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Zack-GLZack-GL
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[PR fluttercandies#27 feature] Repaint when the last candle changed
1 parent 4f942a5 commit 4040e48

5 files changed

Lines changed: 129 additions & 1 deletion

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‎lib/src/candle_data.dart‎

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Original file line numberDiff line numberDiff line change
@@ -71,6 +71,29 @@ class CandleData {
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return result;
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}
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74+
@override
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bool operator ==(Object other) =>
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identical(this, other) ||
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other is CandleData &&
78+
runtimeType == other.runtimeType &&
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timestamp == other.timestamp &&
80+
open == other.open &&
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high == other.high &&
82+
low == other.low &&
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close == other.close &&
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volume == other.volume &&
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trends == other.trends;
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@override
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int get hashCode =>
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timestamp.hashCode ^
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open.hashCode ^
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high.hashCode ^
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low.hashCode ^
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close.hashCode ^
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volume.hashCode ^
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trends.hashCode;
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@override
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String toString() => "<CandleData ($timestamp: $close)>";
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}

‎lib/src/chart_painter.dart‎

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Original file line numberDiff line numberDiff line change
@@ -27,6 +27,8 @@ class ChartPainter extends CustomPainter {
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// Draw time labels (dates) & price labels
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_drawTimeLabels(canvas, params);
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_drawPriceGridAndLabels(canvas, params);
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_drawCurrentPriceLabel(canvas, params);
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_drawCurrentPriceLine(canvas, params);
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// Draw prices, volumes & trend line
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canvas.save();
@@ -107,6 +109,65 @@ class ChartPainter extends CustomPainter {
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});
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}
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112+
void _drawCurrentPriceLabel(
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Canvas canvas,
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PainterParams params,
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) {
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final currentPrice = params.currentPrice;
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if (currentPrice == null) {
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return;
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}
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final priceTp = TextPainter(
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text: TextSpan(
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text: getPriceLabel(currentPrice),
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style: params.style.currentPriceStyle.labelStyle,
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),
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)
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..textDirection = TextDirection.ltr
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..layout();
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129+
final dx = params.chartWidth + 4;
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final dy =
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params.fitPrice(currentPrice).clamp(0, params.chartHeight).toDouble() -
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priceTp.height / 2;
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final padding = params.style.currentPriceStyle.rectPadding;
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final radius = params.style.currentPriceStyle.rectRadius;
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final rectColor = params.style.currentPriceStyle.rectColor;
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final rect = Rect.fromLTWH(
139+
dx, dy, priceTp.width + 2 * padding, priceTp.height + 2 * padding);
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final rrect = RRect.fromRectAndRadius(rect, Radius.circular(radius));
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canvas.drawRRect(rrect, Paint()..color = rectColor);
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priceTp.paint(canvas, Offset(dx + padding, dy + padding));
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}
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void _drawCurrentPriceLine(Canvas canvas, PainterParams params) {
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final currentPrice = params.currentPrice;
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if (currentPrice == null) {
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return;
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}
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final paint = Paint()
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..color = Colors.red
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..strokeWidth = 1
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..style = PaintingStyle.stroke;
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final dashWidth = 4.0;
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final dashSpace = 2.0;
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double startX = 0;
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final clampedPrice =
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params.fitPrice(currentPrice).clamp(0, params.chartHeight).toDouble();
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while (startX < params.chartWidth) {
162+
canvas.drawLine(
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Offset(startX, clampedPrice),
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Offset(startX + dashWidth, clampedPrice),
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paint,
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);
167+
startX += dashWidth + dashSpace;
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}
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}
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void _drawSingleDay(canvas, PainterParams params, int i) {
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final candle = params.candles[i];
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final x = i * params.candleWidth;

‎lib/src/chart_style.dart‎

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Original file line numberDiff line numberDiff line change
@@ -54,6 +54,9 @@ class ChartStyle {
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/// This appears when user clicks on the chart.
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final Color overlayBackgroundColor;
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/// The style of current price labels (on the right of the chart).
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final CurrentPriceStyle currentPriceStyle;
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const ChartStyle({
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this.volumeHeightFactor = 0.2,
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this.priceLabelWidth = 48.0,
@@ -77,5 +80,34 @@ class ChartStyle {
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this.priceGridLineColor = Colors.grey,
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this.selectionHighlightColor = const Color(0x33757575),
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this.overlayBackgroundColor = const Color(0xEE757575),
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this.currentPriceStyle = const CurrentPriceStyle(
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labelStyle: TextStyle(
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fontSize: 12,
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color: Colors.white,
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),
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rectPadding: 4.0,
89+
rectRadius: 2.0,
90+
rectColor: Colors.red),
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});
92+
}
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94+
class CurrentPriceStyle {
95+
const CurrentPriceStyle({
96+
required this.labelStyle,
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required this.rectPadding,
98+
required this.rectRadius,
99+
required this.rectColor,
80100
});
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102+
/// The style of current price labels (on the right of the chart).
103+
final TextStyle labelStyle;
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105+
/// The padding around the current price rect.
106+
final double rectPadding;
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108+
/// The radius of the current price rect.
109+
final double rectRadius;
110+
111+
/// The color of the current price rect.
112+
final Color rectColor;
81113
}

‎lib/src/interactive_chart.dart‎

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Original file line numberDiff line numberDiff line change
@@ -66,6 +66,9 @@ class InteractiveChart extends StatefulWidget {
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/// Provides X-axis offset details.
6767
final ValueChanged<XAxisOffsetDetails>? onXOffsetChanged;
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69+
/// The current price to be displayed on the right side of the chart.
70+
final double? currentPrice;
71+
6972
const InteractiveChart({
7073
Key? key,
7174
required this.candles,
@@ -76,6 +79,7 @@ class InteractiveChart extends StatefulWidget {
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this.overlayInfo,
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this.onTap,
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this.onCandleResize,
82+
this.currentPrice,
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this.onXOffsetChanged,
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}) : this.style = style ?? const ChartStyle(),
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assert(candles.length >= 3,
@@ -192,6 +196,7 @@ class _InteractiveChartState extends State<InteractiveChart> {
192196
tapPosition: _tapPosition,
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leadingTrends: leadingTrends,
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trailingTrends: trailingTrends,
199+
currentPrice: widget.currentPrice,
195200
),
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),
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duration: Duration(milliseconds: 300),

‎lib/src/painter_params.dart‎

Lines changed: 8 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,11 +1,13 @@
11
import 'dart:ui';
2+
23
import 'package:flutter/widgets.dart';
34

4-
import 'chart_style.dart';
55
import 'candle_data.dart';
6+
import 'chart_style.dart';
67

78
class PainterParams {
89
final List<CandleData> candles;
10+
final double? currentPrice;
911
final ChartStyle style;
1012
final Size size;
1113
final double candleWidth;
@@ -23,6 +25,7 @@ class PainterParams {
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2426
PainterParams({
2527
required this.candles,
28+
this.currentPrice,
2629
required this.style,
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required this.size,
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required this.candleWidth,
@@ -97,12 +100,16 @@ class PainterParams {
97100
tapPosition: b.tapPosition,
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leadingTrends: b.leadingTrends,
99102
trailingTrends: b.trailingTrends,
103+
currentPrice:
104+
b.currentPrice != null ? lerpField((p) => p.currentPrice!) : null,
100105
);
101106
}
102107

103108
bool shouldRepaint(PainterParams other) {
104109
if (candles.length != other.candles.length) return true;
105110

111+
if (other.currentPrice != currentPrice) return true;
112+
106113
if (size != other.size ||
107114
candleWidth != other.candleWidth ||
108115
startOffset != other.startOffset ||

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