feat: support domainRaw so one may bind domainRaw to a parameter to b…

…uild custom interaction

examples/specs/interactive_point_domainRaw_binding.vl.json

@@ -0,0 +1,40 @@
+{
+  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+  "data": {"url": "data/cars.json"},
+  "params": [{
+    "name": "min_x",
+    "value": 50,
+    "bind": {
+      "input": "range",
+      "min": 0,
+      "max": 300
+    }
+  }, {
+    "name": "max_x",
+    "value": 250,
+    "bind": {
+      "input": "range",
+      "min": 0,
+      "max": 300
+    }
+  },{
+    "name": "use_custom_x",
+    "value": true,
+    "bind": {
+      "input": "checkbox"
+    }
+  }],
+  "mark": {"type": "circle", "clip": true},
+  "encoding": {
+    "x": {
+      "field": "Horsepower", "type": "quantitative",
+      "scale": {
+        "domainRaw": {"expr": "use_custom_x ? [min_x, max_x] : null"}
+      }
+    },
+    "y": {
+      "field": "Miles_per_Gallon", "type": "quantitative"
+    },
+    "size": {"field": "Cylinders", "type": "quantitative"}
+  }
+}

src/compile/scale/component.ts

@@ -11,7 +11,7 @@ import {Explicit, Split} from '../split';
  * All VgDomain property except domain.
  * (We exclude domain as we have a special "domains" array that allow us merge them all at once in assemble.)
  */
-export type ScaleComponentProps = Omit<VgScale, 'domain' | 'domainRaw' | 'reverse'> & {
+export type ScaleComponentProps = Omit<VgScale, 'domain' | 'reverse'> & {
   domains: VgNonUnionDomain[];
   selectionExtent?: ParameterExtent;
   reverse?: boolean | SignalRef; // Need override since Vega doesn't official support scale reverse yet (though it does in practice)

src/scale.ts

@@ -546,6 +546,13 @@ export interface Scale<ES extends ExprRef | SignalRef = ExprRef | SignalRef> {
     | DomainUnionWith
     | ES;
 
+  /**
+   * An expression for an array of raw values that, if non-null, directly overrides the _domain_ property.
+   * This is useful for supporting interactions such as panning or zooming a scale.
+   * The scale may be initially determined using a data-driven domain, then modified in response to user input by setting the rawDomain value.
+   */
+  domainRaw?: ES;
+
   /**
    * Inserts a single mid-point value into a two-element domain. The mid-point value must lie between the domain minimum and maximum values. This property can be useful for setting a midpoint for [diverging color scales](https://vega.github.io/vega-lite/docs/scale.html#piecewise). The domainMid property is only intended for use with scales supporting continuous, piecewise domains.
    */
@@ -728,6 +735,7 @@ const SCALE_PROPERTY_INDEX: Flag<keyof Scale<any>> = {
   domainMax: 1,
   domainMin: 1,
   domainMid: 1,
+  domainRaw: 1,
   align: 1,
   range: 1,
   rangeMax: 1,
@@ -785,6 +793,7 @@ export function scaleTypeSupportProperty(scaleType: ScaleType, propName: keyof S
     case 'domainMax':
     case 'domainMid':
     case 'domainMin':
+    case 'domainRaw':
     case 'clamp':
       return isContinuousToContinuous(scaleType);
     case 'nice':
@@ -830,6 +839,7 @@ export function channelScalePropertyIncompatability(channel: Channel, propName:
     case 'domain':
     case 'domainMax':
     case 'domainMin':
+    case 'domainRaw':
     case 'range':
     case 'base':
     case 'exponent':