Refactored logic in ThresholdEditor

packages/grafana-ui/src/components/ThresholdsEditor/ThresholdsEditor.test.tsx

@@ -15,25 +15,56 @@ const setup = (propOverrides?: object) => {
   return shallow(<ThresholdsEditor {...props} />).instance() as ThresholdsEditor;
 };
 
+describe('Initialization', () => {
+  it('should add a base threshold if missing', () => {
+    const instance = setup();
+
+    expect(instance.state.thresholds).toEqual([{ index: 0, value: -Infinity, color: '#7EB26D' }]);
+  });
+});
+
 describe('Add threshold', () => {
   it('should add threshold', () => {
     const instance = setup();
 
-    instance.onAddThreshold(0);
+    instance.onAddThreshold(1);
 
-    expect(instance.state.thresholds).toEqual([{ index: 0, value: 50, color: 'rgb(127, 115, 64)' }]);
+    expect(instance.state.thresholds).toEqual([
+      { index: 1, value: 50, color: '#EAB839' },
+      { index: 0, value: -Infinity, color: '#7EB26D' },
+    ]);
   });
 
   it('should add another threshold above a first', () => {
     const instance = setup({
-      thresholds: [{ index: 0, value: 50, color: 'rgb(127, 115, 64)' }],
+      thresholds: [{ index: 0, value: -Infinity, color: '#7EB26D' }, { index: 1, value: 50, color: '#EAB839' }],
     });
 
-    instance.onAddThreshold(1);
+    instance.onAddThreshold(2);
+
+    expect(instance.state.thresholds).toEqual([
+      { index: 2, value: 75, color: '#6ED0E0' },
+      { index: 1, value: 50, color: '#EAB839' },
+      { index: 0, value: -Infinity, color: '#7EB26D' },
+    ]);
+  });
+
+  it('should add another threshold between first and second index', () => {
+    const instance = setup({
+      thresholds: [
+        { index: 0, value: -Infinity, color: '#7EB26D' },
+        { index: 1, value: 50, color: '#EAB839' },
+        { index: 2, value: 75, color: '#6ED0E0' },
+      ],
+    });
+
+    instance.onAddThreshold(2);
 
     expect(instance.state.thresholds).toEqual([
-      { index: 1, value: 75, color: 'rgb(170, 95, 61)' },
-      { index: 0, value: 50, color: 'rgb(127, 115, 64)' },
+      { index: 3, value: 75, color: '#EF843C' },
+      { index: 2, value: 62.5, color: '#6ED0E0' },
+      { index: 1, value: 50, color: '#EAB839' },
+      { index: 0, value: -Infinity, color: '#7EB26D' },
     ]);
   });
 });
@@ -41,23 +72,25 @@ describe('Add threshold', () => {
 describe('change threshold value', () => {
   it('should update value and resort rows', () => {
     const instance = setup();
-    const mockThresholds = [
-      { index: 0, value: 50, color: 'rgba(237, 129, 40, 0.89)' },
-      { index: 1, value: 75, color: 'rgba(237, 129, 40, 0.89)' },
+    const thresholds = [
+      { index: 0, value: -Infinity, color: '#7EB26D' },
+      { index: 1, value: 50, color: '#EAB839' },
+      { index: 2, value: 75, color: '#6ED0E0' },
     ];
 
     instance.state = {
       baseColor: BasicGaugeColor.Green,
-      thresholds: mockThresholds,
+      thresholds,
     };
 
     const mockEvent = { target: { value: 78 } };
 
-    instance.onChangeThresholdValue(mockEvent, mockThresholds[0]);
+    instance.onChangeThresholdValue(mockEvent, thresholds[1]);
 
     expect(instance.state.thresholds).toEqual([
-      { index: 0, value: 78, color: 'rgba(237, 129, 40, 0.89)' },
-      { index: 1, value: 75, color: 'rgba(237, 129, 40, 0.89)' },
+      { index: 0, value: -Infinity, color: '#7EB26D' },
+      { index: 1, value: 78, color: '#EAB839' },
+      { index: 2, value: 75, color: '#6ED0E0' },
     ]);
   });
 });

packages/grafana-ui/src/components/ThresholdsEditor/ThresholdsEditor.tsx

 import React, { PureComponent } from 'react';
-import tinycolor, { ColorInput } from 'tinycolor2';
+// import tinycolor, { ColorInput } from 'tinycolor2';
 
 import { Threshold, BasicGaugeColor } from '../../types';
 import { ColorPicker } from '../ColorPicker/ColorPicker';
 import { PanelOptionsGroup } from '../PanelOptionsGroup/PanelOptionsGroup';
+import { colors } from '../../utils';
 
 export interface Props {
   thresholds: Threshold[];
@@ -19,43 +20,41 @@ export class ThresholdsEditor extends PureComponent<Props, State> {
   constructor(props: Props) {
     super(props);
 
-    this.state = { thresholds: props.thresholds, baseColor: BasicGaugeColor.Green };
+    const thresholds: Threshold[] =
+      props.thresholds.length > 0 ? props.thresholds : [{ index: 0, value: -Infinity, color: colors[0] }];
+    this.state = { thresholds, baseColor: BasicGaugeColor.Green };
   }
 
   onAddThreshold = (index: number) => {
-    const maxValue = 100; // hardcoded for now before we add the base threshold
-    const minValue = 0; // hardcoded for now before we add the base threshold
     const { thresholds } = this.state;
+    const maxValue = 100;
+    const minValue = 0;
+
+    if (index === 0) {
+      return;
+    }
 
     const newThresholds = thresholds.map(threshold => {
       if (threshold.index >= index) {
+        const index = threshold.index + 1;
         threshold = {
           ...threshold,
-          index: threshold.index + 1,
+          index,
+          color: colors[index],
         };
       }
-
       return threshold;
     });
 
     // Setting value to a value between the previous thresholds
-    let value;
-
-    if (index === 0 && thresholds.length === 0) {
-      value = maxValue - (maxValue - minValue) / 2;
-    } else if (index === 0 && thresholds.length > 0) {
-      value = newThresholds[index + 1].value - (newThresholds[index + 1].value - minValue) / 2;
-    } else if (index > newThresholds[newThresholds.length - 1].index) {
-      value = maxValue - (maxValue - newThresholds[index - 1].value) / 2;
-    }
-
-    // Set a color that lies between the previous thresholds
-    let color;
-    if (index === 0 && thresholds.length === 0) {
-      color = tinycolor.mix(BasicGaugeColor.Green, BasicGaugeColor.Red, 50).toRgbString();
-    } else {
-      color = tinycolor.mix(thresholds[index - 1].color as ColorInput, BasicGaugeColor.Red, 50).toRgbString();
-    }
+    const beforeThreshold = newThresholds.filter(threshold => threshold.index === index - 1)[0];
+    const afterThreshold = newThresholds.filter(threshold => threshold.index === index + 1)[0];
+    const beforeThresholdValue = beforeThreshold !== undefined ? Math.max(beforeThreshold.value, minValue) : minValue;
+    const afterThresholdValue = afterThreshold !== undefined ? Math.min(afterThreshold.value, maxValue) : maxValue;
+    const value = afterThresholdValue - (afterThresholdValue - beforeThresholdValue) / 2;
+
+    // Set a color
+    const color = colors[index];
 
     this.setState(
       {