Initial pass at adding a toggle to show mode changes as a line chart

src/components/timeline/LayerLine.svelte

@@ -2,12 +2,13 @@
 
 <script lang="ts">
   import { quadtree as d3Quadtree, type Quadtree } from 'd3-quadtree';
-  import type { ScaleLinear, ScaleTime } from 'd3-scale';
+  import { scalePoint, type ScaleLinear, type ScalePoint, type ScaleTime } from 'd3-scale';
   import { curveLinear, line as d3Line } from 'd3-shape';
   import { createEventDispatcher, onMount, tick } from 'svelte';
   import type { Resource } from '../../types/simulation';
   import type { Axis, LinePoint, QuadtreePoint, ResourceLayerFilter, TimeRange } from '../../types/timeline';
-  import { getYScale, searchQuadtreePoint } from '../../utilities/timeline';
+  import { filterEmpty } from '../../utilities/generic';
+  import { CANVAS_PADDING_Y, getYScale, searchQuadtreePoint } from '../../utilities/timeline';
 
   export let contextmenu: MouseEvent | undefined;
   export let dpr: number = 1;
@@ -22,6 +23,7 @@
   export let mouseout: MouseEvent | undefined;
   export let pointRadius: number = 2;
   export let resources: Resource[] = [];
+  export let showAsLinePlot: boolean = false;
   export let viewTimeRange: TimeRange = { end: 0, start: 0 };
   export let xScaleView: ScaleTime<number, number> | null = null;
   export let yAxes: Axis[] = [];
@@ -33,9 +35,11 @@
   let ctx: CanvasRenderingContext2D | null;
   let mounted: boolean = false;
   let quadtree: Quadtree<QuadtreePoint>;
+  let scaleDomain: Set<string> = new Set();
   let visiblePointsById: Record<number, LinePoint> = {};
-  let yScale: ScaleLinear<number, number, never>;
   let drawPointsRequest: number;
+  let stateLinePlotYScale: ScalePoint<string>;
+  let yScale: ScaleLinear<number, number, never>;
 
   $: canvasHeightDpr = drawHeight * dpr;
   $: canvasWidthDpr = drawWidth * dpr;
@@ -47,10 +51,11 @@
     dpr &&
     // TODO swap filter out for resources which are recomputed when the view changes (i.e. filter changes)
     filter &&
-    lineColor &&
+    lineColor !== undefined &&
     typeof lineWidth === 'number' &&
     typeof pointRadius === 'number' &&
     mounted &&
+    showAsLinePlot !== undefined &&
     points &&
     viewTimeRange &&
     xScaleView &&
@@ -82,17 +87,41 @@
       ctx.clearRect(0, 0, drawWidth, drawHeight);
 
       const [yAxis] = yAxes.filter(axis => yAxisId === axis.id);
-      const domain = yAxis?.scaleDomain || [];
-      yScale = getYScale(domain, drawHeight);
+
+      quadtree = d3Quadtree<QuadtreePoint>()
+        .x(p => p.x)
+        .y(p => p.y)
+        .extent([
+          [0, 0],
+          [drawWidth, drawHeight],
+        ]);
 
       ctx.lineWidth = lineWidth;
       ctx.strokeStyle = lineColor;
+      let line;
+
+      if (showAsLinePlot) {
+        const domain = Array.from(scaleDomain);
+        stateLinePlotYScale = scalePoint()
+          .domain(domain.filter(filterEmpty))
+          .range([drawHeight - CANVAS_PADDING_Y, CANVAS_PADDING_Y]) as ScalePoint<string>;
+
+        line = d3Line<LinePoint>()
+          .x(d => (xScaleView as ScaleTime<number, number, never>)(d.x))
+          .y(d => stateLinePlotYScale(d.y.toString()) as number)
+          .defined(d => d.y !== null) // Skip any gaps in resource data instead of interpolating
+          .curve(curveLinear);
+      } else {
+        const domain = yAxis?.scaleDomain || [];
+        yScale = getYScale(domain, drawHeight) as ScaleLinear<number, number, never>;
+
+        line = d3Line<LinePoint>()
+          .x(d => (xScaleView as ScaleTime<number, number, never>)(d.x))
+          .y(d => yScale(d.y) as number)
+          .defined(d => d.y !== null) // Skip any gaps in resource data instead of interpolating
+          .curve(curveLinear);
+      }
 
-      const line = d3Line<LinePoint>()
-        .x(d => (xScaleView as ScaleTime<number, number, never>)(d.x))
-        .y(d => yScale(d.y))
-        .defined(d => d.y !== null) // Skip any gaps in resource data instead of interpolating
-        .curve(curveLinear);
       ctx.beginPath();
       line.context(ctx)(points);
       ctx.stroke();
@@ -119,7 +148,14 @@
     for (const point of points) {
       if (point.x >= viewTimeRange.start && point.x <= viewTimeRange.end) {
         const x = (xScaleView as ScaleTime<number, number, never>)(point.x);
-        const y = yScale(point.y);
+        let y: number;
+
+        if (showAsLinePlot) {
+          y = stateLinePlotYScale(point.y.toString()) as number;
+        } else {
+          y = yScale(point.y) as number;
+        }
+
         quadtree.add({ id: point.id, x, y });
         visiblePointsById[point.id] = point;
         ctx.drawImage(offscreenPoint, x - pointRadius, y - pointRadius, pointRadius * 2, pointRadius * 2);
@@ -186,6 +222,21 @@
             y,
           });
         }
+      } else if (schema.type === 'string' || schema.type === 'variant') {
+        for (let i = 0; i < values.length; ++i) {
+          const value = values[i];
+          const { x } = value;
+          const y = value.y as number;
+          scaleDomain.add(value.y as string);
+          points.push({
+            id: id++,
+            name,
+            radius: radius,
+            type: 'line',
+            x,
+            y,
+          });
+        }
       }
     }
 

src/components/timeline/LayerXRange.svelte

@@ -222,6 +222,7 @@
     if (e) {
       const { offsetX: x, offsetY: y } = e;
       const points = searchQuadtreeRect<XRangePoint>(quadtree, x, y, drawHeight, maxXWidth, visiblePointsById);
+
       dispatch('mouseOver', { e, layerId: id, points });
     }
   }

src/components/timeline/Row.svelte

@@ -31,7 +31,12 @@
   import effects from '../../utilities/effects';
   import { classNames } from '../../utilities/generic';
   import { getDoyTime } from '../../utilities/time';
-  import { getYAxesWithScaleDomains, TimelineInteractionMode, type TimelineLockStatus } from '../../utilities/timeline';
+  import {
+    getYAxesWithScaleDomains,
+    isXRangeLayer,
+    TimelineInteractionMode,
+    type TimelineLockStatus,
+  } from '../../utilities/timeline';
   import ConstraintViolations from './ConstraintViolations.svelte';
   import LayerActivity from './LayerActivity.svelte';
   import LayerGaps from './LayerGaps.svelte';
@@ -415,21 +420,40 @@
               on:contextMenu
             />
           {/if}
-          {#if layer.chartType === 'x-range'}
-            <LayerXRange
-              {...layer}
-              {contextmenu}
-              {dpr}
-              drawHeight={computedDrawHeight}
-              {drawWidth}
-              filter={layer.filter.resource}
-              {mousemove}
-              {mouseout}
-              resources={resourcesByViewLayerId[layer.id] ?? []}
-              {xScaleView}
-              on:mouseOver={onMouseOver}
-              on:contextMenu
-            />
+          {#if isXRangeLayer(layer)}
+            {#if layer.showAsLinePlot === true}
+              <LayerLine
+                {...layer}
+                {contextmenu}
+                {dpr}
+                drawHeight={computedDrawHeight}
+                {drawWidth}
+                filter={layer.filter.resource}
+                {mousemove}
+                {mouseout}
+                resources={resourcesByViewLayerId[layer.id] ?? []}
+                {viewTimeRange}
+                {xScaleView}
+                yAxes={yAxesWithScaleDomains}
+                on:mouseOver={onMouseOver}
+                on:contextMenu
+              />
+            {:else}
+              <LayerXRange
+                {...layer}
+                {contextmenu}
+                {dpr}
+                drawHeight={computedDrawHeight}
+                {drawWidth}
+                filter={layer.filter.resource}
+                {mousemove}
+                {mouseout}
+                resources={resourcesByViewLayerId[layer.id] ?? []}
+                {xScaleView}
+                on:mouseOver={onMouseOver}
+                on:contextMenu
+              />
+            {/if}
           {/if}
         {/each}
       </div>

src/components/timeline/RowYAxes.svelte

@@ -1,13 +1,13 @@
 <svelte:options immutable={true} />
 
 <script lang="ts">
-  import { axisLeft as d3AxisLeft } from 'd3-axis';
+  import { axisLeft as d3AxisLeft, type AxisScale } from 'd3-axis';
   import { format as d3Format } from 'd3-format';
-  import { select } from 'd3-selection';
+  import { select, type Selection } from 'd3-selection';
   import { createEventDispatcher, tick } from 'svelte';
   import type { Resource } from '../../types/simulation';
-  import type { Axis, Layer, LineLayer } from '../../types/timeline';
-  import { getYScale } from '../../utilities/timeline';
+  import type { Axis, Layer, LineLayer, XRangeLayer } from '../../types/timeline';
+  import { getOrdinalYScale, getYScale } from '../../utilities/timeline';
 
   export let drawHeight: number = 0;
   export let drawWidth: number = 0;
@@ -34,8 +34,55 @@
       const axisClass = 'y-axis';
       gSelection.selectAll(`.${axisClass}`).remove();
 
+      /**
+       * TODO: This is a temporary solution to showing state mode changes as a line chart.
+       * The correct way to do this would be generating a Y axes when the user toggles the line chart,
+       * but for now we're just setting the Y axes dynamically based on the data.
+       */
+      const xRangeLayers = layers.filter(layer => layer.chartType === 'x-range');
+      let i = 0;
+
+      for (const layer of xRangeLayers) {
+        const resources = resourcesByViewLayerId[layer.id];
+        const xRangeAxisG = gSelection.append('g').attr('class', axisClass);
+        xRangeAxisG.selectAll('*').remove();
+
+        if ((layer as XRangeLayer).showAsLinePlot && resources && resources.length > 0) {
+          let domain: string[] = [];
+
+          // Get all the unique ordinal values of the chart.
+          for (const value of resources[0].values) {
+            if (domain.indexOf(value.y as string) === -1) {
+              domain.push(value.y as string);
+            }
+          }
+
+          const scale = getOrdinalYScale(domain, drawHeight);
+          // Don't do any special formatting here because we're dealing with strings.
+          const axisLeft = d3AxisLeft(scale as AxisScale<string>)
+            .tickSizeInner(0)
+            .tickSizeOuter(0)
+            .ticks(domain.length)
+            .tickPadding(2);
+          const axisMargin = 2;
+          const startPosition = -(totalWidth + axisMargin * i);
+          marginWidth += i > 0 ? axisMargin : 0;
+          xRangeAxisG.attr('transform', `translate(${startPosition}, 0)`);
+          xRangeAxisG.style('color', 'black');
+          xRangeAxisG.call(axisLeft);
+          xRangeAxisG.call(g => g.select('.domain').remove());
+
+          totalWidth += getBoundingClientRectWidth(xRangeAxisG.node());
+        }
+
+        drawSeparator(xRangeAxisG);
+        i++;
+      }
+
       for (let i = 0; i < yAxes.length; ++i) {
         const axis = yAxes[i];
+        const axisG = gSelection.append('g').attr('class', axisClass);
+        axisG.selectAll('*').remove();
 
         // Get color for axis by examining associated layers. If more than one layer is associated,
         // use the default axis color, otherwise use the color from the layer.
@@ -53,8 +100,6 @@
         // const labelFontSize = axis.label?.fontSize || 12;
         // const labelText = axis.label.text;
         const tickCount = axis.tickCount || 1;
-        const axisG = gSelection.append('g').attr('class', axisClass);
-        axisG.selectAll('*').remove();
         if (
           tickCount > 0 &&
           axis.scaleDomain &&
@@ -89,31 +134,37 @@
             axisG.call(axisLeft);
             axisG.call(g => g.select('.domain').remove());
           }
-
-          // Draw separator
-          axisG
-            .append('line')
-            .attr('x1', 2)
-            .attr('y1', 0)
-            .attr('x2', 2)
-            .attr('y2', drawHeight)
-            .style('stroke', '#EBECEC')
-            .style('stroke-width', 2);
         }
 
-        const axisGElement: SVGGElement | null = axisG.node();
-        if (axisGElement !== null) {
-          // TODO might be able to save minor perf by getting bounding rect of entire
-          // container instead of each individual axis?
-          totalWidth += axisGElement.getBoundingClientRect().width;
-        }
+        drawSeparator(axisG);
+
+        totalWidth += getBoundingClientRectWidth(axisG.node());
       }
+
       totalWidth += marginWidth;
-      if (totalWidth > 0 && drawWidth !== totalWidth) {
-        dispatch('updateYAxesWidth', totalWidth);
-      }
+      // Dispatch the width so the RowHeader can recalculate the label width.
+      dispatch('updateYAxesWidth', totalWidth);
     }
   }
+
+  function drawSeparator(axisG: Selection<SVGGElement, unknown, null, undefined>): void {
+    axisG
+      .append('line')
+      .attr('x1', 2)
+      .attr('y1', 0)
+      .attr('x2', 2)
+      .attr('y2', drawHeight)
+      .style('stroke', '#EBECEC')
+      .style('stroke-width', 2);
+  }
+
+  function getBoundingClientRectWidth(axisG: SVGGElement | null): number {
+    if (axisG !== null) {
+      return axisG.getBoundingClientRect().width + 4;
+    }
+
+    return 0;
+  }
 </script>
 
 <svg class="row-y-axes">

src/components/timeline/form/TimelineEditorLayerSettings.svelte

@@ -159,6 +159,17 @@
             on:input={onInput}
           />
         </Input>
+        <Input layout="inline">
+          <label for="showAsLinePlot">Show As Line Plot</label>
+          <input
+            style:width="max-content"
+            checked={layerAsXRange.showAsLinePlot}
+            id="showAsLinePlot"
+            name="showAsLinePlot"
+            on:change={onInput}
+            type="checkbox"
+          />
+        </Input>
       {/if}
       <Input layout="inline">
         <label for="id">Layer ID</label>

src/schemas/ui-view-schema.json

@@ -405,6 +405,9 @@
                               "opacity": {
                                 "type": "number"
                               },
+                              "showAsLinePlot": {
+                                "type": "boolean"
+                              },
                               "yAxisId": {
                                 "$ref": "#/definitions/yAxisId"
                               }

src/types/timeline.ts

@@ -196,6 +196,7 @@ export type XRangeLayerColorScheme =
 export interface XRangeLayer extends Layer {
   colorScheme: XRangeLayerColorScheme;
   opacity: number;
+  showAsLinePlot: boolean;
 }
 
 export interface XRangePoint extends Point {