From c4783101a0ec08cdcb81f46a0f10da543dd3c14f Mon Sep 17 00:00:00 2001
From: "Alex A. Naanou" <alex.nanou@gmail.com>
Date: Thu, 17 Aug 2023 17:16:49 +0300
Subject: [PATCH] reworked toolbar dragging (still disabled)...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
---
 grid-n-view.js | 202 ++++++++++++++++++++++++++++++-------------------
 1 file changed, 123 insertions(+), 79 deletions(-)

diff --git a/grid-n-view.js b/grid-n-view.js
index d4fd03a..365984f 100644
--- a/grid-n-view.js
+++ b/grid-n-view.js
@@ -152,6 +152,113 @@ var getTouch = function(evt, id){
 				return evt.targetTouches[k] } } } }
 
 
+// XXX need to check if element already set as movable...
+var moveable = function(elem, options={}){
+	if(elem.dataset.movable){
+		throw new Error('element already movable.') }
+	elem.dataset.movable = true
+	var {
+		cls,
+		handle,
+		bounds,
+		start = function(elem, data){
+			bounds 
+				?? (data.bounds = bounds)
+			return data },
+		beforeMove,
+		move = function(elem, data){
+			elem.style.left = data.x + 'px'
+			elem.style.top = data.y + 'px'
+		},
+		end,
+	} = options
+	handle = typeof(handle) == 'string' ?
+			elem.querySelector(handle)
+		: handle instanceof Element ?
+			handle
+		: elem
+	var data
+
+	var handleMoveStart = function(evt){
+		evt.preventDefault()
+		evt.stopPropagation()
+		if(!data){
+			cls
+				&& elem.classList.add(cls)
+			var x = evt.clientX 
+				?? evt.targetTouches[0].clientX
+			var y = evt.clientY
+				?? evt.targetTouches[0].clientY
+			data = {
+				bounds: false,
+				offset: {
+					x: x - elem.offsetLeft, 
+					y: y - elem.offsetTop,
+				},
+				touch: evt.targetTouches ?
+					evt.targetTouches[0].identifier
+					: undefined,
+			} 
+			if(typeof(start) == 'function'){
+				var res = start(elem, data)
+				data = res != null ?
+					res
+					: data } } }
+	var handleMove = function(evt){
+		if(data){
+			var src = data.touch != null ?
+				getTouch(evt, data.touch)
+				: evt
+			if(!src){
+				return }
+			evt.preventDefault()
+			evt.stopPropagation()
+			var x = src.clientX 
+			var y = src.clientY
+			data.x =
+				data.bounds != null ?
+					Math.min(data.bounds.right,
+						Math.max(data.bounds.left, 
+							x - data.offset.x))
+					: x - data.offset.x
+			data.y =
+				data.bounds != null ?
+					Math.min(data.bounds.bottom,
+						Math.max(data.bounds.top, 
+							y - data.offset.y))
+					: y - data.offset.y
+			// NOTE: we only allow a single requestAnimationFrame(..)
+			// 		to run per frame...
+			if(!data.animate){
+				data.animate = requestAnimationFrame(function(){
+					if(!data){
+						return }
+					move(elem, data)
+					delete data.animate }) } } }
+	var handleMoveEnd = function(evt){
+		if(data){
+			if(evt.targetTouches
+					&& (evt.targetTouches.length == 0 
+						|| getTouch(evt, data.touch))){
+				return }
+			evt.preventDefault()
+			evt.stopPropagation()
+			cls
+				&& elem.classList.remove(cls)
+			end
+				&& end(elem, data) 
+			data = false } }
+
+	// XXX can we reuse these???
+	// 		...i.e. keep the data in the element???
+	handle.addEventListener('mousedown', handleMoveStart)
+	handle.addEventListener('touchstart', handleMoveStart)
+	document.addEventListener('mousemove', handleMove)
+	document.addEventListener('touchmove', handleMove)
+	document.addEventListener('touchend', handleMoveEnd)
+	document.addEventListener('mouseup', handleMoveEnd) }
+
+
 //---------------------------------------------------------------------
 
 // XXX add shift+arrow to select...
@@ -947,87 +1054,24 @@ var Gallery = {
 		toolbar.addEventListener('mouseover', toolbarAutoHideCancel)
 		toolbar.addEventListener('touchstart', toolbarAutoHideCancel)
 
-		/* XXX problems:
-		// 		- too many interactions: autohide, placement, ...
-		// 		- not sure if we need this...
+		/* XXX needs more tweaking...
 		// toolbar: move...
-		var handleToolbarMoveStart = function(evt){
-			evt.preventDefault()
-			evt.stopPropagation()
-			if(!toolbar_moving){
-				toolbar.classList.add('moving')
-				var x = evt.clientX 
-					?? evt.targetTouches[0].clientX
-				var y = evt.clientY
-					?? evt.targetTouches[0].clientY
-				toolbar_moving = {
-					bounds: {
-						x: that.dom.offsetWidth - toolbar.offsetWidth - 20,
-						// XXX this gets off on high magnifications...
-						y: that.dom.offsetHeight - toolbar.offsetHeight - 20,
-					},
-					offset: {
-						x: x - toolbar.offsetLeft, 
-						y: y - toolbar.offsetTop,
-					},
-					touch: evt.targetTouches ?
-						evt.targetTouches[0].identifier
-						: undefined,
-				} } }
-		var handleToolbarMoveEnd = function(evt){
-			if(toolbar_moving){
-				if(evt.targetTouches
-						&& (evt.targetTouches.length == 0 
-							|| getTouch(evt, toolbar_moving.touch))){
-					return }
-				evt.preventDefault()
-				evt.stopPropagation()
-				toolbar.classList.remove('moving')
-				toolbar_moving = false } }
-		// XXX ignore non-local touches...
-		// XXX disable button clicking while moving...
-		var handleToolbarMove = function(evt){
-			if(toolbar_moving){
-				var src = toolbar_moving.touch != null ?
-					getTouch(evt, toolbar_moving.touch)
-					: evt
-				if(!src){
-					return }
-				evt.preventDefault()
-				evt.stopPropagation()
-				var x = src.clientX 
-				var y = src.clientY
-				toolbar_moving.x =
-					toolbar_moving.bounds?.x != null ?
-						Math.min(toolbar_moving.bounds.x,
-							Math.max(0, 
-								x - toolbar_moving.offset.x))
-						: x - toolbar_moving.offset.x
-				toolbar_moving.y =
-					toolbar_moving.bounds?.y != null ?
-						Math.min(toolbar_moving.bounds.y,
-							Math.max(0, 
-								y - toolbar_moving.offset.y))
-						: y - toolbar_moving.offset.y
-				// NOTE: we only allow a single requestAnimationFrame(..)
-				// 		to run per frame...
-				if(!toolbar_moving.animate){
-					toolbar_moving.animate = requestAnimationFrame(function(){
-						if(!toolbar_moving){
-							return }
-						toolbar.style.setProperty('--move-x', toolbar_moving.x + 'px') 
-						toolbar.style.setProperty('--move-y', toolbar_moving.y + 'px') 
-						delete toolbar_moving.animate }) } } }
-		// XXX to drag anywhere on the toolbar we need to prevent 
+		// XXX to drag anywhere on the elem we need to prevent 
 		// 		clicks while dragging...
-		toolbar.querySelector('.drag-handle')
-			.addEventListener('mousedown', handleToolbarMoveStart)
-		toolbar.querySelector('.drag-handle')
-			.addEventListener('touchstart', handleToolbarMoveStart)
-		this.dom.addEventListener('mousemove', handleToolbarMove)
-		this.dom.addEventListener('touchmove', handleToolbarMove)
-		document.addEventListener('touchend', handleToolbarMoveEnd)
-		document.addEventListener('mouseup', handleToolbarMoveEnd)
+		moveable(toolbar, {
+			cls: 'moving',
+			handle: '.drag-handle',
+			// set bounds...
+			start: function(elem, data){
+				data.bounds = {
+					top: 0,
+					left: 0,
+					right: that.dom.offsetWidth - elem.offsetWidth - 20,
+					bottom: that.dom.offsetHeight - elem.offsetHeight - 20,
+				} },
+			move: function(elem, data){
+				elem.style.setProperty('--move-x', data.x + 'px') 
+				elem.style.setProperty('--move-y', data.y + 'px') }, })
 		//*/
 
 		// image clicks...