Java tutorial
/* * Sencha GXT 2.3.1 - Sencha for GWT * Copyright(c) 2007-2013, Sencha, Inc. * licensing@sencha.com * * http://www.sencha.com/products/gxt/license/ */ package com.extjs.gxt.ui.client.dnd; import java.util.ArrayList; import java.util.List; import com.extjs.gxt.ui.client.core.El; import com.extjs.gxt.ui.client.data.ModelData; import com.extjs.gxt.ui.client.data.TreeModel; import com.extjs.gxt.ui.client.dnd.DND.Feedback; import com.extjs.gxt.ui.client.event.DNDEvent; import com.extjs.gxt.ui.client.store.TreeStoreModel; import com.extjs.gxt.ui.client.util.Rectangle; import com.extjs.gxt.ui.client.widget.treepanel.TreePanel; import com.extjs.gxt.ui.client.widget.treepanel.TreePanel.TreeNode; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.Element; import com.google.gwt.user.client.Timer; @SuppressWarnings({ "unchecked", "rawtypes" }) public class TreePanelDropTarget extends DropTarget { protected TreePanel<ModelData> tree; protected TreeNode activeItem, appendItem; protected int status; private boolean allowDropOnLeaf = false; private boolean autoExpand = true, autoScroll = true; private int autoExpandDelay = 800; private boolean restoreTrackMouse; private ScrollSupport scrollSupport; private String scrollElementId; public TreePanelDropTarget(TreePanel tree) { super(tree); this.tree = tree; } /** * Returns the scroll element id. * * @return the scroll element id. */ public String getScrollElementId() { return scrollElementId; } /** * Returns the scroll support instance. * * @return the scroll support */ public ScrollSupport getScrollSupport() { if (scrollSupport == null) { scrollSupport = new ScrollSupport(); } return scrollSupport; } /** * Returns the target's tree. * * @return the tree */ public TreePanel<?> getTree() { return tree; } /** * Returns whether drops are allowed on leaf nodes. * * @return true of drops on leafs are allowed */ public boolean isAllowDropOnLeaf() { return allowDropOnLeaf; } /** * Returns true if auto expand is enabled. * * @return the auto expand state */ public boolean isAutoExpand() { return autoExpand; } /** * Returns true if auto scroll is enabled (defaults to true). * * @return true if auto scroll enabled */ public boolean isAutoScroll() { return autoScroll; } /** * True to allow drops on leaf nodes (defaults to false). * * @param allowDropOnLeaf true to enable drops on leaf nodes */ public void setAllowDropOnLeaf(boolean allowDropOnLeaf) { this.allowDropOnLeaf = allowDropOnLeaf; } /** * True to automatically expand the active tree item when the user hovers over * a collapsed item (defaults to true). Use {@link #setAutoExpandDelay(int)} * to set the delay. * * @param autoExpand true to auto expand */ public void setAutoExpand(boolean autoExpand) { this.autoExpand = autoExpand; } /** * Sets the delay used to auto expand items (defaults to 800). * * @param autoExpandDelay the delay in milliseconds */ public void setAutoExpandDelay(int autoExpandDelay) { this.autoExpandDelay = autoExpandDelay; } /** * True to automatically scroll the tree when the user hovers over the top and * bottom of the tree grid (defaults to true). * * @see ScrollSupport * * @param autoScroll true to enable auto scroll */ public void setAutoScroll(boolean autoScroll) { this.autoScroll = autoScroll; } /** * Sets the element that will be scrolled when auto scroll is enabled * (optional, defaults to null). * * @param scrollElementId the scroll element id */ public void setScrollElementId(String scrollElementId) { this.scrollElementId = scrollElementId; } protected void appendModel(ModelData p, List<ModelData> models, int index) { if (models.size() == 0) return; if (models.get(0) instanceof TreeStoreModel) { // drop is in form from tree store List<ModelData> children = new ArrayList<ModelData>(); for (ModelData tm : models) { ModelData child = tm.get("model"); children.add(child); } if (p == null) { tree.getStore().insert(children, index, false); } else { tree.getStore().insert(p, children, index, false); } for (ModelData tm : models) { ModelData child = tm.get("model"); List sub = (List) ((TreeModel) tm).getChildren(); appendModel(child, sub, 0); } return; } if (p == null) { tree.getStore().insert(models, index, false); } else { tree.getStore().insert(p, models, index, false); } } protected void clearStyles(DNDEvent event) { Insert.get().hide(); event.getStatus().setStatus(false); if (activeItem != null) { tree.getView().onDropChange(activeItem, false); } } protected void handleAppend(DNDEvent event, final TreeNode item) { // clear any active append item if (activeItem != null && activeItem != item) { tree.getView().onDropChange(activeItem, false); } status = -1; Insert.get().hide(); event.getStatus().setStatus(true); if (activeItem != null) { tree.getView().onDropChange(activeItem, false); } if (item != null && item != appendItem && autoExpand && !item.isExpanded()) { Timer t = new Timer() { @Override public void run() { if (item == appendItem) { item.setExpanded(true); } else { } } }; t.schedule(autoExpandDelay); } appendItem = item; activeItem = item; if (activeItem != null) { tree.getView().onDropChange(activeItem, true); } } protected void handleAppendDrop(DNDEvent event, TreeNode item) { List sel = prepareDropData(event.getData(), false); if (sel.size() > 0) { ModelData p = null; if (item != null) { p = item.getModel(); appendModel(p, sel, tree.getStore().getChildCount(item.getModel())); } else { appendModel(p, sel, tree.getStore().getRootItems().size()); } } } protected void handleInsert(DNDEvent event, final TreeNode item) { int height = item.getElement().getOffsetHeight(); int mid = height / 2; int top = item.getElement().getAbsoluteTop(); mid += top; int y = event.getClientY(); boolean before = y < mid; if ((!item.isLeaf() || allowDropOnLeaf) && (feedback == Feedback.BOTH || feedback == Feedback.APPEND) && ((before && y > top + 4) || (!before && y < top + height - 4))) { handleAppend(event, item); return; } // clear any active append item if (activeItem != null && activeItem != item) { tree.getView().onDropChange(activeItem, false); } appendItem = null; status = before ? 0 : 1; if (activeItem != null) { tree.getView().onDropChange(activeItem, false); } activeItem = item; int idx = -1; if (activeItem.getParent() == null) { idx = tree.getStore().getRootItems().indexOf(activeItem); } else { idx = activeItem.getParent().indexOf(item); } String status = "x-tree-drop-ok-between"; if (before && idx == 0) { status = "x-tree-drop-ok-above"; } else if (idx > 1 && !before && item.getParent() != null && idx == item.getParent().getItemCount() - 1) { status = "x-tree-drop-ok-below"; } event.getStatus().setStatus(true, status); if (before) { showInsert(event, item.getElement(), true); } else { showInsert(event, item.getElement(), false); } } protected void handleInsertDrop(DNDEvent event, TreeNode item, int index) { List sel = event.getData(); if (sel.size() > 0) { int idx = -1; if (item.getParent() == null) { idx = tree.getStore().getRootItems().indexOf(item.getModel()); } else { idx = activeItem.getParent().indexOf(item); } idx = status == 0 ? idx : idx + 1; if (item.getParent() == null) { appendModel(null, sel, idx); } else { ModelData p = item.getParent().getModel(); appendModel(p, sel, idx); } } } @Override protected void onDragDrop(DNDEvent event) { super.onDragDrop(event); if (event.getData() == null) return; if (activeItem == null && status == -1) { handleAppendDrop(event, activeItem); } else if (activeItem != null && status == -1) { tree.getView().onDropChange(activeItem, false); handleAppendDrop(event, activeItem); } else if (activeItem != null && status != -1) { handleInsertDrop(event, activeItem, status); } else { event.setCancelled(true); } tree.setTrackMouseOver(restoreTrackMouse); status = -1; activeItem = null; appendItem = null; if (autoScroll) { scrollSupport.stop(); } } @Override protected void onDragEnter(DNDEvent e) { super.onDragEnter(e); e.getStatus().setStatus(false); restoreTrackMouse = tree.isTrackMouseOver(); tree.setTrackMouseOver(false); if (autoScroll) { if (scrollSupport == null) { El scroll = scrollElementId != null ? new El(DOM.getElementById(scrollElementId)) : tree.el(); scrollSupport = new ScrollSupport(scroll); } else if (scrollSupport.getScrollElement() == null) { El scroll = scrollElementId != null ? new El(DOM.getElementById(scrollElementId)) : tree.el(); scrollSupport.setScrollElement(scroll); } scrollSupport.start(); } } @Override protected void onDragFail(DNDEvent event) { super.onDragFail(event); if (autoScroll) { scrollSupport.stop(); } } @Override protected void onDragLeave(DNDEvent e) { super.onDragLeave(e); if (activeItem != null) { tree.getView().onDropChange(activeItem, false); activeItem = null; } tree.setTrackMouseOver(restoreTrackMouse); if (autoScroll) { scrollSupport.stop(); } } @Override protected void onDragMove(DNDEvent event) { event.setCancelled(false); } @Override protected void showFeedback(DNDEvent event) { final TreeNode overItem = tree.findNode(event.getTarget()); if (overItem == null) { clearStyles(event); } if (overItem != null && event.getDropTarget().component == event.getDragSource().component) { TreePanel source = (TreePanel) event.getDragSource().component; List<ModelData> list = source.getSelectionModel().getSelection(); ModelData overModel = overItem.getModel(); for (int i = 0; i < list.size(); i++) { ModelData sel = list.get(i); if (overModel == sel) { clearStyles(event); return; } List<ModelData> children = tree.getStore().getChildren(sel, true); if (children.contains(overItem.getModel())) { clearStyles(event); return; } } } boolean append = feedback == Feedback.APPEND || feedback == Feedback.BOTH; boolean insert = feedback == Feedback.INSERT || feedback == Feedback.BOTH; if (overItem == null) { handleAppend(event, overItem); } else if (insert) { handleInsert(event, overItem); } else if ((!overItem.isLeaf() || allowDropOnLeaf) && append) { handleAppend(event, overItem); } else { if (activeItem != null) { tree.getView().onDropChange(activeItem, false); } status = -1; activeItem = null; appendItem = null; Insert.get().hide(); event.getStatus().setStatus(false); } } private void showInsert(DNDEvent event, Element elem, boolean before) { Insert insert = Insert.get(); insert.show(elem); Rectangle rect = El.fly(elem).getBounds(); int y = before ? rect.y - 2 : (rect.y + rect.height - 4); insert.setBounds(rect.x, y, rect.width, 6); } }