Bug 785535 - Histogram not updating in real when filters are active

Add "gboolean with_filters" to gimp_drawable_calculate_histogram(),
which is passed as FALSE in almost all places, except the histogram
dockable where we want to see both the drawable's unmodified histogram
*and* the histogram after filters are applied.

app/core/gimpdrawable-equalize.c

@@ -39,7 +39,7 @@ gimp_drawable_equalize (GimpDrawable *drawable,
 {
   GimpImage     *image;
   GimpChannel   *selection;
-  GimpHistogram *hist;
+  GimpHistogram *histogram;
   GeglNode      *equalize;
 
   g_return_if_fail (GIMP_IS_DRAWABLE (drawable));
@@ -48,12 +48,12 @@ gimp_drawable_equalize (GimpDrawable *drawable,
   image = gimp_item_get_image (GIMP_ITEM (drawable));
   selection = gimp_image_get_mask (image);
 
-  hist = gimp_histogram_new (FALSE);
+  histogram = gimp_histogram_new (FALSE);
-  gimp_drawable_calculate_histogram (drawable, hist);
+  gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
 
   equalize = gegl_node_new_child (NULL,
                                   "operation", "gimp:equalize",
-                                  "histogram", hist,
+                                  "histogram", histogram,
                                   NULL);
 
   if (! mask_only)
@@ -67,5 +67,5 @@ gimp_drawable_equalize (GimpDrawable *drawable,
     gimp_selection_resume (GIMP_SELECTION (selection));
 
   g_object_unref (equalize);
-  g_object_unref (hist);
+  g_object_unref (histogram);
 }

app/core/gimpdrawable-histogram.c

@@ -19,14 +19,17 @@
 
 #include "config.h"
 
+#include <cairo.h>
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <gegl.h>
 
 #include "core-types.h"
 
 #include "gegl/gimp-gegl-nodes.h"
+#include "gegl/gimptilehandlervalidate.h"
 
 #include "gimpchannel.h"
+#include "gimpdrawable-filters.h"
 #include "gimpdrawable-histogram.h"
 #include "gimphistogram.h"
 #include "gimpimage.h"
@@ -34,7 +37,8 @@
 
 void
 gimp_drawable_calculate_histogram (GimpDrawable  *drawable,
-                                   GimpHistogram *histogram)
+                                   GimpHistogram *histogram,
+                                   gboolean       with_filters)
 {
   GimpImage   *image;
   GimpChannel *mask;
@@ -53,14 +57,21 @@ gimp_drawable_calculate_histogram (GimpDrawable  *drawable,
   if (FALSE)
     {
       GeglNode      *node = gegl_node_new ();
-      GeglNode      *buffer_source;
+      GeglNode      *source;
       GeglNode      *histogram_sink;
       GeglProcessor *processor;
 
-      buffer_source =
+      if (with_filters)
-        gimp_gegl_add_buffer_source (node,
+        {
-                                     gimp_drawable_get_buffer (drawable),
+          source = gimp_drawable_get_source_node (drawable);
-                                     0, 0);
+        }
+      else
+        {
+          source =
+            gimp_gegl_add_buffer_source (node,
+                                         gimp_drawable_get_buffer (drawable),
+                                         0, 0);
+        }
 
       histogram_sink =
         gegl_node_new_child (node,
@@ -68,7 +79,7 @@ gimp_drawable_calculate_histogram (GimpDrawable  *drawable,
                              "histogram", histogram,
                              NULL);
 
-      gegl_node_connect_to (buffer_source,  "output",
+      gegl_node_connect_to (source,         "output",
                             histogram_sink, "input");
 
       if (! gimp_channel_is_empty (mask))
@@ -99,14 +110,50 @@ gimp_drawable_calculate_histogram (GimpDrawable  *drawable,
     }
   else
     {
+      GeglBuffer *buffer = gimp_drawable_get_buffer (drawable);
+
+      if (with_filters && gimp_drawable_has_filters (drawable))
+        {
+          GimpTileHandlerValidate *validate;
+          GeglNode                *node;
+
+          node = gimp_drawable_get_source_node (drawable);
+
+          buffer = gegl_buffer_new (gegl_buffer_get_extent (buffer),
+                                    gegl_buffer_get_format (buffer));
+
+          validate =
+            GIMP_TILE_HANDLER_VALIDATE (gimp_tile_handler_validate_new (node));
+
+          gimp_tile_handler_validate_assign (validate, buffer);
+
+          g_object_unref (validate);
+
+          gimp_tile_handler_validate_invalidate (validate,
+                                                 gegl_buffer_get_extent (buffer));
+
+#if 0
+          /*  this would keep the buffer updated across drawable or
+           *  filter changes, but the histogram is created in one go
+           *  and doesn't need the signal connection
+           */
+          g_signal_connect_object (node, "invalidated",
+                                   G_CALLBACK (gimp_tile_handler_validate_invalidate),
+                                   validate, G_CONNECT_SWAPPED);
+#endif
+        }
+      else
+        {
+          g_object_ref (buffer);
+        }
+
       if (! gimp_channel_is_empty (mask))
         {
           gint off_x, off_y;
 
           gimp_item_get_offset (GIMP_ITEM (drawable), &off_x, &off_y);
 
-          gimp_histogram_calculate (histogram,
+          gimp_histogram_calculate (histogram, buffer,
-                                    gimp_drawable_get_buffer (drawable),
                                     GEGL_RECTANGLE (x, y, width, height),
                                     gimp_drawable_get_buffer (GIMP_DRAWABLE (mask)),
                                     GEGL_RECTANGLE (x + off_x, y + off_y,
@@ -114,10 +161,11 @@ gimp_drawable_calculate_histogram (GimpDrawable  *drawable,
         }
       else
         {
-          gimp_histogram_calculate (histogram,
+          gimp_histogram_calculate (histogram, buffer,
-                                    gimp_drawable_get_buffer (drawable),
                                     GEGL_RECTANGLE (x, y, width, height),
                                     NULL, NULL);
         }
+
+      g_object_unref (buffer);
     }
 }

app/core/gimpdrawable-histogram.h

@@ -22,7 +22,8 @@
 
 
 void   gimp_drawable_calculate_histogram (GimpDrawable  *drawable,
-                                          GimpHistogram *histogram);
+                                          GimpHistogram *histogram,
+                                          gboolean       with_filters);
 
 
 #endif /* __GIMP_HISTOGRAM_H__ */

app/core/gimpdrawable-levels.c

@@ -54,7 +54,7 @@ gimp_drawable_levels_stretch (GimpDrawable *drawable,
   config = g_object_new (GIMP_TYPE_LEVELS_CONFIG, NULL);
 
   histogram = gimp_histogram_new (FALSE);
-  gimp_drawable_calculate_histogram (drawable, histogram);
+  gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
 
   gimp_levels_config_stretch (config, histogram,
                               gimp_drawable_is_rgb (drawable));

app/pdb/color-cmds.c

@@ -647,7 +647,7 @@ histogram_invoker (GimpProcedure         *procedure,
             linear = FALSE;
 
           histogram = gimp_histogram_new (linear);
-          gimp_drawable_calculate_histogram (drawable, histogram);
+          gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
 
           n_bins = gimp_histogram_n_bins (histogram);
 

app/pdb/drawable-color-cmds.c

@@ -418,7 +418,7 @@ drawable_histogram_invoker (GimpProcedure         *procedure,
             linear = FALSE;
 
           histogram = gimp_histogram_new (linear);
-          gimp_drawable_calculate_histogram (drawable, histogram);
+          gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
 
           n_bins = gimp_histogram_n_bins (histogram);
 

app/tools/gimpcurvestool.c

@@ -195,7 +195,7 @@ gimp_curves_tool_initialize (GimpTool     *tool,
     }
 
   histogram = gimp_histogram_new (FALSE);
-  gimp_drawable_calculate_histogram (drawable, histogram);
+  gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
   gimp_histogram_view_set_background (GIMP_HISTOGRAM_VIEW (c_tool->graph),
                                       histogram);
   g_object_unref (histogram);

app/tools/gimplevelstool.c

@@ -191,7 +191,7 @@ gimp_levels_tool_initialize (GimpTool     *tool,
       return FALSE;
     }
 
-  gimp_drawable_calculate_histogram (drawable, l_tool->histogram);
+  gimp_drawable_calculate_histogram (drawable, l_tool->histogram, FALSE);
   gimp_histogram_view_set_histogram (GIMP_HISTOGRAM_VIEW (l_tool->histogram_view),
                                      l_tool->histogram);
 

app/tools/gimpthresholdtool.c

@@ -142,7 +142,7 @@ gimp_threshold_tool_initialize (GimpTool     *tool,
       return FALSE;
     }
 
-  gimp_drawable_calculate_histogram (drawable, t_tool->histogram);
+  gimp_drawable_calculate_histogram (drawable, t_tool->histogram, FALSE);
   gimp_histogram_view_set_histogram (t_tool->histogram_box->view,
                                      t_tool->histogram);
 

app/widgets/gimphistogrameditor.c

@@ -133,12 +133,7 @@ gimp_histogram_editor_init (GimpHistogramEditor *editor)
       N_("Percentile:")
     };
 
-  editor->drawable     = NULL;
+  editor->box = gimp_histogram_box_new ();
-  editor->histogram    = NULL;
-  editor->bg_histogram = NULL;
-  editor->valid        = FALSE;
-  editor->idle_id      = 0;
-  editor->box          = gimp_histogram_box_new ();
 
   gimp_editor_set_show_name (GIMP_EDITOR (editor), TRUE);
 
@@ -481,7 +476,8 @@ gimp_histogram_editor_validate (GimpHistogramEditor *editor)
             }
 
           gimp_drawable_calculate_histogram (editor->drawable,
-                                             editor->histogram);
+                                             editor->histogram,
+                                             TRUE);
         }
       else
         {

tools/pdbgen/pdb/color.pdb

@@ -606,7 +606,7 @@ HELP
         linear = FALSE;
 
       histogram = gimp_histogram_new (linear);
-      gimp_drawable_calculate_histogram (drawable, histogram);
+      gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
 
       n_bins = gimp_histogram_n_bins (histogram);
 

tools/pdbgen/pdb/drawable_color.pdb

@@ -464,7 +464,7 @@ HELP
         linear = FALSE;
 
       histogram = gimp_histogram_new (linear);
-      gimp_drawable_calculate_histogram (drawable, histogram);
+      gimp_drawable_calculate_histogram (drawable, histogram, FALSE);
 
       n_bins = gimp_histogram_n_bins (histogram);