Implement xcb keyboard.

1 files changed, 175 insertions, 3 deletions

diff --git a/src/platform/gui/xcb/Keyboard.cpp b/src/platform/gui/xcb/Keyboard.cpp
index 1a69c3bd..d7559062 100644
--- a/src/platform/gui/xcb/Keyboard.cpp
+++ b/src/platform/gui/xcb/Keyboard.cpp
@@ -1,9 +1,181 @@
 #include "cru/platform/gui/xcb/Keyboard.h"
+#include "cru/platform/gui/Keyboard.h"
+#include "cru/platform/gui/xcb/UiApplication.h"
 
-#include "cru/base/Base.h"
+#include <xcb/xcb.h>
+#include <bitset>
+#include <climits>
+#include <unordered_map>
+#include <utility>
 
 namespace cru::platform::gui::xcb {
-KeyModifier GetCurrentKeyModifiers(XcbUiApplication* application) {
-  NotImplemented();
+// Refer to
+// https://www.x.org/releases/X11R7.7/doc/xproto/x11protocol.html#keysym_encoding
+KeyCode XorgKeysymToKeyCode(xcb_keysym_t keysym) {
+  if (keysym >= 'A' && keysym <= 'Z') {
+    return KeyCode(static_cast<int>(KeyCode::A) + (keysym - 'A'));
+  }
+
+  if (keysym >= 'a' && keysym <= 'z') {
+    return KeyCode(static_cast<int>(KeyCode::A) + (keysym - 'a'));
+  }
+
+  if (keysym >= '0' && keysym <= '9') {
+    return KeyCode(static_cast<int>(KeyCode::N0) + (keysym - '0'));
+  }
+
+  if (keysym >= 0xFFB0 && keysym <= 0xFFB9) {
+    return KeyCode(static_cast<int>(KeyCode::NumPad0) + (keysym - 0xFFB0));
+  }
+
+  if (keysym >= 0xFFBE && keysym <= 0xFFC9) {
+    return KeyCode(static_cast<int>(KeyCode::F1) + (keysym - 0xFFBE));
+  }
+
+  switch (keysym) {
+#define CRU_DEFINE_KEYCODE_MAP(keysym, cru) \
+  case keysym:                              \
+    return cru;
+
+    CRU_DEFINE_KEYCODE_MAP(',', KeyCode::Comma)
+    CRU_DEFINE_KEYCODE_MAP('.', KeyCode::Period)
+    CRU_DEFINE_KEYCODE_MAP('/', KeyCode::Slash)
+    CRU_DEFINE_KEYCODE_MAP(';', KeyCode::Semicolon)
+    CRU_DEFINE_KEYCODE_MAP('\'', KeyCode::Quote)
+    CRU_DEFINE_KEYCODE_MAP('{', KeyCode::LeftSquareBracket)
+    CRU_DEFINE_KEYCODE_MAP('}', KeyCode::RightSquareBracket)
+    CRU_DEFINE_KEYCODE_MAP('-', KeyCode::Minus)
+    CRU_DEFINE_KEYCODE_MAP('=', KeyCode::Equal)
+    CRU_DEFINE_KEYCODE_MAP('\\', KeyCode::BackSlash)
+    CRU_DEFINE_KEYCODE_MAP(0xFF1B, KeyCode::Escape)
+    CRU_DEFINE_KEYCODE_MAP(0xFF09, KeyCode::Tab)
+    CRU_DEFINE_KEYCODE_MAP(0xFFE5, KeyCode::CapsLock)
+    CRU_DEFINE_KEYCODE_MAP(0xFFE1, KeyCode::LeftShift)
+    CRU_DEFINE_KEYCODE_MAP(0xFFE2, KeyCode::RightShift)
+    CRU_DEFINE_KEYCODE_MAP(0xFFE3, KeyCode::LeftCtrl)
+    CRU_DEFINE_KEYCODE_MAP(0xFFE4, KeyCode::RightCtrl)
+    CRU_DEFINE_KEYCODE_MAP(0xFFE9, KeyCode::LeftAlt)
+    CRU_DEFINE_KEYCODE_MAP(0xFFEA, KeyCode::RightAlt)
+    CRU_DEFINE_KEYCODE_MAP(0xFF08, KeyCode::Backspace)
+    CRU_DEFINE_KEYCODE_MAP(0xFF0D, KeyCode::Return)
+    CRU_DEFINE_KEYCODE_MAP(0xFFFF, KeyCode::Delete)
+    CRU_DEFINE_KEYCODE_MAP(0xFF50, KeyCode::Home)
+    CRU_DEFINE_KEYCODE_MAP(0xFF57, KeyCode::End)
+    CRU_DEFINE_KEYCODE_MAP(0xFF55, KeyCode::PageUp)
+    CRU_DEFINE_KEYCODE_MAP(0xFF56, KeyCode::PageDown)
+    CRU_DEFINE_KEYCODE_MAP(0xFF51, KeyCode::Left)
+    CRU_DEFINE_KEYCODE_MAP(0xFF53, KeyCode::Right)
+    CRU_DEFINE_KEYCODE_MAP(0xFF52, KeyCode::Up)
+    CRU_DEFINE_KEYCODE_MAP(0xFF54, KeyCode::Down)
+    CRU_DEFINE_KEYCODE_MAP(' ', KeyCode::Space)
+    default:
+      return KeyCode::Unknown;
+  }
+}
+
+KeyCode XorgKeycodeToCruKeyCode(XcbUiApplication *application,
+                                xcb_keycode_t keycode) {
+  auto connection = application->GetXcbConnection();
+  auto setup = xcb_get_setup(connection);
+  auto min_keycode = setup->min_keycode;
+  auto max_keycode = setup->max_keycode;
+
+  // Get keyboard mapping
+  auto mapping_cookie = xcb_get_keyboard_mapping(connection, keycode, 1);
+  auto *mapping_reply =
+      xcb_get_keyboard_mapping_reply(connection, mapping_cookie, NULL);
+
+  if (!mapping_reply) {
+    throw XcbException("Cannot get keyboard mapping.");
+  }
+
+  auto keysyms_per_keycode = mapping_reply->keysyms_per_keycode;
+  auto *keysyms = xcb_get_keyboard_mapping_keysyms(mapping_reply);
+
+  for (int i = 0; i < keysyms_per_keycode; i++) {
+    auto result = XorgKeysymToKeyCode(keysyms[i]);
+    if (result != KeyCode::Unknown) return result;
+  }
+
+  return KeyCode::Unknown;
+}
+
+namespace {
+using KeymapBitset =
+    std::bitset<sizeof(std::declval<xcb_query_keymap_reply_t>().keys) *
+                CHAR_BIT>;
+
+KeymapBitset GetXorgKeymap(xcb_connection_t *connection) {
+  auto keymap_cookie = xcb_query_keymap(connection);
+  auto keymap_reply = xcb_query_keymap_reply(connection, keymap_cookie, NULL);
+
+  if (!keymap_reply) {
+    throw XcbException("Cannot get keymap.");
+  }
+
+  KeymapBitset result;
+  int counter = 0;
+  for (auto member : keymap_reply->keys) {
+    for (int i = 0; i < sizeof(member); i++) {
+      result[counter] = member & (1 << i);
+      counter++;
+    }
+  }
+
+  return result;
+}
+}  // namespace
+
+std::unordered_map<KeyCode, bool> GetKeyboardState(
+    XcbUiApplication *application) {
+  auto connection = application->GetXcbConnection();
+  auto setup = xcb_get_setup(connection);
+  auto min_keycode = setup->min_keycode;
+  auto max_keycode = setup->max_keycode;
+
+  // Get keyboard mapping
+  auto mapping_cookie = xcb_get_keyboard_mapping(connection, min_keycode,
+                                                 max_keycode - min_keycode + 1);
+  auto *mapping_reply =
+      xcb_get_keyboard_mapping_reply(connection, mapping_cookie, NULL);
+
+  if (!mapping_reply) {
+    throw XcbException("Cannot get keyboard mapping.");
+  }
+
+  auto keysyms_per_keycode = mapping_reply->keysyms_per_keycode;
+  auto *keysyms = xcb_get_keyboard_mapping_keysyms(mapping_reply);
+
+  auto keymap = GetXorgKeymap(connection);
+
+  std::unordered_map<KeyCode, bool> result;
+
+  for (xcb_keycode_t i = min_keycode; i <= max_keycode; i++) {
+    auto keysyms_for_this = keysyms + (i - min_keycode) * keysyms_per_keycode;
+    for (int j = 0; j < keysyms_per_keycode; j++) {
+      auto keycode = XorgKeysymToKeyCode(keysyms_for_this[j]);
+      if (keycode != KeyCode::Unknown) {
+        result[keycode] = keymap[i];
+      }
+    }
+  }
+
+  return result;
+}
+
+// Though X provides GetModifierMapping, it cannot get ALT state.
+KeyModifier GetCurrentKeyModifiers(XcbUiApplication *application) {
+  KeyModifier result{};
+  auto state = GetKeyboardState(application);
+  if (state[KeyCode::LeftShift] || state[KeyCode::RightShift]) {
+    result |= KeyModifiers::Shift;
+  }
+  if (state[KeyCode::LeftCtrl] || state[KeyCode::RightCtrl]) {
+    result |= KeyModifiers::Ctrl;
+  }
+  if (state[KeyCode::LeftAlt] || state[KeyCode::RightAlt]) {
+    result |= KeyModifiers::Alt;
+  }
+  return result;
 }
 }  // namespace cru::platform::gui::xcb