import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
/**
 * Sets/Removes the keyboard focus to the panel.
 *
 * @param focus
 *            If set to true then the focus is moved to the panel, if set to
 *            false the focus is removed
 */
public void setFocus(boolean focus) {
    if (focus) {
        FocusImpl.getFocusImplForPanel().focus(getElement());
    } else {
        FocusImpl.getFocusImplForPanel().blur(getElement());
    }
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
public SuggestionsContainer(CubaSuggestionFieldWidget suggestionFieldWidget) {
    this.suggestionFieldWidget = suggestionFieldWidget;
    container = DOM.createDiv();

    final Element outer = FocusImpl.getFocusImplForPanel().createFocusable();
    DOM.appendChild(outer, container);
    setElement(outer);

    sinkEvents(Event.ONCLICK | Event.ONMOUSEDOWN | Event.ONMOUSEOVER | Event.ONMOUSEOUT | Event.ONFOCUS | Event.ONKEYDOWN);
    addDomHandler(event ->
            selectItem(null), BlurEvent.getType());

    setStylePrimaryName(STYLENAME);
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
protected void performItemCommand(final SuggestionItem item) {
    selectedSuggestion = item;

    Scheduler.ScheduledCommand cmd = item.getScheduledCommand();
    if (cmd != null) {
        FocusImpl.getFocusImplForPanel().blur(getElement());

        Scheduler.get().scheduleFinally(cmd);
    }
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
protected void setFocus(boolean focus) {
    if (focus) {
        FocusImpl.getFocusImplForPanel().focus(getElement());
    } else {
        FocusImpl.getFocusImplForPanel().blur(getElement());
    }
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
/**
 * Focus the element, if possible
 * @param element
 */
public static void focus(Element element) {
  // NOTE(user): This may not work for divs, rather use getFocusImplForPanel
  //               for divs.
  try {
    FocusImpl.getFocusImplForWidget().focus(castToOld(element));
  } catch (Exception e) {
    // Suppress null pointer condition
  }
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
@Override
public void onShow(PopupEventSourcer source) {
  // NOTE(user): Clear selection so that it doesn't get forcibly restored
  // when applying operations. In Firefox, that would take focus away from the
  // suggestion menu.
  selectionHelper.clearSelection();
  FocusImpl.getFocusImplForPanel().focus(menu.getElement());
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
void doItemAction(final SuggestionMenuItem item, boolean fireCommand,
		boolean focus) {
	// Should not perform any action if the item is disabled
	if (!item.isEnabled()) {
		return;
	}

	// Ensure that the item is selected.
	selectItem(item);

	// if the command should be fired and the item has one, fire it
	if (fireCommand && item.getScheduledCommand() != null) {
		// Close this menu and all of its parents.
		selectItem(null);

		// Remove the focus from the menu
		// FocusPanel.impl.blur(getElement());
		FocusImpl.getFocusImplForPanel().blur(getElement());

		// Fire the item's command. The command must be fired in the same
		// event
		// loop or popup blockers will prevent popups from opening.
		final ScheduledCommand cmd = item.getScheduledCommand();
		Scheduler.get().scheduleFinally(new Scheduler.ScheduledCommand() {
			@Override
			public void execute() {
				cmd.execute();
			}
		});
	}
	
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
private void init() {
	Element table = DOM.createTable();
	body = DOM.createTBody();
	DOM.appendChild(table, body);

	Element outer = FocusImpl.getFocusImplForPanel().createFocusable();
	DOM.appendChild(outer, table);
	setElement(outer);

	Roles.getMenubarRole().set(getElement());

	sinkEvents(Event.ONCLICK | Event.ONMOUSEOVER | Event.ONMOUSEOUT
			| Event.ONFOCUS | Event.ONKEYDOWN);

	setStyleName(STYLENAME_DEFAULT);
	addStyleDependentName("vertical");

	// Hide focus outline in Mozilla/Webkit/Opera
	getElement().getStyle().setProperty("outline", "0px");

	// Hide focus outline in IE 6/7
	getElement().setAttribute("hideFocus", "true");

	// Deselect items when blurring without a child menu.
	addDomHandler(new BlurHandler() {
		@Override
		public void onBlur(BlurEvent event) {
			selectItem(null);
		}
	}, BlurEvent.getType());
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
/**
 * Select or deselect this node with the keyboard.
 *
 * @param selected   true if selected, false if not
 * @param stealFocus true to steal focus
 */
void setKeyboardSelected(boolean selected, boolean stealFocus) {
  if (tree.isKeyboardSelectionDisabled()) {
    return;
  }

  // Apply the selected style.
  if (!selected || tree.isFocused || stealFocus) {
    setKeyboardSelectedStyle(selected);
  }

  // Make the node focusable or not.
  Element cellParent = getCellParent();
  if (!selected) {
    // Chrome: Elements remain focusable after removing the tabIndex, so set
    // it to -1 first.
    cellParent.setTabIndex(-1);
    cellParent.removeAttribute("tabIndex");
    cellParent.removeAttribute("accessKey");
  }
  else {
    FocusImpl focusImpl = FocusImpl.getFocusImplForWidget();
    focusImpl.setTabIndex(cellParent, tree.getTabIndex());
    char accessKey = tree.getAccessKey();
    if (accessKey != 0) {
      focusImpl.setAccessKey(cellParent, accessKey);
    }
    if (stealFocus && !tree.cellIsEditing) {
      cellParent.focus();
    }
  }

  // Update the selection model.
  if (KeyboardSelectionPolicy.BOUND_TO_SELECTION == tree.getKeyboardSelectionPolicy()) {
    setSelected(selected);
  }
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
@Override
public void setAccessKey(char key) {
	FocusImpl.getFocusImplForWidget().setAccessKey(getElement(), key);
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
/**
 * TODO(user): use content document to set caret, and issue operation
 *
 * TODO(danilatos): This stuff seems out of date...
 *
 * TODO(danilatos): Make this method trivially idempotent
 *
 * {@inheritDoc}
 */
@Override
public void focus(boolean collapsed) {
  if (!isAttached()) {
    EditorStaticDeps.logger.error().log("Shouldn't focus a detached editor");
    return;
  }

  // focus document
  if (isEditing() && content != null) {
    // first, handle DOM focus
    FocusedPointRange<Node> htmlSelection = getHtmlSelection(); // save before focusing.

    // element causes webkit based browsers to automatically scroll the element into view
    // In wave, we want to be in charge of how things move, so we cancel this behaviour
    // here by first recording the scrollTops of all the editor's ancestors, and
    // then resetting them after calling focus.
    Element docElement = getDocumentHtmlElement();
    maybeSaveAncestorScrollPositions(docElement);
    FocusImpl.getFocusImplForWidget().focus(DomHelper.castToOld(docElement));
    maybeRestoreAncestorScrollPositions(docElement);

    // then, handle the case when selection already existed inside the element:
    if (htmlSelection != null) {
      // NOTE(patcoleman): we may have killed it with the DOM focusing above, so restore
      NativeSelectionUtil.set(htmlSelection);

      if (!collapsed) {
        // if we have selection, and we're not forcibly collapsing it, then nothing needs doing.
        return;
      } else {
        // Otherwise, we might need to adjust it if we're collapsing it. So we'll fall through to
        // the manual selection-restore-with-collapse, but first we save what we have anyway.
        EditorStaticDeps.logger.trace().log("Saving...");
        doSaveSelection();
      }
    }

    // finally, make sure selection is correct:
    safelyRestoreSelection(aggressiveSelectionHelper, collapsed);
    scheduleUpdateNotification(true, true, false, false);
  }
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
public Tree(
    NodeStorage nodeStorage,
    NodeLoader nodeLoader,
    TreeStyles treeStyles,
    EmptyStatus<Tree> emptyStatus) {
  checkNotNull(nodeStorage);
  checkNotNull(nodeLoader);
  checkNotNull(treeStyles);

  this.treeStyles = treeStyles;
  this.treeStyles.styles().ensureInjected();
  this.nodesByDom = new HashMap<>();
  this.focusImpl = FocusImpl.getFocusImplForPanel();
  this.storeHandlers = new GroupingHandlerRegistration();

  ensureTreeElement();
  ensureFocusElement();

  setNodeStorage(nodeStorage);
  setNodeLoader(nodeLoader);
  setSelectionModel(new SelectionModel());
  setGoInto(new DefaultGoInto());
  setView(new TreeView());
  setAllowTextSelection(false);

  disableBrowserContextMenu(true);

  // use as default
  if (emptyStatus == null) {
    emptyStatus = new StatusText<>();
  }
  this.emptyStatus = emptyStatus;
  this.emptyStatus.init(
      this,
      new Predicate<Tree>() {
        @Override
        public boolean apply(@Nullable Tree tree) {
          return tree.getNodeStorage().getRootCount() == 0;
        }
      });
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
/**
 * Give this MenuBar focus.
 */
public void focus() {
	FocusImpl.getFocusImplForPanel().focus(getElement());
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
@Override
public void onBrowserEvent(Event event) {
	SuggestionMenuItem item = findItem(DOM.eventGetTarget(event));
	switch (DOM.eventGetType(event)) {
	case Event.ONCLICK: {
		FocusImpl.getFocusImplForPanel().focus(getElement());
		// Fire an item's command when the user clicks on it.
		if (item != null) {
			doItemAction(item, true, true);
		}
		break;
	}

	case Event.ONMOUSEOVER: {
		if (item != null) {
			itemOver(item, true);
		}
		break;
	}

	case Event.ONMOUSEOUT: {
		if (item != null) {
			itemOver(null, false);
		}
		break;
	}

	case Event.ONFOCUS: {
		selectFirstItemIfNoneSelected();
		break;
	}

	case Event.ONKEYDOWN: {
		int keyCode = event.getKeyCode();
		boolean isRtl = LocaleInfo.getCurrentLocale().isRTL();
		keyCode = KeyCodes.maybeSwapArrowKeysForRtl(keyCode, isRtl);
		switch (keyCode) {
		case KeyCodes.KEY_UP:
			moveSelectionUp();
			eatEvent(event);
			break;
		case KeyCodes.KEY_DOWN:
			moveSelectionDown();
			eatEvent(event);
			break;
		case KeyCodes.KEY_ESCAPE:
			selectItem(null);
			eatEvent(event);
			break;
		case KeyCodes.KEY_TAB:
			selectItem(null);
			break;
		case KeyCodes.KEY_ENTER:
			if (!selectFirstItemIfNoneSelected()) {
				doItemAction(selectedItem, true, true);
				eatEvent(event);
			}
			break;
		} // end switch(keyCode)

		break;
	} // end case Event.ONKEYDOWN
	} // end switch (DOM.eventGetType(event))
	super.onBrowserEvent(event);
}
 

import com.google.gwt.user.client.ui.impl.FocusImpl; //导入依赖的package包/类
/**
 * Blur the element, if possible
 * @param element
 *
 * NOTE(user): Dan thinks this method should be deprecated, but is not
 *               sure why... Dan, please update once you remember.
 */
public static void blur(Element element) {
  FocusImpl.getFocusImplForWidget().blur(castToOld(element));
}