Add support for reverse image list order

Adds new order mode: "reverse".

Signed-off-by: Artem Senichev <[email protected]>

extra/swayimg.1

@@ -42,6 +42,7 @@ Set order of the image list:
 .nf
 \fInone\fR: unsorted, order is system depended;
 \fIalpha\fR: sorted alphabetically (default);
+\fIreverse\fR: reversed alphabetically;
 \fIrandom\fR: randomize list.
 .\" ----------------------------------------------------------------------------
 .IP "\fB\-s\fR, \fB\-\-scale\fR=\fIMODE\fR"

extra/swayimgrc

@@ -79,7 +79,7 @@ shadow = #000000ff
 # Image list configuration
 ################################################################################
 [list]
-# Default order (none/alpha/random)
+# Default order (none/alpha/reverse/random)
 order = alpha
 # Looping list of images (yes/no)
 loop = yes

extra/swayimgrc.5

@@ -153,6 +153,7 @@ Set order of the image list:
 .nf
 \fInone\fR: unsorted, order is system depended;
 \fIalpha\fR: sorted alphabetically (default);
+\fIreverse\fR: reversed alphabetically;
 \fIrandom\fR: randomize list.
 .\" ----------------------------------------------------------------------------
 .IP "\fBloop\fR\fR = \fI[yes|no]\fR"

extra/zsh.completion

@@ -6,7 +6,7 @@
 _arguments \
   '(-g --gallery)'{-g,--gallery}'[start in gallery mode]' \
   '(-r --recursive)'{-r,--recursive}'[read directories recursively]' \
-  '(-o --order)'{-o,--order=}'[set sort order for image list]:order:(none alpha random)' \
+  '(-o --order)'{-o,--order=}'[set sort order for image list]:order:(none alpha reverse random)' \
   '(-s --scale=SCALE)'{-s,--scale=}'[set initial image scale]:scale:(optimal width height fit fill real)' \
   '(-l --slideshow)'{-l,--slideshow}'[activate slideshow mode on startup]' \
   '(-f --fullscreen)'{-f,--fullscreen}'[show image in full screen mode]' \

src/imagelist.c

@@ -36,6 +36,7 @@ static struct image_list ctx;
 static const char* order_names[] = {
     [order_none] = "none",
     [order_alpha] = "alpha",
+    [order_reverse] = "reverse",
     [order_random] = "random",
 };
 
@@ -188,11 +189,20 @@ static size_t next_dir(size_t start, bool forward)
  * Compare sources callback for `qsort`.
  * @return negative if a < b, positive if a > b, 0 otherwise
  */
-static int compare_sources(const void* a, const void* b)
+static int compare_alpha(const void* a, const void* b)
 {
     return strcoll(*(const char**)a, *(const char**)b);
 }
 
+/**
+ * Compare sources callback for `qsort`.
+ * @return negative if a > b, positive if a < b, 0 otherwise
+ */
+static int compare_reverse(const void* a, const void* b)
+{
+    return -strcoll(*(const char**)a, *(const char**)b);
+}
+
 /**
  * Shuffle the image list.
  */
@@ -284,11 +294,21 @@ size_t image_list_init(struct config* cfg, const char** sources, size_t num)
     }
 
     if (ctx.size != 0) {
-        // sort or shuffle
-        if (ctx.order == order_alpha) {
-            qsort(ctx.sources, ctx.size, sizeof(*ctx.sources), compare_sources);
-        } else if (ctx.order == order_random) {
-            shuffle_list();
+        // sort list
+        switch (ctx.order) {
+            case order_none:
+                break;
+            case order_alpha:
+                qsort(ctx.sources, ctx.size, sizeof(*ctx.sources),
+                      compare_alpha);
+                break;
+            case order_reverse:
+                qsort(ctx.sources, ctx.size, sizeof(*ctx.sources),
+                      compare_reverse);
+                break;
+            case order_random:
+                shuffle_list();
+                break;
         }
     }
 

src/imagelist.h

@@ -18,9 +18,10 @@
 
 /** Order of file list. */
 enum list_order {
-    order_none,  ///< Unsorted (system depended)
-    order_alpha, ///< Alphanumeric sort
-    order_random ///< Random order
+    order_none,    ///< Unsorted (system depended)
+    order_alpha,   ///< Alphanumeric sort
+    order_reverse, ///< Reversed alphanumeric sort
+    order_random   ///< Random order
 };
 
 /**

src/main.c

@@ -33,7 +33,7 @@ static const struct cmdarg arguments[] = {
                                   APP_CFG_SECTION, APP_CFG_MODE, APP_MODE_GALLERY },
     { 'r', "recursive",  NULL,    "read directories recursively",
                                   IMGLIST_SECTION, IMGLIST_RECURSIVE, "yes" },
-    { 'o', "order",      "ORDER", "set sort order for image list: none/[alpha]/random",
+    { 'o', "order",      "ORDER", "set sort order for image list: none/[alpha]/reverse/random",
                                   IMGLIST_SECTION, IMGLIST_ORDER, NULL },
     { 's', "scale",      "SCALE", "set initial image scale: [optimal]/fit/width/height/fill/real",
                                   VIEWER_SECTION, VIEWER_SCALE, NULL },