Add additional C trigger example

1 files changed, 73 insertions, 0 deletions

diff --git a/examples/Module/module2.c b/examples/Module/module2.c
new file mode 100644
index 0000000..a319b09
--- /dev/null
+++ b/examples/Module/module2.c
@@ -0,0 +1,73 @@
+/*
+  Trigger example2 in C (Directly calling sc-im code from trigger)
+  to compile
+  gcc -I<path/to/scim/src> -shared -fPIC -o module2.so -g -Wall module2.c
+
+  Copy the resulting module2.so somewhere on the search path, into
+  $HOME/.scim/module or /usr/local/share/scim/module.
+
+  Open sc-im and activate the trigger with the command
+  :trigger a0:a10 "mode=W type=C file=module2.so function=trig_invert"
+
+  Once the trigger has been activated modifying any cell in the specified
+  range (a0:a10), will invoke the trigger function defined below.
+
+  This example trigger function retrieves the new value of the cell and
+  writes a corresponding value to the adjecent cell. If you enter a number
+  into the cell, the value written to the adjecent cell will be its negative,
+  and if you enter a string the value will be the reverse of that string.
+
+*/
+
+#include <stdio.h>
+
+#include "sc.h"
+#include "xmalloc.h"
+#include "trigger.h"
+
+// These functions are part of sc-im itself, and are only visible to the
+// dynamic linker if sc-im has been compiled with "-Wl,--export-dynamic"
+extern void label(register struct ent * v, register char * s, int flushdir);
+extern struct ent *lookat(int row, int col);
+
+static char* strrev(char* s) {
+    int i;
+    char *res;
+    int slen = strlen(s);
+
+    res = scxmalloc(slen+1);
+    if(!res) return NULL;
+    res[slen]=0;
+    for (i=0;i<slen;i++) {
+        res[slen-1-i] = s[i];
+    }
+    return res;
+}
+
+int trig_invert(struct ent *p , int rw) {
+    struct ent *p2;
+    char *s = NULL;
+
+    if(rw != TRG_WRITE) return(1);
+
+    if((p2 = lookat(p->row, p->col+1))) {
+        // if the cell has a label, write its reverse to the target cell
+        if (p->flags & is_label){
+            if (p->label && !(s=strrev(p->label))) return(2);
+            label(p2,s,0);
+            if(s) scxfree(s);
+        }
+        // if the cell has a value, write its negative to the target cell
+        p2->flags &= ~is_valid;
+        p2->flags |= is_changed | iscleared;
+        if (p->flags & is_valid){
+            p2->v=-p->v;
+            p2->flags |= is_changed | is_valid;
+            p2->flags &= ~iscleared;
+            p2->cellerror = CELLOK;
+        }
+    }
+
+    return(0);
+}
+