fix: support x/yOffset without x/y

vega · Oct 12, 2023 · 8bbb98c · 8bbb98c
1 parent f42c534
commit 8bbb98c
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Showing 6 changed files with 134 additions and 38 deletions.
diff --git a/src/compile/mark/encode/position-rect.ts b/src/compile/mark/encode/position-rect.ts
@@ -166,7 +166,14 @@ function positionAndSize(
   const hasSizeFromMarkOrEncoding = !!sizeMixins;
 
   // Otherwise, apply default value
-  const bandSize = getBandSize({channel, fieldDef, markDef, config, scaleType: scale?.get('type'), useVlSizeChannel});
+  const bandSize = getBandSize({
+    channel,
+    fieldDef,
+    markDef,
+    config,
+    scaleType: (scale || offsetScale)?.get('type'),
+    useVlSizeChannel
+  });
 
   sizeMixins = sizeMixins || {
     [vgSizeChannel]: defaultSizeRef(
@@ -190,7 +197,9 @@ function positionAndSize(
    */
 
   const defaultBandAlign =
-    scale?.get('type') === 'band' && isRelativeBandSize(bandSize) && !hasSizeFromMarkOrEncoding ? 'top' : 'middle';
+    (scale || offsetScale)?.get('type') === 'band' && isRelativeBandSize(bandSize) && !hasSizeFromMarkOrEncoding
+      ? 'top'
+      : 'middle';
 
   const vgChannel = vgAlignedPositionChannel(channel, markDef, config, defaultBandAlign);
   const center = vgChannel === 'xc' || vgChannel === 'yc';

diff --git a/src/compile/scale/parse.ts b/src/compile/scale/parse.ts
@@ -1,7 +1,6 @@
-import {getMainChannelFromOffsetChannel, isXorYOffset, ScaleChannel, SCALE_CHANNELS, SHAPE} from '../../channel';
+import {ScaleChannel, SCALE_CHANNELS, SHAPE} from '../../channel';
 import {getFieldOrDatumDef, ScaleDatumDef, TypedFieldDef} from '../../channeldef';
 import {channelHasNestedOffsetScale} from '../../encoding';
-import * as log from '../../log';
 import {GEOSHAPE} from '../../mark';
 import {
   NON_TYPE_DOMAIN_RANGE_VEGA_SCALE_PROPERTIES,
@@ -56,17 +55,6 @@ function parseUnitScaleCore(model: UnitModel): ScaleComponentIndex {
     }
 
     let specifiedScale = fieldOrDatumDef && fieldOrDatumDef['scale'];
-    if (isXorYOffset(channel)) {
-      const mainChannel = getMainChannelFromOffsetChannel(channel);
-      if (!channelHasNestedOffsetScale(encoding, mainChannel)) {
-        // Don't generate scale when the offset encoding shouldn't yield a nested scale
-        if (specifiedScale) {
-          log.warn(log.message.offsetEncodingScaleIgnored(channel));
-        }
-        continue;
-      }
-    }
-
     if (fieldOrDatumDef && specifiedScale !== null && specifiedScale !== false) {
       specifiedScale ??= {};
       const hasNestedOffsetScale = channelHasNestedOffsetScale(encoding, channel);

diff --git a/src/compile/scale/range.ts b/src/compile/scale/range.ts
@@ -221,11 +221,39 @@ function parseScheme(scheme: Scheme | SignalRef): RangeScheme {
   return {scheme};
 }
 
+function fullWidthOrHeightRange(
+  channel: 'x' | 'y',
+  model: UnitModel,
+  scaleType: ScaleType,
+  {center}: {center?: boolean} = {}
+) {
+  // If step is null, use zero to width or height.
+  // Note that we use SignalRefWrapper to account for potential merges and renames.
+  const sizeType = getSizeChannel(channel);
+  const sizeSignal = model.getName(sizeType);
+  const getSignalName = model.getSignalName.bind(model);
+
+  if (channel === Y && hasContinuousDomain(scaleType)) {
+    // For y continuous scale, we have to start from the height as the bottom part has the max value.
+    return center
+      ? [
+          SignalRefWrapper.fromName(name => `${getSignalName(name)}/2`, sizeSignal),
+          SignalRefWrapper.fromName(name => `-${getSignalName(name)}/2`, sizeSignal)
+        ]
+      : [SignalRefWrapper.fromName(getSignalName, sizeSignal), 0];
+  } else {
+    return center
+      ? [
+          SignalRefWrapper.fromName(name => `-${getSignalName(name)}/2`, sizeSignal),
+          SignalRefWrapper.fromName(name => `${getSignalName(name)}/2`, sizeSignal)
+        ]
+      : [0, SignalRefWrapper.fromName(getSignalName, sizeSignal)];
+  }
+}
+
 function defaultRange(channel: ScaleChannel, model: UnitModel): VgRange {
   const {size, config, mark, encoding} = model;
 
-  const getSignalName = model.getSignalName.bind(model);
-
   const {type} = getFieldOrDatumDef(encoding[channel]) as ScaleFieldDef<string> | ScaleDatumDef;
 
   const mergedScaleCmpt = model.getScaleComponent(channel);
@@ -245,18 +273,7 @@ function defaultRange(channel: ScaleChannel, model: UnitModel): VgRange {
         }
       }
 
-      // If step is null, use zero to width or height.
-      // Note that we use SignalRefWrapper to account for potential merges and renames.
-
-      const sizeType = getSizeChannel(channel);
-      const sizeSignal = model.getName(sizeType);
-
-      if (channel === Y && hasContinuousDomain(scaleType)) {
-        // For y continuous scale, we have to start from the height as the bottom part has the max value.
-        return [SignalRefWrapper.fromName(getSignalName, sizeSignal), 0];
-      } else {
-        return [0, SignalRefWrapper.fromName(getSignalName, sizeSignal)];
-      }
+      return fullWidthOrHeightRange(channel, model, scaleType);
     }
 
     case XOFFSET:
@@ -374,6 +391,11 @@ function getOffsetStep(step: Step, offsetScaleType: ScaleType) {
 function getOffsetRange(channel: string, model: UnitModel, offsetScaleType: ScaleType): VgRange {
   const positionChannel = channel === XOFFSET ? 'x' : 'y';
   const positionScaleCmpt = model.getScaleComponent(positionChannel);
+
+  if (!positionScaleCmpt) {
+    return fullWidthOrHeightRange(positionChannel, model, offsetScaleType, {center: true});
+  }
+
   const positionScaleType = positionScaleCmpt.get('type');
   const positionScaleName = model.scaleName(positionChannel);
 

diff --git a/src/stack.ts b/src/stack.ts
@@ -176,16 +176,16 @@ export function stack(m: Mark | MarkDef, encoding: Encoding<string>): StackPrope
       groupbyChannels.push(dimensionChannel);
       groupbyFields.add(dimensionField);
     }
+  }
 
-    const dimensionOffsetChannel = dimensionChannel === 'x' ? 'xOffset' : 'yOffset';
-    const dimensionOffsetDef = encoding[dimensionOffsetChannel];
-    const dimensionOffsetField = isFieldDef(dimensionOffsetDef) ? vgField(dimensionOffsetDef, {}) : undefined;
+  const dimensionOffsetChannel = dimensionChannel === 'x' ? 'xOffset' : 'yOffset';
+  const dimensionOffsetDef = encoding[dimensionOffsetChannel];
+  const dimensionOffsetField = isFieldDef(dimensionOffsetDef) ? vgField(dimensionOffsetDef, {}) : undefined;
 
-    if (dimensionOffsetField && dimensionOffsetField !== stackedField) {
-      // avoid grouping by the stacked field
-      groupbyChannels.push(dimensionOffsetChannel);
-      groupbyFields.add(dimensionOffsetField);
-    }
+  if (dimensionOffsetField && dimensionOffsetField !== stackedField) {
+    // avoid grouping by the stacked field
+    groupbyChannels.push(dimensionOffsetChannel);
+    groupbyFields.add(dimensionOffsetField);
   }
 
   // If the dimension has offset, don't stack anymore

diff --git a/test/compile/scale/range.test.ts b/test/compile/scale/range.test.ts
@@ -132,6 +132,48 @@ describe('compile/scale', () => {
         );
       });
 
+      it('should return [-width/2, width/2] for xOffset without x', () => {
+        const model = parseUnitModelWithScaleExceptRange({
+          mark: 'bar',
+          encoding: {
+            xOffset: {field: 'xSub', type: 'nominal'},
+            y: {field: 'y', type: 'nominal'}
+          }
+        });
+
+        expect(parseRangeForChannel('xOffset', model)).toEqual(
+          makeImplicit([
+            {
+              signal: '-width/2'
+            },
+            {
+              signal: 'width/2'
+            }
+          ])
+        );
+      });
+
+      it('should return [-height/2, height/2] for yOffset without y', () => {
+        const model = parseUnitModelWithScaleExceptRange({
+          mark: 'bar',
+          encoding: {
+            yOffset: {field: 'xSub', type: 'nominal'},
+            x: {field: 'y', type: 'nominal'}
+          }
+        });
+
+        expect(parseRangeForChannel('yOffset', model)).toEqual(
+          makeImplicit([
+            {
+              signal: '-height/2'
+            },
+            {
+              signal: 'height/2'
+            }
+          ])
+        );
+      });
+
       it('should return padded duration range when there is a nested offset with year time scale and default padding', () => {
         const model = parseUnitModelWithScaleExceptRange({
           mark: 'bar',

diff --git a/test/stack.test.ts b/test/stack.test.ts
@@ -1,5 +1,5 @@
 import {NonArgAggregateOp} from '../src/aggregate';
-import {DETAIL, X, Y} from '../src/channel';
+import {DETAIL, X, Y, YOFFSET} from '../src/channel';
 import * as log from '../src/log';
 import {ARC, AREA, BAR, PRIMITIVE_MARKS, RECT} from '../src/mark';
 import {ScaleType} from '../src/scale';
@@ -327,6 +327,41 @@ describe('stack', () => {
       }
     });
 
+    it('should be correct for grouped bar', () => {
+      for (const stackableMark of [BAR, AREA]) {
+        const spec: TopLevel<NormalizedUnitSpec> = {
+          data: {url: 'data/barley.json'},
+          mark: stackableMark,
+          encoding: {
+            x: {field: 'yield', type: 'quantitative'},
+            y: {field: 'variety', type: 'nominal'},
+            yOffset: {field: 'site', type: 'nominal'},
+            color: {field: 'site', type: 'nominal'}
+          }
+        };
+        const _stack = stack(spec.mark, spec.encoding);
+        expect(_stack.fieldChannel).toBe(X);
+        expect(_stack.groupbyChannels).toEqual([Y, YOFFSET]);
+      }
+    });
+
+    it('should be correct for grouped bar without nesting', () => {
+      for (const stackableMark of [BAR, AREA]) {
+        const spec: TopLevel<NormalizedUnitSpec> = {
+          data: {url: 'data/barley.json'},
+          mark: stackableMark,
+          encoding: {
+            x: {field: 'yield', type: 'quantitative'},
+            yOffset: {field: 'site', type: 'nominal'},
+            color: {field: 'site', type: 'nominal'}
+          }
+        };
+        const _stack = stack(spec.mark, spec.encoding);
+        expect(_stack.fieldChannel).toBe(X);
+        expect(_stack.groupbyChannels).toEqual([YOFFSET]);
+      }
+    });
+
     it('should stack even for two plain quantitatives with the orient on the axes', () => {
       for (const mark of [BAR, AREA]) {
         const spec: TopLevel<NormalizedUnitSpec> = {