Fix getBestInitialIntervalValue() problem with values above or below …

…zero, #893.
imaNNeo · Feb 4, 2022 · 9137f08 · 9137f08
1 parent 4917dc4
commit 9137f08
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Showing 6 changed files with 69 additions and 11 deletions.
diff --git a/lib/src/chart/base/axis_chart/axis_chart_helper.dart b/lib/src/chart/base/axis_chart/axis_chart_helper.dart
@@ -29,7 +29,8 @@ class AxisChartHelper {
     final initialValue =
         Utils().getBestInitialIntervalValue(min, max, interval);
     var axisSeek = initialValue;
-    if (!minIncluded && axisSeek == min) {
+    final firstPositionOverlapsWithMin = axisSeek == min;
+    if (!minIncluded && firstPositionOverlapsWithMin) {
       axisSeek += interval;
     }
     final diff = max - min;
@@ -40,9 +41,15 @@ class AxisChartHelper {
         !maxIncluded && lastPositionOverlapsWithMax ? max - interval : max;
 
     final epsilon = interval / 100000;
+    if (minIncluded && !firstPositionOverlapsWithMin) {
+      action(min);
+    }
     while (axisSeek <= end + epsilon) {
       action(axisSeek);
       axisSeek += interval;
     }
+    if (maxIncluded && !lastPositionOverlapsWithMax) {
+      action(max);
+    }
   }
 }
diff --git a/lib/src/utils/utils.dart b/lib/src/utils/utils.dart
@@ -269,12 +269,28 @@ class Utils {
   /// For example if we have -3 to +3, with interval 2. if we start from -3, we get something like this: -3, -1, +1, +3
   /// But the most important point is zero in most cases. with this logic we get this: -2, 0, 2
   double getBestInitialIntervalValue(double min, double max, double interval) {
-    if (min > 0 || max < 0) {
-      return min;
-    }
     if (max - min <= interval) {
       return min;
     }
+
+    if (min > 0 || max < 0) {
+      var minIsNegative = false;
+      if (min < 0) {
+        minIsNegative = true;
+      }
+
+      final mod = min.abs() % interval;
+      if (mod == 0) {
+        return min;
+      }
+      final covered = (min.abs() ~/ interval) * interval;
+      final result = covered + mod + (interval - mod);
+      if (minIsNegative) {
+        return -result;
+      }
+      return result;
+    }
+
     return interval * (min ~/ interval).toDouble();
   }
 

diff --git a/test/chart/bar_chart/bar_chart_painter_test.dart b/test/chart/bar_chart/bar_chart_painter_test.dart
@@ -1120,7 +1120,7 @@ void main() {
 
       barChartPainter.drawTitles(
           _mockBuildContext, _mockCanvasWrapper, barGroupsPosition, holder);
-      expect(results.length, 14);
+      expect(results.length, 16);
     });
   });
 

diff --git a/test/chart/base/axis_chart_helper_test.dart b/test/chart/base/axis_chart_helper_test.dart
@@ -63,11 +63,12 @@ void main() {
           results.add(axisValue);
         },
       );
-      expect(results.length, 4);
+      expect(results.length, 5);
       expect(results[0], 0);
       expect(results[1], 3);
       expect(results[2], 6);
       expect(results[3], 9);
+      expect(results[4], 10);
     });
 
     test('test 4', () {
@@ -87,5 +88,24 @@ void main() {
       expect(results[1], 6);
       expect(results[2], 9);
     });
+
+    test('test 4', () {
+      List<double> results = [];
+      AxisChartHelper().iterateThroughAxis(
+        min: 35,
+        minIncluded: true,
+        max: 130,
+        maxIncluded: true,
+        interval: 50,
+        action: (axisValue) {
+          results.add(axisValue);
+        },
+      );
+      expect(results.length, 4);
+      expect(results[0], 35);
+      expect(results[1], 50);
+      expect(results[2], 100);
+      expect(results[3], 130);
+    });
   });
 }
diff --git a/test/chart/scatter_chart/scatter_chart_painter_test.dart b/test/chart/scatter_chart/scatter_chart_painter_test.dart
@@ -236,7 +236,7 @@ void main() {
         _mockCanvasWrapper,
         holder,
       );
-      verify(_mockCanvasWrapper.drawText(any, any, 0.0)).called(4);
+      verify(_mockCanvasWrapper.drawText(any, any, 0.0)).called(5);
     });
 
     test('test 3', () {
@@ -330,7 +330,7 @@ void main() {
         _mockCanvasWrapper,
         holder,
       );
-      verify(_mockCanvasWrapper.drawText(any, any, 0.0)).called(7);
+      verify(_mockCanvasWrapper.drawText(any, any, 0.0)).called(8);
       expect(leftTitlesCalledValues.contains(0.0), true);
       expect(leftTitlesCalledValues.contains(5.0), true);
       expect(leftTitlesCalledValues.contains(10.0), true);
@@ -396,7 +396,7 @@ void main() {
         _mockCanvasWrapper,
         holder,
       );
-      verify(_mockCanvasWrapper.drawText(any, any, 0.0)).called(7);
+      verify(_mockCanvasWrapper.drawText(any, any, 0.0)).called(8);
       expect(leftTitlesCalledValues.contains(0.0), true);
       expect(leftTitlesCalledValues.contains(5.0), true);
       expect(leftTitlesCalledValues.contains(10.0), true);

diff --git a/test/utils/utils_test.dart b/test/utils/utils_test.dart
@@ -168,8 +168,8 @@ void main() {
     expect(Utils().getBestInitialIntervalValue(-3, 3, 1), -3);
     expect(Utils().getBestInitialIntervalValue(-30, -20, 13), -30);
     expect(Utils().getBestInitialIntervalValue(0, 13, 8), 0);
-    expect(Utils().getBestInitialIntervalValue(1, 13, 7), 1);
-    expect(Utils().getBestInitialIntervalValue(1, 13, 3), 1);
+    expect(Utils().getBestInitialIntervalValue(1, 13, 7), 7);
+    expect(Utils().getBestInitialIntervalValue(1, 13, 3), 3);
     expect(Utils().getBestInitialIntervalValue(-1, 13, 3), 0);
     expect(Utils().getBestInitialIntervalValue(-2, 13, 3), 0);
     expect(Utils().getBestInitialIntervalValue(-3, 13, 3), -3);
@@ -183,6 +183,21 @@ void main() {
     expect(Utils().getBestInitialIntervalValue(-3, 0, 2), -2);
     expect(Utils().getBestInitialIntervalValue(-4, 0, 2), -4);
     expect(Utils().getBestInitialIntervalValue(-0.5, 0.5, 2), -0.5);
+    expect(Utils().getBestInitialIntervalValue(35, 130, 50), 50);
+    expect(Utils().getBestInitialIntervalValue(49, 130, 50), 50);
+    expect(Utils().getBestInitialIntervalValue(50, 130, 50), 50);
+    expect(Utils().getBestInitialIntervalValue(60, 130, 50), 100);
+    expect(Utils().getBestInitialIntervalValue(110, 130, 50), 110);
+    expect(Utils().getBestInitialIntervalValue(90, 180, 50), 100);
+    expect(Utils().getBestInitialIntervalValue(100, 180, 50), 100);
+    expect(Utils().getBestInitialIntervalValue(110, 180, 50), 150);
+    expect(Utils().getBestInitialIntervalValue(170, 180, 50), 170);
+    expect(Utils().getBestInitialIntervalValue(-120, -10, 50), -150);
+    expect(Utils().getBestInitialIntervalValue(-110, -10, 50), -150);
+    expect(Utils().getBestInitialIntervalValue(-100, -10, 50), -100);
+    expect(Utils().getBestInitialIntervalValue(-90, -10, 50), -100);
+    expect(Utils().getBestInitialIntervalValue(-80, -10, 50), -100);
+    expect(Utils().getBestInitialIntervalValue(-150, -10, 50), -150);
   });
 
   test('test convertRadiusToSigma()', () {