com.google.gwt.maps.client.control.Control.java Source code

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Here is the source code for com.google.gwt.maps.client.control.Control.java

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/*
 * Copyright 2008 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 com.google.gwt.maps.client.control;

import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.maps.client.MapWidget;
import com.google.gwt.maps.client.impl.ControlImpl;
import com.google.gwt.maps.jsio.client.Exported;
import com.google.gwt.maps.jsio.client.FieldName;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.ui.Widget;

/**
 * Control is the abstract base class for all Map Control types.
 */
public class Control {

    /**
     * This class should be extended to create a custom control type.
     */
    public abstract static class CustomControl extends Control {

        private final ControlPosition defaultPosition;

        /**
         * Create a new CustomControl which is not printable or selectable.
         * 
         * @param defaultPosition location of the controls on the map.
         */
        protected CustomControl(ControlPosition defaultPosition) {
            this(defaultPosition, false, false);
        }

        /**
         * Create a new CustomControl which can be either printable, selectable or
         * both.
         * 
         * @param defaultPosition
         * @param printable indicates that the control should be visible in the
         *          print output of the map
         * @param selectable indicates that the control will contain text that
         *          should be selectable.
         */
        protected CustomControl(ControlPosition defaultPosition, boolean printable, boolean selectable) {
            super(ControlImpl.impl.createControl(printable, selectable));
            ControlImpl.impl.bind(super.jsoPeer, this);
            this.defaultPosition = defaultPosition;
        }

        /**
         * Returns to the map if the control contains selectable text.
         * 
         * @return <code>true</code> if the control contains selectable text.
         */
        public abstract boolean isSelectable();

        /**
         * Gets the default position of this control.
         * 
         * The default position is used with the one argument
         * {@link MapWidget#addControl(Control)} method.
         * 
         * @return the default position of this control
         */
        @Exported
        protected final ControlPosition getDefaultPosition() {
            return defaultPosition;
        }

        /**
         * Initializes this control with the given map.
         * 
         * This method should instantiate and return the control's widget.
         * 
         * @param map the Google map
         * @return the widget that should be attached to the map
         */
        protected abstract Widget initialize(MapWidget map);

        /**
         * Initializes the control. Called from JavaScript.
         * 
         */
        @FieldName("initialize")
        @Exported
        Element initializeControl(MapWidget map) {
            Widget w = initialize(map);
            map.addControlWidget(w);
            return w.getElement();
        }
    }

    /**
     * Factory method used by JSIO to wrap an existing JSO in a GWT Java object.
     * 
     * @param jsoPeer
     * @return a new instance of control
     */
    public static Control createPeer(JavaScriptObject jsoPeer) {
        return new Control(jsoPeer);
    }

    /**
     * The JSO being wrapped by this class.
     */
    protected final JavaScriptObject jsoPeer;

    /**
     * Constructor for creating a new instance of this class from an existing JSO.
     * 
     * @param jsoPeer
     */
    protected Control(JavaScriptObject jsoPeer) {
        this.jsoPeer = jsoPeer;
    }
}