I am currently working on making a div element, set to "overflow:auto," scroll when a user is dragging an element.
The dragging functionality is functioning correctly, and I am able to retrieve the necessary mouse data, such as the initial x/y position during drag (onDragStart) and the current x/y position while the mouse is in motion.
Although I suspect there may be a flaw in my scrolling logic, my main goal is simply to achieve any form of scrolling within the div element. Any insights into what might be going wrong would be greatly appreciated. Additionally, the project utilizes Material Design.
Please note that ng-metadata is being used to mimic Angular 2 with Angular 1. Any guidance pertaining to either Angular version would be valuable.
@autobind
onDragStart({clientX, clientY}) {
this.initY = clientY;
if (this.isDragging) return;
document.addEventListener('mousemove', this.dragListener = (e) => {
e.preventDefault();
if (Math.max(Math.abs(e.clientX - clientX), Math.abs(e.clientY - clientY)) > 3) {
document.removeEventListener('mousemove', this.dragListener);
document.addEventListener('mousemove', this.onDrag);
this.dragListener = this.onDrag;
this.fileService.dragSource = this.file;
// onDrag needs to be called before Angular can set the proper classes
this._element.toggleClass('dragging', this.isDragging);
this._element.toggleClass('bulk-dragging', this.inBulkDragOp);
this.onDragScroll(e);
this.onDrag(e);
this.drag.emit();
this._scope.$applyAsync();
}
});
}
@autobind
onDrag(e) {
console.log("Dragging...");
console.log(e);
var currentY = e.clientY;
var range = 100; // Range of 100px before scrolling begins... May need tweaking if too responsive
if (currentY > this.initY + range) {
console.log("SCROLL DOWN");
window.scrollTo(0, 500);
} else if (currentY < this.initY - range) {
console.log("SCROLL UP");
}
e.preventDefault();
this._element.css('transform', `translate(${e.clientX - this._element[0].clientWidth / 2}px, ${e.clientY - this._element[0].clientHeight / 2}px)`);
}