Drag a program (HTML + CSS + JavaScript)

DragProgram
Principle: Move the dragged element based on the movement of the mouse. The movement of the mouse is the change of the X and Y coordinates. The movement of the element is the change of the top and left of the style. position. First, you must determine whether to press the mouse or not on the corresponding drag-and-drop element.

Basic Ideas:
Record the drag status (0: not pressed; 1: pressed)
Press {
Status = 1;
Record element x and y values
Record mouse x and y values
}

When moving {
Judge whether the status is 1
If it is 1, then:
Element x = current mouse X-original mouse x + original element x:
Element y = current mouse y-original mouse y + Element Original Y:
}

When releasing {
Status = 0;
Determine whether the database is in the specified range:
Automatic Location Adjustment;
}