ref: 11d352c22055fe42bfd77e044c2590bf1cb9a44f
author: kvik <kvik@a-b.xyz>
date: Thu May 7 11:59:30 EDT 2020
Begin the history
--- /dev/null
+++ b/README
@@ -1,0 +1,39 @@
+# mousetrap(1) — filter for mouse events
+
+`mousetrap(1)` is designed to be interposed between a `nusb/kb(4)` mouse
+driver and the mouse event destination `/dev/mousein`, which provides an
+opportunity to intercept the "raw" mouse events and transform them
+before delivery to the rest of the system.
+
+Example transformations include remapping and hooking up arbitrary
+actions to buttons, which is mainly useful for devices with more buttons
+than the *Plan 9* recognizes. Yet another example might be filtering the
+pointer movement of overly sensitive devices.
+
+If you plan on using this you are expected to modify the source code to
+suit your devices and needs. Some example mappings are provided to
+help with this.
+
+## Usage
+
+`mousetrap(1)` can be installed into place, prior to running `nusb/kb(4)`
+using the `pipefile(1)` utility as follows:
+
+ pipefile -r 'mousetrap -m elecom' /dev/mousein
+ nusb/kb 9
+
+## TODO
+
+In the (near?) future `filterfs(4)` of some designation should be
+replace `pipefile(1)` as a more Plan9esque filtering solution. Sigrid
+of 9front works on this: https://git.sr.ht/~ft/filterfs
+
+Figure out a satisfactory way to integrate this kind of device filtering
+with the *9front* boot mechanism. Currently the `/sys/src/9/boot/nusbrc`
+has to be modified as per above and then a kernel has to be recompiled
+and installed for it to take effect. We agree this kinds of sucks.
+
+A temporary workaround, if you can get away with it, is `kill(1)`ing
+the `nusb/kb` that got assigned to your device at boot and restarting
+it manually. How to do this one is left as an exercise for the brave
+reader. HINT: `/dev/usbevent`.
--- /dev/null
+++ b/mkfile
@@ -1,0 +1,7 @@
+</$objtype/mkfile
+
+TARG=mousetrap
+OFILES=$TARG.$O
+BIN=$home/bin/$objtype
+
+</sys/src/cmd/mkone
--- /dev/null
+++ b/mousetrap.c
@@ -1,0 +1,138 @@
+#include <u.h>
+#include <libc.h>
+
+void
+usage(void)
+{+ fprint(2, "usage: %s [-m map]\n", argv0);
+ exits("usage");+}
+
+enum {+ Left = 0x01, Mid = 0x02, Right = 0x04,
+ Scrld = 0x08, Scrlu = 0x10,
+ Fwd = 0x20, Bwd = 0x40,
+ Fn1 = 0x80, Fn2 = 0x100, Fn3 = 0x200,
+};
+
+typedef struct Butt Butt;
+struct Butt {+ int raw; int cooked;
+ int down;
+ void (*action)(void);
+};
+
+Butt identity[] = {+ {Left, Left, 0, nil},+ {Mid, Mid, 0, nil},+ {Right, Right, 0, nil},+ {Scrld, Scrld, 0, nil},+ {Scrlu, Scrlu, 0, nil},+ {-1, -1, -1, nil},+};
+
+Butt huge[] = {+ {Left, Left, 0, nil},+ {Mid, Mid, 0, nil},+ {Right, Mid, 0, nil},+ {Scrld, Scrld, 0, nil},+ {Scrlu, Scrlu, 0, nil},+ {Fwd, Mid, 0, nil},+ {Bwd, Left, 0, nil},+ {Fn1, Mid, 0, nil},+ {Fn2, Right, 0, nil},+ {Fn3, Right, 0, nil},+ {-1, -1, -1, nil},+};
+
+Butt contour[] = {+ {Left, Left, 0, nil},+ {Mid, Mid, 0, nil},+ {Right, Right, 0, nil},+ {Scrld, Scrld, 0, nil},+ {Scrlu, Scrlu, 0, nil},+ {Fwd, Scrld, 0, nil},+ {Bwd, Scrlu, 0, nil},+ {-1, -1, -1, nil},+};
+
+int
+parsein(int *x, int *y, int *b)
+{+ int nr;
+ char buf[1+12+12+12+1];
+ char *p;
+
+ if((nr = read(0, buf, sizeof buf)) < 0)
+ sysfatal("read: %r");+ if(nr == 0)
+ return 0;
+ buf[nr] = 0;
+
+ *x = strtol(buf+1, &p, 10);
+ if(p == nil)
+ sysfatal("x not a num");+
+ *y = strtol(p, &p, 10);
+ if(p == nil)
+ sysfatal("y not a num");+
+ *b = strtol(p, &p, 10);
+ if(p == nil)
+ sysfatal("b not a num");+
+ return nr;
+}
+
+static int
+buttonmap(Butt *m, int b)
+{+ int r;
+
+ for(r = 0; m->raw != -1; m++){+ if(m->raw & b){+ if(m->action != nil && m->down == 0)
+ m->action();
+ r |= m->cooked;
+ m->down = 1;
+ }else
+ m->down = 0;
+ }
+ return r;
+}
+
+void
+main(int argc, char **argv)
+{+ int x, y, b;
+ char *mapn;
+ Butt *map;
+
+ mapn = "default";
+ ARGBEGIN{+ case 'm':
+ mapn = EARGF(usage());
+ break;
+ default:
+ usage();
+ }ARGEND;
+
+ map = identity;
+ if(strncmp(mapn, "elecom", 6) == 0
+ || strncmp(mapn, "huge", 4) == 0)
+ map = huge;
+ else if(strncmp(mapn, "contour", 7) == 0)
+ map = contour;
+
+ x = y = b = 0;
+ for(;;){+ if(parsein(&x, &y, &b) == 0)
+ break;
+ // x = scale(s, x);
+ // y = scale(s, y);
+ b = buttonmap(map, b);
+
+ fprint(1, "%s%11d %11d %11d", "m", x, y, b);
+ }
+ exits(nil);
+}