From 602fbada4b16720a6278d775e0ed7ab016756a0c Mon Sep 17 00:00:00 2001
From: braks <78412429+bcakmakoglu@users.noreply.github.com>
Date: Thu, 8 Dec 2022 22:20:31 +0100
Subject: [PATCH] fix(core,additional-components): apply translate extent on
 pan

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>
---
 .../src/minimap/MiniMap.vue                   | 14 +++++--
 .../core/src/container/Viewport/Viewport.vue  | 40 ++++++++++++-------
 2 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/packages/additional-components/src/minimap/MiniMap.vue b/packages/additional-components/src/minimap/MiniMap.vue
index 8b3abf13..82eafc2a 100644
--- a/packages/additional-components/src/minimap/MiniMap.vue
+++ b/packages/additional-components/src/minimap/MiniMap.vue
@@ -1,5 +1,5 @@
 <script lang="ts" setup>
-import type { GraphNode } from '@vue-flow/core'
+import type { CoordinateExtent, GraphNode } from '@vue-flow/core'
 import { getBoundsofRects, getConnectedEdges, getRectOfNodes, useVueFlow } from '@vue-flow/core'
 import { zoom, zoomIdentity } from 'd3-zoom'
 import type { D3ZoomEvent } from 'd3-zoom'
@@ -33,7 +33,7 @@ const attrs: Record<string, any> = useAttrs()
 const defaultWidth = 200
 const defaultHeight = 150
 
-const { id, edges, viewport, dimensions, emits, nodes, d3Selection, d3Zoom } = useVueFlow()
+const { id, edges, viewport, translateExtent, dimensions, emits, nodes, d3Selection, d3Zoom } = useVueFlow()
 
 const el = ref<SVGElement>()
 
@@ -128,9 +128,15 @@ watchEffect(
           y: viewport.value.y - event.sourceEvent.movementY * viewScale.value * Math.max(1, viewport.value.zoom),
         }
 
-        const nextTransform = zoomIdentity.translate(position.x, position.y).scale(viewport.value.zoom)
+        const extent: CoordinateExtent = [
+          [0, 0],
+          [dimensions.value.width, dimensions.value.height],
+        ]
 
-        d3Zoom.value.transform(d3Selection.value, nextTransform)
+        const nextTransform = zoomIdentity.translate(position.x, position.y).scale(viewport.value.zoom)
+        const constrainedTransform = d3Zoom.value.constrain()(nextTransform, extent, translateExtent.value)
+
+        d3Zoom.value.transform(d3Selection.value, constrainedTransform)
       }
 
       const zoomAndPanHandler = zoom()
diff --git a/packages/core/src/container/Viewport/Viewport.vue b/packages/core/src/container/Viewport/Viewport.vue
index cc7017bc..6500c1a3 100644
--- a/packages/core/src/container/Viewport/Viewport.vue
+++ b/packages/core/src/container/Viewport/Viewport.vue
@@ -2,7 +2,7 @@
 import type { D3ZoomEvent, ZoomTransform } from 'd3-zoom'
 import { zoom, zoomIdentity } from 'd3-zoom'
 import { pointer, select } from 'd3-selection'
-import type { ViewpaneTransform } from '../../types'
+import type { CoordinateExtent, ViewpaneTransform } from '../../types'
 import { PanOnScrollMode } from '../../types'
 import SelectionPane from '../SelectionPane/SelectionPane.vue'
 import Transform from './Transform.vue'
@@ -40,10 +40,10 @@ let isDragging = $ref(false)
 
 const isConnecting = $computed(() => !!connectionStartHandle)
 
-const viewChanged = (prevTransform: ViewpaneTransform, eventTransform: ZoomTransform): boolean =>
-  (prevTransform.x !== eventTransform.x && !isNaN(eventTransform.x)) ||
-  (prevTransform.y !== eventTransform.y && !isNaN(eventTransform.y)) ||
-  (prevTransform.zoom !== eventTransform.k && !isNaN(eventTransform.k))
+const viewChanged = (prevViewport: ViewpaneTransform, eventTransform: ZoomTransform): boolean =>
+  (prevViewport.x !== eventTransform.x && !isNaN(eventTransform.x)) ||
+  (prevViewport.y !== eventTransform.y && !isNaN(eventTransform.y)) ||
+  (prevViewport.zoom !== eventTransform.k && !isNaN(eventTransform.k))
 
 const eventToFlowTransform = (eventTransform: ZoomTransform): ViewpaneTransform => ({
   x: eventTransform.x,
@@ -53,11 +53,10 @@ const eventToFlowTransform = (eventTransform: ZoomTransform): ViewpaneTransform
 
 const isWrappedWithClass = (event: Event, className: string | undefined) => (event.target as Element).closest(`.${className}`)
 
-const clampedZoom = clamp(defaultZoom, minZoom, maxZoom)
-
-let transform = $ref({
-  ...clampPosition({ x: defaultPosition[0], y: defaultPosition[1] }, translateExtent),
-  zoom: clampedZoom,
+let prevTransform = $ref<ViewpaneTransform>({
+  x: 0,
+  y: 0,
+  zoom: 0,
 })
 
 onMounted(() => {
@@ -80,12 +79,19 @@ onMounted(() => {
 })
 
 onMounted(() => {
+  const bbox = viewportEl.value.getBoundingClientRect()
   const d3Zoom = zoom<HTMLDivElement, any>().scaleExtent([minZoom, maxZoom]).translateExtent(translateExtent)
   const d3Selection = select(viewportEl.value).call(d3Zoom)
   const d3ZoomHandler = d3Selection.on('wheel.zoom')
 
-  const updatedTransform = zoomIdentity.translate(transform.x, transform.y).scale(transform.zoom)
-  d3Zoom.transform(d3Selection, updatedTransform)
+  const updatedTransform = zoomIdentity.translate(defaultPosition[0], defaultPosition[1]).scale(defaultZoom)
+  const extent: CoordinateExtent = [
+    [0, 0],
+    [bbox.width, bbox.height],
+  ]
+
+  const constrainedTransform = d3Zoom.constrain()(updatedTransform, extent, translateExtent)
+  d3Zoom.transform(d3Selection, constrainedTransform)
 
   setState({
     d3Zoom,
@@ -101,7 +107,9 @@ onMounted(() => {
     } else if (!keyPress) {
       d3Zoom.on('zoom', (event: D3ZoomEvent<HTMLDivElement, any>) => {
         setState({ viewport: { x: event.transform.x, y: event.transform.y, zoom: event.transform.k } })
+
         const flowTransform = eventToFlowTransform(event.transform)
+
         emits.move({ event, flowTransform })
       })
     }
@@ -124,7 +132,7 @@ onMounted(() => {
       isDragging = true
     }
 
-    transform = flowTransform
+    prevTransform = flowTransform
 
     emits.moveStart({ event, flowTransform })
   })
@@ -135,9 +143,11 @@ onMounted(() => {
     isZoomingOrPanning = false
     isDragging = false
 
-    if (viewChanged(transform, event.transform)) {
+    if (viewChanged(prevTransform, event.transform)) {
       const flowTransform = eventToFlowTransform(event.transform)
-      transform = flowTransform
+
+      prevTransform = flowTransform
+
       emits.moveEnd({ event, flowTransform })
     }
   })