Resolves: rhbz#919070 offload set span-all-displays to a gtk3 utility

Jaw dropping hack to set a slideshow to span all
monitors if gtk3 is available at runtime

Change-Id: I363f63c9855d5cb1f92d65d0b34add0c60f7263c

5 files changed, 162 insertions, 0 deletions

diff --git a/Repository.mk b/Repository.mk
index 0c60145a31d7..4ba21b25e8cd 100644
--- a/Repository.mk
+++ b/Repository.mk
@@ -87,6 +87,9 @@ $(eval $(call gb_Helper_register_executables,OOO, \
 	$(if $(ENABLE_NPAPI_FROM_BROWSER),pluginapp.bin) \
 	soffice_bin \
 	spadmin.bin \
+	$(if $(filter $(GUIBASE)$(ENABLE_GTK),unxTRUE), \
+		xid-fullscreen-on-all-monitors \
+	) \
 	$(if $(filter $(GUIBASE)$(ENABLE_TDE),unxTRUE), \
 		tdefilepicker \
 	) \
diff --git a/scp2/source/ooo/file_library_ooo.scp b/scp2/source/ooo/file_library_ooo.scp
index 45d23513bc67..3bf6ec93333b 100644
--- a/scp2/source/ooo/file_library_ooo.scp
+++ b/scp2/source/ooo/file_library_ooo.scp
@@ -123,6 +123,16 @@ File gid_File_Bin_KdeFilePicker
     Name = "kdefilepicker";
 End
 #endif
+
+#ifdef ENABLE_GTK
+File gid_File_Bin_XidFullscreen
+    BIN_FILE_BODY;
+    Styles = (PACKED);
+    Dir = gid_Brand_Dir_Program;
+    Name = "xid-fullscreen-on-all-monitors";
+End
+#endif
+
 #endif
 
 #ifdef MACOSX
diff --git a/vcl/Module_vcl.mk b/vcl/Module_vcl.mk
index d0f8f88ec495..961a958b6996 100644
--- a/vcl/Module_vcl.mk
+++ b/vcl/Module_vcl.mk
@@ -39,6 +39,7 @@ $(eval $(call gb_Module_add_targets,vcl,\
 
 ifneq ($(ENABLE_GTK),)
 $(eval $(call gb_Module_add_targets,vcl,\
+    Executable_xid_fullscreen_on_all_monitors \
     Library_vclplug_gtk \
 ))
 endif
diff --git a/vcl/unx/gtk/window/gtksalframe.cxx b/vcl/unx/gtk/window/gtksalframe.cxx
index 16a2cf4ceec9..062a19863450 100644
--- a/vcl/unx/gtk/window/gtksalframe.cxx
+++ b/vcl/unx/gtk/window/gtksalframe.cxx
@@ -30,6 +30,9 @@
 #include <generic/genprn.h>
 #include <generic/geninst.h>
 #include <headless/svpgdi.hxx>
+#include <osl/file.hxx>
+#include <rtl/bootstrap.hxx>
+#include <rtl/process.h>
 #include <vcl/floatwin.hxx>
 #include <vcl/svapp.hxx>
 #include <vcl/window.hxx>
@@ -90,6 +93,8 @@
 #define GSM_DBUS_INTERFACE      "org.gnome.SessionManager"
 #endif
 
+#include <config_folders.h>
+
 // make compile on gtk older than 2.10
 #if GTK_MINOR_VERSION < 10
 #define GDK_SUPER_MASK      (1 << 26)
@@ -3528,10 +3533,54 @@ gboolean GtkSalFrame::signalFocus( GtkWidget*, GdkEventFocus* pEvent, gpointer f
     return sal_False;
 }
 
+#if !GTK_CHECK_VERSION(3,8,0)
+static OString getDisplayString()
+{
+    int nParams = rtl_getAppCommandArgCount();
+    OUString aParam;
+    for( int i = 0; i < nParams; i++ )
+    {
+        rtl_getAppCommandArg( i, &aParam.pData );
+        if( i < nParams-1 && (aParam == "-display" || aParam == "--display" ) )
+        {
+            rtl_getAppCommandArg( i+1, &aParam.pData );
+            return OUStringToOString( aParam, osl_getThreadTextEncoding() );
+        }
+    }
+    return OString();
+}
+#endif
+
 gboolean GtkSalFrame::signalMap( GtkWidget *pWidget, GdkEvent*, gpointer frame )
 {
     GtkSalFrame* pThis = (GtkSalFrame*)frame;
 
+#if !GTK_CHECK_VERSION(3,8,0)
+    //Spawn off a helper program that will attempt to set this fullscreen
+    //window to span all displays.
+    if (pThis->m_bFullscreen && pThis->m_bSpanMonitorsWhenFullscreen)
+    {
+        GdkWindow* gdkwin = gtk_widget_get_window(pThis->m_pWindow);
+        if (gdkwin)
+        {
+            OUString sProgramURL( "$BRAND_BASE_DIR/" LIBO_LIBEXEC_FOLDER "/xid-fullscreen-on-all-monitors");
+            rtl::Bootstrap::expandMacros(sProgramURL);
+            OUString sProgram;
+            if (osl::FileBase::getSystemPathFromFileURL(sProgramURL, sProgram) == osl::File::E_None)
+            {
+                OString sFinalProgram(OUStringToOString(sProgram, osl_getThreadTextEncoding())
+                    + " " + OString::number((int)GDK_WINDOW_XID(gdkwin)));
+                OString sDisplay(getDisplayString());
+                if (!sDisplay.isEmpty())
+                {
+                    sFinalProgram += "--display " + sDisplay;
+                }
+                system(sFinalProgram.getStr());
+            }
+        }
+    }
+#endif
+
     bool bSetFocus = pThis->m_bSetFocusOnMap;
     pThis->m_bSetFocusOnMap = false;
 
diff --git a/vcl/unx/gtk/window/xid_fullscreen_on_all_monitors.c b/vcl/unx/gtk/window/xid_fullscreen_on_all_monitors.c
new file mode 100644
index 000000000000..00554b1df021
--- /dev/null
+++ b/vcl/unx/gtk/window/xid_fullscreen_on_all_monitors.c
@@ -0,0 +1,99 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <dlfcn.h>
+#include <stdlib.h>
+
+typedef int Window;
+typedef union  _GdkEvent GdkEvent;
+typedef struct _GdkWindow GdkWindow;
+typedef struct _GdkDisplay GdkDisplay;
+typedef struct _GdkScreen GdkScreen;
+
+typedef enum
+{
+    GDK_FULLSCREEN_ON_CURRENT_MONITOR,
+    GDK_FULLSCREEN_ON_ALL_MONITORS
+} GdkFullscreenMode;
+
+int main(int argc, char *argv[])
+{
+    void *handle;
+    void (*gtk_init)(int*, char***);
+    GdkWindow* (*gdk_x11_window_foreign_new_for_display)(GdkDisplay*, Window);
+    GdkDisplay* (*gdk_display_get_default)(void);
+    GdkEvent* (*gdk_event_get)(void);
+    void (*gtk_main_do_event)(GdkEvent*);
+    void (*gdk_event_free)(GdkEvent*);
+    void (*gdk_window_fullscreen)(GdkWindow *);
+    void (*gdk_window_set_fullscreen_mode)(GdkWindow *, GdkFullscreenMode);
+
+    GdkEvent *event;
+    GdkWindow *window;
+    int windowid;
+
+    handle = dlopen("libgtk-3.so.0", RTLD_LAZY);
+    if( NULL == handle )
+        return -1;
+
+    gtk_init = (void (*) (int*, char***))
+        dlsym(handle, "gtk_init");
+    gdk_x11_window_foreign_new_for_display = (GdkWindow* (*)(GdkDisplay*, Window))
+        dlsym(handle, "gdk_x11_window_foreign_new_for_display");
+    gdk_display_get_default = (GdkDisplay* (*)(void))
+        dlsym(handle, "gdk_display_get_default");
+    gdk_event_get = (GdkEvent* (*)(void))
+        dlsym(handle, "gdk_event_get");
+    gtk_main_do_event = (void (*)(GdkEvent*))
+        dlsym(handle, "gtk_main_do_event");
+    gdk_event_free = (void (*)(GdkEvent*))
+        dlsym(handle, "gdk_event_free");
+    gdk_window_fullscreen = (void (*)(GdkWindow *))
+        dlsym(handle, "gdk_window_fullscreen");
+    gdk_window_set_fullscreen_mode = (void (*)(GdkWindow *, GdkFullscreenMode))
+        dlsym(handle, "gdk_window_set_fullscreen_mode");
+
+    if (!gtk_init ||
+        !gdk_x11_window_foreign_new_for_display ||
+        !gdk_display_get_default ||
+        !gdk_event_get ||
+        !gtk_main_do_event ||
+        !gdk_event_free ||
+        !gdk_window_fullscreen ||
+        !gdk_window_set_fullscreen_mode)
+    {
+        dlclose(handle);
+        return -1;
+    }
+
+    gtk_init(&argc, &argv);
+
+    windowid = atoi(argv[1]);
+
+    window = gdk_x11_window_foreign_new_for_display(gdk_display_get_default(), windowid);
+    if (!window)
+    {
+        dlclose(handle);
+        return -1;
+    }
+
+    gdk_window_set_fullscreen_mode(window, GDK_FULLSCREEN_ON_ALL_MONITORS);
+    gdk_window_fullscreen(window);
+
+    while ((event = gdk_event_get()) != NULL)
+    {
+        gtk_main_do_event(event);
+        gdk_event_free(event);
+    }
+
+    dlclose(handle);
+    return 0;
+}
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
+