From 374764d6f2c64129ae940e685e7b693e34922560 Mon Sep 17 00:00:00 2001
From: jin <jin@hyoo.ru>
Date: Sun, 29 Dec 2024 16:25:39 +0300
Subject: [PATCH] $mol_dom_point, $mol_dom_range, $mol_dom = $mol_dom_context

---
 dom/dom.ts         |   5 +++
 dom/point/point.ts | 106 +++++++++++++++++++++++++++++++++++++++++++++
 dom/range/range.ts |  61 ++++++++++++++++++++++++++
 3 files changed, 172 insertions(+)
 create mode 100644 dom/dom.ts
 create mode 100644 dom/point/point.ts
 create mode 100644 dom/range/range.ts

diff --git a/dom/dom.ts b/dom/dom.ts
new file mode 100644
index 0000000000..2a29b3223a
--- /dev/null
+++ b/dom/dom.ts
@@ -0,0 +1,5 @@
+namespace $ {
+	
+	export var $mol_dom = $mol_dom_context
+	
+}
diff --git a/dom/point/point.ts b/dom/point/point.ts
new file mode 100644
index 0000000000..4cb5ad3261
--- /dev/null
+++ b/dom/point/point.ts
@@ -0,0 +1,106 @@
+namespace $ {
+	
+	export class $mol_dom_point extends Object {
+		
+		constructor(
+			public node: Node,
+			public pos: number,
+		) { super() }
+		
+		static start( node: Node ) {
+			return new this( node, 0 )
+		} 
+		
+		static end( node: Node ) {
+			const length = node.nodeValue?.length ?? node.childNodes.length
+			return new this( node, length )
+		}
+		
+		to( point: $mol_dom_point ) {
+			this.node = point.node
+			this.pos = point.pos
+		}
+		
+		to_start() {
+			this.pos = 0
+			return this
+		}
+		
+		to_end() {
+			this.pos = this.node.nodeValue?.length ?? this.node.childNodes.length
+			return this
+		}
+		
+		is_start() {
+			return this.pos <= 0
+		}
+		
+		is_end() {
+			return this.pos >= ( this.node.nodeValue?.length ?? this.node.childNodes.length )
+		}
+		
+		char_backward( root: Element ): $mol_dom_point {
+			return this.backward( ()=> {
+				if( this.node === root && this.is_start() ) return true
+				if( this.node.nodeType !== this.node.TEXT_NODE ) return false
+				if( this.is_start() ) return false
+				this.pos -= 1
+				return true
+			} )
+		}
+		
+		char_forward( root: Element ): $mol_dom_point {
+			return this.forward( ()=> {
+				if( this.node === root && this.is_end() ) return true
+				if( this.node.nodeType !== this.node.TEXT_NODE ) return false
+				if( this.is_end() ) return false
+				this.pos += 1
+				return true
+			} )
+		}
+		
+		backward( check: ()=> boolean ): $mol_dom_point {
+			
+			if( check() ) return this
+			
+			if( !this.is_start() ) {
+				const kid = this.node.childNodes[ this.pos - 1 ]
+				this.node = kid
+				this.to_end()
+				return this.backward( check )
+			}
+			
+			const parent = this.node.parentElement
+			if( !parent ) return this
+			
+			const offset = [ ... parent.childNodes ].indexOf( this.node as ChildNode )
+			this.node = parent
+			this.pos = offset
+			return this.backward( check )
+			
+		}
+		
+		forward( check: ()=> boolean ): $mol_dom_point {
+			
+			if( check() ) return this
+			
+			if( !this.is_end() ) {
+				const kid = this.node.childNodes[ this.pos ]
+				this.node = kid
+				this.to_start()
+				return this.forward( check )
+			}
+			
+			const parent = this.node.parentElement
+			if( !parent ) return this
+			
+			const offset = [ ... parent.childNodes ].indexOf( this.node as ChildNode ) + 1
+			this.node = parent
+			this.pos = offset
+			return this.forward( check )
+			
+		}
+		
+	}
+	
+}
diff --git a/dom/range/range.ts b/dom/range/range.ts
new file mode 100644
index 0000000000..e4a2ff8081
--- /dev/null
+++ b/dom/range/range.ts
@@ -0,0 +1,61 @@
+namespace $ {
+	export class $mol_dom_range extends Object {
+		
+		constructor(
+			readonly head: $mol_dom_point,
+			readonly foot: $mol_dom_point,
+		) { super() }
+		
+		static from_selection( sel = $mol_dom_context.getSelection()! ) {
+			return this.from_native( sel?.getRangeAt(0) )
+		}
+		
+		static from_native( range: Range ) {
+			return new this(
+				new $mol_dom_point( range.startContainer, range.startOffset ),
+				new $mol_dom_point( range.endContainer, range.endOffset ),
+			)
+		}
+		
+		static inside( node: Node ) {
+			return new this(
+				$mol_dom_point.start( node ),
+				$mol_dom_point.end( node ),
+			)
+		}
+		
+		static around( node: Node ) {
+			
+			const parent = node.parentNode!
+			const pos = [ ... parent.childNodes ].indexOf( node as ChildNode )
+			
+			return new this(
+				new $mol_dom_point( parent, pos ),
+				new $mol_dom_point( parent, pos + 1 ),
+			)
+			
+		}
+		
+		is_empty() {
+			return this.head.node === this.foot.node && this.head.pos === this.foot.pos
+		}
+		
+		clear() {
+			this.native().deleteContents()
+		}
+		
+		select() {
+			const sel = $mol_dom_context.document.getSelection()!
+			sel.removeAllRanges()
+			sel.addRange( this.native() )
+		}
+		
+		native() {
+			const range = $mol_dom_context.document.createRange()
+			range.setEnd( this.foot.node, this.foot.pos )
+			range.setStart( this.head.node, this.head.pos )
+			return range
+		}
+		
+	}
+}