Add clipboard feature

Use GTK to take the text from the clipboard.
Add `/paste` command which pastes this text now to console window.

src/command/cmd_defs.c

@@ -2415,6 +2415,19 @@ static struct cmd_t command_defs[] =
         CMD_NOARGS
         CMD_NOEXAMPLES
     },
+
+    { "/paste",
+        parse_args, 0, 0, NULL,
+        CMD_NOSUBFUNCS
+        CMD_MAINFUNC(cmd_paste)
+        CMD_NOTAGS
+        CMD_SYN(
+            "/paste")
+        CMD_DESC(
+            "Paste clipboard.")
+        CMD_NOARGS
+        CMD_NOEXAMPLES
+    },
 };
 
 static GHashTable *search_index;

src/command/cmd_funcs.c

@@ -93,6 +93,7 @@
 
 #ifdef HAVE_GTK
 #include "ui/tray.h"
+#include "tools/clipboard.h"
 #endif
 
 #ifdef HAVE_PYTHON
@@ -8575,3 +8576,16 @@ cmd_reload(ProfWin *window, const char *const command, gchar **args)
     prefs_reload();
     return TRUE;
 }
+
+gboolean
+cmd_paste(ProfWin *window, const char *const command, gchar **args)
+{
+#ifdef HAVE_GTK
+    char *buf = clipboard_get();
+    cons_show(buf);
+#else
+    cons_show("This version of Profanity has not been built with GTK support enabled. It is needed for the clipboard feature to work.");
+#endif
+
+    return TRUE;
+}

src/command/cmd_funcs.h

@@ -228,4 +228,6 @@ gboolean cmd_omemo_clear_device_list(ProfWin *window, const char *const command,
 
 gboolean cmd_save(ProfWin *window, const char *const command, gchar **args);
 gboolean cmd_reload(ProfWin *window, const char *const command, gchar **args);
+
+gboolean cmd_paste(ProfWin *window, const char *const command, gchar **args);
 #endif

src/tools/clipboard.c

@@ -0,0 +1,65 @@
+/*
+ * clipboard.c
+ *
+ * Copyright (C) 2019 Michael Vetter <jubalh@iodoru.org>
+ *
+ * This file is part of Profanity.
+ *
+ * Profanity is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Profanity 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Profanity.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link the code of portions of this program with the OpenSSL library under
+ * certain conditions as described in each individual source file, and
+ * distribute linked combinations including the two.
+ *
+ * You must obey the GNU General Public License in all respects for all of the
+ * code used other than OpenSSL. If you modify file(s) with this exception, you
+ * may extend this exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this exception
+ * statement from your version. If you delete this exception statement from all
+ * source files in the program, then also delete it here.
+ *
+ */
+
+#include "config.h"
+
+#ifdef HAVE_GTK
+#include <gtk/gtk.h>
+#include <glib.h>
+#include <stdlib.h>
+
+#include "log.h"
+
+void clipboard_init(int argc, char **argv) {
+    gtk_init(&argc, &argv);
+}
+
+char *clipboard_get(void) {
+    gchar *clip;
+
+    GtkClipboard *cl = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
+    gtk_clipboard_clear(cl);
+
+    if(cl==NULL) {
+        log_error("Could not get clipboard");
+        return NULL;
+    }
+
+    //while(!gtk_clipboard_wait_is_text_available(cld)) {}
+
+    clip = gtk_clipboard_wait_for_text(cl);
+    return clip;
+}
+
+#endif

src/tools/clipboard.h

@@ -0,0 +1,43 @@
+/*
+ * clipboard.h
+ *
+ * Copyright (C) 2019 Michael Vetter <jubalh@iodoru.org>
+ *
+ * This file is part of Profanity.
+ *
+ * Profanity is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Profanity 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Profanity.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link the code of portions of this program with the OpenSSL library under
+ * certain conditions as described in each individual source file, and
+ * distribute linked combinations including the two.
+ *
+ * You must obey the GNU General Public License in all respects for all of the
+ * code used other than OpenSSL. If you modify file(s) with this exception, you
+ * may extend this exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this exception
+ * statement from your version. If you delete this exception statement from all
+ * source files in the program, then also delete it here.
+ *
+ */
+
+#ifndef UI_CLIPBOARD_H
+#define UI_CLIPBOARD_H
+
+#ifdef HAVE_GTK
+void clipboard_init(int argc, char **argv);
+char *clipboard_get(void);
+#endif
+
+#endif