gwt.material.design.client.ui.table.CellBasedWidgetImpl.java Source code

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Here is the source code for gwt.material.design.client.ui.table.CellBasedWidgetImpl.java

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/*
 * #%L
 * GwtMaterial
 * %%
 * Copyright (C) 2015 - 2017 GwtMaterialDesign
 * %%
 * 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.
 * #L%
 */
/*
 * Copyright 2010 Google Inc.
 *
 * 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 gwt.material.design.client.ui.table;

import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Element;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.Widget;

import java.util.HashSet;
import java.util.Locale;
import java.util.Set;

/**
 * Implementation used by various cell based widgets.
 *
 * @author Ben Dol
 */
class CellBasedWidgetImpl {

    /**
     * The singleton impl instance.
     */
    private static CellBasedWidgetImpl impl;

    /**
     * Get the singleton instance.
     *
     * @return the {@link CellBasedWidgetImpl} instance
     */
    public static CellBasedWidgetImpl get() {
        if (impl == null) {
            impl = GWT.create(CellBasedWidgetImpl.class);
        }
        return impl;
    }

    /**
     * The set of natively focusable elements.
     */
    final Set<String> focusableTypes;

    CellBasedWidgetImpl() {
        focusableTypes = new HashSet<String>();
        focusableTypes.add("select");
        focusableTypes.add("input");
        focusableTypes.add("textarea");
        focusableTypes.add("option");
        focusableTypes.add("button");
        focusableTypes.add("label");
    }

    /**
     * Check if an element is focusable. If an element is focusable, the cell
     * widget should not steal focus from it.
     *
     * @param elem the element
     * @return true if the element is focusable, false if not
     */
    public boolean isFocusable(Element elem) {
        return focusableTypes.contains(elem.getTagName().toLowerCase(Locale.ROOT)) || elem.getTabIndex() >= 0;
    }

    /**
     * Process an event on a target cell.
     *
     * @param widget the {@link Widget} on which the event occurred
     * @param event the event to handle
     */
    public void onBrowserEvent(Widget widget, Event event) {
    }

    /**
     * Takes in an html string and processes it, adding support for events.
     *
     * @param html the html string to process
     * @return the processed html string
     */
    public SafeHtml processHtml(SafeHtml html) {
        return html;
    }

    /**
     * Reset focus on an element.
     *
     * @param command the command to execute when resetting focus
     */
    public void resetFocus(ScheduledCommand command) {
        command.execute();
    }

    /**
     * Sink events on the widget.
     *
     * @param widget the {@link Widget} that will handle the events
     * @param typeNames the names of the events to sink
     */
    public final void sinkEvents(Widget widget, Set<String> typeNames) {
        if (typeNames == null) {
            return;
        }

        int eventsToSink = 0;
        for (String typeName : typeNames) {
            int typeInt = Event.getTypeInt(typeName);
            if (typeInt < 0) {
                widget.sinkBitlessEvent(typeName);
            } else {
                typeInt = sinkEvent(widget, typeName);
                if (typeInt > 0) {
                    eventsToSink |= typeInt;
                }
            }
        }
        if (eventsToSink > 0) {
            widget.sinkEvents(eventsToSink);
        }
    }

    /**
     * Get the event bits to sink for an event type.
     *
     * @param widget the {@link Widget} that will handle the events
     * @param typeName the name of the event to sink
     * @return the event bits to sink, or -1 if no events to sink
     */
    protected int sinkEvent(Widget widget, String typeName) {
        return Event.getTypeInt(typeName);
    }
}