Feature detection suggestion

release/internal/drag-operation-controller.d.ts

@@ -29,7 +29,7 @@ export declare class DragOperationController {
     private _iterationIntervalId;
     constructor(_initialEvent: TouchEvent, _config: Config, _sourceNode: HTMLElement, _dragOperationEndedCb: (config: Config, event: TouchEvent, state: DragOperationState) => void);
     private _setup();
-    private _cleanup();
+    cleanup();
     private _onTouchMove(event);
     private _onTouchEndOrCancel(event);
     private _dragAndDropProcessModelIteration();

src/index.ts

@@ -27,6 +27,8 @@ function onTouchstart( e:TouchEvent ) {
     // only allow one drag operation at a time
     if( activeDragOperation ) {
         console.log( "dnd-poly: drag operation already active" );
+        // try avoid infinite loop on iOS if something happened with draggable dom object (disappeared or changed during drag)
+        activeDragOperation.cleanup();
         return;
     }
 

src/internal/drag-operation-controller.ts

@@ -173,7 +173,7 @@ export class DragOperationController {
             console.log( "dnd-poly: dragstart cancelled" );
             // dragstart has been prevented -> cancel d'n'd
             this._dragOperationState = DragOperationState.CANCELLED;
-            this._cleanup();
+            this.cleanup();
             return false;
         }
 
@@ -245,7 +245,7 @@ export class DragOperationController {
         return true;
     }
 
-    private _cleanup() {
+    public cleanup() {
 
         console.log( "dnd-poly: cleanup" );
 
@@ -304,7 +304,7 @@ export class DragOperationController {
 
             if( !startDrag ) {
 
-                this._cleanup();
+                this.cleanup();
                 return;
             }
 
@@ -398,7 +398,7 @@ export class DragOperationController {
 
         // drag operation did not even start
         if( this._dragOperationState === DragOperationState.POTENTIAL ) {
-            this._cleanup();
+            this.cleanup();
             return;
         }
 
@@ -796,7 +796,7 @@ export class DragOperationController {
 
         // drag operation over and out
         this._dragOperationState = DragOperationState.ENDED;
-        this._cleanup();
+        this.cleanup();
     }
 
     //</editor-fold>

src/internal/feature-detection.ts

@@ -12,15 +12,29 @@ export function detectFeatures():DetectedFeatures {
         userAgentSupportingNativeDnD: undefined
     };
 
-    const isBlinkEngine = !!((<any>window).chrome) || /chrome/i.test( navigator.userAgent );
-
-    features.userAgentSupportingNativeDnD = !(
-        // if is mobile safari or android browser -> no native dnd
-        (/iPad|iPhone|iPod|Android/.test( navigator.userAgent ))
-        || // OR
-        //if is blink(chrome/opera) with touch events enabled -> no native dnd
-        (isBlinkEngine && ("ontouchstart" in document.documentElement))
-    );
+    // const isBlinkEngine = !!((<any>window).chrome) || /chrome/i.test( navigator.userAgent );
+
+    // features.userAgentSupportingNativeDnD = !(
+    //     // if is mobile safari or android browser -> no native dnd
+    //     (/iPad|iPhone|iPod|Android/.test( navigator.userAgent ))
+    //     || // OR
+    //     //if is blink(chrome/opera) with touch events enabled -> no native dnd
+    //     (isBlinkEngine && ("ontouchstart" in document.documentElement))
+    // );
+
+    if (/iPad|iPhone|iPod/.test(navigator.userAgent)) {
+        // from iOS 11 and higher are supported
+        features.userAgentSupportingNativeDnD = !/(OS \d_)|(OS 10_)/.test(navigator.userAgent);
+    }
+    else
+        if (/Android/.test(navigator.userAgent)) {
+            // from Chrome Mobile 54 and higher are supported
+            features.userAgentSupportingNativeDnD = !/(Chrome\/5[0-3]\.)|(Chrome\/[1-4]\d\.)|(Chrome\/\d\.)/.test(navigator.userAgent);
+        }
+        else {
+            // should work on all ten years old desktop browsers and younger
+            features.userAgentSupportingNativeDnD = true;
+        }
 
     return features;
 }