output: Add footnote support.

[pspp] / src / output / render.h

diff --git a/src/output/render.h b/src/output/render.h
index 14f87b50c1bf404cdbeeb1b8db49eecc8580038a..c3f852f80a6b811e64c363c78279bea7516b68c8 100644 (file)
--- a/src/output/render.h
+++ b/src/output/render.h
@@ -31,18 +31,49 @@ enum render_line_style
     RENDER_N_LINES
   };
 
+/* Parameters for rendering a table_item to a device.
+
+
+   Coordinate system
+   =================
+
+   The rendering code assumes that larger 'x' is to the right and larger 'y'
+   toward the bottom of the page.
+
+   The rendering code assumes that the table being rendered has its upper left
+   corner at (0,0) in device coordinates.  This is usually not the case from
+   the driver's perspective, so the driver should expect to apply its own
+   offset to coordinates passed to callback functions.
+
+
+   Callback functions
+   ==================
+
+   For each of the callback functions, AUX is passed as the 'aux' member of the
+   render_params structure.
+
+   The device is expected to transform numerical footnote index numbers into
+   footnote markers.  The existing drivers use str_format_26adic() to transform
+   index 0 to "a", index 1 to "b", and so on.  The FOOTNOTE_IDX supplied to
+   each function is the footnote index number for the first footnote in the
+   cell.  If a cell contains more than one footnote, then the additional
+   footnote indexes increase sequentially, e.g. the second footnote has index
+   FOOTNOTE_IDX + 1.
+*/
 struct render_params
   {
     /* Measures CELL's width.  Stores in *MIN_WIDTH the minimum width required
        to avoid splitting a single word across multiple lines (normally, this
        is the width of the longest word in the cell) and in *MAX_WIDTH the
-       minimum width required to avoid line breaks other than at new-lines. */
+       minimum width required to avoid line breaks other than at new-lines.
+       */
     void (*measure_cell_width) (void *aux, const struct table_cell *cell,
+                                int footnote_idx,
                                 int *min_width, int *max_width);
 
     /* Returns the height required to render CELL given a width of WIDTH. */
     int (*measure_cell_height) (void *aux, const struct table_cell *cell,
-                                int width);
+                                int footnote_idx, int width);
 
     /* Given that there is space measuring WIDTH by HEIGHT to render CELL,
        where HEIGHT is insufficient to render the entire height of the cell,
@@ -55,7 +86,7 @@ struct render_params
        Optional.  If NULL, the rendering engine assumes that all breakpoints
        are acceptable. */
     int (*adjust_break) (void *aux, const struct table_cell *cell,
-                         int width, int height);
+                         int footnote_idx, int width, int height);
 
     /* Draws a generalized intersection of lines in the rectangle whose
        top-left corner is (BB[TABLE_HORZ][0], BB[TABLE_VERT][0]) and whose
@@ -75,6 +106,7 @@ struct render_params
        of the cell that lies within CLIP should actually be drawn, although BB
        should used to determine the layout of the cell. */
     void (*draw_cell) (void *aux, const struct table_cell *cell,
+                       int footnote_idx,
                        int bb[TABLE_N_AXES][2], int clip[TABLE_N_AXES][2]);
 
     /* Auxiliary data passed to each of the above functions. */