The trendline bug: a line continued past its second anchor at a different
slope. Two conventions were fighting, and both were wrong.
Lightweight Charts spaces bars evenly however much time separates them — a
weekend is forty-nine hours and one bar wide. The renderer extended the line by
interpolating between bar indices, which looked straight but disagreed with the
server, since price_at() advances per second. Measured on real bars that reached
147 points: the chart drew a level the alerts did not believe in. Making the
renderer match price_at() fixed the disagreement and made the visible kick worse,
because now the line really did climb an hour's worth of slope across a one-bar
maintenance break.
Neither convention is what a person means by drawing a line. A trendline advances
per bar, so both sides now evaluate in bar space: a new bar_space module the
runtime uses to position sloped levels, mirrored by indexAt() in the chart. The
line is straight on screen and the alert fires where it is drawn.
Also, from testing against the live chart:
- A plain click with the trendline tool armed did nothing and left the tool
armed, so the next click began a new line — which is how the slope change was
first noticed. Click-click and press-drag-release are both supported now, with
the rubber band following the cursor between clicks.
- Hand-placed levels are armed, fire once, then disarm themselves, and can be
re-armed from the sidebar. Verified end to end: created armed, tripped within
thirty seconds, disarmed, re-armed.
- Layers is collapsible.
- The 1h moving averages are gone; only the daily set remains.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
There was no way to say "tell me when ES reaches 7800". The only user-settable
alert was a drawn trendline, placed by clicking two points on a canvas — so you
could not hit an exact price, and making the line flat was fiddly.
A price alert is a manual line with zero slope. Reusing that rather than
building a parallel concept means it inherits JSON persistence, renaming,
recolouring, deletion, clustering, and the rule that a hand-placed level alerts
whatever its confluence score. The only genuinely new code is the input, an
endpoint that takes a price instead of two anchors, and the decision to render
zero-slope manual lines as price lines — which spans the chart and labels the
axis, instead of drawing a stubby two-point segment.
Zero-slope lines also skip drag handles, hit-testing and the "end line here"
menu: a price line has no endpoints to grab. They are managed from the sidebar.
Unlabelled alerts are named by their price, since "1d resistance" does not say
which alert fired.
Verified live: a level typed 25 points above price clusters as resistance at
that price and stays quiet, as it should until price arrives.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
