Add CanvasPointer API (#308)

* Add position rounding feature

Replaces previous impls. which only worked on some items, and were triggered when unexpected e.g. clicking a node that hadn't been moved.

Update test expectations

* Narrow TS types - readonly

* nit - Clean up, Doc

* nit - Clean up legacy accessors

Marks as deprecated

* Fix TS type - IContextMenuOptions.scale

* [Refactor] dist2 for use in pointer API

* Add CanvasPointer - API for pointer events

Add TS strict types
Add final click drag distance math
Add option to retain events

* nit - Rename

* nit

* Remove Subgraph - unused & not maintained

* Remove live_mode

Unused, not maintained.

* Update README

Remove live_mode reference

* Update delete selected - include reroutes & groups

* Bypass link menu if alt/shift pressed

* Remove old dragged_node interface

Incomplete impl. - unused.
Superceded by selectedItems

* Fix top/left edge of rectangles not in hitbox

* [Refactor] Match function names to interface names

* Add interface to find widgets by Point

LGraphNode.getWidgetOnPos

* Add widget search param - includeDisabled

* nit - Doc

* Rewrite canvas mouse handling

- Rewrites most pointer handling to use CanvasPointer callbacks
- All callbacks are declared ahead of time during the initial pointerdown event, logically grouped together
- Drastically simplifies the alteration or creation of new click / drag interactions
- Click events are all clicks, rather than some processed on mouse down, others on mouse up

- Functions return instead of setting and repeatedly checking multiple state vars
- Removes all lines that needed THIRTEEN tab indents

* Split middle click out from processMouseDown

* Use pointer API for link menus

* Narrow canvas event interfaces

* Fix canvas event types

Replaces original workarounds with final types

* Refactor - deprecated isInsideRectangle

* Add canvas hovering over state

- Centralises cursor set behaviour
- Provides simple downstream override

* nit

* [Refactor] Use measure functions

* Add double-click API to CanvasPointer

a

* nit - Doc

* Allow larger gap between double click events

* Rewrite double-click into CanvasPointer actions

* Improve double-click UX

Prefer down events over up events

* Add production defaults

* Add middle-click handling

* Remove debug code

* Remove redundant code

* Fix add reroute alt-click adds two undo steps

* Fix click on connected input disconnects

Old behaviour was to disconnect, then recreate a new link on drop.

* Add module export: CanvasPointer

src/LGraph.ts

@@ -826,9 +826,6 @@ export class LGraph implements LinkNetwork, Serialisable<SerialisableGraph> {
                 const canvas = this.list_of_graphcanvas[i]
                 if (canvas.selected_nodes[node.id])
                     delete canvas.selected_nodes[node.id]
-
-                if (canvas.node_dragged == node)
-                    canvas.node_dragged = null
             }
         }
 
@@ -1222,18 +1219,6 @@ export class LGraph implements LinkNetwork, Serialisable<SerialisableGraph> {
         // @ts-expect-error
         this.canvasAction(c => c.onConnectionChange?.())
     }
-    /**
-     * returns if the graph is in live mode
-     */
-    isLive(): boolean {
-        if (!this.list_of_graphcanvas) return false
-
-        for (let i = 0; i < this.list_of_graphcanvas.length; ++i) {
-            const c = this.list_of_graphcanvas[i]
-            if (c.live_mode) return true
-        }
-        return false
-    }
     /**
      * clears the triggered slot animation in all links (stop visual animation)
      */
@@ -1334,7 +1319,7 @@ export class LGraph implements LinkNetwork, Serialisable<SerialisableGraph> {
 
         const node = this.getNodeById(link.target_id)
         node?.disconnectInput(link.target_slot)
-        
+
         link.disconnect(this)
     }