Add linux alert (#294)

Very early WIP implementation of gtk dialog alert to fix #278 (please ignore the commented out code etc. just trying to get stuff working)

Progress so far:

No longer chokes on `#include <gtk/gtk.h>` - currently need to tweak the borrowed snippet from #278 as an example to create an alert doesn't work as is, I think

Things to note/note to self:
- [x] I have to rework the `discover.ml` so it can use the pkg_config functionality on linux but behave as normal on other systems

- [x] Fix GTK crash on opening dialog - things compile but the function to open a dialog causes a crash, note this also happens in a separate project when I try and create a dialog with the same function (might be specific to my machine or more likely a bug in the code)

azure-pipelines.yml

@@ -18,7 +18,7 @@ jobs:
     # ESY__NPM_ROOT: /opt/hostedtoolcache/node/8.14.0/x64/lib/node_modules/esy
 
   steps:
-  - script: sudo apt-get install -y libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libegl1-mesa-dev mesa-utils mesa-utils-extra ragel
+  - script: sudo apt-get install -y libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libegl1-mesa-dev mesa-utils mesa-utils-extra ragel libgtk-3-dev
   - template: .ci/use-node.yml
   - template: .ci/restore-build-cache.yml
   - template: .ci/esy-build-steps.yml

src/Native/ReveryGtk.h

@@ -0,0 +1,3 @@
+extern "C" {
+void revery_alert_gtk(void *pWin, const char *szMessage);
+}

src/Native/config/discover.ml

@@ -1,21 +1,41 @@
-type os =
-  | Windows 
-  | Mac 
-  | Linux 
-  | Unknown 
+module C = Configurator.V1
+
+type os = Windows | Mac | Linux | Unknown
+
+type config = {libs: string list; cflags: string list; flags: string list}
+
+let get_mac_config () =
+  {cflags= ["-I"; "."; "-x"; "objective-c"]; libs= []; flags= []}
+
+let get_linux_config c =
+  let default = {libs= []; cflags= []; flags= []} in
+  match C.Pkg_config.get c with
+  | None -> default
+  | Some pc -> (
+    match C.Pkg_config.query pc ~package:"gtk+-3.0" with
+    | None -> default
+    | Some conf -> {libs= conf.libs; cflags= conf.cflags; flags= []} )
+
 let uname () =
   let ic = Unix.open_process_in "uname" in
-  let uname = input_line ic in let () = close_in ic in uname
+  let uname = input_line ic in
+  let () = close_in ic in
+  uname
+
 let get_os =
   match Sys.os_type with
   | "Win32" -> Windows
-  | _ ->
-      (match uname () with
-       | "Darwin" -> Mac
-       | "Linux" -> Linux
-       | _ -> Unknown)
-let c_flags =
-  match get_os with | Mac -> ["-I"; "."; "-x"; "objective-c"] | _ -> []
-let flags = []
-;;Configurator.V1.Flags.write_sexp "c_flags.sexp" c_flags;
-  Configurator.V1.Flags.write_sexp "flags.sexp" flags
+  | _ -> (
+    match uname () with "Darwin" -> Mac | "Linux" -> Linux | _ -> Unknown )
+
+let () =
+  C.main ~name:"discover" (fun c ->
+      let conf =
+        match get_os with
+        | Mac -> get_mac_config ()
+        | Linux -> get_linux_config c
+        | _ -> {libs= []; flags= []; cflags= []}
+      in
+      C.Flags.write_sexp "flags.sexp" conf.flags ;
+      C.Flags.write_sexp "c_flags.sexp" conf.cflags ;
+      C.Flags.write_sexp "c_library_flags.sexp" conf.libs )

src/Native/dialog.cpp

@@ -1,41 +1,45 @@
 #include <stdio.h>
 
-#include <caml/mlvalues.h>
-#include <caml/memory.h>
 #include <caml/alloc.h>
 #include <caml/callback.h>
+#include <caml/memory.h>
+#include <caml/mlvalues.h>
 
 #ifdef WIN32
-  #include "ReveryWin32.h"
+#include "ReveryWin32.h"
 #elif __APPLE__
-  #include "ReveryCocoa.h"
+#include "ReveryCocoa.h"
+#else
+#include "ReveryGtk.h"
 #endif
 
 extern "C" {
-  CAMLprim value
-  revery_alertSupported() {
-  #ifdef WIN32
-      return Val_true;
-  #elif __APPLE__
-      return Val_true;
-  #else
-      return Val_false;
-  #endif
-  }
+CAMLprim value revery_alertSupported() {
+#ifdef WIN32
+  return Val_true;
+#elif __APPLE__
+  return Val_true;
+#elif __linux__
+  return Val_true;
+#else
+  return Val_false;
+#endif
+}
 
-  CAMLprim value
-  revery_alert(value vWindow, value vMessage) {
-      CAMLparam2(vWindow, vMessage);
-      const char *szMessage = String_val(vMessage);
-      void* pWin = (void *)vWindow;
+CAMLprim value revery_alert(value vWindow, value vMessage) {
+  CAMLparam2(vWindow, vMessage);
+  const char *szMessage = String_val(vMessage);
+  void *pWin = (void *)vWindow;
 
-  #ifdef WIN32
-      revery_alert_win32(pWin, szMessage);
-  #elif __APPLE__
-      revery_alert_cocoa(pWin, szMessage);
-  #else
-      printf("WARNING - Not implemented: alert");
-  #endif
-      return Val_unit;
-  }
+#ifdef WIN32
+  revery_alert_win32(pWin, szMessage);
+#elif __APPLE__
+  revery_alert_cocoa(pWin, szMessage);
+#elif __linux__
+  revery_alert_gtk(pWin, szMessage);
+#else
+  printf("WARNING - Not implemented: alert");
+#endif
+  return Val_unit;
+}
 }

src/Native/dialog_gtk.c

@@ -0,0 +1,33 @@
+#ifdef __linux__
+#include <gtk/gtk.h>
+
+// The callback to g_signal_connect MUST be an `activate` function
+static void activate(GtkApplication *app, const char *user_data) {
+  GtkWidget *dialog;
+
+  GtkDialogFlags flags = GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT;
+  dialog = gtk_message_dialog_new(NULL, flags, GTK_MESSAGE_INFO,
+                                  GTK_BUTTONS_CLOSE, user_data);
+  gtk_dialog_run(GTK_DIALOG(dialog));
+  gtk_widget_destroy(dialog);
+}
+
+void revery_alert_gtk(void *pWin, const char *szMessage) {
+  /*
+   * TODO:
+   * 1. figure out how to convert the pointer from an X11 window handle
+   * to a GTK window, see (for inspiration):
+   * https://gist.github.com/mmozeiko/2401933b1fa89e5d5bd238b33eab0465
+   *
+   * 2. Get reference to revery application, is there an existing
+   * gtk application reference when a glfw window is created that can be reused?
+   */
+  GtkApplication *app;
+  app = gtk_application_new("org.gtk.revery", G_APPLICATION_FLAGS_NONE);
+  g_signal_connect(app, "activate", G_CALLBACK(activate), (gpointer)szMessage);
+  /* argv the final argument to run can be set to NULL in which case argc should
+   * be set to 0 */
+  g_application_run(G_APPLICATION(app), 0, NULL);
+  g_object_unref(app);
+}
+#endif

src/Native/dune

@@ -4,12 +4,13 @@
     (preprocess (pps lwt_ppx))
     (library_flags (:include flags.sexp))
     (js_of_ocaml (javascript_files dialog.js))
-    (c_names dialog_cocoa dialog_win32)
+    (c_names dialog_cocoa dialog_win32 dialog_gtk)
     (cxx_names dialog)
     (c_flags (:include c_flags.sexp))
+    (c_library_flags (:include c_library_flags.sexp))
     (libraries reglfw))
 
 (rule
-(targets c_flags.sexp flags.sexp)
+(targets flags.sexp c_flags.sexp c_library_flags.sexp)
 (deps (:discover config/discover.exe))
 (action (run %{discover})))