[Plplot-cvs] SF.net SVN: plplot:[11255] trunk

[<hba...@us...>]

Revision: 11255
          http://plplot.svn.sourceforge.net/plplot/?rev=11255&view=rev
Author:   hbabcock
Date:     2010-10-10 21:17:11 +0000 (Sun, 10 Oct 2010)

Log Message:
-----------
Add a string length calculation option to PLplot core and the cairo driver. If a driver can calculate the length of a string it should set pls->has_string_length. Then, when asked to render a string it should check pls->get_string_length. If pls->get_string_length is set then it should return the length of the string instead of rendering it. Currently set to return the length in pixels.

Modified Paths:
--------------
    trunk/drivers/cairo.c
    trunk/include/plstrm.h

Modified: trunk/drivers/cairo.c
===================================================================
--- trunk/drivers/cairo.c	2010-10-10 18:12:08 UTC (rev 11254)
+++ trunk/drivers/cairo.c	2010-10-10 21:17:11 UTC (rev 11255)
@@ -694,6 +694,13 @@
     pango_layout_set_markup( layout, aStream->pangoMarkupString, -1 );
     pango_layout_get_pixel_size( layout, &textXExtent, &textYExtent );
 
+    /* If asked, set the string length and return */
+    if (pls->get_string_length)
+    {
+	pls->string_length = textXExtent;
+	return;
+    }
+
     /* Set font aliasing */
     context          = pango_layout_get_context( layout );
     cairoFontOptions = cairo_font_options_create();
@@ -1139,8 +1146,8 @@
     pls->dev_gradient = 1;           /* driver renders gradient */
     pls->dev_arc      = 1;           /* Supports driver-level arcs */
     pls->plbuf_write  = interactive; /* Activate plot buffer */
+    pls->has_string_length = 1;      /* Driver supports string length calculations */
 
-
     if ( pls->xlength <= 0 || pls->ylength <= 0 )
     {
         pls->xlength = PLCAIRO_DEFAULT_X;

Modified: trunk/include/plstrm.h
===================================================================
--- trunk/include/plstrm.h	2010-10-10 18:12:08 UTC (rev 11254)
+++ trunk/include/plstrm.h	2010-10-10 21:17:11 UTC (rev 11255)
@@ -187,7 +187,11 @@
  * page		PLINT	Page count for output stream
  * linepos	PLINT	Line count for output stream
  * pdfs		PDFstrm* PDF stream pointer
- * dev_mem_alpha PLINT  The user supplied memory buffer supports alpha values
+ * dev_mem_alpha     PLINT  The user supplied memory buffer supports alpha values
+ * has_string_length PLINT  The driver can calculate the lengths of strings
+ * string_length     PLINT  Set to the length of the current string by the driver
+ * get_string_length PLINT  Tells the driver to calculate the length of the string
+ *                             but not to render it.
  *
  * These are used by the escape function (for area fill, etc).
  *
@@ -777,6 +781,9 @@
     PLBOOL     stream_closed;
     PLINT      line_style;
     PLINT      dev_mem_alpha;
+    PLINT      has_string_length;
+    PLINT      string_length;
+    PLINT      get_string_length;
 } PLStream;
 
 /*--------------------------------------------------------------------------*\


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