[gimp/alxsa/tiff-reducedimage-option] plug-ins: fix #8127 Option to load reduced TIFFs

[Alx Sa <sawyeralex src gnome org>]

commit c518746878a2a25a8c469d6b54438d0bdb385ccc
Author: Alx Sa <cmyk student gmail com>
Date:   Sat Jun 11 16:35:17 2022 +0000

    plug-ins: fix #8127 Option to load reduced TIFFs
    
    Adds a toggle to let users load TIFF pages with FILETYPE_REDUCEDIMAGE
    tags. The specs do not state that these are always thumbnails, and they
    may have other uses. We assume that if only one page with this metadata
    exists then it is a thumbnail; otherwise, the toggle option is
    enabled on load.

 plug-ins/file-tiff/file-tiff-load.c | 134 ++++++++++++++++++++++++++----------
 plug-ins/file-tiff/file-tiff-load.h |  12 +++-
 2 files changed, 109 insertions(+), 37 deletions(-)
---
diff --git a/plug-ins/file-tiff/file-tiff-load.c b/plug-ins/file-tiff/file-tiff-load.c
index f61bfe34be..0085251649 100644
--- a/plug-ins/file-tiff/file-tiff-load.c
+++ b/plug-ins/file-tiff/file-tiff-load.c
@@ -153,12 +153,14 @@ static void               convert_int2uint (guchar            *buffer,
                                             gint               height,
                                             gint               stride);
 
-static gboolean           load_dialog      (TIFF              *tif,
-                                            const gchar       *help_id,
+static gboolean           load_dialog      (const gchar       *help_id,
                                             TiffSelectedPages *pages,
                                             const gchar       *extra_message,
                                             DefaultExtra      *default_extra);
 
+static void       tiff_dialog_show_reduced (GtkWidget         *toggle,
+                                            gpointer           data);
+
 
 static TiffSaveVals tsvals =
 {
@@ -291,6 +293,7 @@ load_image (GFile        *file,
   GimpColorProfile  *first_profile      = NULL;
   const gchar       *extra_message      = NULL;
   gint               li;
+  gint               selectable_pages;
 
   *image = 0;
   gimp_progress_init_printf (_("Opening '%s'"),
@@ -351,6 +354,7 @@ load_image (GFile        *file,
 
   pages.pages = NULL;
   pages.n_filtered_pages = pages.n_pages;
+  pages.n_reducedimage_pages = pages.n_pages;
 
   pages.filtered_pages  = g_new0 (gint, pages.n_pages);
   for (li = 0; li < pages.n_pages; li++)
@@ -430,7 +434,7 @@ load_image (GFile        *file,
             {
               /* file_type is a mask but we will only filter out pages
                * that only have FILETYPE_REDUCEDIMAGE set */
-              pages.filtered_pages[li] = -1;
+              pages.filtered_pages[li] = TIFF_REDUCEDFILE;
               pages.n_filtered_pages--;
               g_debug ("Page %d is a FILETYPE_REDUCEDIMAGE thumbnail.\n", li);
             }
@@ -445,8 +449,12 @@ load_image (GFile        *file,
               if (TIFFGetField (tif, TIFFTAG_COMPRESSION, &compression) &&
                   compression == COMPRESSION_OJPEG)
                 {
-                  pages.filtered_pages[li] = -1;
+                  pages.filtered_pages[li] = TIFF_MISC_THUMBNAIL;
                   pages.n_filtered_pages--;
+                  /* This is used to conditionally show reduced images
+                   * if they're not a thumbnail
+                   */
+                  pages.n_reducedimage_pages--;
                   g_debug ("Page %d is most likely a thumbnail.\n", li);
                 }
             }
@@ -480,9 +488,15 @@ load_image (GFile        *file,
     }
   TIFFSetDirectory (tif, 0);
 
+  pages.show_reduced = FALSE;
+  if (pages.n_reducedimage_pages - pages.n_filtered_pages > 1)
+    pages.show_reduced = TRUE;
+
+  pages.tif = tif;
+
   if (run_mode == GIMP_RUN_INTERACTIVE &&
       (pages.n_pages > 1 || extra_message) &&
-      ! load_dialog (tif, LOAD_PROC, &pages,
+      ! load_dialog (LOAD_PROC, &pages,
                      extra_message, &default_extra))
     {
       TIFFClose (tif);
@@ -490,8 +504,13 @@ load_image (GFile        *file,
 
       return GIMP_PDB_CANCEL;
     }
+
+  selectable_pages = pages.n_filtered_pages;
+  if (pages.show_reduced)
+    selectable_pages = pages.n_reducedimage_pages;
+
   /* Adjust pages to take filtered out pages into account. */
-  if (pages.o_pages > pages.n_filtered_pages)
+  if (pages.o_pages > selectable_pages)
     {
       gint fi;
       gint sel_index = 0;
@@ -499,7 +518,8 @@ load_image (GFile        *file,
 
       for (fi = 0; fi < pages.o_pages && sel_index < pages.n_pages; fi++)
         {
-          if (pages.filtered_pages[fi] == -1)
+          if ((pages.show_reduced && pages.filtered_pages[fi] == TIFF_MISC_THUMBNAIL) ||
+              (! pages.show_reduced && pages.filtered_pages[fi] <= TIFF_MISC_THUMBNAIL))
             {
               sel_add++;
             }
@@ -2596,19 +2616,20 @@ convert_int2uint (guchar *buffer,
 }
 
 static gboolean
-load_dialog (TIFF              *tif,
-             const gchar       *help_id,
+load_dialog (const gchar       *help_id,
              TiffSelectedPages *pages,
              const gchar       *extra_message,
              DefaultExtra      *default_extra)
 {
   GtkWidget  *dialog;
   GtkWidget  *vbox;
-  GtkWidget  *selector    = NULL;
+  GtkWidget  *show_reduced = NULL;
   GtkWidget  *crop_option = NULL;
   GtkWidget  *extra_radio = NULL;
   gboolean    run;
 
+  pages->selector         = NULL;
+
   dialog = gimp_dialog_new (_("Import from TIFF"), PLUG_IN_ROLE,
                             NULL, 0,
                             gimp_standard_help_func, help_id,
@@ -2630,35 +2651,37 @@ load_dialog (TIFF              *tif,
   gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))),
                       vbox, TRUE, TRUE, 0);
 
+  show_reduced = gtk_check_button_new_with_mnemonic (_("_Show reduced images?"));
+  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (show_reduced),
+                                pages->show_reduced);
+  /* Assumption: If there's only one reduced image, then
+   * it's a thumbnail and we'll disable the toggle option.
+   */
+  if (! pages->show_reduced)
+    gtk_widget_set_sensitive (GTK_WIDGET (show_reduced), FALSE);
+  gtk_box_pack_start (GTK_BOX (vbox), show_reduced, TRUE, TRUE, 0);
+
+  g_signal_connect (show_reduced, "toggled",
+                    G_CALLBACK (tiff_dialog_show_reduced),
+                    pages);
+
   if (pages->n_pages > 1)
     {
-      gint i, j;
-
       /* Page Selector */
-      selector = gimp_page_selector_new ();
-      gtk_widget_set_size_request (selector, 300, 200);
-      gtk_box_pack_start (GTK_BOX (vbox), selector, TRUE, TRUE, 0);
+      pages->selector = gimp_page_selector_new ();
+      gtk_widget_set_size_request (pages->selector, 300, 200);
+      gtk_box_pack_start (GTK_BOX (vbox), pages->selector, TRUE, TRUE, 0);
 
-      gimp_page_selector_set_n_pages (GIMP_PAGE_SELECTOR (selector),
+      gimp_page_selector_set_n_pages (GIMP_PAGE_SELECTOR (pages->selector),
                                       pages->n_filtered_pages);
-      gimp_page_selector_set_target (GIMP_PAGE_SELECTOR (selector), pages->target);
-
-      for (i = 0, j = 0; i < pages->n_pages && j < pages->n_filtered_pages; i++)
-        {
-          if (pages->filtered_pages[i] != -1)
-            {
-              const gchar *name = tiff_get_page_name (tif);
-
-              if (name)
-                gimp_page_selector_set_page_label (GIMP_PAGE_SELECTOR (selector),
-                                                   j, name);
-              j++;
-            }
+      gimp_page_selector_set_target (GIMP_PAGE_SELECTOR (pages->selector), pages->target);
 
-          TIFFReadDirectory (tif);
-        }
+      /* Load a set number of pages, based on whether "Show Reduced Images"
+       * is checked
+       */
+      tiff_dialog_show_reduced (show_reduced, pages);
 
-      g_signal_connect_swapped (selector, "activate",
+      g_signal_connect_swapped (pages->selector, "activate",
                                 G_CALLBACK (gtk_window_activate_default),
                                 dialog);
 
@@ -2705,10 +2728,10 @@ load_dialog (TIFF              *tif,
       if (pages->n_pages > 1)
         {
           pages->target =
-            gimp_page_selector_get_target (GIMP_PAGE_SELECTOR (selector));
+            gimp_page_selector_get_target (GIMP_PAGE_SELECTOR (pages->selector));
 
           pages->pages =
-            gimp_page_selector_get_selected_pages (GIMP_PAGE_SELECTOR (selector),
+            gimp_page_selector_get_selected_pages (GIMP_PAGE_SELECTOR (pages->selector),
                                                    &pages->n_pages);
 
           pages->keep_empty_space =
@@ -2717,10 +2740,10 @@ load_dialog (TIFF              *tif,
           /* select all if none selected */
           if (pages->n_pages == 0)
             {
-              gimp_page_selector_select_all (GIMP_PAGE_SELECTOR (selector));
+              gimp_page_selector_select_all (GIMP_PAGE_SELECTOR (pages->selector));
 
               pages->pages =
-                gimp_page_selector_get_selected_pages (GIMP_PAGE_SELECTOR (selector),
+                gimp_page_selector_get_selected_pages (GIMP_PAGE_SELECTOR (pages->selector),
                                                        &pages->n_pages);
             }
         }
@@ -2728,3 +2751,42 @@ load_dialog (TIFF              *tif,
 
   return run;
 }
+
+static void
+tiff_dialog_show_reduced (GtkWidget *toggle,
+                                 gpointer   data)
+{
+  gint selectable_pages;
+  gint i, j;
+  TiffSelectedPages *pages = (TiffSelectedPages*) data;
+  pages->show_reduced = gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (toggle));
+
+  /* Clear current pages from selection */
+  gimp_page_selector_set_n_pages (GIMP_PAGE_SELECTOR (pages->selector), 0);
+  /* Jump back to start of the TIFF file */
+  TIFFSetDirectory (pages->tif, 0);
+
+  selectable_pages = pages->n_filtered_pages;
+  if (pages->show_reduced)
+    selectable_pages = pages->n_reducedimage_pages;
+
+  gimp_page_selector_set_n_pages (GIMP_PAGE_SELECTOR (pages->selector),
+                                  selectable_pages);
+
+  for (i = 0, j = 0; i < pages->n_pages && j < selectable_pages; i++)
+    {
+      if ((pages->show_reduced && pages->filtered_pages[i] != TIFF_MISC_THUMBNAIL) ||
+          (! pages->show_reduced && pages->filtered_pages[i] > TIFF_MISC_THUMBNAIL))
+        {
+          const gchar *name = tiff_get_page_name (pages->tif);
+
+          if (name)
+            gimp_page_selector_set_page_label (GIMP_PAGE_SELECTOR (pages->selector),
+                                               j, name);
+          j++;
+        }
+
+      TIFFReadDirectory (pages->tif);
+    }
+
+}
diff --git a/plug-ins/file-tiff/file-tiff-load.h b/plug-ins/file-tiff/file-tiff-load.h
index d4d10beaf7..bd8d6f210f 100644
--- a/plug-ins/file-tiff/file-tiff-load.h
+++ b/plug-ins/file-tiff/file-tiff-load.h
@@ -24,15 +24,25 @@
 
 #define LOAD_PROC      "file-tiff-load"
 
+typedef enum
+{
+  TIFF_REDUCEDFILE    = -2,
+  TIFF_MISC_THUMBNAIL = -1
+} TIFF_THUMBNAIL_TYPE;
+
 typedef struct
 {
+  TIFF                   *tif;
   gint                    o_pages;
   gint                    n_pages;
   gint                   *pages;
-  gint                   *filtered_pages;   /* thumbnail is marked as -1 */
+  gint                   *filtered_pages;   /* thumbnail is marked as < 0 */
   gint                    n_filtered_pages;
+  gint                    n_reducedimage_pages;
+  GtkWidget              *selector;
   GimpPageSelectorTarget  target;
   gboolean                keep_empty_space;
+  gboolean                show_reduced;
 } TiffSelectedPages;