From 09fd3a752f9406dcc4b1d626b02ec1b3c2f0109c Mon Sep 17 00:00:00 2001
From: Konstantinos Kaloutas <konstantinos@logseq.com>
Date: Wed, 21 Sep 2022 14:08:48 +0300
Subject: [PATCH] chore: add distribute method

---
 .../components/ContextMenu/ContextMenu.tsx    |   6 +-
 tldraw/packages/core/src/lib/TLApp/TLApp.ts   | 109 +++++++++++++++++-
 2 files changed, 111 insertions(+), 4 deletions(-)

diff --git a/tldraw/apps/tldraw-logseq/src/components/ContextMenu/ContextMenu.tsx b/tldraw/apps/tldraw-logseq/src/components/ContextMenu/ContextMenu.tsx
index 8b3a8a2e1..f434eca25 100644
--- a/tldraw/apps/tldraw-logseq/src/components/ContextMenu/ContextMenu.tsx
+++ b/tldraw/apps/tldraw-logseq/src/components/ContextMenu/ContextMenu.tsx
@@ -1,5 +1,5 @@
 import { useApp } from '@tldraw/react'
-import { MOD_KEY, AlignType } from '@tldraw/core'
+import { MOD_KEY, AlignType, DistributeType } from '@tldraw/core'
 import { observer } from 'mobx-react-lite'
 import { TablerIcon } from '../icons'
 import { Button } from '../Button'
@@ -46,14 +46,14 @@ export const ContextMenu = observer(function ContextMenu({
                 <Button title="Align center horizontally" onClick={() => runAndTransition(() => app.align(AlignType.CenterHorizontal))}><TablerIcon name="layout-align-center" /></Button>
                 <Button title="Align right" onClick={() => runAndTransition(() => app.align(AlignType.Right))}><TablerIcon name="layout-align-right" /></Button>
                 <Separator.Root className="tl-toolbar-separator" orientation="vertical" />
-                <Button title="Distribute horizontally"><TablerIcon name="layout-distribute-horizontal" /></Button>
+                <Button title="Distribute horizontally" onClick={() => runAndTransition(() => app.distribute(DistributeType.Horizontal))}><TablerIcon name="layout-distribute-vertical" /></Button>
               </div>
               <div className="tl-menu-button-row pt-0">
                 <Button title="Align top" onClick={() => runAndTransition(() => app.align(AlignType.Top))}><TablerIcon name="layout-align-top" /></Button>
                 <Button title="Align center vertically" onClick={() => runAndTransition(() => app.align(AlignType.CenterVertical))}><TablerIcon name="layout-align-middle" /></Button>
                 <Button title="Align bottom" onClick={() => runAndTransition(() => app.align(AlignType.Bottom))}><TablerIcon name="layout-align-bottom" /></Button>
                 <Separator.Root className="tl-toolbar-separator" orientation="vertical" />
-                <Button title="Distribute vertically"><TablerIcon name="layout-distribute-vertical" /></Button>
+                <Button title="Distribute vertically" onClick={() => runAndTransition(() => app.distribute(DistributeType.Vertical  ))}><TablerIcon name="layout-distribute-horizontal" /></Button>
               </div>
               <ReactContextMenu.Separator className="menu-separator" />
             </>
diff --git a/tldraw/packages/core/src/lib/TLApp/TLApp.ts b/tldraw/packages/core/src/lib/TLApp/TLApp.ts
index d12dd1a46..0731bbb65 100644
--- a/tldraw/packages/core/src/lib/TLApp/TLApp.ts
+++ b/tldraw/packages/core/src/lib/TLApp/TLApp.ts
@@ -17,7 +17,7 @@ import type {
   TLEvents,
   TLHandle,
 } from '../../types'
-import { AlignType } from '../../types'
+import { AlignType, DistributeType } from '../../types'
 import { KeyUtils, BoundsUtils, isNonNullable, createNewLineBinding } from '../../utils'
 import type { TLShape, TLShapeConstructor, TLShapeModel } from '../shapes'
 import { TLApi } from '../TLApi'
@@ -420,6 +420,113 @@ export class TLApp<
     return this
   }
 
+
+  distribute = (type: DistributeType, shapes: S[] = this.selectedShapesArray): this => {
+    if (shapes.length < 2) return this
+
+    const deltaMap = Object.fromEntries(this.getDistributions(shapes, type).map((d) => [d.id, d]))
+
+    shapes.forEach(shape => shape.update(deltaMap[shape.id] ? { point: deltaMap[shape.id].next } : shape))
+
+    this.persist()
+    return this
+  }
+
+  getDistributions = (shapes: TLShape[], type: DistributeType) => {
+    const entries = shapes.map((shape) => {
+      const bounds = shape.getBounds();
+      return {
+        id: shape.id,
+        point: [bounds.minX, bounds.minY],
+        bounds: bounds,
+        center: shape.getCenter(),
+      }
+    })
+
+    const len = entries.length
+    const commonBounds = BoundsUtils.getCommonBounds(entries.map(({ bounds }) => bounds))
+
+    const results: { id: string; prev: number[]; next: number[] }[] = []
+
+    switch (type) {
+      case DistributeType.Horizontal: {
+        const span = entries.reduce((a, c) => a + c.bounds.width, 0)
+
+        if (span > commonBounds.width) {
+          const left = entries.sort((a, b) => a.bounds.minX - b.bounds.minX)[0]
+
+          const right = entries.sort((a, b) => b.bounds.maxX - a.bounds.maxX)[0]
+
+          const entriesToMove = entries
+            .filter((a) => a !== left && a !== right)
+            .sort((a, b) => a.center[0] - b.center[0])
+
+          const step = (right.center[0] - left.center[0]) / (len - 1)
+
+          const x = left.center[0] + step
+
+          entriesToMove.forEach(({ id, point, bounds }, i) => {
+            results.push({
+              id,
+              prev: point,
+              next: [x + step * i - bounds.width / 2, bounds.minY],
+            })
+          })
+        } else {
+          const entriesToMove = entries.sort((a, b) => a.center[0] - b.center[0])
+
+          let x = commonBounds.minX
+          const step = (commonBounds.width - span) / (len - 1)
+
+          entriesToMove.forEach(({ id, point, bounds }) => {
+            results.push({ id, prev: point, next: [x, bounds.minY] })
+            x += bounds.width + step
+          })
+        }
+        break
+      }
+      case DistributeType.Vertical: {
+        const span = entries.reduce((a, c) => a + c.bounds.height, 0)
+
+        if (span > commonBounds.height) {
+          const top = entries.sort((a, b) => a.bounds.minY - b.bounds.minY)[0]
+
+          const bottom = entries.sort((a, b) => b.bounds.maxY - a.bounds.maxY)[0]
+
+          const entriesToMove = entries
+            .filter((a) => a !== top && a !== bottom)
+            .sort((a, b) => a.center[1] - b.center[1])
+
+          const step = (bottom.center[1] - top.center[1]) / (len - 1)
+
+          const y = top.center[1] + step
+
+          entriesToMove.forEach(({ id, point, bounds }, i) => {
+            results.push({
+              id,
+              prev: point,
+              next: [bounds.minX, y + step * i - bounds.height / 2],
+            })
+          })
+        } else {
+          const entriesToMove = entries.sort((a, b) => a.center[1] - b.center[1])
+
+          let y = commonBounds.minY
+          const step = (commonBounds.height - span) / (len - 1)
+
+          entriesToMove.forEach(({ id, point, bounds }) => {
+            results.push({ id, prev: point, next: [bounds.minX, y] })
+            y += bounds.height + step
+          })
+        }
+
+        break
+      }
+    }
+
+    return results
+  }
+
   /* --------------------- Assets --------------------- */
 
   @observable assets: Record<string, TLAsset> = {}