Java tutorial
/* * Ext GWT - Ext for GWT * Copyright(c) 2007-2009, Ext JS, LLC. * licensing@extjs.com * * http://extjs.com/license */ package com.extjs.gxt.ui.client.dnd; import java.util.List; import com.extjs.gxt.ui.client.binder.TreeBinder; 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.util.Rectangle; import com.extjs.gxt.ui.client.widget.tree.Tree; import com.extjs.gxt.ui.client.widget.tree.TreeItem; import com.google.gwt.user.client.Element; import com.google.gwt.user.client.Timer; /** * A <code>DropTarget</code> implementation for Trees. * * <p /> * The implementation of onDragDrop expects either a list of TreeItems when * using only a Tree, or a list of TreeModel instances if using a TreeBinder. * * @deprecated {@link TreePanelDropTarget} */ public class TreeDropTarget extends DropTarget { protected TreeBinder<ModelData> binder; protected Tree tree; protected TreeItem activeItem, appendItem; protected int status; private boolean allowDropOnLeaf = false; private boolean autoExpand = true; private int autoExpandDelay = 800; /** * Creates a new tree drop target. * * @param tree the target tree */ public TreeDropTarget(Tree tree) { super(tree); this.tree = tree; } /** * Creates a new tree drop target. * * @param binder the target tree binder */ public TreeDropTarget(TreeBinder<ModelData> binder) { this(binder.getTree()); this.binder = binder; } /** * Returns the auto expand delay in milliseconds. * * @return the delay */ public int getAutoExpandDelay() { return autoExpandDelay; } /** * Returns the target's tree binder. * * @return the tree binder */ public TreeBinder<ModelData> getBinder() { return binder; } /** * Returns the target's tree. * * @return the tree */ public Tree 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; } /** * 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 (defualts to 800). * * @param autoExpandDelay the delay in milliseconds */ public void setAutoExpandDelay(int autoExpandDelay) { this.autoExpandDelay = autoExpandDelay; } protected void handleAppend(DNDEvent event, final TreeItem item) { // clear any active append item if (activeItem != null && activeItem != item) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); } status = -1; Insert.get().hide(); event.getStatus().setStatus(true); if (activeItem != null) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); } if (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; activeItem.el().firstChild().addStyleName("my-tree-drop"); } @SuppressWarnings("unchecked") protected void appendModel(ModelData p, TreeModel model, int index) { ModelData child = model.get("model"); if (p == null) { binder.getTreeStore().insert(child, index, false); } else { binder.getTreeStore().insert(p, child, index, false); } List<TreeModel> children = (List) model.getChildren(); for (int i = 0; i < children.size(); i++) { appendModel(child, children.get(i), i); } } @SuppressWarnings("unchecked") protected void handleAppendDrop(DNDEvent event, TreeItem item) { List sel = event.getData(); if (sel.size() > 0) { if (sel.get(0) instanceof ModelData) { TreeModel tm = (TreeModel) sel.get(0); ModelData p = item.getModel(); appendModel(p, tm, item.getItemCount()); } else { for (int i = 0; i < sel.size(); i++) { TreeItem ti = (TreeItem) sel.get(i); item.add(ti); } } } } protected void handleInsert(DNDEvent event, final TreeItem item) { // clear any active append item if (activeItem != null && activeItem != item) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); } int height = item.getOffsetHeight(); int mid = height / 2; int top = item.getAbsoluteTop(); mid += top; int y = event.getClientY(); boolean before = y < mid; if (!item.isLeaf() || allowDropOnLeaf) { if ((before && y > top + 4) || (!before && y < top + height - 4)) { handleAppend(event, item); return; } } appendItem = null; status = before ? 0 : 1; if (activeItem != null) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); } activeItem = item; int idx = activeItem.getParentItem().indexOf(item); String status = "x-tree-drop-ok-between"; if (before && idx == 0) { status = "x-tree-drop-ok-above"; } else if (idx > 1 && !before && idx == item.getParentItem().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); } } @SuppressWarnings("unchecked") protected void handleInsertDrop(DNDEvent event, TreeItem item, int index) { List sel = event.getData(); if (sel.size() > 0) { int idx = item.getParentItem().indexOf(item); idx = status == 0 ? idx : idx + 1; if (sel.get(0) instanceof ModelData) { ModelData p = item.getParentItem().getModel(); appendModel(p, (TreeModel) sel.get(0), idx); } else { for (int i = 0; i < sel.size(); i++) { TreeItem ti = (TreeItem) sel.get(i); item.add(ti, idx); } } } } @Override protected void onDragDrop(DNDEvent event) { super.onDragDrop(event); if (activeItem != null && status == -1) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); if (event.getData() != null) { handleAppendDrop(event, activeItem); } } else if (activeItem != null && status != -1) { if (event.getData() != null) { handleInsertDrop(event, activeItem, status); } } else { event.setCancelled(true); } } @Override protected void onDragEnter(DNDEvent e) { super.onDragEnter(e); e.getStatus().setStatus(false); } @Override protected void onDragLeave(DNDEvent e) { super.onDragLeave(e); if (activeItem != null) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); activeItem = null; } } @Override protected void onDragMove(DNDEvent event) { event.setCancelled(false); } @Override protected void showFeedback(DNDEvent event) { final TreeItem item = tree.findItem(event.getTarget()); if (item == null) { event.getStatus().setStatus(false); return; } if (event.getDropTarget().component == event.getDragSource().component) { Tree source = (Tree) event.getDragSource().component; TreeItem sel = source.getSelectedItem(); List<TreeItem> children = sel.getItems(true); if (children.contains(item)) { event.getStatus().setStatus(false); return; } } boolean append = feedback == Feedback.APPEND || feedback == Feedback.BOTH; boolean insert = feedback == Feedback.INSERT || feedback == Feedback.BOTH; if (insert) { handleInsert(event, item); } else if ((!item.isLeaf() || allowDropOnLeaf) && append) { handleAppend(event, item); } else { if (activeItem != null) { activeItem.el().firstChild().removeStyleName("my-tree-drop"); } 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(); 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); } }