further refactor js

Turn the div adapters into injectable files so that each PdfContainer can be customized. And the adapters can be used in different PdfContainers as well.

src/main/resources/static/js/multitool/DragDropManager.js

@@ -0,0 +1,90 @@
+
+
+class DragDropManager {
+    dragContainer;
+    movePageTo;
+    pageDragging;
+    draggelEl;
+    draggedImageEl;
+    hoveredEl;
+
+    constructor(id) {
+        this.dragContainer = document.getElementById(id);
+        this.pageDragging = false;
+        this.hoveredEl = undefined;
+        this.draggelEl = undefined
+        this.draggedImageEl = undefined;
+
+        this.startDraggingPage = this.startDraggingPage.bind(this);
+        this.onDragEl = this.onDragEl.bind(this);
+        this.stopDraggingPage = this.stopDraggingPage.bind(this);
+    }
+
+    startDraggingPage(div, imageSrc) {
+        this.pageDragging = true;
+        this.draggedEl = div;
+        div.classList.add('dragging');
+        const imgEl = document.createElement('img');
+        imgEl.classList.add('dragged-img');
+        imgEl.src = imageSrc;
+        this.draggedImageEl = imgEl;
+        this.draggedImageEl.style.left = screenX;
+        this.draggedImageEl.style.right = screenY;
+        this.dragContainer.appendChild(imgEl);
+        window.addEventListener('mouseup', this.stopDraggingPage)
+        window.addEventListener('mousemove', this.onDragEl)
+    }
+
+    onDragEl(mouseEvent) {
+        const { clientX, clientY } = mouseEvent;
+        if(this.draggedImageEl) {
+            this.draggedImageEl.style.left = `${clientX}px`;
+            this.draggedImageEl.style.top = `${clientY}px`;
+        }
+    }
+
+    
+    stopDraggingPage() {
+        window.removeEventListener('mousemove', this.onDragEl);
+        window.removeEventListener('mouseup', this.stopDraggingPage)
+        this.draggedImageEl = undefined;
+        this.pageDragging = false;
+        this.draggedEl.classList.remove('dragging');
+        this.hoveredEl.classList.remove('draghover');
+        this.dragContainer.childNodes.forEach((dragChild) => {
+            this.dragContainer.removeChild(dragChild);
+        })
+        this.movePageTo(this.draggedEl, this.hoveredEl);
+    }
+
+    setActions({ movePageTo }) {
+        this.movePageTo = movePageTo;
+    }
+
+
+    adapt(div) {
+        const onDragStart = () => {
+            this.startDraggingPage(div, div.querySelector('img').src);
+        }
+        
+        const onMouseEnter = () => {
+            if (this.pageDragging) {
+                this.hoveredEl = div;
+                div.classList.add('draghover');
+            }
+        }
+
+        const onMouseLeave = () => {
+            this.hoveredEl = undefined
+            div.classList.remove('draghover');
+        }
+
+        div.addEventListener('dragstart', onDragStart);
+        div.addEventListener('mouseenter', onMouseEnter);
+        div.addEventListener('mouseleave', onMouseLeave);
+
+        return div;
+    }
+}
+
+export default DragDropManager;