, XCB_BUTTON_INDEX_ANY, window, XCB_MOD_MASK_ANY);
+
+  auto buttons = grab_button->buttons;
+  for (size_t i = 0; i < grab_button->count; ++i) {
+    auto button    = buttons[i].button;
+    auto modifiers = buttons[i].modifiers;
+    window_grab_button(backend, window, button, modifiers);
+  }
+}
+
 static void backend_merge_effects(
   backend_t *backend,
   const effect_t *effects,
@@ -601,6 +617,8 @@ static void backend_merge_effects(
     case ZDWM_EFFECT_BIND_KEY:
       backend_bind_key(backend, &e->as.bind_key);
       break;
+    case ZDWM_EFFECT_GRAB_BUTTON:
+      backend_grab_button(backend, &e->as.grab_button);
     }
   }
 }

src/backend/x11/common.c

@@ -0,0 +1,71 @@
+#include "common.h"
+
+#include <stddef.h>
+#include <stdint.h>
+#include <xcb/xproto.h>
+
+#include "base/macros.h"
+#include "core/types.h"
+
+typedef struct modifier_map_t {
+  modifier_bit_t modifier;
+  xcb_mod_mask_t mask;
+} modifier_map_t;
+
+static constexpr modifier_map_t modifier_map[] = {
+  {ZDWM_MOD_SHIFT, XCB_MOD_MASK_SHIFT},
+  {ZDWM_MOD_CONTROL, XCB_MOD_MASK_CONTROL},
+  {ZDWM_MOD_1, XCB_MOD_MASK_1},
+  {ZDWM_MOD_2, XCB_MOD_MASK_2},
+  {ZDWM_MOD_3, XCB_MOD_MASK_3},
+  {ZDWM_MOD_4, XCB_MOD_MASK_4},
+  {ZDWM_MOD_5, XCB_MOD_MASK_5},
+};
+
+modifier_mask_t modifiers_xcb_to_zdwm(uint16_t mask) {
+  modifier_mask_t mods = ZDWM_MOD_NONE;
+  for (size_t i = 0; i < countof(modifier_map); ++i) {
+    auto item = &modifier_map[i];
+    if (mask & item->mask) mods |= item->modifier;
+  }
+  return mods;
+}
+
+uint16_t modifiers_zdwm_to_xcb(modifier_mask_t mask) {
+  uint16_t mods = 0U;
+  for (size_t i = 0; i < countof(modifier_map); ++i) {
+    auto item = &modifier_map[i];
+    if (mask & item->modifier) mods |= item->mask;
+  }
+  return mods;
+}
+
+typedef struct button_map_t {
+  button_t zdwm_button;
+  xcb_button_index_t xcb_button;
+} button_map_t;
+
+static constexpr button_map_t button_map[] = {
+  {ZDWM_BUTTON_LEFT, XCB_BUTTON_INDEX_1},
+  {ZDWM_BUTTON_RIGHT, XCB_BUTTON_INDEX_3},
+  {ZDWM_BUTTON_MIDDLE, XCB_BUTTON_INDEX_2},
+  /* TODO: 后续可以考虑加上鼠标滚轮事件 */
+};
+
+button_t button_xcb_to_zdwm(xcb_button_t button) {
+  for (size_t i = 0; i < countof(button_map); ++i) {
+    auto item = &button_map[i];
+    if (button == item->xcb_button) return item->zdwm_button;
+  }
+
+  return ZDWM_BUTTON_NONE;
+}
+
+xcb_button_t button_zdwm_to_xcb(button_t button) {
+  for (size_t i = 0; i < countof(button_map); ++i) {
+    auto item = &button_map[i];
+    if (button == item->zdwm_button) return item->xcb_button;
+  }
+
+  return XCB_BUTTON_INDEX_ANY;
+}

src/backend/x11/common.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <stdint.h>
+#include <xcb/xproto.h>
+
+#include "core/types.h"
+
+modifier_mask_t modifiers_xcb_to_zdwm(uint16_t mask);
+uint16_t modifiers_zdwm_to_xcb(modifier_mask_t mask);
+
+button_t button_xcb_to_zdwm(xcb_button_t button);
+xcb_button_t button_zdwm_to_xcb(button_t button);

src/backend/x11/event.c

@@ -9,8 +9,8 @@
 #include <xcb/xcb_keysyms.h>
 #include <xcb/xproto.h>
 
+#include "backend/x11/common.h"
 #include "backend/x11/window.h"
-#include "base/macros.h"
 #include "base/memory.h"
 #include "core/backend.h"
 #include "core/types.h"
@@ -233,29 +233,6 @@ static bool handle_configure_request(
   return true;
 }
 
-static modifier_mask_t get_modifiers(uint16_t mask) {
-  typedef struct modifier_map_t {
-    modifier_bit_t modifier;
-    xcb_mod_mask_t mask;
-  } modifier_map_t;
-  static constexpr modifier_map_t modifier_map[] = {
-    {ZDWM_MOD_SHIFT, XCB_MOD_MASK_SHIFT},
-    {ZDWM_MOD_CONTROL, XCB_MOD_MASK_CONTROL},
-    {ZDWM_MOD_1, XCB_MOD_MASK_1},
-    {ZDWM_MOD_2, XCB_MOD_MASK_2},
-    {ZDWM_MOD_3, XCB_MOD_MASK_3},
-    {ZDWM_MOD_4, XCB_MOD_MASK_4},
-    {ZDWM_MOD_5, XCB_MOD_MASK_5},
-  };
-
-  auto mods = ZDWM_MOD_NONE;
-  for (size_t i = 0; i < countof(modifier_map); ++i) {
-    auto item = &modifier_map[i];
-    if (mask & item->mask) mods |= item->modifier;
-  }
-  return mods;
-}
-
 static bool handle_key_press(
   backend_t *backend,
   event_t *event,
@@ -269,39 +246,18 @@ static bool handle_key_press(
   event->type                   = ZDWM_EVENT_KEY_PRESS;
   event->as.key_press.keycode   = keycode;
   event->as.key_press.keysym    = keysym;
-  event->as.key_press.modifiers = get_modifiers(xcb_event->state);
+  event->as.key_press.modifiers = modifiers_xcb_to_zdwm(xcb_event->state);
 
   return true;
 }
 
-static bool get_button(xcb_button_t button_detail, uint32_t *button) {
-  assert(button != nullptr);
-  switch (button_detail) {
-  case XCB_BUTTON_INDEX_1:
-    *button = ZDWM_BUTTON_LEFT;
-    return true;
-  case XCB_BUTTON_INDEX_2:
-    *button = ZDWM_BUTTON_RIGHT;
-    return true;
-  case XCB_BUTTON_INDEX_3:
-    *button = ZDWM_BUTTON_MIDDLE;
-    return true;
-  case XCB_BUTTON_INDEX_4:
-  case XCB_BUTTON_INDEX_5:
-    /* TODO: 后续可以考虑加上鼠标滚轮事件 */
-  default:
-    return false;
-  }
-}
-
 static bool fill_button_event(
   const xcb_button_press_event_t *xcb_event,
   pointer_button_event_t *data
 ) {
-  uint32_t button = 0;
-  if (!get_button(xcb_event->detail, &button)) return false;
+  auto button = button_xcb_to_zdwm(xcb_event->detail);
 
-  data->modifiers = get_modifiers(xcb_event->state);
+  data->modifiers = modifiers_xcb_to_zdwm(xcb_event->state);
   data->button    = button;
   data->window    = xcb_event->event;
   data->root      = (point_t){.x = xcb_event->root_x, .y = xcb_event->root_y};

src/backend/x11/window.c

@@ -8,6 +8,7 @@
 #include <xcb/xcb_keysyms.h>
 #include <xcb/xproto.h>
 
+#include "backend/x11/common.h"
 #include "backend/x11/cursor.h"
 #include "base/macros.h"
 #include "base/memory.h"
@@ -463,3 +464,26 @@ void window_change_cursor(
   xcb_params_cw_t params = {.cursor = cursor_get_xcb_cursor(backend, cursor)};
   xcb_aux_change_window_attributes(conn, window, XCB_CW_CURSOR, &params);
 }
+
+void window_grab_button(
+  backend_t *backend,
+  xcb_window_t window,
+  button_t button,
+  modifier_mask_t modifiers
+) {
+  auto xcb_button = button_zdwm_to_xcb(button);
+  if (xcb_button == XCB_BUTTON_INDEX_ANY) return;
+
+  xcb_grab_button(
+    backend->conn,
+    false, /* 事件仅发送给抓取者，不发送给其他窗口 */
+    window,
+    XCB_EVENT_MASK_BUTTON_PRESS | XCB_EVENT_MASK_BUTTON_RELEASE,
+    XCB_GRAB_MODE_ASYNC,
+    XCB_GRAB_MODE_SYNC,
+    XCB_WINDOW_NONE,
+    XCB_CURSOR_NONE,
+    xcb_button,
+    modifiers_zdwm_to_xcb(modifiers)
+  );
+}

src/backend/x11/window.h

@@ -124,3 +124,10 @@ void window_change_cursor(
   xcb_window_t window,
   cursor_t cursor
 );
+
+void window_grab_button(
+  backend_t *backend,
+  xcb_window_t window,
+  button_t button,
+  modifier_mask_t modifiers
+);