Implemented auto calculate interval function, and used for titles, an…

…d grid lines, it prevents performance issues, like #101.
imaNNeo · May 24, 2020 · 19fe35d · 19fe35d
1 parent 12be214
commit 19fe35d
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Showing 9 changed files with 166 additions and 32 deletions.
diff --git a/lib/src/chart/bar_chart/bar_chart_painter.dart b/lib/src/chart/bar_chart/bar_chart_painter.dart
@@ -284,6 +284,8 @@ class BarChartPainter extends AxisChartPainter<BarChartData> with TouchHandler<B
 
     // Left Titles
     final leftTitles = targetData.titlesData.leftTitles;
+    final leftInterval =
+        leftTitles.interval ?? getEfficientInterval(viewSize.height, data.verticalDiff);
     if (leftTitles.showTitles) {
       double verticalSeek = data.minY;
       while (verticalSeek <= data.maxY) {
@@ -309,12 +311,14 @@ class BarChartPainter extends AxisChartPainter<BarChartData> with TouchHandler<B
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        verticalSeek += leftTitles.interval;
+        verticalSeek += leftInterval;
       }
     }
 
     // Right Titles
     final rightTitles = targetData.titlesData.rightTitles;
+    final rightInterval =
+        rightTitles.interval ?? getEfficientInterval(viewSize.height, data.verticalDiff);
     if (rightTitles.showTitles) {
       double verticalSeek = data.minY;
       while (verticalSeek <= data.maxY) {
@@ -340,7 +344,7 @@ class BarChartPainter extends AxisChartPainter<BarChartData> with TouchHandler<B
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        verticalSeek += rightTitles.interval;
+        verticalSeek += rightInterval;
       }
     }
 

diff --git a/lib/src/chart/base/axis_chart/axis_chart_data.dart b/lib/src/chart/base/axis_chart/axis_chart_data.dart
@@ -6,6 +6,7 @@ import 'package:fl_chart/src/chart/base/axis_chart/axis_chart_painter.dart';
 import 'package:fl_chart/src/chart/base/base_chart/base_chart_data.dart';
 import 'package:fl_chart/src/utils/lerp.dart';
 import 'package:flutter/material.dart';
+import 'package:fl_chart/src/utils/utils.dart';
 
 /// This is the base class for axis base charts data
 /// that contains a [FlGridData] that holds data for showing grid lines,
@@ -27,6 +28,12 @@ abstract class AxisChartData extends BaseChartData with EquatableMixin {
   /// A background color which is drawn behind th chart.
   Color backgroundColor;
 
+  /// Difference of [maxY] and [minY]
+  double get verticalDiff => maxY - minY;
+
+  /// Difference of [maxX] and [minX]
+  double get horizontalDiff => maxX - minX;
+
   AxisChartData({
     FlGridData gridData,
     FlAxisTitleData axisTitleData,
@@ -243,8 +250,8 @@ class SideTitles with EquatableMixin {
   /// [textStyle] determines the text style of them,
   /// [margin] determines margin of texts from the border line,
   ///
-  /// by default, texts are showing with 1.0 interval,
-  /// you can change this value using [interval],
+  /// texts are showing with provided [interval],
+  /// or you can let it be null to be calculated using [getEfficientInterval],
   ///
   /// you can change rotation of drawing titles using [rotateAngle].
   SideTitles({
@@ -264,7 +271,7 @@ class SideTitles with EquatableMixin {
               fontSize: 11,
             ),
         margin = margin ?? 6,
-        interval = interval ?? 1.0,
+        interval = interval,
         rotateAngle = rotateAngle ?? 0.0;
 
   /// Lerps a [SideTitles] based on [t] value, check [Tween.lerp].
@@ -352,7 +359,7 @@ class FlGridData with EquatableMixin {
   /// Determines showing or hiding all horizontal lines.
   final bool drawHorizontalLine;
 
-  /// Determines interval between horizontal lines.
+  /// Determines interval between horizontal lines, left it null to be auto calculated.
   final double horizontalInterval;
 
   /// Gives you a y value, and gets a [FlLine] that represents specified line.
@@ -364,7 +371,7 @@ class FlGridData with EquatableMixin {
   /// Determines showing or hiding all vertical lines.
   final bool drawVerticalLine;
 
-  /// Determines interval between vertical lines.
+  /// Determines interval between vertical lines, left it null to be auto calculated.
   final double verticalInterval;
 
   /// Gives you a x value, and gets a [FlLine] that represents specified line.
@@ -407,11 +414,11 @@ class FlGridData with EquatableMixin {
     CheckToShowGrid checkToShowVerticalLine,
   })  : show = show ?? true,
         drawHorizontalLine = drawHorizontalLine ?? true,
-        horizontalInterval = horizontalInterval ?? 1.0,
+        horizontalInterval = horizontalInterval,
         getDrawingHorizontalLine = getDrawingHorizontalLine ?? defaultGridLine,
         checkToShowHorizontalLine = checkToShowHorizontalLine ?? showAllGrids,
         drawVerticalLine = drawVerticalLine ?? false,
-        verticalInterval = verticalInterval ?? 1.0,
+        verticalInterval = verticalInterval,
         getDrawingVerticalLine = getDrawingVerticalLine ?? defaultGridLine,
         checkToShowVerticalLine = checkToShowVerticalLine ?? showAllGrids;
 

diff --git a/lib/src/chart/base/axis_chart/axis_chart_painter.dart b/lib/src/chart/base/axis_chart/axis_chart_painter.dart
@@ -4,6 +4,7 @@ import 'package:fl_chart/src/chart/bar_chart/bar_chart_painter.dart';
 import 'package:fl_chart/src/chart/base/base_chart/base_chart_painter.dart';
 import 'package:fl_chart/src/chart/line_chart/line_chart_painter.dart';
 import 'package:fl_chart/src/extensions/canvas_extension.dart';
+import 'package:fl_chart/src/utils/utils.dart';
 import 'package:flutter/material.dart';
 
 import 'axis_chart_data.dart';
@@ -201,14 +202,15 @@ abstract class AxisChartPainter<D extends AxisChartData> extends BaseChartPainte
     final Size usableViewSize = getChartUsableDrawSize(viewSize);
     // Show Vertical Grid
     if (data.gridData.drawVerticalLine) {
-      double verticalSeek = data.minX + data.gridData.verticalInterval;
+      final int verticalInterval = data.gridData.verticalInterval ??
+          getEfficientInterval(viewSize.width, data.horizontalDiff);
+      double verticalSeek = data.minX + verticalInterval;
 
       final double delta = data.maxX - data.minX;
-      final int count = delta ~/ data.gridData.verticalInterval;
+      final int count = delta ~/ verticalInterval;
       final double lastPosition = count * verticalSeek;
       final bool lastPositionOverlapsWithBorder = lastPosition == data.maxX;
-      final end =
-          lastPositionOverlapsWithBorder ? data.maxX - data.gridData.verticalInterval : data.maxX;
+      final end = lastPositionOverlapsWithBorder ? data.maxX - verticalInterval : data.maxX;
 
       while (verticalSeek <= end) {
         if (data.gridData.checkToShowVerticalLine(verticalSeek)) {
@@ -223,21 +225,22 @@ abstract class AxisChartPainter<D extends AxisChartData> extends BaseChartPainte
           final double y2 = usableViewSize.height + getTopOffsetDrawSize();
           canvas.drawDashedLine(Offset(x1, y1), Offset(x2, y2), _gridPaint, flLineStyle.dashArray);
         }
-        verticalSeek += data.gridData.verticalInterval;
+        verticalSeek += verticalInterval;
       }
     }
 
     // Show Horizontal Grid
     if (data.gridData.drawHorizontalLine) {
-      double horizontalSeek = data.minY + data.gridData.horizontalInterval;
+      final int horizontalInterval = data.gridData.horizontalInterval ??
+          getEfficientInterval(viewSize.height, data.verticalDiff);
+      double horizontalSeek = data.minY + horizontalInterval;
 
       final double delta = data.maxY - data.minY;
-      final int count = delta ~/ data.gridData.horizontalInterval;
+      final int count = delta ~/ horizontalInterval;
       final double lastPosition = count * horizontalSeek;
       final bool lastPositionOverlapsWithBorder = lastPosition == data.maxY;
 
-      final end =
-          lastPositionOverlapsWithBorder ? data.maxY - data.gridData.horizontalInterval : data.maxY;
+      final end = lastPositionOverlapsWithBorder ? data.maxY - horizontalInterval : data.maxY;
 
       while (horizontalSeek <= end) {
         if (data.gridData.checkToShowHorizontalLine(horizontalSeek)) {
@@ -253,7 +256,7 @@ abstract class AxisChartPainter<D extends AxisChartData> extends BaseChartPainte
           canvas.drawDashedLine(Offset(x1, y1), Offset(x2, y2), _gridPaint, flLine.dashArray);
         }
 
-        horizontalSeek += data.gridData.horizontalInterval;
+        horizontalSeek += horizontalInterval;
       }
     }
   }

diff --git a/lib/src/chart/base/base_chart/base_chart_data.dart b/lib/src/chart/base/base_chart/base_chart_data.dart
@@ -1,4 +1,5 @@
 import 'package:equatable/equatable.dart';
+import 'package:fl_chart/src/utils/utils.dart';
 import 'package:flutter/material.dart';
 
 import 'base_chart_painter.dart';
@@ -127,9 +128,9 @@ typedef GetTitleFunction = String Function(double value);
 
 /// The default [SideTitles.getTitles] function.
 ///
-/// It maps the axis number to a string and returns it.
+/// formats the axis number to a shorter string using [formatNumber].
 String defaultGetTitle(double value) {
-  return '$value';
+  return formatNumber(value);
 }
 
 /// This class holds the touch response details.

diff --git a/lib/src/chart/line_chart/line_chart_painter.dart b/lib/src/chart/line_chart/line_chart_painter.dart
@@ -842,6 +842,8 @@ class LineChartPainter extends AxisChartPainter<LineChartData>
 
     // Left Titles
     final leftTitles = targetData.titlesData.leftTitles;
+    final leftInterval =
+        leftTitles.interval ?? getEfficientInterval(viewSize.height, data.verticalDiff);
     if (leftTitles.showTitles) {
       double verticalSeek = data.minY;
       while (verticalSeek <= data.maxY) {
@@ -867,12 +869,14 @@ class LineChartPainter extends AxisChartPainter<LineChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        verticalSeek += leftTitles.interval;
+        verticalSeek += leftInterval;
       }
     }
 
     // Top titles
     final topTitles = targetData.titlesData.topTitles;
+    final topInterval =
+        topTitles.interval ?? getEfficientInterval(viewSize.width, data.horizontalDiff);
     if (topTitles.showTitles) {
       double horizontalSeek = data.minX;
       while (horizontalSeek <= data.maxX) {
@@ -899,12 +903,14 @@ class LineChartPainter extends AxisChartPainter<LineChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        horizontalSeek += topTitles.interval;
+        horizontalSeek += topInterval;
       }
     }
 
     // Right Titles
     final rightTitles = targetData.titlesData.rightTitles;
+    final rightInterval =
+        rightTitles.interval ?? getEfficientInterval(viewSize.height, data.verticalDiff);
     if (rightTitles.showTitles) {
       double verticalSeek = data.minY;
       while (verticalSeek <= data.maxY) {
@@ -931,12 +937,14 @@ class LineChartPainter extends AxisChartPainter<LineChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        verticalSeek += rightTitles.interval;
+        verticalSeek += rightInterval;
       }
     }
 
     // Bottom titles
     final bottomTitles = targetData.titlesData.bottomTitles;
+    final bottomInterval =
+        bottomTitles.interval ?? getEfficientInterval(viewSize.width, data.horizontalDiff);
     if (bottomTitles.showTitles) {
       double horizontalSeek = data.minX;
       while (horizontalSeek <= data.maxX) {
@@ -961,7 +969,7 @@ class LineChartPainter extends AxisChartPainter<LineChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        horizontalSeek += bottomTitles.interval;
+        horizontalSeek += bottomInterval;
       }
     }
   }

diff --git a/lib/src/chart/scatter_chart/scatter_chart_painter.dart b/lib/src/chart/scatter_chart/scatter_chart_painter.dart
@@ -65,6 +65,8 @@ class ScatterChartPainter extends AxisChartPainter<ScatterChartData>
 
     // Left Titles
     final leftTitles = targetData.titlesData.leftTitles;
+    final leftInterval =
+        leftTitles.interval ?? getEfficientInterval(viewSize.height, data.verticalDiff);
     if (leftTitles.showTitles) {
       double verticalSeek = data.minY;
       while (verticalSeek <= data.maxY) {
@@ -90,12 +92,14 @@ class ScatterChartPainter extends AxisChartPainter<ScatterChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        verticalSeek += leftTitles.interval;
+        verticalSeek += leftInterval;
       }
     }
 
     // Top titles
     final topTitles = targetData.titlesData.topTitles;
+    final topInterval =
+        topTitles.interval ?? getEfficientInterval(viewSize.width, data.horizontalDiff);
     if (topTitles.showTitles) {
       double horizontalSeek = data.minX;
       while (horizontalSeek <= data.maxX) {
@@ -122,12 +126,14 @@ class ScatterChartPainter extends AxisChartPainter<ScatterChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        horizontalSeek += topTitles.interval;
+        horizontalSeek += topInterval;
       }
     }
 
     // Right Titles
     final rightTitles = targetData.titlesData.rightTitles;
+    final rightInterval =
+        rightTitles.interval ?? getEfficientInterval(viewSize.height, data.verticalDiff);
     if (rightTitles.showTitles) {
       double verticalSeek = data.minY;
       while (verticalSeek <= data.maxY) {
@@ -154,12 +160,14 @@ class ScatterChartPainter extends AxisChartPainter<ScatterChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        verticalSeek += rightTitles.interval;
+        verticalSeek += rightInterval;
       }
     }
 
     // Bottom titles
     final bottomTitles = targetData.titlesData.bottomTitles;
+    final bottomInterval =
+        bottomTitles.interval ?? getEfficientInterval(viewSize.width, data.horizontalDiff);
     if (bottomTitles.showTitles) {
       double horizontalSeek = data.minX;
       while (horizontalSeek <= data.maxX) {
@@ -186,7 +194,7 @@ class ScatterChartPainter extends AxisChartPainter<ScatterChartData>
         tp.paint(canvas, Offset(x, y));
         canvas.restore();
 
-        horizontalSeek += bottomTitles.interval;
+        horizontalSeek += bottomInterval;
       }
     }
   }