Files
TelemetryMonitor/lib/ui/chart_painter.dart

285 lines
8.7 KiB
Dart

import 'package:flutter/material.dart';
import '../layout/chart_config.dart';
import '../layout/layout_controller.dart';
import '../session/session_controller.dart';
/// Stateless per-frame painter. Reads everything fresh from the controllers
/// each `paint()` — no internal state.
class ChartPainter extends CustomPainter {
ChartPainter({
required this.channel,
required this.session,
required this.layout,
required this.isDark,
this.hoverLocalPos,
});
final int channel;
final SessionController session;
final LayoutController layout;
final bool isDark;
final Offset? hoverLocalPos;
@override
void paint(Canvas canvas, Size size) {
final padLeft = 32.0, padRight = 4.0, padTop = 4.0, padBottom = 16.0;
final plotW = size.width - padLeft - padRight;
final plotH = size.height - padTop - padBottom;
if (plotW <= 0 || plotH <= 0) return;
// Theme-dependent palette.
final bgColor = isDark ? const Color(0xFF1E1F22) : const Color(0xFFF7F7F4);
final lineColor =
isDark ? const Color(0xFF5EA8FF) : const Color(0xFF185FA5);
final hatchColor =
isDark ? const Color(0x66D17050) : const Color(0x55993C1D);
final markerColor =
isDark ? const Color(0xCCD17050) : const Color(0xAA993C1D);
final cursorColor =
isDark ? const Color(0xCCBBBBBB) : const Color(0xAA444444);
// Background.
final bgPaint = Paint()..color = bgColor;
canvas.drawRect(
Rect.fromLTWH(padLeft, padTop, plotW, plotH),
bgPaint,
);
// Compute window.
final newest = session.packets.newest;
final oldestUs = session.packets.oldest?.timestampUs.toInt() ?? 0;
final newestUs = newest?.timestampUs.toInt() ??
DateTime.now().microsecondsSinceEpoch;
final win = session.viewState.currentWindow(
nowUs: newestUs,
oldestUs: oldestUs,
newestUs: newestUs,
);
// Decimate.
final cols = session.decimator.decimate(
channel: channel,
buffer: session.packets,
startUs: win.startUs,
endUs: win.endUs,
pixelWidth: plotW.round(),
);
final gaps = session.decimator.computeGaps(
channel: channel,
buffer: session.packets,
startUs: win.startUs,
endUs: win.endUs,
pixelWidth: plotW.round(),
);
// Y range.
final cfg = layout.configFor(channel);
var yMin = cfg.yMin, yMax = cfg.yMax;
if (cfg.yMode == YMode.auto) {
double lo = double.infinity, hi = double.negativeInfinity;
for (final c in cols) {
if (!c.hasData) continue;
if (c.min < lo) lo = c.min;
if (c.max > hi) hi = c.max;
}
if (lo.isFinite && hi.isFinite && hi > lo) {
yMin = lo;
yMax = hi;
}
}
final ySpan = (yMax - yMin).abs() < 1e-12 ? 1.0 : (yMax - yMin);
double xForCol(int col) => padLeft + col + 0.5;
double yForVal(double v) =>
padTop + plotH * (1 - (v - yMin) / ySpan);
// Everything that draws into the plot area must stay within it; a
// Y-zoom can push line segments outside [padTop, padTop+plotH].
canvas.save();
canvas.clipRect(Rect.fromLTWH(padLeft, padTop, plotW, plotH));
// Hatched gap rectangles.
final hatchPaint = Paint()
..color = hatchColor
..style = PaintingStyle.fill;
for (final g in gaps.hatchedRanges) {
final x0 = xForCol(g.startPx);
final x1 = xForCol(g.endPx + 1);
canvas.drawRect(
Rect.fromLTRB(x0, padTop, x1, padTop + plotH),
hatchPaint,
);
}
// Polyline.
final linePaint = Paint()
..color = lineColor
..strokeWidth = 1.2
..style = PaintingStyle.stroke;
final path = Path();
bool started = false;
for (var i = 0; i < cols.length; i++) {
final c = cols[i];
// Real missing-data gap: break the polyline.
if (c.isGap) {
started = false;
continue;
}
// Empty column (no packet fell here — sub-packet-period zoom). Let the
// path interpolate across.
if (!c.hasData) continue;
final x = xForCol(i);
final yMinPx = yForVal(c.max); // Higher value = smaller y.
final yMaxPx = yForVal(c.min);
if (!started) {
path.moveTo(x, (yMinPx + yMaxPx) / 2);
started = true;
} else {
path.lineTo(x, (yMinPx + yMaxPx) / 2);
}
// Min/max vertical span to surface intra-column variation.
if ((yMaxPx - yMinPx).abs() > 0.5) {
canvas.drawLine(Offset(x, yMinPx), Offset(x, yMaxPx), linePaint);
}
}
canvas.drawPath(path, linePaint);
// Sub-pixel marker lines.
final markerPaint = Paint()
..color = markerColor
..strokeWidth = 1;
for (final px in gaps.markerPixels) {
final x = xForCol(px);
canvas.drawLine(
Offset(x, padTop),
Offset(x, padTop + plotH),
markerPaint,
);
}
// Cursor crosshair + data dot (still inside the plot clip).
int? hoverCol;
double? hoverY;
int? hoverTsUs;
if (hoverLocalPos != null) {
final hx = hoverLocalPos!.dx;
final hy = hoverLocalPos!.dy;
if (hx >= padLeft &&
hx <= padLeft + plotW &&
hy >= padTop &&
hy <= padTop + plotH) {
final col = (hx - padLeft).floor().clamp(0, cols.length - 1);
hoverCol = col;
hoverTsUs = win.startUs +
(((col + 0.5) / plotW) * (win.endUs - win.startUs)).round();
final cursorPaint = Paint()
..color = cursorColor
..strokeWidth = 1;
canvas.drawLine(
Offset(xForCol(col), padTop),
Offset(xForCol(col), padTop + plotH),
cursorPaint,
);
if (cols[col].hasData) {
hoverY = (cols[col].min + cols[col].max) / 2;
final yPx = yForVal(hoverY);
canvas.drawLine(
Offset(padLeft, yPx),
Offset(padLeft + plotW, yPx),
cursorPaint,
);
canvas.drawCircle(
Offset(xForCol(col), yPx),
3,
Paint()..color = lineColor,
);
}
}
}
canvas.restore();
// Cursor readout box (outside the clip so it can overlay labels).
if (hoverCol != null) {
final tStr = hoverTsUs != null ? _fmtTime(hoverTsUs) : '';
final yStr = hoverY != null ? hoverY.toStringAsFixed(3) : '';
_drawReadout(canvas, 'x=$tStr y=$yStr',
Offset(padLeft + 4, padTop + 2));
}
// Axes labels.
_drawText(canvas, '${yMax.toStringAsFixed(2)}',
Offset(padLeft - 4, padTop), align: TextAlign.right);
_drawText(canvas, '${yMin.toStringAsFixed(2)}',
Offset(padLeft - 4, padTop + plotH - 12), align: TextAlign.right);
_drawText(canvas, _fmtTime(win.startUs),
Offset(padLeft, size.height - 14));
_drawText(canvas, _fmtTime(win.endUs),
Offset(size.width - padRight, size.height - 14),
align: TextAlign.right);
}
void _drawReadout(Canvas c, String s, Offset where) {
final textColor =
isDark ? const Color(0xFFEEEEEE) : const Color(0xFF222222);
final bgColor =
isDark ? const Color(0xCC2A2B2E) : const Color(0xCCFFFFFF);
final borderColor =
isDark ? const Color(0x66FFFFFF) : const Color(0x44000000);
final tp = TextPainter(
text: TextSpan(
text: s,
style: TextStyle(
fontFamily: 'monospace',
fontSize: 10,
color: textColor,
),
),
textDirection: TextDirection.ltr,
)..layout();
final bgRect = Rect.fromLTWH(
where.dx,
where.dy,
tp.width + 8,
tp.height + 4,
);
c.drawRRect(
RRect.fromRectAndRadius(bgRect, const Radius.circular(3)),
Paint()..color = bgColor,
);
c.drawRRect(
RRect.fromRectAndRadius(bgRect, const Radius.circular(3)),
Paint()
..color = borderColor
..style = PaintingStyle.stroke
..strokeWidth = 0.5,
);
tp.paint(c, Offset(where.dx + 4, where.dy + 2));
}
void _drawText(Canvas c, String s, Offset where,
{TextAlign align = TextAlign.left}) {
final tp = TextPainter(
text: TextSpan(
text: s,
style: const TextStyle(fontSize: 9, color: Colors.grey),
),
textDirection: TextDirection.ltr,
textAlign: align,
)..layout();
final dx = align == TextAlign.right ? where.dx - tp.width : where.dx;
tp.paint(c, Offset(dx, where.dy));
}
String _fmtTime(int us) {
final d = DateTime.fromMicrosecondsSinceEpoch(us);
return '${d.hour.toString().padLeft(2, '0')}:'
'${d.minute.toString().padLeft(2, '0')}:'
'${d.second.toString().padLeft(2, '0')}.'
'${d.millisecond.toString().padLeft(3, '0')}';
}
@override
bool shouldRepaint(ChartPainter old) => true; // Per-frame repaint.
}