Add FlKeyEventPlugin

ci/licenses_golden/licenses_flutter

@@ -1202,6 +1202,8 @@ FILE: ../../../flutter/shell/platform/linux/fl_json_message_codec.cc
 FILE: ../../../flutter/shell/platform/linux/fl_json_message_codec_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_json_method_codec.cc
 FILE: ../../../flutter/shell/platform/linux/fl_json_method_codec_test.cc
+FILE: ../../../flutter/shell/platform/linux/fl_key_event_plugin.cc
+FILE: ../../../flutter/shell/platform/linux/fl_key_event_plugin.h
 FILE: ../../../flutter/shell/platform/linux/fl_message_codec.cc
 FILE: ../../../flutter/shell/platform/linux/fl_message_codec_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_method_call.cc

shell/platform/linux/BUILD.gn

@@ -79,6 +79,7 @@ source_set("flutter_linux") {
     "fl_engine.cc",
     "fl_json_message_codec.cc",
     "fl_json_method_codec.cc",
+    "fl_key_event_plugin.cc",
     "fl_message_codec.cc",
     "fl_method_call.cc",
     "fl_method_channel.cc",

shell/platform/linux/fl_key_event_plugin.cc

@@ -0,0 +1,255 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/shell/platform/linux/fl_key_event_plugin.h"
+#include "flutter/shell/platform/linux/public/flutter_linux/fl_basic_message_channel.h"
+#include "flutter/shell/platform/linux/public/flutter_linux/fl_json_message_codec.h"
+
+static constexpr char kChannelName[] = "flutter/keyevent";
+static constexpr char kTypeKey[] = "type";
+static constexpr char kTypeValueUp[] = "keyup";
+static constexpr char kTypeValueDown[] = "keydown";
+static constexpr char kKeymapKey[] = "keymap";
+static constexpr char kKeyCodeKey[] = "keyCode";
+static constexpr char kScanCodeKey[] = "scanCode";
+static constexpr char kModifiersKey[] = "modifiers";
+static constexpr char kToolkitKey[] = "toolkit";
+static constexpr char kUnicodeScalarValuesKey[] = "unicodeScalarValues";
+
+static constexpr char kGLFWToolkit[] = "glfw";
+static constexpr char kLinuxKeymap[] = "linux";
+
+struct _FlKeyEventPlugin {
+  GObject parent_instance;
+
+  FlBasicMessageChannel* channel;
+};
+
+G_DEFINE_TYPE(FlKeyEventPlugin, fl_key_event_plugin, G_TYPE_OBJECT)
+
+// Converts a Gdk key code to its GLFW equivalent.
+// TODO(robert-ancell) Create a "gtk" toolkit in Flutter so we don't have to
+// convert values. https://github.com/flutter/flutter/issues/57603
+static int gdk_keyval_to_glfw_key_code(guint keyval) {
+  switch (keyval) {
+    case GDK_KEY_space:
+      return 32;
+    case GDK_KEY_apostrophe:
+      return 39;
+    case GDK_KEY_comma:
+      return 44;
+    case GDK_KEY_minus:
+      return 45;
+    case GDK_KEY_period:
+      return 46;
+    case GDK_KEY_slash:
+      return 47;
+    case GDK_KEY_0:
+      return 48;
+    case GDK_KEY_1:
+      return 49;
+    case GDK_KEY_2:
+      return 50;
+    case GDK_KEY_3:
+      return 51;
+    case GDK_KEY_4:
+      return 52;
+    case GDK_KEY_5:
+      return 53;
+    case GDK_KEY_6:
+      return 54;
+    case GDK_KEY_7:
+      return 55;
+    case GDK_KEY_8:
+      return 56;
+    case GDK_KEY_9:
+      return 57;
+    case GDK_KEY_semicolon:
+      return 59;
+    case GDK_KEY_equal:
+      return 61;
+    case GDK_KEY_a:
+      return 65;
+    case GDK_KEY_b:
+      return 66;
+    case GDK_KEY_c:
+      return 67;
+    case GDK_KEY_d:
+      return 68;
+    case GDK_KEY_e:
+      return 69;
+    case GDK_KEY_f:
+      return 70;
+    case GDK_KEY_g:
+      return 71;
+    case GDK_KEY_h:
+      return 72;
+    case GDK_KEY_i:
+      return 73;
+    case GDK_KEY_j:
+      return 74;
+    case GDK_KEY_k:
+      return 75;
+    case GDK_KEY_l:
+      return 76;
+    case GDK_KEY_m:
+      return 77;
+    case GDK_KEY_n:
+      return 78;
+    case GDK_KEY_o:
+      return 79;
+    case GDK_KEY_p:
+      return 80;
+    case GDK_KEY_q:
+      return 81;
+    case GDK_KEY_r:
+      return 82;
+    case GDK_KEY_s:
+      return 83;
+    case GDK_KEY_t:
+      return 84;
+    case GDK_KEY_u:
+      return 85;
+    case GDK_KEY_v:
+      return 86;
+    case GDK_KEY_w:
+      return 87;
+    case GDK_KEY_x:
+      return 88;
+    case GDK_KEY_y:
+      return 89;
+    case GDK_KEY_z:
+      return 90;
+    case GDK_KEY_bracketleft:
+      return 91;
+    case GDK_KEY_bracketright:
+      return 92;
+    case GDK_KEY_grave:
+      return 96;
+    case GDK_KEY_Escape:
+      return 256;
+    case GDK_KEY_Return:
+      return 257;
+    case GDK_KEY_Tab:
+      return 258;
+    case GDK_KEY_BackSpace:
+      return 259;
+    case GDK_KEY_Insert:
+      return 260;
+    case GDK_KEY_Delete:
+      return 261;
+    case GDK_KEY_Right:
+      return 262;
+    case GDK_KEY_Left:
+      return 263;
+    case GDK_KEY_Down:
+      return 264;
+    case GDK_KEY_Up:
+      return 265;
+    case GDK_KEY_Page_Up:
+      return 266;
+    case GDK_KEY_Page_Down:
+      return 267;
+    case GDK_KEY_Home:
+      return 268;
+    case GDK_KEY_End:
+      return 269;
+    case GDK_KEY_Shift_L:
+      return 340;
+    case GDK_KEY_Control_L:
+      return 341;
+    case GDK_KEY_Alt_L:
+      return 342;
+    case GDK_KEY_Super_L:
+      return 343;
+    case GDK_KEY_Shift_R:
+      return 344;
+    case GDK_KEY_Control_R:
+      return 345;
+    case GDK_KEY_Alt_R:
+      return 346;
+    case GDK_KEY_Super_R:
+      return 347;
+    default:
+      return 0;
+  }
+}
+
+// Converts a Gdk key state to its GLFW equivalent.
+int64_t gdk_state_to_glfw_modifiers(guint8 state) {
+  int64_t modifiers = 0;
+
+  if ((state & GDK_SHIFT_MASK) != 0)
+    modifiers |= 0x0001;
+  if ((state & GDK_CONTROL_MASK) != 0)
+    modifiers |= 0x0002;
+  if ((state & GDK_MOD1_MASK) != 0)
+    modifiers |= 0x0004;
+  if ((state & GDK_SUPER_MASK) != 0)
+    modifiers |= 0x0008;
+
+  return modifiers;
+}
+
+static void fl_key_event_plugin_dispose(GObject* object) {
+  FlKeyEventPlugin* self = FL_KEY_EVENT_PLUGIN(object);
+
+  g_clear_object(&self->channel);
+
+  G_OBJECT_CLASS(fl_key_event_plugin_parent_class)->dispose(object);
+}
+
+static void fl_key_event_plugin_class_init(FlKeyEventPluginClass* klass) {
+  G_OBJECT_CLASS(klass)->dispose = fl_key_event_plugin_dispose;
+}
+
+static void fl_key_event_plugin_init(FlKeyEventPlugin* self) {}
+
+FlKeyEventPlugin* fl_key_event_plugin_new(FlBinaryMessenger* messenger) {
+  g_return_val_if_fail(FL_IS_BINARY_MESSENGER(messenger), nullptr);
+
+  FlKeyEventPlugin* self = FL_KEY_EVENT_PLUGIN(
+      g_object_new(fl_key_event_plugin_get_type(), nullptr));
+
+  g_autoptr(FlJsonMessageCodec) codec = fl_json_message_codec_new();
+  self->channel = fl_basic_message_channel_new(messenger, kChannelName,
+                                               FL_MESSAGE_CODEC(codec));
+
+  return self;
+}
+
+void fl_key_event_plugin_send_key_event(FlKeyEventPlugin* self,
+                                        GdkEventKey* event) {
+  g_return_if_fail(FL_IS_KEY_EVENT_PLUGIN(self));
+  g_return_if_fail(event != nullptr);
+
+  const gchar* type;
+  if (event->type == GDK_KEY_PRESS)
+    type = kTypeValueDown;
+  else if (event->type == GDK_KEY_RELEASE)
+    type = kTypeValueUp;
+  else
+    return;
+
+  int64_t scan_code = event->hardware_keycode;
+  int64_t key_code = gdk_keyval_to_glfw_key_code(event->keyval);
+  int64_t modifiers = gdk_state_to_glfw_modifiers(event->state);
+  int64_t unicodeScalarValues = gdk_keyval_to_unicode(event->keyval);
+
+  g_autoptr(FlValue) message = fl_value_new_map();
+  fl_value_set_string_take(message, kTypeKey, fl_value_new_string(type));
+  fl_value_set_string_take(message, kKeymapKey,
+                           fl_value_new_string(kLinuxKeymap));
+  fl_value_set_string_take(message, kScanCodeKey, fl_value_new_int(scan_code));
+  fl_value_set_string_take(message, kToolkitKey,
+                           fl_value_new_string(kGLFWToolkit));
+  fl_value_set_string_take(message, kKeyCodeKey, fl_value_new_int(key_code));
+  fl_value_set_string_take(message, kModifiersKey, fl_value_new_int(modifiers));
+  if (unicodeScalarValues != 0)
+    fl_value_set_string_take(message, kUnicodeScalarValuesKey,
+                             fl_value_new_int(unicodeScalarValues));
+
+  fl_basic_message_channel_send(self->channel, message, nullptr, nullptr,
+                                nullptr);
+}

shell/platform/linux/fl_key_event_plugin.h

@@ -0,0 +1,49 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_LINUX_FL_KEY_EVENT_PLUGIN_H_
+#define FLUTTER_SHELL_PLATFORM_LINUX_FL_KEY_EVENT_PLUGIN_H_
+
+#include "flutter/shell/platform/linux/public/flutter_linux/fl_binary_messenger.h"
+
+#include <gdk/gdk.h>
+
+G_BEGIN_DECLS
+
+G_DECLARE_FINAL_TYPE(FlKeyEventPlugin,
+                     fl_key_event_plugin,
+                     FL,
+                     KEY_EVENT_PLUGIN,
+                     GObject);
+
+/**
+ * FlKeyEventPlugin:
+ *
+ * #FlKeyEventPlugin is a plugin that implements the shell side
+ * of SystemChannels.keyEvent from the Flutter services library.
+ */
+
+/**
+ * fl_key_event_plugin_new:
+ * @messenger: an #FlBinaryMessenger.
+ *
+ * Creates a #FlKeyEventPlugin.
+ *
+ * Returns: a new #FlKeyEventPlugin.
+ */
+FlKeyEventPlugin* fl_key_event_plugin_new(FlBinaryMessenger* messenger);
+
+/**
+ * fl_key_event_plugin_send_key_event:
+ * @plugin: an #FlKeyEventPlugin.
+ * @event: a #GdkEventKey.
+ *
+ * Sends a key event to Flutter.
+ */
+void fl_key_event_plugin_send_key_event(FlKeyEventPlugin* plugin,
+                                        GdkEventKey* event);
+
+G_END_DECLS
+
+#endif  // FLUTTER_SHELL_PLATFORM_LINUX_FL_KEY_EVENT_PLUGIN_H_