Adding proposed view history patch ref. bakkeby#327

Author: bakkeby

README.md

@@ -19,6 +19,8 @@ Browsing patches? There is a [map of patches](https://coggle.it/diagram/X9IiSSM6
 
 ### Changelog:
 
+2023-01-18 - Added the view history patch
+
 2022-10-08 - Added the alt-tab patch
 
 2022-08-12 - Added the nametag patch
@@ -802,6 +804,11 @@ Browsing patches? There is a [map of patches](https://coggle.it/diagram/X9IiSSM6
       - adds configurable gaps between windows differentiating between outer, inner, horizontal and
         vertical gaps
 
+   - viewhistory
+      - adds a tag change history that is longer than the default current and previous tag
+      - `MOD`+Tab (`view(0)`) can be pressed multiple times to go further back to earlier tag
+        selections
+
    - [viewontag](https://dwm.suckless.org/patches/viewontag/)
       - follow a window to the tag it is being moved to
 

dwm.c

@@ -76,6 +76,7 @@
 #define Button8                 8
 #define Button9                 9
 #define NUMTAGS                 9
+#define NUMVIEWHIST             NUMTAGS
 #define BARRULES                20
 #if TAB_PATCH
 #define MAXTABS                 50
@@ -499,7 +500,11 @@ struct Monitor {
 	#endif // SETBORDERPX_PATCH
 	unsigned int seltags;
 	unsigned int sellt;
+	#if VIEW_HISTORY_PATCH
+	unsigned int tagset[NUMVIEWHIST];
+	#else
 	unsigned int tagset[2];
+	#endif // VIEW_HISTORY_PATCH
 	int showbar;
 	#if TAB_PATCH
 	int showtab;
@@ -1607,7 +1612,12 @@ createmon(void)
 
 	m = ecalloc(1, sizeof(Monitor));
 	#if !EMPTYVIEW_PATCH
+	#if VIEW_HISTORY_PATCH
+	for (i = 0; i < LENGTH(m->tagset); i++)
+		m->tagset[i] = 1;
+	#else
 	m->tagset[0] = m->tagset[1] = 1;
+	#endif // VIEW_HISTORY_PATCH
 	#endif // EMPTYVIEW_PATCH
 	m->mfact = mfact;
 	m->nmaster = nmaster;
@@ -4917,7 +4927,20 @@ view(const Arg *arg)
 	#if BAR_TAGPREVIEW_PATCH
 	tagpreviewswitchtag();
 	#endif // BAR_TAGPREVIEW_PATCH
+	#if VIEW_HISTORY_PATCH
+	if (!arg->ui) {
+		selmon->seltags += 1;
+		if (selmon->seltags == LENGTH(selmon->tagset))
+			selmon->seltags = 0;
+	} else {
+		if (selmon->seltags == 0)
+			selmon->seltags = LENGTH(selmon->tagset) - 1;
+		else
+			selmon->seltags -= 1;
+	}
+	#else
 	selmon->seltags ^= 1; /* toggle sel tagset */
+	#endif // VIEW_HISTORY_PATCH
 	if (arg->ui & TAGMASK)
 		selmon->tagset[selmon->seltags] = arg->ui & TAGMASK;
 	#if PERTAG_PATCH

patches.def.h

@@ -1311,6 +1311,16 @@
  */
 #define VANITYGAPS_MONOCLE_PATCH 0
 
+/* By default MOD+Tab will take the user back to the previous tag only. If the user keeps
+ * using MOD+Tab then the view will switch back and forth between the current and previous tag.
+ * This patch allows dwm to keep a longer history of previous tag changes such that MOD+Tab can
+ * be pressed multiple times to go further back to earlier tag selections.
+ *
+ * The number of history elements is defined by the NUMVIEWHIST macro in dwm.c and defaults to
+ * the number of tags in the system.
+ */
+#define VIEW_HISTORY_PATCH 0
+
 /* Follow a window to the tag it is being moved to.
  * https://dwm.suckless.org/patches/viewontag/
  */