Java tutorial
/* * Copyright 2014 John Ahlroos * * 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 fi.jasoft.dragdroplayouts.client.ui.horizontallayout; import com.google.gwt.user.client.ui.UIObject; import com.google.gwt.user.client.ui.Widget; import com.google.gwt.user.client.ui.WidgetCollection; import com.vaadin.client.MouseEventDetailsBuilder; import com.vaadin.client.Util; import com.vaadin.client.ui.VHorizontalLayout; import com.vaadin.client.ui.dd.VDragEvent; import com.vaadin.client.ui.orderedlayout.Slot; import com.vaadin.shared.MouseEventDetails; import com.vaadin.shared.ui.dd.HorizontalDropLocation; import fi.jasoft.dragdroplayouts.DDHorizontalLayout; import fi.jasoft.dragdroplayouts.client.VDragFilter; import fi.jasoft.dragdroplayouts.client.ui.Constants; import fi.jasoft.dragdroplayouts.client.ui.LayoutDragMode; import fi.jasoft.dragdroplayouts.client.ui.VDragDropUtil; import fi.jasoft.dragdroplayouts.client.ui.VLayoutDragDropMouseHandler; import fi.jasoft.dragdroplayouts.client.ui.VLayoutDragDropMouseHandler.DragStartListener; import fi.jasoft.dragdroplayouts.client.ui.interfaces.VDDHasDropHandler; import fi.jasoft.dragdroplayouts.client.ui.interfaces.VDragImageProvider; import fi.jasoft.dragdroplayouts.client.ui.interfaces.VHasDragFilter; import fi.jasoft.dragdroplayouts.client.ui.interfaces.VHasDragImageReferenceSupport; import fi.jasoft.dragdroplayouts.client.ui.interfaces.VHasDragMode; import fi.jasoft.dragdroplayouts.client.ui.interfaces.VHasIframeShims; import fi.jasoft.dragdroplayouts.client.ui.util.IframeCoverUtility; /** * Client side implementation for {@link DDHorizontalLayout} * * @author John Ahlroos / www.jasoft.fi * @since 0.4.0 */ public class VDDHorizontalLayout extends VHorizontalLayout implements VHasDragMode, VDDHasDropHandler<VDDHorizontalLayoutDropHandler>, DragStartListener, VHasDragFilter, VHasDragImageReferenceSupport, VHasIframeShims { public static final String OVER = "v-ddorderedlayout-over"; public static final String OVER_SPACED = OVER + "-spaced"; private Widget currentlyEmphasised; private VDDHorizontalLayoutDropHandler dropHandler; private VDragFilter dragFilter; private final IframeCoverUtility iframeCoverUtility = new IframeCoverUtility(); private final VLayoutDragDropMouseHandler ddMouseHandler = new VLayoutDragDropMouseHandler(this, LayoutDragMode.NONE); // Value delegated from state private double cellLeftRightDropRatio = DDHorizontalLayoutState.DEFAULT_HORIZONTAL_DROP_RATIO; private LayoutDragMode mode = LayoutDragMode.NONE; private boolean iframeCovers = false; public VDDHorizontalLayout() { super(); } @Override protected void onLoad() { super.onLoad(); ddMouseHandler.addDragStartListener(this); setDragMode(mode); iframeShimsEnabled(iframeCovers); } @Override protected void onUnload() { super.onUnload(); ddMouseHandler.removeDragStartListener(this); ddMouseHandler.updateDragMode(LayoutDragMode.NONE); iframeCoverUtility.setIframeCoversEnabled(false, getElement(), LayoutDragMode.NONE); } /** * Removes any applies drag and drop style applied by emphasis() */ protected void deEmphasis() { if (currentlyEmphasised != null) { // Universal over style UIObject.setStyleName(currentlyEmphasised.getElement(), OVER, false); UIObject.setStyleName(currentlyEmphasised.getElement(), OVER_SPACED, false); // Horizontal styles UIObject.setStyleName(currentlyEmphasised.getElement(), OVER + "-" + HorizontalDropLocation.LEFT.toString().toLowerCase(), false); UIObject.setStyleName(currentlyEmphasised.getElement(), OVER + "-" + HorizontalDropLocation.CENTER.toString().toLowerCase(), false); UIObject.setStyleName(currentlyEmphasised.getElement(), OVER + "-" + HorizontalDropLocation.RIGHT.toString().toLowerCase(), false); currentlyEmphasised = null; } } /** * Returns the horizontal location within the cell when hoovering over the cell. By default the * cell is devided into three parts: left,center,right with the ratios 10%,80%,10%; * * @param container The widget container * @param event The drag event * @return The horizontal drop location */ protected HorizontalDropLocation getHorizontalDropLocation(Widget container, VDragEvent event) { return VDragDropUtil.getHorizontalDropLocation(container.getElement(), Util.getTouchOrMouseClientX(event.getCurrentGwtEvent()), cellLeftRightDropRatio); } /** * A hook for extended components to post process the the drop before it is sent to the server. * Useful if you don't want to override the whole drop handler. */ protected boolean postDropHook(VDragEvent drag) { // Extended classes can add content here... return true; } /** * A hook for extended components to post process the the enter event. Useful if you don't want to * override the whole drophandler. */ protected void postEnterHook(VDragEvent drag) { // Extended classes can add content here... } /** * A hook for extended components to post process the the leave event. Useful if you don't want to * override the whole drophandler. */ protected void postLeaveHook(VDragEvent drag) { // Extended classes can add content here... } /** * A hook for extended components to post process the the over event. Useful if you don't want to * override the whole drophandler. */ protected void postOverHook(VDragEvent drag) { // Extended classes can add content here... } /** * Can be used to listen to drag start events, must return true for the drag to commence. Return * false to interrupt the drag: */ public boolean dragStart(Widget widget, LayoutDragMode mode) { return getDragMode() != LayoutDragMode.NONE && dragFilter.isDraggable(widget); } /** * Updates the drop details while dragging. This is needed to ensure client side criterias can * validate the drop location. * * @param widget The container which we are hovering over * @param event The drag event */ protected void updateDropDetails(Widget widget, VDragEvent event) { if (widget == null) { return; } /* * The horizontal position within the cell{ */ event.getDropDetails().put(Constants.DROP_DETAIL_HORIZONTAL_DROP_LOCATION, getHorizontalDropLocation(widget, event)); /* * The index over which the drag is. Can be used by a client side criteria to verify that a drag * is over a certain index. */ int index = -1; if (widget instanceof Slot) { WidgetCollection captionsAndSlots = getChildren(); int realIndex = 0; for (int i = 0; i < captionsAndSlots.size(); i++) { Widget w = captionsAndSlots.get(i); if (w == widget) { index = realIndex; break; } else if (w instanceof Slot) { realIndex++; } } } event.getDropDetails().put(Constants.DROP_DETAIL_TO, index); // Add mouse event details MouseEventDetails details = MouseEventDetailsBuilder.buildMouseEventDetails(event.getCurrentGwtEvent(), getElement()); event.getDropDetails().put(Constants.DROP_DETAIL_MOUSE_EVENT, details.serialize()); } /** * Empasises the drop location of the component when hovering over a hildComponentContainer. * Passing null as the container removes any previous emphasis. * * @param container The container which we are hovering over * @param event The drag event */ protected void emphasis(Widget container, VDragEvent event) { // Remove emphasis from previous hovers deEmphasis(); // validate container if (container == null || !getElement().isOrHasChild(container.getElement())) { return; } currentlyEmphasised = container; UIObject.setStyleName(container.getElement(), OVER, true); // Add drop location specific style if (container.getElement().equals(this.getElement())) { UIObject.setStyleName(container.getElement(), OVER + "-" + HorizontalDropLocation.CENTER.toString().toLowerCase(), true); } else { UIObject.setStyleName(container.getElement(), OVER + "-" + getHorizontalDropLocation(container, event).toString().toLowerCase(), true); } } /** * Returns the current drag mode which determines how the drag is visualized */ public LayoutDragMode getDragMode() { return ddMouseHandler.getDragMode(); } /** * Creates a drop handler if one does not already exist and updates it from the details received * from the server. * * @param childUidl The UIDL */ public void setDropHandler(VDDHorizontalLayoutDropHandler dropHandler) { this.dropHandler = dropHandler; } /** * Get the drop handler attached to the Layout */ public VDDHorizontalLayoutDropHandler getDropHandler() { return dropHandler; } public VDragFilter getDragFilter() { return dragFilter; } IframeCoverUtility getIframeCoverUtility() { return iframeCoverUtility; } VLayoutDragDropMouseHandler getMouseHandler() { return ddMouseHandler; } public double getCellLeftRightDropRatio() { return cellLeftRightDropRatio; } public void setCellLeftRightDropRatio(float cellLeftRightDropRatio) { this.cellLeftRightDropRatio = cellLeftRightDropRatio; } @Override public void setDragFilter(VDragFilter filter) { this.dragFilter = filter; } @Override public void iframeShimsEnabled(boolean enabled) { iframeCovers = enabled; iframeCoverUtility.setIframeCoversEnabled(enabled, getElement(), mode); } @Override public boolean isIframeShimsEnabled() { return iframeCovers; } @Override public void setDragMode(LayoutDragMode mode) { this.mode = mode; ddMouseHandler.updateDragMode(mode); iframeShimsEnabled(iframeCovers); } @Override public void setDragImageProvider(VDragImageProvider provider) { ddMouseHandler.setDragImageProvider(provider); } }