Java tutorial
/* * This library is part of OpenCms - * the Open Source Content Management System * * Copyright (c) Alkacon Software GmbH (http://www.alkacon.com) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * For further information about Alkacon Software, please see the * company website: http://www.alkacon.com * * For further information about OpenCms, please see the * project website: http://www.opencms.org * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package org.opencms.gwt.client.ui; import org.opencms.gwt.client.ui.I_CmsButton.ButtonStyle; import org.opencms.gwt.client.ui.css.I_CmsLayoutBundle; import org.opencms.gwt.client.util.CmsPositionBean; import org.opencms.util.CmsStringUtil; import com.google.gwt.core.client.GWT; 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.dom.client.HasClickHandlers; import com.google.gwt.event.logical.shared.CloseEvent; import com.google.gwt.event.logical.shared.CloseHandler; import com.google.gwt.event.logical.shared.ResizeEvent; import com.google.gwt.event.logical.shared.ResizeHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.resources.client.CssResource; import com.google.gwt.uibinder.client.UiBinder; import com.google.gwt.uibinder.client.UiConstructor; import com.google.gwt.uibinder.client.UiField; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.Element; import com.google.gwt.user.client.Event; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.Composite; import com.google.gwt.user.client.ui.PopupPanel; import com.google.gwt.user.client.ui.Widget; /** * Provides a menu button.<p> * * @since 8.0.0 */ public class CmsMenuButton extends Composite implements HasClickHandlers { /** * @see com.google.gwt.uibinder.client.UiBinder */ interface I_CmsMenuButtonUiBinder extends UiBinder<Widget, CmsMenuButton> { // GWT interface, nothing to do here } /** * The menu CSS interface.<p> */ interface I_MenuButtonCss extends CssResource { /** Access method.<p> * * @return the CSS class name */ String button(); /** Access method.<p> * * @return the CSS class name */ String connect(); /** Access method.<p> * * @return the CSS class name */ String hidden(); /** Access method.<p> * * @return the CSS class name */ String menu(); /** Access method.<p> * * @return the CSS class name */ String showAbove(); /** Access method.<p> * * @return the CSS class name */ String toolbarMode(); } /** The default pop-up width. */ private static final int DEFAULT_WIDTH = 650; /** Stores the toolbar width. */ private static int m_toolbarWidth; /** The ui-binder instance for this class. */ private static I_CmsMenuButtonUiBinder uiBinder = GWT.create(I_CmsMenuButtonUiBinder.class); /** The menu button. */ @UiField protected CmsPushButton m_button; /** The menu content. */ protected CmsPopup m_popup; /** Registration of the window resize handler. */ protected HandlerRegistration m_resizeRegistration; /** A DIV element for the arrow that connects the popup with the button. */ private Element m_arrow = DOM.createDiv(); /** Flag if the menu is open. */ private boolean m_isOpen; /** Flag if the menu opens to the right hand side. */ private boolean m_isOpenRight; /** Flag if the button is in toolbar mode. */ private boolean m_isToolbarMode; /** * Constructor.<p> * * @param buttonText the menu button text * @param imageClass the menu button image sprite class */ @UiConstructor public CmsMenuButton(String buttonText, String imageClass) { this(); if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(buttonText)) { m_button.setText(buttonText); } m_button.setImageClass(imageClass); } /** * Constructor.<p> */ private CmsMenuButton() { initWidget(uiBinder.createAndBindUi(this)); m_button.setSize(I_CmsButton.Size.big); m_button.setButtonStyle(ButtonStyle.MENU, null); m_isOpen = false; m_popup = new CmsPopup(); m_popup.setModal(false); m_popup.setAutoHideEnabled(true); m_popup.setWidth(DEFAULT_WIDTH); m_popup.removePadding(); m_popup.addCloseHandler(new CloseHandler<PopupPanel>() { public void onClose(CloseEvent<PopupPanel> event) { if (event.isAutoClosed()) { autoClose(); if (m_resizeRegistration != null) { m_resizeRegistration.removeHandler(); m_resizeRegistration = null; } } } }); } /** * @see com.google.gwt.event.dom.client.HasClickHandlers#addClickHandler(com.google.gwt.event.dom.client.ClickHandler) */ public HandlerRegistration addClickHandler(ClickHandler handler) { return addDomHandler(handler, ClickEvent.getType()); } /** * Removes all content from menu.<p> */ public void clear() { m_popup.clear(); } /** * Closes the menu and fires the on toggle event.<p> */ public void closeMenu() { m_popup.hide(); setButtonUp(); if (m_resizeRegistration != null) { m_resizeRegistration.removeHandler(); m_resizeRegistration = null; } } /** * Disables the menu button.<p> * * @param disabledReason the reason to set in the button title */ public void disable(String disabledReason) { m_button.disable(disabledReason); DOM.setElementPropertyBoolean(getElement(), "disabled", true); } /** * Enables or disables the button.<p> */ public void enable() { m_button.enable(); DOM.setElementPropertyBoolean(getElement(), "disabled", false); } /** * Hides the menu content as well as the menu connector.<p> */ public void hide() { m_popup.hide(); } /** * Returns if the menu is open.<p> * * @return <code>true</code> if the menu is opened */ public boolean isOpen() { return m_isOpen; } /** * Returns the isOpenRight.<p> * * @return the isOpenRight */ public boolean isOpenRight() { return m_isOpenRight; } /** * Returns the isToolbarMode.<p> * * @return the isToolbarMode */ public boolean isToolbarMode() { return m_isToolbarMode; } /** * @see com.google.gwt.user.client.ui.Composite#onBrowserEvent(com.google.gwt.user.client.Event) */ @Override public void onBrowserEvent(Event event) { // Should not act on button if disabled. if (isEnabled() == false) { return; } super.onBrowserEvent(event); } /** * Opens the menu and fires the on toggle event.<p> */ public void openMenu() { m_isOpen = true; m_button.setDown(true); m_popup.show(); positionPopup(); m_resizeRegistration = Window.addResizeHandler(new ResizeHandler() { public void onResize(ResizeEvent event) { positionPopup(); } }); } /** * Enables or disables the button.<p> * * @param enabled if true, enables the button, else disables it */ public void setEnabled(boolean enabled) { if (enabled) { enable(); } else { m_button.setEnabled(enabled); DOM.setElementPropertyBoolean(getElement(), "disabled", true); } } /** * This will set the menu content widget.<p> * * @param widget the widget to set as content */ public void setMenuWidget(Widget widget) { m_popup.remove(widget); m_popup.add(widget); } /** * Sets the isOpenRight.<p> * * @param isOpenRight the isOpenRight to set */ public void setOpenRight(boolean isOpenRight) { m_isOpenRight = isOpenRight; } /** * Sets the isToolbarMode.<p> * * @param isToolbarMode the isToolbarMode to set */ public void setToolbarMode(boolean isToolbarMode) { m_isToolbarMode = isToolbarMode; if (m_isToolbarMode) { // important, so a click on the button won't trigger the auto-close m_popup.addAutoHidePartner(getElement()); } else { m_popup.removeAutoHidePartner(getElement()); } } /** * Shows the menu content as well as the menu connector.<p> */ public void show() { m_popup.show(); } /** * Called on auto close.<p> */ protected void autoClose() { setButtonUp(); } /** * Returns the popup content.<p> * * @return the popup content */ protected CmsPopup getPopup() { return m_popup; } /** * Hides the menu content without altering the button state.<p> */ protected void hideMenu() { m_popup.hide(); if (m_resizeRegistration != null) { m_resizeRegistration.removeHandler(); m_resizeRegistration = null; } } /** * Returns if this button is enabled.<p> * * @return <code>true</code> if the button is enabled */ protected boolean isEnabled() { return !DOM.getElementPropertyBoolean(getElement(), "disabled"); } /** * Positions the menu popup the button.<p> */ protected void positionPopup() { int spaceAssurance = 20; int space = getToolbarWidth() + (2 * spaceAssurance); // get the window client width int windowWidth = Window.getClientWidth(); // get the min left position int minLeft = (windowWidth - space) / 2; if (minLeft < spaceAssurance) { minLeft = spaceAssurance; } // get the max right position int maxRight = minLeft + space; // get the middle button position CmsPositionBean buttonPosition = CmsPositionBean.generatePositionInfo(m_button.getElement()); int buttonMiddle = (buttonPosition.getLeft() - Window.getScrollLeft()) + (buttonPosition.getWidth() / 2); // get the content width int contentWidth = m_popup.getOffsetWidth(); // the optimum left position is in the middle of the button minus the half content width // assume that the optimum fits into the space int contentLeft = buttonMiddle - (contentWidth / 2); if (minLeft > contentLeft) { // if the optimum left position of the popup is outside the min left position: // move the popup to the right (take the min left position as left) contentLeft = minLeft; } else if ((contentLeft + contentWidth) > maxRight) { // if the left position plus the content width is outside the max right position: // move the popup to the left (take the max right position minus the content width) contentLeft = maxRight - contentWidth; } // limit the right position if the popup is right outside the window if ((contentLeft + contentWidth + spaceAssurance) > windowWidth) { contentLeft = windowWidth - contentWidth - spaceAssurance; } // limit the left position if the popup is left outside the window if (contentLeft < spaceAssurance) { contentLeft = spaceAssurance; } int arrowSpace = 10; int arrowWidth = I_CmsLayoutBundle.INSTANCE.gwtImages().menuArrowTopImage().getWidth(); int arrowHeight = I_CmsLayoutBundle.INSTANCE.gwtImages().menuArrowTopImage().getHeight(); // the optimum position for the arrow is in the middle of the button int arrowLeft = buttonMiddle - contentLeft - (arrowWidth / 2); if ((arrowLeft + arrowWidth + arrowSpace) > contentWidth) { // limit the arrow position if the maximum is reached (content width 'minus x') arrowLeft = contentWidth - arrowWidth - arrowSpace; } else if ((arrowLeft - arrowSpace) < 0) { // limit the arrow position if the minimum is reached ('plus x') arrowLeft = arrowWidth + arrowSpace; } int arrowTop = -(arrowHeight - 2); String arrowClass = I_CmsLayoutBundle.INSTANCE.dialogCss().menuArrowTop(); int contentTop = (((buttonPosition.getTop() + buttonPosition.getHeight()) - Window.getScrollTop()) + arrowHeight) - 2; if (!m_isToolbarMode) { contentTop = (buttonPosition.getTop() + buttonPosition.getHeight() + arrowHeight) - 2; int contentHeight = m_popup.getOffsetHeight(); int windowHeight = Window.getClientHeight(); if (((contentHeight + spaceAssurance) < windowHeight) && ((buttonPosition.getTop() - Window.getScrollTop()) > contentHeight) && (((contentHeight + spaceAssurance + contentTop) - Window.getScrollTop()) > windowHeight)) { // content fits into the window height, // there is enough space above the button // and there is to little space below the button // so show above contentTop = ((buttonPosition.getTop() - arrowHeight) + 2) - contentHeight; arrowTop = contentHeight - 1; arrowClass = I_CmsLayoutBundle.INSTANCE.dialogCss().menuArrowBottom(); } } else { contentLeft = contentLeft - Window.getScrollLeft(); m_popup.setPositionFixed(); } m_arrow.setClassName(arrowClass); m_arrow.getStyle().setLeft(arrowLeft, Unit.PX); m_arrow.getStyle().setTop(arrowTop, Unit.PX); m_popup.showArrow(m_arrow); m_popup.setPopupPosition(contentLeft + Window.getScrollLeft(), contentTop); } /** * Returns the toolbar width.<p> * * @return the toolbar width */ private int getToolbarWidth() { if (m_toolbarWidth > 0) { return m_toolbarWidth; } String toolbarWidthConstant = I_CmsLayoutBundle.INSTANCE.constants().css().toolbarWidth().toLowerCase(); int posPX = toolbarWidthConstant.indexOf("px"); if (posPX != -1) { try { m_toolbarWidth = Integer.parseInt(toolbarWidthConstant.substring(0, posPX)); return m_toolbarWidth; } catch (NumberFormatException ex) { // noop } } return 930; } /** * Sets button to state up, hides menu fragments (not the content pop-up) and fires the toggle event.<p> */ private void setButtonUp() { m_isOpen = false; m_button.setDown(false); } }