From a9298e89e39691452a883b053cb138d077938372 Mon Sep 17 00:00:00 2001
From: nick black <dankamongmen@gmail.com>
Date: Sun, 23 Feb 2020 04:14:48 -0500
Subject: [PATCH] selector: scroll with mouse #305

---
 src/lib/debug.h    | 27 +++++++++++++++++++++++++++
 src/lib/internal.h |  1 +
 src/lib/selector.c | 29 +++++++++++++++++++++++++++++
 src/poc/selector.c |  4 ++++
 4 files changed, 61 insertions(+)
 create mode 100644 src/lib/debug.h

diff --git a/src/lib/debug.h b/src/lib/debug.h
new file mode 100644
index 000000000..4a08ca52a
--- /dev/null
+++ b/src/lib/debug.h
@@ -0,0 +1,27 @@
+// this file ought not be installed, nor referenced in releases.
+// strictly debugging hacks.
+
+#ifndef NOTCURSES_DEBUG
+#define NOTCURSES_DEBUG
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static inline void
+dump_plane_info(const struct notcurses* nc){
+  const struct ncplane* p = nc->top;
+  int d = 0;
+  while(p){
+    fprintf(stderr, "%02d] abs: %d/%d len: %d/%d cursor: %d/%d\n", d, p->absy,
+            p->absx, p->leny, p->lenx, p->y, p->x);
+    ++d;
+    p = p->z;
+  }
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/lib/internal.h b/src/lib/internal.h
index 0a088f3e4..05fc859d9 100644
--- a/src/lib/internal.h
+++ b/src/lib/internal.h
@@ -179,6 +179,7 @@ typedef struct ncselector {
   uint64_t titlechannels;      // title channels
   uint64_t footchannels;       // secondary and footer channels
   uint64_t boxchannels;        // border channels
+  int uarrowy, darrowy, arrowx;// location of scrollarrows, -1 if not present
 } ncselector;
 
 typedef struct ncdirect {
diff --git a/src/lib/selector.c b/src/lib/selector.c
index ac3c35079..3be20615c 100644
--- a/src/lib/selector.c
+++ b/src/lib/selector.c
@@ -80,6 +80,10 @@ ncselector_draw(ncselector* n){
   if(n->maxdisplay && n->maxdisplay < n->itemcount){
     n->ncp->channels = n->descchannels;
     ncplane_putegc_yx(n->ncp, yoff, bodywidth - (n->longdesc + 3) + xoff, "↑", NULL);
+    n->uarrowy = yoff;
+    n->arrowx = bodywidth - (n->longdesc + 3) + xoff;
+  }else{
+    n->darrowy = n->uarrowy = n->arrowx = -1;
   }
   unsigned printidx = n->startdisp;
   int bodyoffset = dimx - bodywidth + 2;
@@ -115,6 +119,7 @@ ncselector_draw(ncselector* n){
   if(n->maxdisplay && n->maxdisplay < n->itemcount){
     n->ncp->channels = n->descchannels;
     ncplane_putegc_yx(n->ncp, yoff, bodywidth - (n->longdesc + 3) + xoff, "↓", NULL);
+    n->darrowy = yoff;
   }
   return notcurses_render(n->ncp->nc);
 }
@@ -174,6 +179,7 @@ ncselector* ncselector_create(ncplane* n, int y, int x, const selector_options*
   ns->titlechannels = opts->titlechannels;
   ns->footchannels = opts->footchannels;
   ns->boxchannels = opts->boxchannels;
+  ns->darrowy = ns->uarrowy = ns->arrowx = -1;
   if(opts->itemcount){
     if(!(ns->items = malloc(sizeof(*ns->items) * opts->itemcount))){
       free(ns->title); free(ns->secondary); free(ns->footer);
@@ -321,6 +327,29 @@ bool ncselector_offer_input(ncselector* n, const ncinput* nc){
   }else if(nc->id == NCKEY_DOWN){
     ncselector_nextitem(n);
     return true;
+  }else if(nc->id == NCKEY_SCROLL_UP){
+    ncselector_previtem(n);
+    return true;
+  }else if(nc->id == NCKEY_SCROLL_DOWN){
+    ncselector_nextitem(n);
+    return true;
+  }else if(nc->id == NCKEY_RELEASE && ncplane_mouseevent_p(n->ncp, nc)){
+    int y = nc->y, x = nc->x;
+    ncplane_translate(ncplane_stdplane(n->ncp), n->ncp, &y, &x);
+    if(y == n->uarrowy && x == n->arrowx){
+      ncselector_previtem(n);
+      return true;
+    }else if(y == n->darrowy && x == n->arrowx){
+      ncselector_nextitem(n);
+      return true;
+    }else{
+      // FIXME we probably only want to consider it a click if both the release
+      // and the depress happened to be on us. for now, just check release.
+      // FIXME verify we're on the right line
+      // FIXME verify we're on the left of the split
+      // FIXME verify that we're on a visible glyph
+    }
+    return true;
   }
   return false;
 }
diff --git a/src/poc/selector.c b/src/poc/selector.c
index a1ac8851b..c166ba5a2 100644
--- a/src/poc/selector.c
+++ b/src/poc/selector.c
@@ -54,6 +54,10 @@ int main(void){
   if(nc == NULL){
     return EXIT_FAILURE;
   }
+  if(notcurses_mouse_enable(nc)){
+    notcurses_stop(nc);
+    return EXIT_FAILURE;
+  }
   selector_options sopts;
   memset(&sopts, 0, sizeof(sopts));
   sopts.maxdisplay = 4;