flutter_package / dart_pdf

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David PHAM-VAN
1b098ee2 1 parent ae776e60

Improve PieChart

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Showing 2 changed files with 175 additions and 37 deletions
... ... @@ -35,7 +35,6 @@ class ChartLegend extends StatelessWidget {
this.direction = Axis.vertical,
this.decoration,
this.padding = const EdgeInsets.all(5),
this.maxWidth = 200,
});
final TextStyle? textStyle;
... ... @@ -48,8 +47,6 @@ class ChartLegend extends StatelessWidget {
final EdgeInsets padding;
final double maxWidth;
Widget _buildLegend(Context context, Dataset dataset) {
final style = Theme.of(context).defaultTextStyle.merge(textStyle);
... ... @@ -62,13 +59,9 @@ class ChartLegend extends StatelessWidget {
margin: const EdgeInsets.only(right: 5),
child: dataset.legendShape(),
),
ConstrainedBox(
constraints: BoxConstraints(maxWidth: maxWidth),
child: Text(
dataset.legend!,
style: textStyle,
softWrap: false,
),
Text(
dataset.legend!,
style: textStyle,
),
],
);
... ... @@ -82,6 +75,9 @@ class ChartLegend extends StatelessWidget {
direction: direction,
spacing: 10,
runSpacing: 10,
crossAxisAlignment: direction == Axis.horizontal
? WrapCrossAlignment.center
: WrapCrossAlignment.start,
children: <Widget>[
for (final Dataset dataset in datasets)
if (dataset.legend != null) _buildLegend(context, dataset)
... ...
... ... @@ -109,7 +109,7 @@ class PieGrid extends ChartGrid {
}
}
enum PieLegendPosition { none, auto, inside }
enum PieLegendPosition { none, auto, inside, outside }
class PieDataSet extends Dataset {
PieDataSet({
... ... @@ -123,16 +123,22 @@ class PieDataSet extends Dataset {
this.surfaceOpacity = 1,
this.offset = 0,
this.legendStyle,
this.legendAlign,
this.legendPosition = PieLegendPosition.auto,
this.legendLineWidth = 1.0,
this.legendLineColor = PdfColors.black,
Widget? legendWidget,
this.legendOffset = 20,
}) : drawBorder = drawBorder ?? borderColor != null && color != borderColor,
assert((drawBorder ?? borderColor != null && color != borderColor) ||
drawSurface),
_legendWidget = legendWidget,
super(
legend: legend,
color: color,
);
final double value;
final num value;
late double angleStart;
... ... @@ -150,18 +156,124 @@ class PieDataSet extends Dataset {
final TextStyle? legendStyle;
final TextAlign? legendAlign;
final PieLegendPosition legendPosition;
Widget? _legendWidget;
final double legendOffset;
final double legendLineWidth;
final PdfColor legendLineColor;
PdfPoint? _legendAnchor;
PdfPoint? _legendPivot;
PdfPoint? _legendStart;
bool get _isFullCircle => angleEnd - angleStart >= pi * 2;
@override
void layout(Context context, BoxConstraints constraints,
{bool parentUsesSize = false}) {
// final size = constraints.biggest;
final _offset = _isFullCircle ? 0 : offset;
// ignore: avoid_as
final grid = Chart.of(context).grid as PieGrid;
final len = grid.pieSize + offset;
final len = grid.pieSize + _offset;
var x = -len;
var y = -len;
var w = len * 2;
var h = len * 2;
final lp = legendPosition == PieLegendPosition.auto
? (angleEnd - angleStart > pi / 6
? PieLegendPosition.inside
: PieLegendPosition.outside)
: legendPosition;
// Find the legend position
final bisect = _isFullCircle ? 1 / 4 * pi : (angleStart + angleEnd) / 2;
final _legendAlign = legendAlign ??
(lp == PieLegendPosition.inside
? TextAlign.center
: (bisect > pi ? TextAlign.right : TextAlign.left));
_legendWidget ??= legend == null
? null
: Text(legend!, style: legendStyle, textAlign: _legendAlign);
if (_legendWidget != null) {
_legendWidget!.layout(context,
BoxConstraints(maxWidth: grid.pieSize, maxHeight: grid.pieSize));
assert(_legendWidget!.box != null);
final ls = _legendWidget!.box!.size;
// final style = Theme.of(context).defaultTextStyle.merge(legendStyle);
switch (lp) {
case PieLegendPosition.outside:
final o = grid.pieSize + legendOffset;
final cx = sin(bisect) * (_offset + o);
final cy = cos(bisect) * (_offset + o);
_legendStart = PdfPoint(
sin(bisect) * (_offset + grid.pieSize + legendOffset * 0.1),
cos(bisect) * (_offset + grid.pieSize + legendOffset * 0.1),
);
_legendPivot = PdfPoint(cx, cy);
if (bisect > pi) {
_legendAnchor = PdfPoint(
cx - legendOffset / 2 * 0.8,
cy,
);
_legendWidget!.box = PdfRect.fromPoints(
PdfPoint(
cx - legendOffset / 2 - ls.x,
cy - ls.y / 2,
),
ls);
w = max(w, (-cx + legendOffset / 2 + ls.x) * 2);
h = max(h, cy.abs() * 2 + ls.y);
x = -w / 2;
y = -h / 2;
} else {
_legendAnchor = PdfPoint(
cx + legendOffset / 2 * 0.8,
cy,
);
_legendWidget!.box = PdfRect.fromPoints(
PdfPoint(
cx + legendOffset / 2,
cy - ls.y / 2,
),
ls);
w = max(w, (cx + legendOffset / 2 + ls.x) * 2);
h = max(h, cy.abs() * 2 + ls.y);
x = -w / 2;
y = -h / 2;
}
break;
case PieLegendPosition.inside:
final o = _isFullCircle ? 0 : grid.pieSize * 2 / 3;
final cx = sin(bisect) * (_offset + o);
final cy = cos(bisect) * (_offset + o);
_legendWidget!.box = PdfRect.fromPoints(
PdfPoint(
cx - ls.x / 2,
cy - ls.y / 2,
),
ls);
break;
default:
break;
}
}
box = PdfRect(-len, -len, len * 2, len * 2);
box = PdfRect(x, y, w, h);
}
void _shape(Context context) {
... ... @@ -178,11 +290,15 @@ class PieDataSet extends Dataset {
final ex = cx + sin(angleEnd) * grid.pieSize;
final ey = cy + cos(angleEnd) * grid.pieSize;
context.canvas
..moveTo(cx, cy)
..lineTo(sx, sy)
..bezierArc(sx, sy, grid.pieSize, grid.pieSize, ex, ey,
large: angleEnd - angleStart > pi);
if (_isFullCircle) {
context.canvas.drawEllipse(0, 0, grid.pieSize, grid.pieSize);
} else {
context.canvas
..moveTo(cx, cy)
..lineTo(sx, sy)
..bezierArc(sx, sy, grid.pieSize, grid.pieSize, ex, ey,
large: angleEnd - angleStart > pi);
}
}
@override
... ... @@ -224,23 +340,49 @@ class PieDataSet extends Dataset {
}
void paintLegend(Context context) {
if (legendPosition != PieLegendPosition.none && legend != null) {
// ignore: avoid_as
final grid = Chart.of(context).grid as PieGrid;
final bisect = (angleStart + angleEnd) / 2;
final o = grid.pieSize * 2 / 3;
final cx = sin(bisect) * (offset + o);
final cy = cos(bisect) * (offset + o);
Widget.draw(
Text(legend!, style: legendStyle, textAlign: TextAlign.center),
offset: PdfPoint(cx, cy),
context: context,
alignment: Alignment.center,
constraints: const BoxConstraints(maxWidth: 200, maxHeight: 200),
);
if (legendPosition != PieLegendPosition.none && _legendWidget != null) {
if (_legendAnchor != null &&
_legendPivot != null &&
_legendStart != null) {
context.canvas
..saveContext()
..moveTo(_legendStart!.x, _legendStart!.y)
..lineTo(_legendPivot!.x, _legendPivot!.y)
..lineTo(_legendAnchor!.x, _legendAnchor!.y)
..setLineWidth(legendLineWidth)
..setLineCap(PdfLineCap.round)
..setLineJoin(PdfLineJoin.round)
..setStrokeColor(legendLineColor)
..strokePath()
..restoreContext();
}
_legendWidget!.paint(context);
}
}
@override
void debugPaint(Context context) {
super.debugPaint(context);
// ignore: avoid_as
final grid = Chart.of(context).grid as PieGrid;
final bisect = (angleStart + angleEnd) / 2;
final cx = sin(bisect) * (offset + grid.pieSize + legendOffset);
final cy = cos(bisect) * (offset + grid.pieSize + legendOffset);
if (_legendWidget != null) {
context.canvas
..saveContext()
..moveTo(0, 0)
..lineTo(cx, cy)
..setLineWidth(0.5)
..setLineDashPattern([3, 1])
..setStrokeColor(PdfColors.blue)
..strokePath()
..restoreContext();
}
}
}
... ...