From 9a852f21f1f9ad9d44cfe4d21e6c8f165760dfb0 Mon Sep 17 00:00:00 2001
From: Nikita Rokotyan <nikita@exaforce.com>
Date: Wed, 30 Oct 2024 15:55:47 -0700
Subject: [PATCH] Component | Axis: Tick label collision iterations and
 transitions

---
 packages/ts/src/components/axis/index.ts | 45 +++++++++++++-----------
 packages/ts/src/components/axis/style.ts |  8 ++++-
 2 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/packages/ts/src/components/axis/index.ts b/packages/ts/src/components/axis/index.ts
index 2b90b11be..abd572f15 100644
--- a/packages/ts/src/components/axis/index.ts
+++ b/packages/ts/src/components/axis/index.ts
@@ -212,6 +212,7 @@ export class Axis<Datum> extends XYComponentCore<Datum, AxisConfigInterface<Datu
     const tickText = selection.selectAll<SVGTextElement, number | Date>('g.tick > text')
       .filter(tickValue => tickValues.some((t: number | Date) => isEqual(tickValue, t))) // We use isEqual to compare Dates
       .classed(s.tickLabel, true)
+      .classed(s.tickLabelHideable, Boolean(config.tickTextHideOverlapping))
       .style('fill', config.tickTextColor) as Selection<SVGTextElement, number, SVGGElement, unknown> | Selection<SVGTextElement, Date, SVGGElement, unknown>
 
 
@@ -281,29 +282,33 @@ export class Axis<Datum> extends XYComponentCore<Datum, AxisConfigInterface<Datu
       node._visible = true
     })
 
+    // We do three iterations because not all overlapping labels can be resolved in the first iteration
+    const numIterations = 3
+    for (let i = 0; i < numIterations; i += 1) {
     // Run collision detection and set labels visibility
-    selection.each((d, i, elements) => {
-      const label1 = elements[i] as SVGOverlappingTextElement
-      const isLabel1Visible = label1._visible
-      if (!isLabel1Visible) return
-
-      // Calculate bounding rect of point's label
-      const label1BoundingRect = label1.getBoundingClientRect()
-
-      for (let j = i + 1; j < elements.length; j += 1) {
-        if (i === j) continue
-        const label2 = elements[j] as SVGOverlappingTextElement
-        const isLabel2Visible = label2._visible
-        if (isLabel2Visible) {
-          const label2BoundingRect = label2.getBoundingClientRect()
-          const intersect = rectIntersect(label1BoundingRect, label2BoundingRect, -5)
-          if (intersect) {
-            label2._visible = false
-            break
+      selection.each((d, i, elements) => {
+        const label1 = elements[i] as SVGOverlappingTextElement
+        const isLabel1Visible = label1._visible
+        if (!isLabel1Visible) return
+
+        // Calculate bounding rect of point's label
+        const label1BoundingRect = label1.getBoundingClientRect()
+
+        for (let j = i + 1; j < elements.length; j += 1) {
+          if (i === j) continue
+          const label2 = elements[j] as SVGOverlappingTextElement
+          const isLabel2Visible = label2._visible
+          if (isLabel2Visible) {
+            const label2BoundingRect = label2.getBoundingClientRect()
+            const intersect = rectIntersect(label1BoundingRect, label2BoundingRect, -5)
+            if (intersect) {
+              label2._visible = false
+              break
+            }
           }
         }
-      }
-    })
+      })
+    }
 
     // Hide the overlapping labels
     selection.each((d, i, elements) => {
diff --git a/packages/ts/src/components/axis/style.ts b/packages/ts/src/components/axis/style.ts
index bfd94b101..80c36d9a1 100644
--- a/packages/ts/src/components/axis/style.ts
+++ b/packages/ts/src/components/axis/style.ts
@@ -18,6 +18,7 @@ export const globalStyles = injectGlobal`
     --vis-axis-tick-label-text-decoration: none;
     --vis-axis-label-font-size: 14px;
     --vis-axis-tick-line-width: 1px;
+    --vis-axis-tick-label-hide-transition: opacity 400ms ease-in-out;
     --vis-axis-grid-line-width: 1px;
     /* --vis-axis-domain-line-width: // Undefined by default to allow fallback to var(--vis-axis-grid-line-width) */
 
@@ -99,7 +100,6 @@ export const tick = css`
     text-decoration: var(--vis-axis-tick-label-text-decoration);
     stroke: none;
   }
-
 `
 
 export const label = css`
@@ -113,3 +113,9 @@ export const label = css`
 export const tickLabel = css`
   label: tick-label;
 `
+
+export const tickLabelHideable = css`
+  label: tick-label-hideable;
+  opacity: 0;
+  transition: var(--vis-axis-tick-label-hide-transition);
+`