1.概述

在12.0系统Launcher3进行定制化开发中，对于hotseat的开发中，由功能需求要求禁止拖动图标到Hotseat的功能，而拖拽也是在workspace.java中处理的
接下来就从workspace.java 开始找解决的办法

2.Launcher3禁止拖动图标到Hotseat相关代码分析

packages/apps/Launcher3/src/com/android/launcher3/DropTarget.java
packages/apps/Launcher3/src/com/android/launcher3/Workspace.java

3.Launcher3禁止拖动图标到Hotseat功能分析和实现
3.1DropTarget.java相关拖拽的接口

public interface DropTarget {class DragObject {        void onDrop(DragObject dragObject, DragOptions options);void onDragEnter(DragObject dragObject);void onDragOver(DragObject dragObject);void onDragExit(DragObject dragObject);/*** Check if a drop action can occur at, or near, the requested location.* This will be called just before onDrop.* @return True if the drop will be accepted, false otherwise.*/boolean acceptDrop(D