sl0ppty: the status line says what the pointer is on

The frame's affordances are nearly all one character wide, and the widest one
is invisible: a border that splits when you click it looks exactly like a
border. Hovering anything now puts a word in the middle of the status line.

Read off the hit list rather than tracked. Anything that registers a hit gets a
hint by being named in one table, and nothing has to remember to raise or clear
one — which also means the hint cannot disagree about what is under the pointer
with the thing that would actually be clicked, since both are the same lookup.
The status line is drawn after everything else has registered, so the list is
complete by the time it asks.

It is centred in what is left between the two ends rather than in the row.
Centring it in the row would put it under the session name on a narrow screen,
and a hint that overwrites the thing it is explaining is worse than no hint; it
is simply not drawn when it does not fit, which has a test with a deliberately
long pane title.

Two of that test's checks were wrong before they were right, in the ordinary
way: one searched for a substring that also occurs in the text on the right,
and one assumed forty-four columns was too narrow to fit a hint when it was
not. Both now assert against measured positions rather than my guess at them.

1 files changed, 162 insertions, 0 deletions

diff --git a/tests/test_hints.py b/tests/test_hints.py
new file mode 100644
index 0000000..4f6a5d6
--- /dev/null
+++ b/tests/test_hints.py
@@ -0,0 +1,162 @@
+#!/usr/bin/env python3
+"""A word in the middle of the status line for whatever the pointer is on.
+
+The frame's affordances are mostly one character wide, and a border that splits
+when clicked looks exactly like a border. The hint is read off the hit list
+rather than tracked, so anything that registers a hit gets one by being named
+in the table and nothing has to remember to raise it.
+"""
+import os
+import sys
+import tempfile
+
+from harness import Session, check, report
+
+SH = ["/bin/sh", "-c", 'printf "\\033]2;p\\007"; stty raw -echo; cat']
+
+
+def cfg(text):
+    f = tempfile.NamedTemporaryFile("w", suffix=".kdl", delete=False)
+    f.write(text)
+    f.close()
+    return f.name
+
+
+def hover(s, x, y):
+    s.send(rf"\e[<35;{x + 1};{y + 1}M")
+
+
+def bar(s):
+    return s.snapshot().text[-2]
+
+
+def hit(s, prefix):
+    return [h for h in s.snapshot().hits if h["action"].startswith(prefix)][0]
+
+
+def test_each_button_says_what_it_does():
+    with Session(SH, cols=96, rows=18) as s:
+        s.settle(20)
+        s.api("split", dir="cols")
+        s.settle(20)
+        check("nothing is said before the pointer is on anything",
+              "minimise" not in bar(s) and "close" not in bar(s), repr(bar(s)))
+
+        for prefix, word in (("minimize:", "minimise"),
+                             ("zoom:", "fill the tab"),
+                             ("close:", "close this pane")):
+            h = hit(s, prefix)
+            hover(s, h["x"], h["y"])
+            check(f"{prefix[:-1]} says its word", word in bar(s), repr(bar(s)))
+
+
+def test_the_zoom_hint_says_which_way_it_goes():
+    with Session(SH, cols=96, rows=18) as s:
+        s.settle(20)
+        s.api("split", dir="cols")
+        s.settle(20)
+        h = hit(s, "zoom:")
+        hover(s, h["x"], h["y"])
+        check("it offers to fill the tab", "fill the tab" in bar(s), repr(bar(s)))
+
+        s.send(r"\x01z")
+        s.settle(20)
+        h = hit(s, "zoom:")          # the button moved with the pane
+        hover(s, h["x"], h["y"])
+        check("and to undo it once it is zoomed",
+              "back to the layout" in bar(s), repr(bar(s)))
+
+
+def test_a_border_names_the_direction_it_would_split():
+    with Session(SH, cols=96, rows=22) as s:
+        s.settle(20)
+        p = s.pane()
+        for x, y, word in (
+                (p["x"], p["y"] + 2, "split left"),
+                (p["x"] + p["w"] - 1, p["y"] + 2, "split right"),
+                (p["x"] + 6, p["y"] + p["h"] - 1, "split down")):
+            hover(s, x, y)
+            check(f"the border says {word}", word in bar(s), repr(bar(s)))
+
+
+def test_the_gap_and_the_strip_and_the_bar():
+    with Session(SH, cols=96, rows=20) as s:
+        s.settle(20)
+        s.api("split", dir="cols")
+        s.settle(20)
+        left = s.panes()[0]
+        hover(s, left["x"] + left["w"], left["y"] + 3)
+        check("the gap between panes offers a resize",
+              "drag to resize" in bar(s), repr(bar(s)))
+
+        t = hit(s, "tab:")
+        hover(s, t["x"] + 1, t["y"])
+        check("a tab offers to switch", "switch to this tab" in bar(s),
+              repr(bar(s)))
+        n = hit(s, "newtab")
+        hover(s, n["x"] + 1, n["y"])
+        check("+tab offers a new one", "new tab" in bar(s), repr(bar(s)))
+
+        s.send(r"\x01m")
+        s.settle(20)
+        gone = [p for p in s.panes() if p["w"] <= 1][0]["id"]
+        e = [h for h in s.snapshot().hits
+             if h["action"] == f"focus:{gone}" and h["h"] == 1][0]
+        hover(s, e["x"] + 1, e["y"])
+        check("a pane put away offers to come back",
+              "open this pane" in bar(s), repr(bar(s)))
+
+
+def test_the_hint_never_writes_over_the_line_it_shares():
+    with Session(SH, cols=96, rows=18) as s:
+        s.settle(20)
+        s.api("split", dir="cols")
+        s.settle(20)
+        h = hit(s, "close:")
+        hover(s, h["x"], h["y"])
+        row = bar(s)
+        left_end = len(row.rstrip()) and row.index("p")           # the pane name
+        hint_at = row.index("close this pane")
+        right_at = row.rindex("pane 1/2" if "pane 1/2" in row else "pane 2/2")
+        check("the pane index on the right survives", right_at > 0, repr(row))
+        check("and the hint sits between the two ends, touching neither",
+              left_end < hint_at
+              and hint_at + len("close this pane") < right_at, repr(row))
+
+    # A long name leaves no room between the ends, so the hint is dropped
+    # rather than drawn over the thing it would be explaining.
+    wordy = ["/bin/sh", "-c",
+             'printf "\\033]2;a-very-long-pane-title-indeed\\007"; '
+             'stty raw -echo; cat']
+    with Session(wordy, cols=60, rows=18) as s:
+        s.settle(20)
+        h = hit(s, "close:")
+        hover(s, h["x"], h["y"])
+        row = bar(s)
+        check("with no room between them the hint gives way to the line",
+              "close this pane" not in row
+              and "a-very-long-pane-title-indeed" in row
+              and "pane 1/1" in row, repr(row))
+
+
+def test_hints_can_be_turned_off():
+    conf = cfg("hints false\n")
+    with Session(SH, cols=96, rows=18, config=conf) as s:
+        s.settle(20)
+        s.api("split", dir="cols")
+        s.settle(20)
+        h = hit(s, "close:")
+        hover(s, h["x"], h["y"])
+        check("hints false says nothing", "close this pane" not in bar(s),
+              repr(bar(s)))
+    os.unlink(conf)
+
+
+if __name__ == "__main__":
+    test_each_button_says_what_it_does()
+    test_the_zoom_hint_says_which_way_it_goes()
+    test_a_border_names_the_direction_it_would_split()
+    test_the_gap_and_the_strip_and_the_bar()
+    test_the_hint_never_writes_over_the_line_it_shares()
+    test_hints_can_be_turned_off()
+    sys.exit(report())