1 files changed, 106 insertions, 0 deletions
diff --git a/gs/psi/idisp.c b/gs/psi/idisp.c
new file mode 100644
index 000000000..e26ec19a2
--- /dev/null
+++ b/gs/psi/idisp.c
@@ -0,0 +1,106 @@
+/* Copyright (C) 2001-2006 Artifex Software, Inc.
+   All Rights Reserved.
+  
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   This software is distributed under license and may not be copied, modified
+   or distributed except as expressly authorized under the terms of that
+   license.  Refer to licensing information at http://www.artifex.com/
+   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
+   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
+*/
+
+/* idisp.c */
+/* $Id$ */
+
+/*
+ * This allows the interpreter to set the callback structure 
+ * of the "display" device.  This must set at the end of 
+ * initialization and before the device is used.
+ * This is harmless if the 'display' device is not included.
+ * If gsapi_set_display_callback() is not called, this code
+ * won't even be used.
+ */
+
+#include "stdio_.h"
+#include "stdpre.h"
+#include "iapi.h"
+#include "ghost.h"
+#include "gp.h"
+#include "gscdefs.h"
+#include "gsmemory.h"
+#include "gstypes.h"
+#include "gsdevice.h"
+#include "iref.h"
+#include "imain.h"
+#include "iminst.h"
+#include "oper.h"
+#include "ostack.h"
+#include "gx.h"
+#include "gxdevice.h"
+#include "gxdevmem.h"
+#include "idisp.h"
+#include "gdevdevn.h"
+#include "gsequivc.h"
+#include "gdevdsp.h"
+#include "gdevdsp2.h"
+
+int
+display_set_callback(gs_main_instance *minst, display_callback *callback)
+{
+    i_ctx_t *i_ctx_p = minst->i_ctx_p;
+    bool was_open;
+    int code;
+    int exit_code = 0;
+    os_ptr op = osp;
+    gx_device *dev;
+    gx_device_display *ddev;
+
+    /* If display device exists, copy prototype if needed and return
+     *  device true
+     * If it doesn't exist, return
+     *  false
+     */
+    const char getdisplay[] = 
+      "devicedict /display known dup { /display finddevice exch } if";
+    code = gs_main_run_string(minst, getdisplay, 0, &exit_code, 
+	&minst->error_object);
+    if (code < 0)
+       return code;
+
+    op = osp;
+    check_type(*op, t_boolean);
+    if (op->value.boolval) {
+	/* display device was included in Ghostscript so we need
+	 * to set the callback structure pointer within it.
+	 * If the device is already open, close it before
+	 * setting callback, then reopen it.
+	 */
+	check_read_type(op[-1], t_device);
+	dev = op[-1].value.pdevice;
+	
+	was_open = dev->is_open;
+	if (was_open) {
+	    code = gs_closedevice(dev);
+	    if (code < 0)
+		return_error(code);
+	}
+
+	ddev = (gx_device_display *) dev;
+	ddev->callback = callback;
+
+	if (was_open) {
+	    code = gs_opendevice(dev);
+	    if (code < 0) {
+		dprintf("**** Unable to open the display device, quitting.\n");
+		return_error(code);
+	    }
+	}
+	pop(1);	/* device */
+    }
+    pop(1);	/* boolean */
+    return 0;
+}
+
+