New feature for the %xd() (display a preloaded image) skin tag.

It can now automatically load the correct subimage from a strip (assuming the strip is in the correct order)  by giving a tag for the 2nd param.
example: %xd(F, %mp) which is equivilant to %?mp<%xd(Fa)|%xd(Fb)|%xd(Fc)|%xd(Fd)|%xd(Fe)>
You can also set the subimage offset.. i.e %xd(E, %mm, -1) which means "show nothing for the first value of %mm and use the bitmap strip for the remaining values"

if a tag+offset is <0 or greater than the number of subimages in a strip he image is cleared (I'm open to changing this if someone has a better idea)

cabbiev2.176x220x16.wps is an example of how to use this

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27717 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 63 insertions, 16 deletions

diff --git a/apps/gui/skin_engine/skin_parser.c b/apps/gui/skin_engine/skin_parser.c
index a3cb68915b..c5acd1fd75 100644
--- a/apps/gui/skin_engine/skin_parser.c
+++ b/apps/gui/skin_engine/skin_parser.c
@@ -232,27 +232,39 @@ static int parse_image_display(struct skin_element *element,
     char sublabel = text[1];
     int subimage;
     struct gui_img *img;
+    struct image_display *id = skin_buffer_alloc(sizeof(struct image_display));
 
     /* sanity check */
     img = find_image(label, wps_data);
-    if (!img)
+    if (!img || !id)
     {
         token->value.i = label; /* so debug works */
         return WPS_ERROR_INVALID_PARAM;
     }
-
-    if ((subimage = get_image_id(sublabel)) != -1)
+    id->label = label;
+    id->offset = 0;
+    
+    if (element->params_count > 1)
     {
-        if (subimage >= img->num_subimages)
-            return WPS_ERROR_INVALID_PARAM;
-
-        /* Store sub-image number to display in high bits */
-        token->value.i = label | (subimage << 8);
-        return 4; /* We have consumed 2 bytes */
-    } else {
-        token->value.i = label;
-        return 3; /* We have consumed 1 byte */
+        id->token = element->params[1].data.code->data;
+        if (element->params_count > 2)
+            id->offset = element->params[2].data.number;
     }
+    else
+    {
+        id->token = NULL;
+        if ((subimage = get_image_id(sublabel)) != -1)
+        {
+            if (subimage >= img->num_subimages)
+                return WPS_ERROR_INVALID_PARAM;
+            id->subimage = subimage;
+            token->value.i = label | (subimage << 8);
+        } else {
+            id->subimage = 0;
+        }
+    }
+    token->value.data = id;
+    return 0;
 }
 
 static int parse_image_load(struct skin_element *element,
diff --git a/apps/gui/skin_engine/skin_render.c b/apps/gui/skin_engine/skin_render.c
index 895746370e..e254c62cf9 100644
--- a/apps/gui/skin_engine/skin_render.c
+++ b/apps/gui/skin_engine/skin_render.c
@@ -144,11 +144,36 @@ static bool do_non_text_tags(struct gui_wps *gwps, struct skin_draw_info *info,
 #ifdef HAVE_LCD_BITMAP
         case SKIN_TOKEN_IMAGE_PRELOAD_DISPLAY:
         {
-            char n = token->value.i & 0xFF;
-            int subimage = token->value.i >> 8;
+            struct image_display *id = token->value.data;
+            char n = id->label;
             struct gui_img *img = find_image(n, data);
             if (img && img->loaded)
-                img->display = subimage;
+            {
+                if (id->token == NULL)
+                {
+                    img->display = id->subimage;
+                }
+                else
+                {
+                    char buf[16];
+                    const char *out;
+                    int a = TOKEN_VALUE_ONLY;
+                    out = get_token_value(gwps, id->token, buf, sizeof(buf), &a);
+                    /* NOTE: get_token_value() returns values starting at 1! */
+                    if (a == -1)
+                        a = (out && *out) ? 1 : 2;
+                    a--;
+                    a += id->offset;
+                    /* If the token returned a value which is higher than
+                     * the amount of subimages clear the image. */
+                    if (a<0 || a >= img->num_subimages)
+                    {
+                        clear_image_pos(gwps, img);
+                    }
+                    else
+                        img->display = a;
+                }
+            }
             break;
         }
 #ifdef HAVE_ALBUMART
@@ -230,7 +255,8 @@ static void do_tags_in_hidden_conditional(struct skin_element* branch,
             /* clear all pictures in the conditional and nested ones */
             if (token->type == SKIN_TOKEN_IMAGE_PRELOAD_DISPLAY)
             {
-                struct gui_img *img = find_image(token->value.i&0xFF, data);
+                struct image_display *id = token->value.data;
+                struct gui_img *img = find_image(id->label, data);
                 clear_image_pos(gwps, img);
             }
             else if (token->type == SKIN_TOKEN_PEAKMETER)
diff --git a/apps/gui/skin_engine/wps_internals.h b/apps/gui/skin_engine/wps_internals.h
index 709dbc6ff7..e42fc5a53b 100644
--- a/apps/gui/skin_engine/wps_internals.h
+++ b/apps/gui/skin_engine/wps_internals.h
@@ -49,6 +49,9 @@
 #define WPS_ALIGN_CENTER 64
 #define WPS_ALIGN_LEFT 128
 
+
+#define TOKEN_VALUE_ONLY 0xDEADD0D0
+
 #ifdef HAVE_ALBUMART
 
 /* albumart definitions */
@@ -80,6 +83,12 @@ struct gui_img {
     int display;
 };
 
+struct image_display {
+    char label;
+    int subimage;
+    struct wps_token *token; /* the token to get the subimage number from */
+    int offset; /* offset into the bitmap strip to start */
+};
 
 struct progressbar {
     enum skin_token_type type;