Patch: pango font metrics

[Thomas Fitzsimmons <fitzsim at redhat dot com>]

Hello,

This patch updates GdkFontMetrics to use the Pango API where before it
used XLFDs.  It is a temporary fix and doesn't produce precise metrics;
Graydon's GdkClasspathFontPeerMetrics patches will supersede this work
when the supporting Java2D code is activated.

OK to commit?

Tom

2003-12-01  Thomas Fitzsimmons  <fitzsim@redhat.com>

	* gnu/java/awt/peer/gtk/GdkFontMetrics.java (GdkFontMetrics):
	Pass font name, not XLFD, to initState.
	(stringWidth(String, int, String)): New method.
	(stringWidth(String)): Call new stringWidth.
	(getLeading): Always return 0.
	* jni/gtk-peer/gnu_java_awt_peer_gtk_GdkFontMetrics.c
	(initState): New Pango implementation.
	(stringWidth): Likewise.

Index: gnu/java/awt/peer/gtk/GdkFontMetrics.java
===================================================================
RCS file: /cvs/gcc/gcc/libjava/gnu/java/awt/peer/gtk/GdkFontMetrics.java,v
retrieving revision 1.2
diff -u -r1.2 GdkFontMetrics.java
--- gnu/java/awt/peer/gtk/GdkFontMetrics.java	13 Jul 2003 15:09:20 -0000	1.2
+++ gnu/java/awt/peer/gtk/GdkFontMetrics.java	1 Dec 2003 18:07:00 -0000
@@ -50,16 +50,20 @@
                        MAX_ADVANCE = 4;
 
   private int[] metrics;
-  private native int[] initState (String xlfd, int pts);
+  private native int[] initState (String fname, int size);
 
   public GdkFontMetrics (Font font)
   {
     super (font);
-    metrics = initState (((GtkFontPeer)font.getPeer ()).getXLFD (), 
-			 font.getSize ());
+    metrics = initState (font.getName (), font.getSize ());
   }
 
-  native public int stringWidth (String str);
+  native public int stringWidth (String fname, int size, String str);
+
+  public int stringWidth (String str)
+  {
+    return stringWidth (font.getName (), font.getSize (), str);
+  }
 
   public int charWidth (char ch)
   {
@@ -71,15 +75,10 @@
     return stringWidth (new String (data, off, len));
   }
 
-  /* 
-     Sun's Motif implementation always returns 0 or 1 here (???), but
-     going by the X11 man pages, it seems as though we should return
-     font.ascent + font.descent.
-  */
+  // Sun's Motif implementation always returns 0 or 1 here (???).
   public int getLeading ()
   {
-    return 1;
-//      return metrics[ASCENT] + metrics[DESCENT];
+    return 0;
   }
 
   public int getAscent ()
Index: jni/gtk-peer/gnu_java_awt_peer_gtk_GdkFontMetrics.c
===================================================================
RCS file: /cvs/gcc/gcc/libjava/jni/gtk-peer/gnu_java_awt_peer_gtk_GdkFontMetrics.c,v
retrieving revision 1.1
diff -u -r1.1 gnu_java_awt_peer_gtk_GdkFontMetrics.c
--- jni/gtk-peer/gnu_java_awt_peer_gtk_GdkFontMetrics.c	31 Jan 2003 17:54:14 -0000	1.1
+++ jni/gtk-peer/gnu_java_awt_peer_gtk_GdkFontMetrics.c	1 Dec 2003 18:07:01 -0000
@@ -51,49 +51,74 @@
 {
   jintArray array;
   jint *metrics;
-  const char *cfname;
-  char *xlfd;
-  GdkFont *font;
-  XFontStruct *xfont;
-
-  cfname = (*env)->GetStringUTFChars (env, fname, NULL);
-  xlfd = g_strdup_printf (cfname, (size * 10));
-  (*env)->ReleaseStringUTFChars (env, fname, cfname);
+  const char *font_name;
+  PangoFontDescription *font_desc;
+  PangoContext *context;
+  PangoFontMetrics *pango_metrics;
 
   array = (*env)->NewIntArray (env, NUM_METRICS);
+
   metrics = (*env)->GetIntArrayElements (env, array, NULL);
+  font_name = (*env)->GetStringUTFChars (env, fname, NULL);
 
   gdk_threads_enter ();
-  font = gdk_font_load (xlfd);
-  xfont = GDK_FONT_XFONT (font);
 
-  metrics[ASCENT]      = font->ascent;
-  metrics[MAX_ASCENT]  = xfont->max_bounds.ascent;
-  metrics[DESCENT]     = font->descent;
-  metrics[MAX_DESCENT] = xfont->max_bounds.descent;
-  metrics[MAX_ADVANCE] = xfont->max_bounds.width;
+  font_desc = pango_font_description_from_string (font_name);
+  pango_font_description_set_size (font_desc, size * PANGO_SCALE);
+
+  context = gdk_pango_context_get();
+  pango_context_set_font_description (context, font_desc);
+
+  pango_metrics = pango_context_get_metrics (context, font_desc, NULL);
+
+  metrics[ASCENT] =
+    pango_font_metrics_get_ascent (pango_metrics) / PANGO_SCALE;
+  metrics[MAX_ASCENT]  = metrics[ASCENT];
+  metrics[DESCENT] =
+    pango_font_metrics_get_descent (pango_metrics) / PANGO_SCALE;
+  metrics[MAX_DESCENT] = metrics[DESCENT];
+  metrics[MAX_ADVANCE] =
+    pango_font_metrics_get_approximate_char_width (pango_metrics) / PANGO_SCALE;
+
+  pango_font_metrics_unref (pango_metrics);
+
+  pango_font_description_free (font_desc);
+
   gdk_threads_leave ();
 
-  g_free (xlfd);
+  (*env)->ReleaseStringUTFChars (env, fname, font_name);
   (*env)->ReleaseIntArrayElements (env, array, metrics, 0);
 
-  NSA_SET_PTR (env, obj, font);
-
   return array;
 }
 
 JNIEXPORT jint JNICALL Java_gnu_java_awt_peer_gtk_GdkFontMetrics_stringWidth
-  (JNIEnv *env, jobject obj, jstring str)
+  (JNIEnv *env, jobject obj, jstring fname, jint size, jstring str)
 {
-  GdkFont *font;
+  PangoFontDescription *font_desc;
+  PangoContext *context;
+  PangoLayout *layout;
+  int width = 0;
   const char *cstr;
-  jint width;
+  const char *font_name;
 
-  font = (GdkFont *) NSA_GET_PTR (env, obj);
   cstr = (*env)->GetStringUTFChars (env, str, NULL);
 
   gdk_threads_enter ();
-  width = gdk_string_width (font, cstr);
+
+  font_desc = pango_font_description_from_string (font_name);
+  pango_font_description_set_size (font_desc, size * PANGO_SCALE);
+
+  context = gdk_pango_context_get();
+  pango_context_set_font_description (context, font_desc);
+
+  layout = pango_layout_new (context);
+
+  pango_layout_set_text (layout, cstr, -1);
+  pango_layout_get_pixel_size (layout, &width, NULL);
+
+  pango_font_description_free (font_desc);
+
   gdk_threads_leave ();
 
   (*env)->ReleaseStringUTFChars (env, str, cstr);