Java tutorial
/* * Copyright 2000-2014 Vaadin Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.vaadin.client.ui; import com.google.gwt.core.client.Scheduler; import com.google.gwt.core.client.Scheduler.ScheduledCommand; import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.NodeList; import com.google.gwt.dom.client.TableRowElement; import com.google.gwt.dom.client.TableSectionElement; import com.google.gwt.event.dom.client.BlurEvent; import com.google.gwt.event.dom.client.BlurHandler; import com.google.gwt.event.dom.client.FocusEvent; import com.google.gwt.event.dom.client.FocusHandler; import com.google.gwt.event.dom.client.HasBlurHandlers; import com.google.gwt.event.dom.client.HasFocusHandlers; import com.google.gwt.event.dom.client.HasKeyDownHandlers; import com.google.gwt.event.dom.client.HasKeyPressHandlers; import com.google.gwt.event.dom.client.KeyCodes; import com.google.gwt.event.dom.client.KeyDownEvent; import com.google.gwt.event.dom.client.KeyDownHandler; import com.google.gwt.event.dom.client.KeyPressEvent; import com.google.gwt.event.dom.client.KeyPressHandler; import com.google.gwt.event.dom.client.KeyUpEvent; import com.google.gwt.event.dom.client.KeyUpHandler; import com.google.gwt.event.dom.client.LoadEvent; import com.google.gwt.event.dom.client.LoadHandler; import com.google.gwt.event.logical.shared.CloseEvent; import com.google.gwt.event.logical.shared.CloseHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.Command; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.MenuBar; import com.google.gwt.user.client.ui.MenuItem; import com.google.gwt.user.client.ui.PopupPanel; import com.google.gwt.user.client.ui.RootPanel; import com.google.gwt.user.client.ui.impl.FocusImpl; import com.vaadin.client.Focusable; import com.vaadin.client.WidgetUtil; public class VContextMenu extends VOverlay implements SubPartAware { private ActionOwner actionOwner; private final CMenuBar menu = new CMenuBar(); private int left; private int top; private Element focusedElement; private VLazyExecutor delayedImageLoadExecutioner = new VLazyExecutor(100, new ScheduledCommand() { @Override public void execute() { imagesLoaded(); } }); /** * This method should be used only by Client object as only one per client * should exists. Request an instance via client.getContextMenu(); * * @param cli * to be set as an owner of menu */ public VContextMenu() { super(true, false, true); setWidget(menu); setStyleName("v-contextmenu"); getElement().setId(DOM.createUniqueId()); addCloseHandler(new CloseHandler<PopupPanel>() { @Override public void onClose(CloseEvent<PopupPanel> event) { Element currentFocus = WidgetUtil.getFocusedElement(); if (focusedElement != null && (currentFocus == null || menu.getElement().isOrHasChild(currentFocus) || RootPanel.getBodyElement().equals(currentFocus))) { focusedElement.focus(); focusedElement = null; } } }); } protected void imagesLoaded() { if (isVisible()) { show(); } } /** * Sets the element from which to build menu * * @param ao */ public void setActionOwner(ActionOwner ao) { actionOwner = ao; } /** * Shows context menu at given location IF it contain at least one item. * * @param left * @param top */ public void showAt(int left, int top) { final Action[] actions = actionOwner.getActions(); if (actions == null || actions.length == 0) { // Only show if there really are actions return; } this.left = left; this.top = top; menu.clearItems(); for (int i = 0; i < actions.length; i++) { final Action a = actions[i]; menu.addItem(new MenuItem(a.getHTML(), true, a)); } // Attach onload listeners to all images WidgetUtil.sinkOnloadForImages(menu.getElement()); // Store the currently focused element, which will be re-focused when // context menu is closed focusedElement = WidgetUtil.getFocusedElement(); // reset height (if it has been previously set explicitly) setHeight(""); setPopupPositionAndShow(new PositionCallback() { @Override public void setPosition(int offsetWidth, int offsetHeight) { // mac FF gets bad width due GWT popups overflow hacks, // re-determine width offsetWidth = menu.getOffsetWidth(); int left = VContextMenu.this.left; int top = VContextMenu.this.top; if (offsetWidth + left > Window.getClientWidth()) { left = left - offsetWidth; if (left < 0) { left = 0; } } if (offsetHeight + top > Window.getClientHeight()) { top = Math.max(0, Window.getClientHeight() - offsetHeight); } if (top == 0) { setHeight(Window.getClientHeight() + "px"); } setPopupPosition(left, top); /* * Move keyboard focus to menu, deferring the focus setting so * the focus is certainly moved to the menu in all browser after * the positioning has been done. */ Scheduler.get().scheduleDeferred(new Command() { @Override public void execute() { // Focus the menu. menu.setFocus(true); // Unselect previously selected items menu.selectItem(null); } }); } }); } public void showAt(ActionOwner ao, int left, int top) { setActionOwner(ao); showAt(left, top); } /** * Extend standard Gwt MenuBar to set proper settings and to override * onPopupClosed method so that PopupPanel gets closed. */ class CMenuBar extends MenuBar implements HasFocusHandlers, HasBlurHandlers, HasKeyDownHandlers, HasKeyPressHandlers, Focusable, LoadHandler, KeyUpHandler { public CMenuBar() { super(true); addDomHandler(this, LoadEvent.getType()); addDomHandler(this, KeyUpEvent.getType()); } @Override public void onPopupClosed(PopupPanel sender, boolean autoClosed) { super.onPopupClosed(sender, autoClosed); // make focusable, as we don't need access key magic we don't need // to // use FocusImpl.createFocusable getElement().setTabIndex(0); hide(); } /* * public void onBrowserEvent(Event event) { // Remove current selection * when mouse leaves if (DOM.eventGetType(event) == Event.ONMOUSEOUT) { * Element to = DOM.eventGetToElement(event); if * (!DOM.isOrHasChild(getElement(), to)) { DOM.setElementProperty( * super.getSelectedItem().getElement(), "className", * super.getSelectedItem().getStylePrimaryName()); } } * * super.onBrowserEvent(event); } */ private MenuItem getItem(int index) { return super.getItems().get(index); } @Override public HandlerRegistration addFocusHandler(FocusHandler handler) { return addDomHandler(handler, FocusEvent.getType()); } @Override public HandlerRegistration addBlurHandler(BlurHandler handler) { return addDomHandler(handler, BlurEvent.getType()); } @Override public HandlerRegistration addKeyDownHandler(KeyDownHandler handler) { return addDomHandler(handler, KeyDownEvent.getType()); } @Override public HandlerRegistration addKeyPressHandler(KeyPressHandler handler) { return addDomHandler(handler, KeyPressEvent.getType()); } public void setFocus(boolean focus) { if (focus) { FocusImpl.getFocusImplForPanel().focus(getElement()); } else { FocusImpl.getFocusImplForPanel().blur(getElement()); } } @Override public void focus() { setFocus(true); } @Override public void onLoad(LoadEvent event) { // Handle icon onload events to ensure shadow is resized correctly delayedImageLoadExecutioner.trigger(); } @Override public void onKeyUp(KeyUpEvent event) { // Allow to close context menu with ESC if (event.getNativeKeyCode() == KeyCodes.KEY_ESCAPE) { hide(); } } } @Override public com.google.gwt.user.client.Element getSubPartElement(String subPart) { int index = Integer.parseInt(subPart.substring(6)); // ApplicationConnection.getConsole().log( // "Searching element for selection index " + index); MenuItem item = menu.getItem(index); // ApplicationConnection.getConsole().log("Item: " + item); // Item refers to the td, which is the parent of the clickable element return item.getElement().getFirstChildElement().cast(); } @Override public String getSubPartName(com.google.gwt.user.client.Element subElement) { if (getElement().isOrHasChild(subElement)) { com.google.gwt.dom.client.Element e = subElement; { while (e != null && !e.getTagName().toLowerCase().equals("tr")) { e = e.getParentElement(); // ApplicationConnection.getConsole().log("Found row"); } } com.google.gwt.dom.client.TableSectionElement parentElement = (TableSectionElement) e .getParentElement(); NodeList<TableRowElement> rows = parentElement.getRows(); for (int i = 0; i < rows.getLength(); i++) { if (rows.getItem(i) == e) { // ApplicationConnection.getConsole().log( // "Found index for row" + 1); return "option" + i; } } return null; } else { return null; } } /** * Hides context menu if it is currently shown by given action owner. * * @param actionOwner */ public void ensureHidden(ActionOwner actionOwner) { if (this.actionOwner == actionOwner) { hide(); } } }