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.dom.client.Element; import com.google.gwt.editor.client.IsEditor; import com.google.gwt.editor.client.LeafValueEditor; import com.google.gwt.editor.client.adapters.TakesValueEditor; import com.google.gwt.event.dom.client.*; import com.google.gwt.event.logical.shared.HasValueChangeHandlers; import com.google.gwt.event.logical.shared.ValueChangeEvent; import com.google.gwt.event.logical.shared.ValueChangeHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.HasValue; import de.swm.commons.mobile.client.SWMMobile; import de.swm.commons.mobile.client.event.DragController; import de.swm.commons.mobile.client.event.DragEvent; import de.swm.commons.mobile.client.event.DragEventsHandler; import de.swm.commons.mobile.client.utils.Utils; import java.util.ArrayList; import java.util.List; import java.util.logging.Logger; /** * Flip-Switch (boolean widget) with data binding. * */ public class FlipSwitch extends SWMMobileWidgetBase implements DragEventsHandler, ClickHandler, HasValueChangeHandlers<Boolean>, IsEditor<LeafValueEditor<Boolean>>, HasValue<Boolean>, HasClickHandlers, HasFocusHandlers, HasBlurHandlers { private static final Logger LOGGER = Logger.getLogger(FlipSwitch.class.getName()); private static final int DURATION = 200; private static final double MIDDLE = 0.5; protected boolean myEnabled = true; protected boolean myValue = true; protected final HTML myHtml = new HTML(); private LeafValueEditor<Boolean> editor; private final List<DragEventsHandler> dragHandlers = new ArrayList<DragEventsHandler>(); private String option1 = "On"; private String option2 = "Off"; /** * Default constructor. */ public FlipSwitch() { initWidget(myHtml); setStyleName(SWMMobile.getTheme().getMGWTCssBundle().getFlipSwitchCss().flipSwitch()); myHtml.addClickHandler(this); updateUI(); } private void updateUI() { myHtml.setHTML("<div></div><div></div><div><div><div>" + this.option1 + "</div><div></div><div>" + this.option2 + "</div></div></div>"); } @Override public void onInitialLoad() { super.onInitialLoad(); if (!myValue) { updateFlipPosition(0); } } @Override public void onLoad() { super.onLoad(); DragController.get().addDragEventsHandler(this); } @Override public void onUnload() { DragController.get().removeDragEventsHandler(this); } @Override public void onDragStart(DragEvent e) { if (!myEnabled) { return; } DragController.get().captureDragEvents(this); Utils.setTransitionDuration(getFilpElement(), 0); for (DragEventsHandler toNotify : this.dragHandlers) { toNotify.onDragStart(e); } } @Override public void onDragMove(DragEvent e) { if (!myEnabled) { return; } e.stopPropagation(); Element flip = getFilpElement(); int x = Utils.getTranslateX(flip); int newX = (int) (x + e.getOffsetX()); int onPosition = getOnPosition(); int offPosition = getOffPosition(); if (newX > onPosition) { newX = onPosition; } else if (newX < offPosition) { newX = offPosition; } if (newX != x) { Utils.setTranslateX(flip, newX); } for (DragEventsHandler toNotify : this.dragHandlers) { toNotify.onDragMove(e); } } @Override public void onDragEnd(DragEvent e) { if (!myEnabled) { return; } DragController.get().releaseDragCapture(this); Element flip = getFilpElement(); int x = Utils.getTranslateX(flip); int onPosition = getOnPosition(); int offPosition = getOffPosition(); if (x == onPosition) { setValue(true, false, 0, true); } else if (x == offPosition) { setValue(false, false, 0, true); } else { float ratio = (float) x / (float) (offPosition - onPosition); boolean newValue = ratio < MIDDLE; int duration = (int) ((MIDDLE - Math.abs(ratio - MIDDLE)) * DURATION); LOGGER.info("ratio " + ratio + " duration " + duration); setValue(newValue, true, duration, true); } for (DragEventsHandler toNotify : this.dragHandlers) { toNotify.onDragEnd(e); } } /** * Manually sets the value. * * @param value * the new value * @param forceUpdateFlipPosition * tue updated the position * @param duration * the duration af the animation in ms */ private void setValue(boolean value, boolean forceUpdateFlipPosition, int duration, boolean fireEvents) { if (myValue != value) { myValue = value; updateFlipPosition(duration); if (fireEvents) { ValueChangeEvent.fire(this, myValue); } } else if (forceUpdateFlipPosition) { updateFlipPosition(duration); } } public boolean isEnabled() { return myEnabled; } /** * Enables/disables the widget. * * @param enabled * true if enabled. */ public void setEnabled(boolean enabled) { if (enabled == myEnabled) { return; } if (enabled) { removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getFlipSwitchCss().disabled()); } else { addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getFlipSwitchCss().disabled()); } myEnabled = enabled; } @Override public void onClick(ClickEvent event) { if (myEnabled) { setValue(!myValue); } } /** * Updates the flip position. * * @param duration * the duration of the animation */ private void updateFlipPosition(int duration) { Utils.setTransitionDuration(getFilpElement(), duration); Element flip = getFilpElement(); if (myValue) { Utils.setTranslateX(flip, getOnPosition()); } else { Utils.setTranslateX(flip, getOffPosition()); } } private Element getFilpElement() { return (Element) getElement().getChild(2).getChild(0); } private int getOnPosition() { return 0; } /** * Returns the absolute off potion * * @return the sreen postion */ private int getOffPosition() { Element flip = getFilpElement(); Element parent = flip.getParentElement(); int flipWidth = flip.getScrollWidth(); int parentWidth = parent.getClientWidth(); return parentWidth - flipWidth; } @Override public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) { return this.addHandler(handler, ValueChangeEvent.getType()); } @Override public LeafValueEditor<Boolean> asEditor() { if (editor == null) { editor = TakesValueEditor.of(this); } return editor; } @Override public void setValue(Boolean value) { if (value != null) { setValue(value, false, DURATION, true); } } @Override public void setValue(Boolean value, boolean fireEvents) { this.setValue(value, true, DURATION, fireEvents); } public Boolean getValue() { return myValue; } @Override public HandlerRegistration addClickHandler(ClickHandler handler) { return myHtml.addClickHandler(handler); } /** * Add a drag handler to the widget. * * @param hanlder * a drag handler. * @return the drag handler. */ public HandlerRegistration addDragHandler(final DragEventsHandler hanlder) { HandlerRegistration registration = new HandlerRegistration() { @Override public void removeHandler() { dragHandlers.remove(hanlder); } }; dragHandlers.add(hanlder); return registration; } @Override public HandlerRegistration addBlurHandler(BlurHandler handler) { return myHtml.addDomHandler(handler, BlurEvent.getType()); } @Override public HandlerRegistration addFocusHandler(FocusHandler handler) { return myHtml.addDomHandler(handler, FocusEvent.getType()); } /** * Gets the Name of the second option. * @return the String of the second option. */ public String getOption2() { return option2; } /** * Sets the Name of the second option. * @param option2 the String of the second option. */ public void setOption2(String option2) { this.option2 = option2; this.updateUI(); } /** * Gets the Name of the first option. * @return the String of the first option. */ public String getOption1() { return option1; } /** * Gets the Name of the first option. * @param option1 the String of the first option. */ public void setOption1(String option1) { this.option1 = option1; this.updateUI(); } }