com.google.gwt.user.client.Event.NativePreviewHandler Java Examples

/**
 * ExtendedPopupPanel
 */
public ExtendedPopupPanel(boolean autoHide, boolean modal) {
	super(autoHide, modal);

	// Ensures when mouseup / onclick / ondblclick event is disabled drag flag and not consumed by popup
	Event.addNativePreviewHandler(new NativePreviewHandler() {
		@Override
		public void onPreviewNativeEvent(NativePreviewEvent event) {
			int type = event.getTypeInt();
			if (type == Event.ONMOUSEUP || type == Event.ONCLICK || type == Event.ONDBLCLICK) {
				Main.get().activeFolderTree.disableDragged();
			}
		}
	});
}
 

private void updateHandler() {
	if (this.previewHandler != null) {
		this.previewHandler.removeHandler();
		this.previewHandler = null;
	}
	if (this.focused) {
		this.previewHandler = Event.addNativePreviewHandler(new NativePreviewHandler() {
			@Override
			public void onPreviewNativeEvent(NativePreviewEvent event) {
				CompositeFocusHelper.this.previewNativeEvent(event);
			}
		});
	}
}
 

@Override
protected void init() {
    super.init();

    dummyRootMenuBar = GWT.create(MyVMenuBar.class);

    CustomMenuItem item = GWT.create(CustomMenuItem.class);
    dummyRootMenuBar.getItems().add(item);

    contextMenuWidget = new MyVMenuBar(true, dummyRootMenuBar);
    item.setSubMenu(contextMenuWidget);

    // application connection that is used for all our overlays
    MyVOverlay.setApplicationConnection(this.getConnection());

    registerRpc(ContextMenuClientRpc.class, new ContextMenuClientRpc() {
        @Override
        public void showContextMenu(int x, int y) {
            showMenu(x, y);
        }
    });

    Event.addNativePreviewHandler(new NativePreviewHandler() {
        @Override
        public void onPreviewNativeEvent(NativePreviewEvent event) {
            if (event.getTypeInt() == Event.ONKEYDOWN
                    && contextMenuWidget.isPopupShowing()) {
                boolean handled = contextMenuWidget.handleNavigation(
                        event.getNativeEvent().getKeyCode(),
                        event.getNativeEvent().getCtrlKey(),
                        event.getNativeEvent().getShiftKey());

                if (handled) {
                    event.cancel();
                }
            }
        }
    });
}
 

/**
 * Initiates the drag only on the first move event
 *
 * @param originalEvent
 *            the original Mouse Down event. Only events on elements are
 *            passed in here (Element.as() is safe without check here)
 */
protected void initiateDragOnMove(final NativeEvent originalEvent) {
    EventTarget eventTarget = originalEvent.getEventTarget();

    boolean stopEventPropagation = false;

    Element targetElement = Element.as(eventTarget);
    Widget target = WidgetUtil.findWidget(targetElement, null);
    Widget targetParent = target.getParent();

    // Stop event propagation and prevent default behaviour if
    // - target is *not* a VTabsheet.TabCaption or
    // - drag mode is caption mode and widget is caption
    boolean isTabCaption = WidgetUtil.findWidget(target.getElement(), TabCaption.class) != null;
    boolean isCaption = VDragDropUtil.isCaptionOrCaptionless(targetParent);

    if (dragMode == LayoutDragMode.CLONE && isTabCaption == false) {

        stopEventPropagation = true;

        // overwrite stopEventPropagation flag again if
        // - root implements VHasDragFilter but
        // - target is not part of its drag filter and
        // - target is not a GWT Label based widget
        if (root instanceof VHasDragFilter) {
            if (((VHasDragFilter) root).getDragFilter()
                    .isDraggable(target) == false &&
	(target instanceof LabelBase) == false) {
                    stopEventPropagation = false;
            }
        }

        if (root instanceof VHasGrabFilter) {
            VGrabFilter grabFilter = ((VHasGrabFilter) root).getGrabFilter();
            if (grabFilter != null && !grabFilter.canBeGrabbed(root, target)) {
                return;
            }
        }
    }

    if (dragMode == LayoutDragMode.CAPTION && isCaption) {
        stopEventPropagation = true;
    }

    if (isElementNotDraggable(targetElement)) {
        stopEventPropagation = false;
    }

    if (stopEventPropagation) {
        originalEvent.stopPropagation();
        originalEvent.preventDefault();

        // Manually focus as preventDefault() will also cancel focus
        targetElement.focus();
    }

    mouseDownHandlerReg = Event
            .addNativePreviewHandler(new NativePreviewHandler() {

                @Override
                public void onPreviewNativeEvent(NativePreviewEvent event) {
                    int type = event.getTypeInt();
                    if (type == Event.ONMOUSEUP
                            || type == Event.ONTOUCHCANCEL
                            || type == Event.ONTOUCHEND) {
                        mouseDownHandlerReg.removeHandler();
                        mouseDownHandlerReg = null;

                    } else if (type == Event.ONMOUSEMOVE
                            || type == Event.ONTOUCHMOVE) {
                        mouseDownHandlerReg.removeHandler();
                        mouseDownHandlerReg = null;
                        initiateDrag(originalEvent);
                    }
                }
            });
}
 

@Override
// Exception squid:S1604 - GWT 2.7 does not support Java 8
@SuppressWarnings("squid:S1604")
public void accept(final VDragEvent drag, final UIDL configuration, final VAcceptCallback callback) {

    if (isDragStarting(drag)) {
        final NativePreviewHandler nativeEventHandler = new NativePreviewHandler() {
            @Override
            public void onPreviewNativeEvent(final NativePreviewEvent event) {
                if (isEscKey(event) || isMouseUp(event)) {
                    try {
                        hideDropTargetHints(configuration);
                    } finally {
                        nativeEventHandlerRegistration.removeHandler();
                    }
                }
            }
        };

        nativeEventHandlerRegistration = Event.addNativePreviewHandler(nativeEventHandler);
        setMultiRowDragDecoration(drag);
    }

    final int childCount = configuration.getChildCount();
    accepted = false;
    for (int childIndex = 0; childIndex < childCount; childIndex++) {
        final VAcceptCriterion crit = getCriteria(configuration, childIndex);
        crit.accept(drag, configuration.getChildUIDL(childIndex), this);
        if (Boolean.TRUE.equals(accepted)) {
            callback.accepted(drag);
            return;
        }
    }

    // if no VAcceptCriterion accepts and the mouse is release, an error
    // message is shown
    if (Event.ONMOUSEUP == Event.getTypeInt(drag.getCurrentGwtEvent().getType())) {
        showErrorNotification(drag);
    }

    errorMessage = configuration.getStringAttribute(ERROR_MESSAGE);
}