Java tutorial
/* * Copyright 2011 SWM Services GmbH. * * 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 de.swm.commons.mobile.client.widgets; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.Timer; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.Widget; import de.swm.commons.mobile.client.SWMMobile; import de.swm.commons.mobile.client.base.PanelBase; import de.swm.commons.mobile.client.event.*; import de.swm.commons.mobile.client.utils.Utils; /** * List panel which contains list items an is typically placed inside a {@link de.swm.commons.mobile.client.widgets.scroll.ScrollPanel}. * */ public class ListPanel extends PanelBase implements ClickHandler, DragEventsHandler { private static final int DRAG_DELAY = 75; private static final int DRAG_MOVE_DELAY = 1000; private boolean myShowArrow; protected int mySelected = -1; // allow access in derived classes private boolean mySelectable = true; /** applies the flex style if set **/ private boolean isFlex = false; /** * Default constructor. */ public ListPanel() { addDomHandler(this, ClickEvent.getType()); setStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelCss().listPanel()); } /** * Adds a selection handler. * * @param handler * selection handler * @return handle to remove this handler. */ public HandlerRegistration addSelectionChangedHandler(SelectionChangedHandler handler) { return this.addHandler(handler, SelectionChangedEvent.TYPE); } @Override public void onLoad() { super.onLoad(); DragController.get().addDragEventsHandler(this); } @Override public void onUnload() { DragController.get().removeDragEventsHandler(this); } @Override public void add(Widget w) { if (w instanceof ListItem) { super.add(w); if (SWMMobile.getOsDetection().isIOs()) { Utils.setTranslateY(w.getElement(), 0); // anti-flickering on iOS. } } else { ListItem listItem = new ListItem(); super.add(listItem); listItem.add(w); if (myShowArrow) { Chevron chevron = new Chevron(); listItem.add(chevron); } } } @Override public void onClick(ClickEvent e) { if (mySelected >= 0 && getWidgetCount() > mySelected) { ListItem item = (ListItem) getWidget(mySelected); if (!item.getDisabled()) { SelectionChangedEvent selectionChangedEvent = new SelectionChangedEvent(mySelected, e.getNativeEvent().getEventTarget()); this.fireEvent(selectionChangedEvent); item.removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelCss().pressed()); } mySelected = -1; } } /** * Global visibility of the right arrow * * @param show * true if shown */ public void setShowArrow(boolean show) { myShowArrow = show; for (int i = 0; i < getWidgetCount(); i++) { ListItem listItem = (ListItem) getWidget(i); listItem.setShowArrowFromParent(show); } } public boolean getShowArrow() { return myShowArrow; } public void setSelectable(boolean selectable) { mySelectable = selectable; } public boolean getSelectable() { return mySelectable; } /** * Returns true is the css rendering is flexible. * * @return the isFlex */ public boolean isFlex() { return isFlex; } /** * Enabled/disables flexible css rendering. * * @param isFlex * the isFlex to set */ public void setFlex(boolean isFlex) { this.isFlex = isFlex; if (isFlex) { addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelFlexCss().flex()); addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelFlexCss().modify()); } else { removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelFlexCss().flex()); removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelFlexCss().modify()); } } @Override public void onDragStart(DragEvent e) { if (mySelectable) { mySelected = Utils.getTargetItemIndex(getElement(), e.getNativeEvent().getEventTarget()); if (mySelected >= 0) { final Timer timer = new Timer() { @Override public void run() { if (mySelected >= 0 && getWidgetCount() > 0 && mySelected < getWidgetCount()) { ListItem item = (ListItem) getWidget(mySelected); if (!item.getDisabled()) { getWidget(mySelected).addStyleName( SWMMobile.getTheme().getMGWTCssBundle().getListPanelCss().pressed()); } } } }; timer.schedule(DRAG_DELAY); } } } @Override public void onDragMove(DragEvent e) { if (mySelected >= 0) { getWidget(mySelected) .removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelCss().pressed()); final Timer timer = new Timer() { @Override public void run() { mySelected = -1; } }; timer.schedule(DRAG_MOVE_DELAY); } } @Override public void onDragEnd(DragEvent e) { if (mySelected >= 0) { getWidget(mySelected) .removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getListPanelCss().pressed()); // _selected = -1; need to keep the selected value for click event. } } /** * Returns th list item on index position * * @param index * the index * @return the position */ public ListItem getItem(int index) { return (ListItem) getWidget(index); } /** * Html code for the right arrow called chevron. * * * * */ static class Chevron extends HTML { /** * Default constructor. */ public Chevron() { super("<div class=\"" + SWMMobile.getTheme().getMGWTCssBundle().getListPanelCss().chevron() + "\"><span></span><span></span></div>"); } } }