[wing/wip/eventwindow] Add event window class

[Ignacio Casal Quinteiro <icq src gnome org>]

commit 7b091701f0a4c563d8e6f6efe6b5c779de9cded3
Author: Ignacio Casal Quinteiro <qignacio amazon com>
Date:   Wed Apr 5 17:28:37 2017 +0200

    Add event window class
    
    Provides a way to listen to global events by creating an
    invisible window.

 wing/meson.build       |    2 +
 wing/wing.h            |    1 +
 wing/wingeventwindow.c |  353 ++++++++++++++++++++++++++++++++++++++++++++++++
 wing/wingeventwindow.h |   54 ++++++++
 4 files changed, 410 insertions(+), 0 deletions(-)
---
diff --git a/wing/meson.build b/wing/meson.build
index c696a68..14fdaae 100644
--- a/wing/meson.build
+++ b/wing/meson.build
@@ -1,5 +1,6 @@
 headers = [
   'wing.h',
+  'wingeventwindow.h',
   'wingversionmacros.h',
   'wingnamedpipeclient.h',
   'wingnamedpipeconnection.h',
@@ -15,6 +16,7 @@ private_headers = [
 ]
 
 sources = [
+  'wingeventwindow.c',
   'wing-init.c',
   'wingnamedpipeclient.c',
   'wingnamedpipeconnection.c',
diff --git a/wing/wing.h b/wing/wing.h
index 2280725..146655d 100644
--- a/wing/wing.h
+++ b/wing/wing.h
@@ -21,6 +21,7 @@
 #define __WING_H__
 
 #include <wing/wingversionmacros.h>
+#include <wing/wingeventwindow.h>
 #include <wing/wingnamedpipeclient.h>
 #include <wing/wingnamedpipelistener.h>
 #include <wing/wingnamedpipeconnection.h>
diff --git a/wing/wingeventwindow.c b/wing/wingeventwindow.c
new file mode 100644
index 0000000..dc746c2
--- /dev/null
+++ b/wing/wingeventwindow.c
@@ -0,0 +1,353 @@
+/*
+ * Copyright © 2017 NICE s.r.l.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the licence or (at
+ * your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Ignacio Casal Quinteiro <ignacio casal nice-software com>
+ */
+
+#include "wingeventwindow.h"
+#include <gio/gio.h>
+#include <glib.h>
+
+#define WINDOW_USER_DATA_KEY L"WING_EVENT_WINDOW"
+
+typedef LRESULT (CALLBACK *WinProcHook) (HWND   hWnd,
+                                         UINT   message,
+                                         WPARAM wParam,
+                                         LPARAM lParam);
+
+typedef struct
+{
+  WingEventCallback callback;
+  gpointer user_data;
+} Message;
+
+struct _WingEventWindow
+{
+  GObject parent_instance;
+
+  gchar *name;
+  wchar_t *namew;
+  HWND hwnd;
+  guint watch_id;
+  GIOChannel *channel;
+  GHashTable *messages;
+};
+
+enum
+{
+    PROP_0,
+    PROP_NAME,
+    LAST_PROP
+};
+
+static GParamSpec *props[LAST_PROP];
+
+static void wing_event_window_initable_iface_init (GInitableIface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (WingEventWindow,
+                         wing_event_window,
+                         G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
+                                                wing_event_window_initable_iface_init))
+
+static Message *
+create_message (WingEventCallback callback,
+                gpointer          user_data)
+{
+  Message *message;
+
+  message = g_slice_new (Message);
+  message->callback = callback;
+  message->user_data = user_data;
+
+  return message;
+}
+
+static void
+free_message (Message *message)
+{
+    g_slice_free (Message, message);
+}
+
+static void
+wing_event_window_finalize (GObject *object)
+{
+  WingEventWindow *window = WING_EVENT_WINDOW (object);
+
+  g_free (window->name);
+  g_free (window->namew);
+  DestroyWindow (window->hwnd);
+
+  G_OBJECT_CLASS (wing_event_window_parent_class)->finalize (object);
+}
+
+static void
+wing_event_window_dispose (GObject *object)
+{
+  WingEventWindow *window = WING_EVENT_WINDOW (object);
+
+  if (window->watch_id != 0)
+    {
+      g_source_remove (window->watch_id);
+      window->watch_id = 0;
+    }
+
+  g_clear_pointer (&window->messages, g_hash_table_unref);
+
+  if (window->channel != NULL)
+    {
+      g_io_channel_shutdown (window->channel, FALSE, NULL);
+      g_io_channel_unref (window->channel);
+      window->channel = NULL;
+    }
+
+  G_OBJECT_CLASS (wing_event_window_parent_class)->dispose (object);
+}
+
+static void
+wing_event_window_get_property (GObject    *object,
+                                guint       prop_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  WingEventWindow *window = WING_EVENT_WINDOW (object);
+
+  switch (prop_id)
+    {
+    case PROP_NAME:
+      g_value_set_string (value, window->name);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+wing_event_window_set_property (GObject      *object,
+                                guint         prop_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  WingEventWindow *window = WING_EVENT_WINDOW (object);
+
+  switch (prop_id)
+    {
+    case PROP_NAME:
+      window->name = g_value_dup_string (value);
+      if (window->name != NULL)
+        window->namew = g_utf8_to_utf16 (window->name, -1, NULL, NULL, NULL);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static LRESULT CALLBACK
+wnd_proc (HWND   hwnd,
+          UINT   message,
+          WPARAM wparam,
+          LPARAM lparam)
+{
+  if (message == WM_NCCREATE)
+    {
+      CREATESTRUCT *cs = (CREATESTRUCT *)lparam;
+      SetPropW (hwnd, WINDOW_USER_DATA_KEY, (HANDLE)cs->lpCreateParams);
+      return 1;
+    }
+  else if (message == WM_DESTROY)
+    {
+      PostQuitMessage (0);
+      return 0;
+    }
+  else
+    {
+      WingEventWindow *window = WING_EVENT_WINDOW (GetProp (hwnd, WINDOW_USER_DATA_KEY));
+      Message *m;
+
+      m = (Message *)g_hash_table_lookup (window->messages, GUINT_TO_POINTER(message));
+      if (m != NULL)
+        {
+          if (m->callback (window, wparam, lparam, m->user_data))
+            return 0;
+        }
+
+      return DefWindowProc (hwnd, message, wparam, lparam);
+    }
+}
+
+static ATOM
+register_window_class (WingEventWindow *window)
+{
+  WNDCLASSEX wc;
+
+  wc.cbSize = sizeof (WNDCLASSEX);
+
+  wc.style = CS_HREDRAW | CS_VREDRAW;
+  wc.lpfnWndProc = wnd_proc;
+  wc.cbClsExtra = 0;
+  wc.cbWndExtra = 0;
+  wc.hInstance = GetModuleHandle (NULL);
+  wc.hIcon = NULL;
+  wc.hCursor = NULL;
+  wc.hbrBackground = NULL;
+  wc.lpszMenuName = NULL;
+  wc.lpszClassName = window->namew;
+  wc.hIconSm = NULL;
+
+  return RegisterClassEx (&wc);
+}
+
+static gboolean
+recv_windows_message (GIOChannel  *channel,
+                      GIOCondition cond,
+                      gpointer     data)
+{
+  GIOStatus status;
+  MSG msg;
+
+  while (TRUE)
+    {
+      gsize bytes_read;
+
+      status = g_io_channel_read_chars (channel, (gchar *)&msg, sizeof (MSG),
+                                        &bytes_read, NULL);
+
+      if (status == G_IO_STATUS_AGAIN)
+        continue;
+
+      break;
+    }
+
+  if (status == G_IO_STATUS_NORMAL)
+    DispatchMessage (&msg);
+
+  return TRUE;
+}
+
+static void
+wing_event_window_class_init (WingEventWindowClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = wing_event_window_finalize;
+  object_class->dispose = wing_event_window_dispose;
+  object_class->get_property = wing_event_window_get_property;
+  object_class->set_property = wing_event_window_set_property;
+
+  props[PROP_NAME] =
+    g_param_spec_string ("name",
+                         "Name",
+                         "Name",
+                         NULL,
+                         G_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_properties (object_class, LAST_PROP, props);
+}
+
+static void
+wing_event_window_init (WingEventWindow *window)
+{
+  window->messages = g_hash_table_new_full (g_direct_hash,
+                                            g_direct_equal,
+                                            NULL,
+                                            (GDestroyNotify)free_message);
+}
+
+static gboolean
+wing_event_window_initable_init (GInitable     *initable,
+                                 GCancellable  *cancellable,
+                                 GError       **error)
+{
+  WingEventWindow *window = WING_EVENT_WINDOW (initable);
+  long style;
+
+  if (g_cancellable_set_error_if_cancelled (cancellable, error))
+    return FALSE;
+
+
+  if (!register_window_class (window))
+    {
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                           "Window Registration Failed");
+      return FALSE;
+    }
+
+  window->hwnd = CreateWindowW (window->namew, window->namew, WS_POPUPWINDOW,
+                                0, 100000, 1, 1, NULL, NULL,
+                                GetModuleHandle (NULL), window);
+  if (!window->hwnd)
+    {
+      gchar *err_msg;
+
+      err_msg = g_win32_error_message (GetLastError ());
+
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "Could not create window '%s': %s",
+                   window->name, err_msg);
+      g_free (err_msg);
+      return FALSE;
+    }
+
+  /* Special style to remove the application from the Windows taskbar */
+  ShowWindow (window->hwnd, SW_HIDE);
+  style = GetWindowLong (window->hwnd, GWL_EXSTYLE);
+  style |= WS_EX_TOOLWINDOW; /* flags don't work - windows remains in taskbar */
+  style &= ~(WS_EX_APPWINDOW);
+  SetWindowLong (window->hwnd, GWL_EXSTYLE, style);
+  ShowWindow (window->hwnd, SW_SHOW);
+
+  window->channel = g_io_channel_win32_new_messages ((gsize)window->hwnd);
+  g_io_channel_set_encoding (window->channel, NULL, NULL);
+  window->watch_id = g_io_add_watch (window->channel, G_IO_IN, recv_windows_message, window);
+
+  return TRUE;
+}
+
+static void
+wing_event_window_initable_iface_init (GInitableIface *iface)
+{
+  iface->init = wing_event_window_initable_init;
+}
+
+WingEventWindow *
+wing_event_window_new (const gchar  *name,
+                       GError      **error)
+{
+  return g_initable_new (WING_TYPE_EVENT_WINDOW,
+                         NULL, error,
+                         "name", name,
+                         NULL);
+}
+
+void
+wing_event_window_connect (WingEventWindow   *window,
+                           guint              message,
+                           WingEventCallback  callback,
+                           gpointer           user_data)
+{
+  Message *m;
+
+  g_return_if_fail(WING_IS_EVENT_WINDOW(window));
+  g_return_if_fail(callback != NULL);
+
+  m = create_message(callback, user_data);
+  g_hash_table_insert(window->messages, GUINT_TO_POINTER(message), m);
+}
+
+/* ex:set ts=4 et: */
diff --git a/wing/wingeventwindow.h b/wing/wingeventwindow.h
new file mode 100644
index 0000000..e2e8ff2
--- /dev/null
+++ b/wing/wingeventwindow.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright © 2017 NICE s.r.l.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the licence or (at
+ * your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Ignacio Casal Quinteiro <ignacio casal nice-software com>
+ */
+
+#ifndef WING_EVENT_WINDOW_H
+#define WING_EVENT_WINDOW_H
+
+#include <glib-object.h>
+#include <wing/wingversionmacros.h>
+
+#include <Windows.h>
+
+G_BEGIN_DECLS
+
+#define WING_TYPE_EVENT_WINDOW (wing_event_window_get_type ())
+
+WING_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (WingEventWindow, wing_event_window, DCV, WIN32_EVENT_WINDOW, GObject)
+
+typedef gboolean (* WingEventCallback)    (WingEventWindow *window,
+                                           WPARAM           wparam,
+                                           LPARAM           lparam,
+                                           gpointer         user_data);
+
+WING_AVAILABLE_IN_ALL
+WingEventWindow         *wing_event_window_new             (const gchar       *name,
+                                                            GError           **error);
+
+WING_AVAILABLE_IN_ALL
+void                    wing_event_window_connect          (WingEventWindow   *window,
+                                                            guint              message,
+                                                            WingEventCallback  callback,
+                                                            gpointer           user_data);
+
+G_END_DECLS
+
+#endif /* WING_EVENT_WINDOW_H */
+
+/* ex:set ts=4 et: */