Java tutorial
/* * Copyright 2014-2015 CyberVision, Inc. * * 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 org.kaaproject.avro.ui.gwt.client.widget; import org.kaaproject.avro.ui.gwt.client.util.Utils; import com.google.gwt.core.client.GWT; import com.google.gwt.dom.client.Element; import com.google.gwt.dom.client.Style.Unit; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; 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.resources.client.ImageResource; import com.google.gwt.safecss.shared.SafeStyles; import com.google.gwt.safecss.shared.SafeStylesBuilder; import com.google.gwt.safecss.shared.SafeStylesUtils; import com.google.gwt.safehtml.client.SafeHtmlTemplates; import com.google.gwt.safehtml.shared.SafeHtml; import com.google.gwt.safehtml.shared.SafeUri; import com.google.gwt.uibinder.client.UiConstructor; 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.ToggleButton; public class ActionsButton extends ToggleButton { private static Template template; private PopupPanel actionsPopup; private MenuBar menu = new MenuBar(true); interface Template extends SafeHtmlTemplates { @Template("<div tabindex=\"0\" style=\"vertical-align:middle;\">" + "<span style='{0}'></span>" + "<span>{1}</span>" + "</div>") SafeHtml menuImageItemContent(SafeStyles style, String text); @Template("<div tabindex=\"0\" style=\"vertical-align:middle;\">" + "<span>{0}</span>" + "</div>") SafeHtml menuItemContent(String text); } @UiConstructor public ActionsButton(ImageResource imageResource, String text) { super(); if (template == null) { template = GWT.create(Template.class); } getElement().getStyle().setPaddingRight(20, Unit.PX); int index = 0; if (imageResource != null) { getElement().getStyle().setPaddingLeft(20, Unit.PX); SafeUri uri = imageResource.getSafeUri(); int width = imageResource.getWidth(); int height = imageResource.getHeight(); int paddingLeft = width; String background = "url(\"" + uri.asString() + "\") no-repeat scroll right center"; Element imageSpan = DOM.createElement("span"); imageSpan.setInnerText(" "); imageSpan.getStyle().setProperty("background", background); imageSpan.getStyle().setWidth(width, Unit.PX); imageSpan.getStyle().setHeight(height, Unit.PX); imageSpan.getStyle().setPaddingLeft(paddingLeft, Unit.PX); imageSpan.getStyle().setMarginRight(10, Unit.PX); DOM.insertChild(getElement(), imageSpan, index++); } Element caretSpan = DOM.createElement("span"); caretSpan.setClassName(Utils.avroUiStyle.buttonCaret()); DOM.insertChild(getElement(), caretSpan, index); Element textElement = DOM.createElement("span"); textElement.setInnerText(text); DOM.insertChild(caretSpan, textElement, 0); actionsPopup = new PopupPanel(true, false); actionsPopup.addStyleName(Utils.avroUiStyle.actionPopup()); actionsPopup.setWidget(menu); actionsPopup.addCloseHandler(new CloseHandler<PopupPanel>() { @Override public void onClose(CloseEvent<PopupPanel> event) { ActionsButton.this.setDown(false); } }); actionsPopup.addAutoHidePartner(getElement()); addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { if (!actionsPopup.isShowing()) { // Instantiate the popup and show it. final Element parent = ActionsButton.this.getElement(); actionsPopup.setPopupPositionAndShow(new PopupPanel.PositionCallback() { public void setPosition(int offsetWidth, int offsetHeight) { int left = parent.getAbsoluteLeft(); int top = parent.getAbsoluteTop() + parent.getOffsetHeight() + 2; if (left + actionsPopup.getOffsetWidth() > Window.getClientWidth()) { left = parent.getAbsoluteRight() - actionsPopup.getOffsetWidth(); } actionsPopup.setPopupPosition(left, top); } }); } else { actionsPopup.hide(); } } }); } public HandlerRegistration addMenuItem(String text, final ActionMenuItemListener listener) { return addMenuItem(null, text, listener); } public HandlerRegistration addMenuItem(ImageResource image, String text, final ActionMenuItemListener listener) { SafeHtml html = null; if (image != null) { SafeUri uri = image.getSafeUri(); int left = image.getLeft(); int top = image.getTop(); int width = image.getWidth(); int height = image.getHeight(); int paddingRight = width + 8; String background = "url(\"" + uri.asString() + "\") no-repeat " + (-left + "px ") + (-top + "px"); SafeStylesBuilder builder = new SafeStylesBuilder(); builder.trustedNameAndValue("background", background).width(width, Unit.PX).height(height, Unit.PX) .paddingRight(paddingRight, Unit.PX); SafeStyles style = SafeStylesUtils.fromTrustedString(builder.toSafeStyles().asString()); html = template.menuImageItemContent(style, text); } else { html = template.menuItemContent(text); } final MenuItem item = new MenuItem(html, new Command() { @Override public void execute() { if (actionsPopup != null && actionsPopup.isVisible()) actionsPopup.hide(); listener.onMenuItemSelected(); } }); menu.addItem(item); HandlerRegistration registration = new HandlerRegistration() { @Override public void removeHandler() { menu.removeItem(item); } }; return registration; } public void clearItems() { menu.clearItems(); } public static interface ActionMenuItemListener { void onMenuItemSelected(); } }