Driver for X-based viewer. Used by pangocairo-view and pangoxft-view

2006-02-01  Behdad Esfahbod  <behdad@gnome.org>

        * examples/viewer-x.c, examples/viewer-x.h: Driver for X-based
        viewer.  Used by pangocairo-view and pangoxft-view currently.

        * examples/Makefile.am, examples/cairoview.c, examples/xftview.c,
        examples/pangoft2topgm.c, examples/renderdemo.h,
        examples/renderdemo.c: Adjust to the above change.

9 files changed, 377 insertions, 326 deletions

diff --git a/ChangeLog b/ChangeLog
index 19f1aa07..0c0ed05d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2006-02-01  Behdad Esfahbod  <behdad@gnome.org>
 
+	* examples/viewer-x.c, examples/viewer-x.h: Driver for X-based
+	viewer.  Used by pangocairo-view and pangoxft-view currently.
+
+	* examples/Makefile.am, examples/cairoview.c, examples/xftview.c,
+	examples/pangoft2topgm.c, examples/renderdemo.h,
+	examples/renderdemo.c: Adjust to the above change.
+
+2006-02-01  Behdad Esfahbod  <behdad@gnome.org>
+
 	* examples/viewer.c: Removed.
 
 2006-02-01  Behdad Esfahbod  <behdad@gnome.org>
diff --git a/examples/Makefile.am b/examples/Makefile.am
index b9c1420f..0d2dc42d 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -36,8 +36,8 @@ endif
 
 pangoft2_view_SOURCES =			\
 	pangoft2topgm.c				\
-	renderdemo.c				\
-	renderdemo.h				
+	renderdemo.h				\
+	renderdemo.c
 pangoft2_view_LDADD =					\
 	../pango/libpango-$(PANGO_API_VERSION).la	\
 	../pango/libpangoft2-$(PANGO_API_VERSION).la	\
@@ -51,8 +51,11 @@ noinst_PROGRAMS += pangoxft-view
 endif
 
 pangoxft_view_SOURCES =				\
-	xftview.c				\
-	renderdemo.c				
+	renderdemo.h				\
+	renderdemo.c				\
+	viewer-x.h				\
+	viewer-x.c				\
+	xftview.c
 pangoxft_view_LDADD =					\
 	../pango/libpango-$(PANGO_API_VERSION).la	\
 	../pango/libpangoft2-$(PANGO_API_VERSION).la	\
@@ -72,8 +75,11 @@ endif
 endif
 
 pangocairo_view_SOURCES =			\
-	cairoview.c				\
-	renderdemo.c				
+	renderdemo.h				\
+	renderdemo.c				\
+	viewer-x.h				\
+	viewer-x.c				\
+	cairoview.c
 pangocairo_view_LDADD =					\
 	../pango/libpango-$(PANGO_API_VERSION).la	\
 	../pango/libpangoft2-$(PANGO_API_VERSION).la	\
diff --git a/examples/cairoview.c b/examples/cairoview.c
index b58a74ed..061c1abb 100644
--- a/examples/cairoview.c
+++ b/examples/cairoview.c
@@ -1,8 +1,8 @@
 /* Pango
  * cairoview.c: Example program to view a UTF-8 encoding file
- *              using Cairo to render result
+ *              using PangoCairo to render result
  *
- * Copyright (C) 2005 Red Hat, Inc.
+ * Copyright (C) 1999,2004,2005 Red Hat, Inc.
  * Copyright (C) 2001 Sun Microsystems
  *
  * This library is free software; you can redistribute it and/or
@@ -21,41 +21,20 @@
  * Boston, MA 02111-1307, USA.
  */
 
-#include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
-
 #include "renderdemo.h"
+#include "viewer-x.h"
 
 #include <pango/pangocairo.h>
 #include <cairo-xlib.h>
 
-static Region update_region = NULL;
-static PangoContext *context;
-static Display *display;
-int screen;
-static Window window;
-gboolean show_borders;
-
-typedef struct
-{
-  cairo_t *cr;
-  int x_offset;
-  int y_offset;
-} RenderData;
-
 static void
-do_cairo_render (PangoLayout *layout,
+render_callback (PangoLayout *layout,
 		 int          x,
 		 int          y,
-		 gpointer     data)
+		 gpointer     data,
+		 gboolean     show_borders)
 {
-  RenderData *render_data = data;
-  cairo_t *cr = render_data->cr;
+  cairo_t *cr = (cairo_t *)data;
 
   cairo_move_to (cr, x, y);
   pango_cairo_show_layout (cr, layout);
@@ -91,11 +70,11 @@ do_cairo_render (PangoLayout *layout,
 }
 
 static void
-do_cairo_transform (PangoContext *context,
+transform_callback (PangoContext *context,
 		    PangoMatrix  *matrix,
 		    gpointer      data)
 {
-  RenderData *render_data = data;
+  cairo_t *cr = (cairo_t *)data;
   cairo_matrix_t cairo_matrix;
 
   if (matrix)
@@ -112,182 +91,65 @@ do_cairo_transform (PangoContext *context,
       cairo_matrix_init_identity (&cairo_matrix);
     }
 
-  cairo_matrix_translate (&cairo_matrix,
-			  render_data->x_offset,
-			  render_data->y_offset);
-
-  cairo_set_matrix (render_data->cr, &cairo_matrix);
+  cairo_set_matrix (cr, &cairo_matrix);
       
   pango_context_set_matrix (context, matrix);
-  pango_cairo_update_context (render_data->cr, context);
+  pango_cairo_update_context (cr, context);
 }
 
 void
-update (void)
+do_init (Display *display,
+	 int screen,
+	 /* output */
+	 PangoContext **context,
+	 int *width,
+	 int *height)
 {
-  RenderData render_data;
-  cairo_surface_t *surface;
+  PangoFontMap *fontmap;
   cairo_t *cr;
-  Pixmap pixmap;
-  GC gc;
-  XRectangle extents;
-  int width, height;
-
-  /* Create a temporary pixmap and a Cairo context pointing to it */
-  XClipBox (update_region, &extents);
+  cairo_surface_t *surface;
+  fontmap = pango_cairo_font_map_get_default ();
+  pango_cairo_font_map_set_resolution (PANGO_CAIRO_FONT_MAP (fontmap), opt_dpi);
+  *context = pango_cairo_font_map_create_context (PANGO_CAIRO_FONT_MAP (fontmap));
 
-  width = extents.width;
-  height = extents.height;
+  /* This is annoying ... we have to create a temporary surface just to
+   * get the extents of the text.
+   */
+  surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, 1, 1);
+  cr = cairo_create (surface);
+  cairo_surface_destroy (surface);
+  do_output (*context, NULL, transform_callback, cr, width, height, FALSE);
+  cairo_destroy (cr);
+}
 
-  pixmap = XCreatePixmap (display, window, width, height,
-			  DefaultDepth (display, screen));
+void
+do_render (Display *display,
+	   int screen,
+	   Window window,
+	   Pixmap pixmap,
+	   PangoContext *context,
+	   int width,
+	   int height,
+	   gboolean show_borders)
+{
+  cairo_t *cr;
+  cairo_surface_t *surface;
 
   surface = cairo_xlib_surface_create (display, pixmap,
 				       DefaultVisual (display, screen),
 				       width, height);
-							      
 
-  cr = render_data.cr = cairo_create (surface);
+  cr = cairo_create (surface);
   cairo_surface_destroy (surface);
   
-  render_data.x_offset = - extents.x;
-  render_data.y_offset = - extents.y;
-
-  do_cairo_transform (context, NULL, &render_data);
+  transform_callback (context, NULL, cr);
 
-  /* Clip to the current update region and fill with white */
-  cairo_rectangle (cr, extents.x, extents.y, extents.width, extents.height);
-  
-  cairo_clip (cr);
   cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
   cairo_paint (cr);
   
   /* Draw the text in black */
   cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
-  do_output (context, do_cairo_render, do_cairo_transform, &render_data, NULL, NULL);
-  cairo_destroy (cr);
-
-  /* Copy the updated area onto the window */
-  gc = XCreateGC (display, pixmap, 0, NULL);
-
-  XCopyArea (display, pixmap, window, gc,
-	     0, 0,
-	     extents.width, extents.height, extents.x, extents.y);
-
-  XFreeGC (display, gc);
-  XFreePixmap (display, pixmap);
-	     
-  XDestroyRegion (update_region);
-  update_region = NULL;
-}
-
-static void
-expose (XExposeEvent *xev)
-{
-  XRectangle  r;
-  if (!update_region)
-    update_region = XCreateRegion ();
-
-  r.x = xev->x;
-  r.y = xev->y;
-  r.width = xev->width;
-  r.height = xev->height;
-  XUnionRectWithRegion (&r, update_region, update_region);
-}
-
-int main (int argc, char **argv)
-{
-  PangoFontMap *fontmap;
-  XEvent xev;
-  unsigned long bg;
-  int width, height;
-  XSizeHints size_hints;
-  RenderData render_data;
-  unsigned int quit_keycode;
-  unsigned int borders_keycode;
-  cairo_surface_t *surface;
-  
-  g_type_init();
-
-  parse_options (argc, argv);
+  do_output (context, render_callback, transform_callback, cr, NULL, NULL, show_borders);
 
-  display = XOpenDisplay (NULL);
-  if (!display)
-    fail ("Cannot open display %s\n", XDisplayName (NULL));
-  screen = DefaultScreen (display);
-
-  fontmap = pango_cairo_font_map_get_default ();
-  pango_cairo_font_map_set_resolution (PANGO_CAIRO_FONT_MAP (fontmap), opt_dpi);
-  context = pango_cairo_font_map_create_context (PANGO_CAIRO_FONT_MAP (fontmap));
-
-  /* This is annoying ... we have to create a temporary surface just to
-   * get the extents of the text.
-   */
-  surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, 1, 1);
-  render_data.cr = cairo_create (surface);
-  cairo_surface_destroy (surface);
-  render_data.x_offset = 0;
-  render_data.y_offset = 0;
-  do_output (context, NULL, do_cairo_transform, &render_data, &width, &height);
-  cairo_destroy (render_data.cr);
-
-  bg = WhitePixel (display, screen);
-
-  window = XCreateSimpleWindow (display, DefaultRootWindow (display),
-				0, 0, width, height, 0,
-				bg, bg);
-  XSelectInput (display, window, ExposureMask | KeyPressMask);
-  
-  XMapWindow (display, window);
-  XmbSetWMProperties (display, window,
-		      get_options_string (),
-		      NULL, NULL, 0, NULL, NULL, NULL);
-  
-  memset ((char *)&size_hints, 0, sizeof (XSizeHints));
-  size_hints.flags = PSize | PMaxSize;
-  size_hints.width = width; size_hints.height = height; /* for compat only */
-  size_hints.max_width = width; size_hints.max_height = height;
-  
-  XSetWMNormalHints (display, window, &size_hints);
-
-  borders_keycode = XKeysymToKeycode(display, 'B');
-  quit_keycode = XKeysymToKeycode(display, 'Q');
-
-  while (1)
-    {
-      if (!XPending (display) && update_region)
-	update ();
-	
-      XNextEvent (display, &xev);
-      switch (xev.xany.type) {
-      case KeyPress:
-	if (xev.xkey.keycode == quit_keycode)
-	  goto done;
-	else if (xev.xkey.keycode == borders_keycode)
-	  {
-	    XRectangle  r;
-	    show_borders = !show_borders;
-
-	    if (!update_region)
-	      update_region = XCreateRegion ();
-
-	    r.x = 0;
-	    r.y = 0;
-	    r.width = width;
-	    r.height = height;
-	    XUnionRectWithRegion (&r, update_region, update_region);
-	  }
-	break;
-      case Expose:
-	expose (&xev.xexpose);
-	break;
-      }
-    }
-
-done:
-
-  g_object_unref (context);
-  finalize ();
-
-  return 0;
+  cairo_destroy (cr);
 }
diff --git a/examples/pangoft2topgm.c b/examples/pangoft2topgm.c
index f47e3a22..85da627c 100644
--- a/examples/pangoft2topgm.c
+++ b/examples/pangoft2topgm.c
@@ -1,8 +1,8 @@
 /* Pango
  * pangoft2topgm.c: Example program to view a UTF-8 encoding file
- *                  using Pango to render result.
+ *                  using PangoFT2 to render result.
  *
- * Copyright (C) 1999 Red Hat Software
+ * Copyright (C) 1999,2004,2005 Red Hat, Inc.
  * Copyright (C) 2001 Sun Microsystems
  *
  * This library is free software; you can redistribute it and/or
@@ -102,7 +102,7 @@ main(int argc, char *argv[])
       int width, height;
       int run;
 
-      do_output (context, NULL, NULL, NULL, &width, &height);
+      do_output (context, NULL, NULL, NULL, &width, &height, FALSE);
       
       bitmap.width = width;
       bitmap.pitch = (bitmap.width + 3) & ~3;
@@ -113,7 +113,7 @@ main(int argc, char *argv[])
       memset (buf, 0x00, bitmap.pitch * bitmap.rows);
 
       for (run = 0; run < opt_runs; run++)
-	do_output (context, ft2_render, NULL, &bitmap, &width, &height);
+	do_output (context, ft2_render, NULL, &bitmap, &width, &height, FALSE);
 
       if (gen_output)
         {
diff --git a/examples/renderdemo.c b/examples/renderdemo.c
index 0cf1b14f..6e3ff981 100644
--- a/examples/renderdemo.c
+++ b/examples/renderdemo.c
@@ -39,7 +39,7 @@
 
 const char *prog_name;
 
-gboolean opt_display = FALSE;
+gboolean opt_display = TRUE;
 int opt_dpi = 96;
 const char *opt_font = MAKE_FONT_NAME (DEFAULT_FONT_FAMILY, DEFAULT_FONT_SIZE);
 gboolean opt_header = FALSE;
@@ -165,7 +165,8 @@ output_body (PangoContext   *context,
 	     RenderCallback  render_cb,
 	     gpointer        cb_data,
 	     int            *width,
-	     int            *height)
+	     int            *height,
+	     gboolean        show_borders)
 {
   PangoLayout *layout;
   PangoRectangle logical_rect;
@@ -193,11 +194,16 @@ output_body (PangoContext   *context,
       layout = make_layout (context, text, size);
       pango_layout_get_extents (layout, NULL, &logical_rect);
       
+      /* TODO: instead of these two calls, we really should call
+       * pango_layout_get_effective_width when that's implemented.
+       */
+      *width = MAX (*width, PANGO_PIXELS (pango_layout_get_width (layout)));
       *width = MAX (*width, PANGO_PIXELS (logical_rect.width));
+
       *height += PANGO_PIXELS (logical_rect.height);
 
       if (render_cb)
-	(*render_cb) (layout, 0, dy, cb_data);
+	(*render_cb) (layout, 0, dy, cb_data, show_borders);
       
       dy += PANGO_PIXELS (logical_rect.height);
 
@@ -223,7 +229,8 @@ do_output (PangoContext     *context,
 	   TransformCallback transform_cb,
 	   gpointer          cb_data,
 	   int              *width_out,
-	   int              *height_out)
+	   int              *height_out,
+	   gboolean          show_borders)
 {
   PangoLayout *layout;
   PangoRectangle logical_rect;
@@ -258,7 +265,7 @@ do_output (PangoContext     *context,
       height += PANGO_PIXELS (logical_rect.height);
       
       if (render_cb)
-	(*render_cb) (layout, x, y, cb_data);
+	(*render_cb) (layout, x, y, cb_data, show_borders);
       
       y += PANGO_PIXELS (logical_rect.height);
       
@@ -270,7 +277,7 @@ do_output (PangoContext     *context,
 
   set_transform (context, transform_cb, cb_data, &matrix);
   
-  output_body (context, text, NULL, NULL, &rotated_width, &rotated_height);
+  output_body (context, text, NULL, NULL, &rotated_width, &rotated_height, show_borders);
   
   transform_point (&matrix, 0,             0,              &p1x, &p1y);
   transform_point (&matrix, rotated_width, 0,              &p2x, &p2y);
@@ -289,7 +296,7 @@ do_output (PangoContext     *context,
   set_transform (context, transform_cb, cb_data, &matrix);
   
   if (render_cb)
-    output_body (context, text, render_cb, cb_data, &rotated_width, &rotated_height);
+    output_body (context, text, render_cb, cb_data, &rotated_width, &rotated_height, show_borders);
 
   width = MAX (width, maxx - minx);
   height += maxy - miny;
@@ -380,39 +387,39 @@ parse_options (int argc, char *argv[])
   {
     {"no-auto-dir",	0, G_OPTION_FLAG_REVERSE, G_OPTION_ARG_NONE,	&opt_auto_dir,
      "No layout direction according to contents",			NULL },
-    {"display",	0, 0, G_OPTION_ARG_NONE,				&opt_display,
-     "Show output using ImageMagick", 					NULL },
+    {"no-display",	'q', G_OPTION_FLAG_REVERSE, G_OPTION_ARG_NONE,	&opt_display,
+     "Do not display (just save to file or whatever)",			NULL },
     {"dpi",		0, 0, G_OPTION_ARG_INT,				&opt_dpi,
-     "Set the dpi", 							NULL },  
+     "Set the resolution", 						NULL },  
     {"ellipsize",	0, 0, G_OPTION_ARG_CALLBACK,			&parse_ellipsis,
      "Ellipsization mode",  "start/middle/end"				     },  
-    {"font",		0, 0,G_OPTION_ARG_STRING,			&opt_font,
-     "Set the font name", 						NULL },  
+    {"font",		0, 0, G_OPTION_ARG_STRING,			&opt_font,
+     "Set the font description", 					NULL },  
     {"header",		0, 0, G_OPTION_ARG_NONE,			&opt_header,
      "Display the options in the output",				NULL },
-    {"hinting",	0, 0, G_OPTION_ARG_CALLBACK,				&parse_hinting,
-     "Hinting style", "none/auto/full"					     },  
+    {"hinting",		0, 0, G_OPTION_ARG_CALLBACK,			&parse_hinting,
+     "Hinting style",	"none/auto/full"				     },  
     {"indent",		0, 0, G_OPTION_ARG_INT,				&opt_indent,
      "Width in points to indent paragraphs", 				NULL },  
     {"margin",		0, 0, G_OPTION_ARG_INT,				&opt_margin,
      "Set the margin on the output in pixels", 				NULL },  
-    {"makup",		0, 0, G_OPTION_ARG_NONE,			&opt_markup,
-     "Interpret contents as Pango markup", 				NULL },
-    {"output",		0, 0,G_OPTION_ARG_STRING,			&opt_output,
-     "Name of output file", 						NULL },  
-    {"pangorc",		0, 0,G_OPTION_ARG_STRING,			&opt_pangorc,
+    {"markup",		0, 0, G_OPTION_ARG_NONE,			&opt_markup,
+     "Interpret text as Pango markup", 					NULL },
+    {"output",		'o', 0,G_OPTION_ARG_STRING,			&opt_output,
+     "Save rendered image to output file", 				NULL },  
+    {"pangorc",		0, 0, G_OPTION_ARG_STRING,			&opt_pangorc,
      "pangorc file to use (default is ./pangorc)", 			NULL },  
     {"rtl",		0, 0, G_OPTION_ARG_NONE,			&opt_rtl,
-     "Set base dir to RTL", 						NULL },
+     "Set base direction to right-to-left", 				NULL },
     {"rotate",		0, 0, G_OPTION_ARG_INT,				&opt_rotate,
      "Angle at which to rotate results", 				NULL },  
-    {"runs",		0, 0, G_OPTION_ARG_INT,				&opt_runs,
-     "Render text this many times", 					NULL },  
-    {"text",		0, 0,G_OPTION_ARG_STRING,			&opt_text,
+    {"runs",		'n', 0, G_OPTION_ARG_INT,			&opt_runs,
+     "Run Pango layout engine this many times", 			NULL },  
+    {"text",		't', 0, G_OPTION_ARG_STRING,			&opt_text,
      "Text to display (instead of a file)", 				NULL },  
     {"waterfall",	0, 0, G_OPTION_ARG_NONE,			&opt_waterfall,
      "Create a waterfall display", 					NULL },
-    {"width",		0, 0, G_OPTION_ARG_INT,				&opt_width,
+    {"width",		'w', 0, G_OPTION_ARG_INT,			&opt_width,
      "Width in points to which to wrap output", 			NULL },  
     {NULL }
   };
@@ -447,9 +454,6 @@ parse_options (int argc, char *argv[])
       g_printerr ("Usage: %s [OPTION...] FILE\n", prog_name);
       exit (1);
     }
-  
-  if (!opt_output)
-    opt_display = TRUE;
 
   /* Get the text
    */
diff --git a/examples/renderdemo.h b/examples/renderdemo.h
index d79df1a6..f18636a2 100644
--- a/examples/renderdemo.h
+++ b/examples/renderdemo.h
@@ -32,7 +32,8 @@ typedef enum {
 typedef void (*RenderCallback) (PangoLayout *layout,
 				int          x,
 				int          y,
-				gpointer     data);
+				gpointer     data,
+				gboolean     show_borders);
 typedef void (*TransformCallback) (PangoContext *context,
 				   PangoMatrix  *transform,
 				   gpointer      data);
@@ -46,8 +47,8 @@ void   do_output          (PangoContext     *context,
 			   TransformCallback transform_cb,
 			   gpointer          cb_data,
 			   int              *width,
-			   int              *height);
-void   update             (void);
+			   int              *height,
+			   gboolean          show_borders);
 void   finalize           (void);
 void   fc_substitute_func (FcPattern        *pattern,
 			   gpointer          data);
diff --git a/examples/viewer-x.c b/examples/viewer-x.c
new file mode 100644
index 00000000..6546612b
--- /dev/null
+++ b/examples/viewer-x.c
@@ -0,0 +1,169 @@
+/* viewer-x.c: Common code X-based rendering demos
+ *
+ * Copyright (C) 1999,2004,2005 Red Hat, Inc.
+ * Copyright (C) 2001 Sun Microsystems
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "viewer-x.h"
+#include "renderdemo.h"
+
+/* initialized by main() */
+static Display *display;
+static int screen;
+static Window window;
+static Pixmap pixmap;
+
+/* initialized by do_init() */
+static PangoContext *context;
+static int width, height;
+
+/* runtime stuff */
+static Region update_region = NULL;
+static gboolean show_borders;
+
+static void
+update (void)
+{
+  GC gc;
+  XRectangle extents;
+  int width, height;
+
+  XClipBox (update_region, &extents);
+
+  width = extents.width;
+  height = extents.height;
+
+  gc = XCreateGC (display, pixmap, 0, NULL);
+
+  XCopyArea (display, pixmap, window, gc,
+	     extents.x, extents.y,
+	     extents.width, extents.height,
+	     extents.x, extents.y);
+
+  XFreeGC (display, gc);
+	     
+  XDestroyRegion (update_region);
+  update_region = NULL;
+}
+
+static void
+expose (XExposeEvent *xev)
+{
+  XRectangle  r;
+
+  if (!update_region)
+    update_region = XCreateRegion ();
+
+  r.x = xev->x;
+  r.y = xev->y;
+  r.width = xev->width;
+  r.height = xev->height;
+
+  XUnionRectWithRegion (&r, update_region, update_region);
+}
+
+int
+main (int argc, char **argv)
+{
+  XEvent xev;
+  unsigned long bg;
+  XSizeHints size_hints;
+  unsigned int quit_keycode;
+  unsigned int borders_keycode;
+  
+  g_type_init();
+
+  parse_options (argc, argv);
+
+  display = XOpenDisplay (NULL);
+  if (!display)
+    fail ("Cannot open display %s\n", XDisplayName (NULL));
+  screen = DefaultScreen (display);
+
+  do_init (display, screen, &context, &width, &height);
+
+  bg = WhitePixel (display, screen);
+  window = XCreateSimpleWindow (display, DefaultRootWindow (display),
+				0, 0, width, height, 0,
+				bg, bg);
+  pixmap = XCreatePixmap (display, window, width, height,
+			  DefaultDepth (display, screen));
+  XSelectInput (display, window, ExposureMask | KeyPressMask);
+  
+  XMapWindow (display, window);
+  XmbSetWMProperties (display, window,
+		      get_options_string (),
+		      NULL, NULL, 0, NULL, NULL, NULL);
+  
+  memset ((char *)&size_hints, 0, sizeof (XSizeHints));
+  size_hints.flags = PSize | PMaxSize;
+  size_hints.width = width; size_hints.height = height; /* for compat only */
+  size_hints.max_width = width; size_hints.max_height = height;
+  
+  XSetWMNormalHints (display, window, &size_hints);
+
+  borders_keycode = XKeysymToKeycode(display, 'B');
+  quit_keycode = XKeysymToKeycode(display, 'Q');
+
+  do_render (display, screen, window, pixmap, context, width, height, show_borders);
+
+  while (1)
+    {
+      if (!XPending (display) && update_region)
+	update ();
+	
+      XNextEvent (display, &xev);
+      switch (xev.xany.type) {
+      case KeyPress:
+	if (xev.xkey.keycode == quit_keycode)
+	  goto done;
+	else if (xev.xkey.keycode == borders_keycode)
+	  {
+	    XRectangle  r;
+	    show_borders = !show_borders;
+	    do_render (display, screen, window, pixmap, context, width, height, show_borders);
+
+	    if (!update_region)
+	      update_region = XCreateRegion ();
+
+	    r.x = 0;
+	    r.y = 0;
+	    r.width = width;
+	    r.height = height;
+	    XUnionRectWithRegion (&r, update_region, update_region);
+	  }
+	break;
+      case Expose:
+	expose (&xev.xexpose);
+	break;
+      }
+    }
+
+done:
+
+  g_object_unref (context);
+  XFreePixmap (display, pixmap);
+  finalize ();
+
+  return 0;
+}
diff --git a/examples/viewer-x.h b/examples/viewer-x.h
new file mode 100644
index 00000000..6ff528bb
--- /dev/null
+++ b/examples/viewer-x.h
@@ -0,0 +1,43 @@
+/* viewer-x.h: Common code X-based rendering demos
+ *
+ * Copyright (C) 1999,2004,2005 Red Hat, Inc.
+ * Copyright (C) 2001 Sun Microsystems
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <pango/pango.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+/* to be implemented by the backend-specific part */
+
+void do_init (Display *display,
+	      int screen,
+	      /* output */
+	      PangoContext **context,
+	      int *width,
+	      int *height);
+
+void do_render (Display *display,
+		int screen,
+		Window window,
+		Pixmap pixmap,
+		PangoContext *context,
+		int width,
+		int height,
+		gboolean show_borders);
diff --git a/examples/xftview.c b/examples/xftview.c
index c050b6a3..f9ba6f6a 100644
--- a/examples/xftview.c
+++ b/examples/xftview.c
@@ -1,8 +1,8 @@
 /* Pango
- * pangoft2topgm.c: Example program to view a UTF-8 encoding file
- *                  using Pango to render result.
+ * xftview.c: Example program to view a UTF-8 encoding file
+ *            using PangoXft to render result
  *
- * Copyright (C) 1999,2004 Red Hat, Inc.
+ * Copyright (C) 1999,2004,2005 Red Hat, Inc.
  * Copyright (C) 2001 Sun Microsystems
  *
  * This library is free software; you can redistribute it and/or
@@ -21,25 +21,19 @@
  * Boston, MA 02111-1307, USA.
  */
 
-#include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-
 #include "renderdemo.h"
+#include "viewer-x.h"
 
 #include <pango/pangoxft.h>
 
-static Region update_region = NULL;
-static XftDraw *draw;
-static PangoContext *context;
-
 static void
-xft_render (PangoLayout *layout,
-	    int          x,
-	    int          y,
-	    gpointer     data)
+render_callback (PangoLayout *layout,
+		 int          x,
+		 int          y,
+		 gpointer     data,
+		 gboolean     show_borders)
 {
+  XftDraw *draw = (XftDraw *)data;
   XftColor color;
 
   color.color.red = 0x0;
@@ -48,103 +42,66 @@ xft_render (PangoLayout *layout,
   color.color.alpha = 0xffff;
 
   pango_xft_render_layout (draw, &color, layout, x, y);
+
+  /*
+  if (show_borders)
+    {
+      PangoContext *context;
+      PangoXftFontMap *fontmap;
+      PangoRenderer *renderer;
+      PangoRectangle ink, logical;
+      
+      pango_layout_get_extents (layout, &ink, &logical);
+
+      context = pango_layout_get_context (layout);
+      fontmap = (PangoXftFontMap *)pango_context_get_font_map (context);
+
+      humm, we cannot go on, as the following is private api.
+      need to implement pango_font_map_get_renderer...
+
+      renderer = _pango_xft_font_map_get_renderer (fontmap);
+    }
+  */
 }
 
 void
-update (void)
+do_init (Display *display,
+	 int screen,
+	 /* output */
+	 PangoContext **context,
+	 int *width,
+	 int *height)
 {
-  XRectangle area;
+  XftInit (NULL);
+  *context = pango_xft_get_context (display, screen);
+  do_output (*context, NULL, NULL, NULL, width, height, FALSE);
+}
+
+void
+do_render (Display *display,
+	   int screen,
+	   Window window,
+	   Pixmap pixmap,
+	   PangoContext *context,
+	   int width,
+	   int height,
+	   gboolean show_borders)
+{
+  XftDraw *draw;
   XftColor color;
 
-  XClipBox (update_region, &area);
-  XftDrawSetClip (draw, update_region);
-  XDestroyRegion (update_region);
-  update_region = NULL;
+  draw = XftDrawCreate (display, pixmap,
+			DefaultVisual (display, screen),
+			DefaultColormap (display, screen));
 
   color.color.red = 0xffff;
   color.color.blue = 0xffff;
   color.color.green = 0xffff;
   color.color.alpha = 0xffff;
 
-  XftDrawRect (draw, &color,
-	       area.x, area.y, area.width, area.height);
+  XftDrawRect (draw, &color, 0, 0, width, height);
 
-  do_output (context, xft_render, NULL, draw, NULL, NULL);
-}
-
-static void
-expose (XExposeEvent *xev)
-{
-  XRectangle area;
-  
-  if (!update_region)
-    update_region = XCreateRegion ();
-
-  area.x = xev->x;
-  area.y = xev->y;
-  area.width = xev->width;
-  area.height = xev->height;
-
-  XUnionRectWithRegion (&area, update_region, update_region);
-}
+  do_output (context, render_callback, NULL, draw, NULL, NULL, show_borders);
 
-int main (int argc, char **argv)
-{
-  Display *display;
-  int screen;
-  Window window;
-  XEvent xev;
-  unsigned long bg;
-  int width, height;
-  XSizeHints size_hints;
-  
-  g_type_init();
-
-  XftInit (NULL);
-  
-  parse_options (argc, argv);
-
-  display = XOpenDisplay (NULL);
-  if (!display)
-    fail ("Cannot open display %s\n", XDisplayName (NULL));
-
-  screen = DefaultScreen (display);
-  bg = WhitePixel (display, screen);
-
-  context = pango_xft_get_context (display, screen);
-  do_output (context, NULL, NULL, NULL, &width, &height);
-
-  window = XCreateSimpleWindow (display, DefaultRootWindow (display),
-				0, 0, width, height, 0,
-				bg, bg);
-  XSelectInput (display, window, ExposureMask);
-  
-  XMapWindow (display, window);
-  draw = XftDrawCreate (display, window,
-			DefaultVisual (display, screen),
-			DefaultColormap (display, screen));
-  XmbSetWMProperties (display, window,
-		      get_options_string (),
-		      NULL, NULL, 0, NULL, NULL, NULL);
-
-  memset ((char *)&size_hints, 0, sizeof (XSizeHints));
-  size_hints.flags = PSize | PMaxSize;
-  size_hints.width = width; size_hints.height = height; /* for compat only */
-  size_hints.max_width = width; size_hints.max_height = height;
-  
-  XSetWMNormalHints (display, window, &size_hints);
-
-  while (1)
-    {
-      if (!XPending (display) && update_region)
-	update ();
-	
-      XNextEvent (display, &xev);
-      if (xev.xany.type == Expose)
-	{
-	  expose (&xev.xexpose);
-	}
-    }
-  
-  return 0;
+  XftDrawDestroy (draw);
 }