Add FlKeyEventChannel

Author: robert-ancell

ci/licenses_golden/licenses_flutter

@@ -1196,6 +1196,8 @@ FILE: ../../../flutter/shell/platform/linux/fl_engine.cc
 FILE: ../../../flutter/shell/platform/linux/fl_engine_private.h
 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_key_event_channel.cc
+FILE: ../../../flutter/shell/platform/linux/fl_key_event_channel.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_renderer.cc

shell/platform/linux/BUILD.gn

@@ -72,6 +72,7 @@ source_set("flutter_linux") {
     "fl_dart_project.cc",
     "fl_engine.cc",
     "fl_json_message_codec.cc",
+    "fl_key_event_channel.cc",
     "fl_message_codec.cc",
     "fl_renderer.cc",
     "fl_renderer_x11.cc",

shell/platform/linux/fl_key_event_channel.cc

@@ -0,0 +1,65 @@
+// 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_channel.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"
+
+struct _FlKeyEventChannel {
+  GObject parent_instance;
+
+  FlBasicMessageChannel* channel;
+};
+
+G_DEFINE_TYPE(FlKeyEventChannel, fl_key_event_channel, G_TYPE_OBJECT)
+
+static void fl_key_event_channel_dispose(GObject* object) {
+  FlKeyEventChannel* self = FL_KEY_EVENT_CHANNEL(object);
+
+  g_clear_object(&self->channel);
+
+  G_OBJECT_CLASS(fl_key_event_channel_parent_class)->dispose(object);
+}
+
+static void fl_key_event_channel_class_init(FlKeyEventChannelClass* klass) {
+  G_OBJECT_CLASS(klass)->dispose = fl_key_event_channel_dispose;
+}
+
+static void fl_key_event_channel_init(FlKeyEventChannel* self) {}
+
+FlKeyEventChannel* fl_key_event_channel_new(FlBinaryMessenger* messenger) {
+  g_return_val_if_fail(FL_IS_BINARY_MESSENGER(messenger), nullptr);
+
+  FlKeyEventChannel* self = FL_KEY_EVENT_CHANNEL(
+      g_object_new(fl_key_event_channel_get_type(), nullptr));
+
+  g_autoptr(FlJsonMessageCodec) codec = fl_json_message_codec_new();
+  self->channel = fl_basic_message_channel_new(messenger, "flutter/keyevent",
+                                               FL_MESSAGE_CODEC(codec));
+
+  return self;
+}
+
+void fl_key_event_channel_send_key_event(FlKeyEventChannel* self,
+                                         const gchar* type,
+                                         int64_t key_code,
+                                         int64_t scan_code,
+                                         int64_t modifiers,
+                                         int64_t unicodeScalarValues) {
+  g_autoptr(FlValue) message = fl_value_new_map();
+  fl_value_set_string_take(message, "type", fl_value_new_string(type));
+  fl_value_set_string_take(message, "keymap", fl_value_new_string("linux"));
+  fl_value_set_string_take(message, "keyCode", fl_value_new_int(key_code));
+  fl_value_set_string_take(message, "scanCode", fl_value_new_int(scan_code));
+  fl_value_set_string_take(message, "modifiers", fl_value_new_int(modifiers));
+  // FIXME(robert-ancell) Using GLFW toolkit as Flutter doesn't understand
+  // anything else
+  fl_value_set_string_take(message, "toolkit", fl_value_new_string("glfw"));
+  if (unicodeScalarValues != 0)
+    fl_value_set_string_take(message, "unicodeScalarValues",
+                             fl_value_new_int(unicodeScalarValues));
+
+  fl_basic_message_channel_send(self->channel, message, nullptr, nullptr,
+                                nullptr);
+}

shell/platform/linux/fl_key_event_channel.h

@@ -0,0 +1,44 @@
+// 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_CHANNEL_H_
+#define FLUTTER_SHELL_PLATFORM_LINUX_FL_KEY_EVENT_CHANNEL_H_
+
+#include "flutter/shell/platform/linux/public/flutter_linux/fl_binary_messenger.h"
+
+G_BEGIN_DECLS
+
+G_DECLARE_FINAL_TYPE(FlKeyEventChannel,
+                     fl_key_event_channel,
+                     FL,
+                     KEY_EVENT_CHANNEL,
+                     GObject);
+
+/**
+ * FlKeyEventChannel:
+ *
+ * #FlKeyEventChannel is a platform channel that implements the shell side
+ * of SystemChannels.keyEvent from the Flutter services library.
+ */
+
+/**
+ * fl_key_event_channel_new:
+ * @messenger: an #FlBinaryMessenger
+ *
+ * Creates a new key event channel.
+ *
+ * Returns: a new #FlKeyEventChannel
+ */
+FlKeyEventChannel* fl_key_event_channel_new(FlBinaryMessenger* messenger);
+
+void fl_key_event_channel_send_key_event(FlKeyEventChannel* channel,
+                                         const gchar* type,
+                                         int64_t key_code,
+                                         int64_t scan_code,
+                                         int64_t modifiers,
+                                         int64_t unicodeScalarValues);
+
+G_END_DECLS
+
+#endif  // FLUTTER_SHELL_PLATFORM_LINUX_FL_KEY_EVENT_CHANNEL_H_

shell/platform/linux/fl_view.cc

@@ -5,6 +5,7 @@
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_view.h"
 
 #include "flutter/shell/platform/linux/fl_engine_private.h"
+#include "flutter/shell/platform/linux/fl_key_event_channel.h"
 #include "flutter/shell/platform/linux/fl_renderer_x11.h"
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_engine.h"
 
@@ -19,12 +20,160 @@ struct _FlView {
   FlRendererX11* renderer;
   FlEngine* engine;
   int64_t button_state;
+
+  // Flutter system channels
+  FlKeyEventChannel* key_event_channel;
 };
 
 enum { PROP_FLUTTER_PROJECT = 1, PROP_LAST };
 
 G_DEFINE_TYPE(FlView, fl_view, GTK_TYPE_WIDGET)
 
+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;
+  }
+}
+
 // Convert a GDK button event into a Flutter event and send to the engine
 static gboolean fl_view_send_pointer_button_event(FlView* self,
                                                   GdkEventButton* event) {
@@ -74,6 +223,10 @@ static void fl_view_constructed(GObject* object) {
 
   self->renderer = fl_renderer_x11_new();
   self->engine = fl_engine_new(self->project, FL_RENDERER(self->renderer));
+
+  // Create system channels
+  FlBinaryMessenger* messenger = fl_engine_get_binary_messenger(self->engine);
+  self->key_event_channel = fl_key_event_channel_new(messenger);
 }
 
 static void fl_view_set_property(GObject* object,
@@ -115,6 +268,7 @@ static void fl_view_dispose(GObject* object) {
   g_clear_object(&self->project);
   g_clear_object(&self->renderer);
   g_clear_object(&self->engine);
+  g_clear_object(&self->key_event_channel);
 
   G_OBJECT_CLASS(fl_view_parent_class)->dispose(object);
 }
@@ -137,7 +291,8 @@ static void fl_view_realize(GtkWidget* widget) {
   window_attributes.visual = gtk_widget_get_visual(widget);
   window_attributes.event_mask =
       gtk_widget_get_events(widget) | GDK_EXPOSURE_MASK |
-      GDK_POINTER_MOTION_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK;
+      GDK_POINTER_MOTION_MASK | GDK_BUTTON_PRESS_MASK |
+      GDK_BUTTON_RELEASE_MASK | GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK;
 
   gint window_attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
 
@@ -205,6 +360,29 @@ static gboolean fl_view_motion_notify_event(GtkWidget* widget,
   return TRUE;
 }
 
+static gboolean fl_view_key_press_event(GtkWidget* widget, GdkEventKey* event) {
+  FlView* self = FL_VIEW(widget);
+
+  fl_key_event_channel_send_key_event(
+      self->key_event_channel, "keydown",
+      gdk_keyval_to_glfw_key_code(event->keyval), event->hardware_keycode, 0,
+      gdk_keyval_to_unicode(event->keyval));
+
+  return TRUE;
+}
+
+static gboolean fl_view_key_release_event(GtkWidget* widget,
+                                          GdkEventKey* event) {
+  FlView* self = FL_VIEW(widget);
+
+  fl_key_event_channel_send_key_event(
+      self->key_event_channel, "keyup",
+      gdk_keyval_to_glfw_key_code(event->keyval), event->hardware_keycode, 0,
+      gdk_keyval_to_unicode(event->keyval));
+
+  return TRUE;
+}
+
 static void fl_view_class_init(FlViewClass* klass) {
   G_OBJECT_CLASS(klass)->constructed = fl_view_constructed;
   G_OBJECT_CLASS(klass)->set_property = fl_view_set_property;
@@ -215,6 +393,8 @@ static void fl_view_class_init(FlViewClass* klass) {
   GTK_WIDGET_CLASS(klass)->button_press_event = fl_view_button_press_event;
   GTK_WIDGET_CLASS(klass)->button_release_event = fl_view_button_release_event;
   GTK_WIDGET_CLASS(klass)->motion_notify_event = fl_view_motion_notify_event;
+  GTK_WIDGET_CLASS(klass)->key_press_event = fl_view_key_press_event;
+  GTK_WIDGET_CLASS(klass)->key_release_event = fl_view_key_release_event;
 
   g_object_class_install_property(
       G_OBJECT_CLASS(klass), PROP_FLUTTER_PROJECT,
@@ -225,7 +405,9 @@ static void fl_view_class_init(FlViewClass* klass) {
                                    G_PARAM_STATIC_STRINGS)));
 }
 
-static void fl_view_init(FlView* self) {}
+static void fl_view_init(FlView* self) {
+  gtk_widget_set_can_focus(GTK_WIDGET(self), TRUE);
+}
 
 G_MODULE_EXPORT FlView* fl_view_new(FlDartProject* project) {
   return static_cast<FlView*>(