/**
 * Copyright 2006 mapeasy.sf.net.
 * 
 * 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.
 */

/**
 * 地圖移動
 *
 * @author Tim.Wu Michael.Young
 */
function MoveAction(mapModel) {
	
	// inherit from BaseAction
	BaseAction.apply(this, new Array(mapModel));

	//~ Method
	/**
	 * 構(gòu)造函數(shù)
	 */
	{
		// 注冊 Command 對象的監(jiān)聽器
		command.addListener("goup", this);
		command.addListener("godown", this);
		command.addListener("goleft", this);
		command.addListener("goright", this);
	}

	this.propertyChange = function(param, newValue) {
		if (newValue != null && newValue == this.model.getId()) {
			var newX = this.model.getViewerCenterCoord().x;
			var newY = this.model.getViewerCenterCoord().y;
			if (param == "goup") {
				newY = this.model.getViewerCenterCoord().y + this.model.getZoom().getViewerBound().getHeight() / 2;
			}
			if (param == "godown") {
				newY = this.model.getViewerCenterCoord().y - this.model.getZoom().getViewerBound().getHeight() / 2;
			}
			if (param == "goleft") {
				newX = this.model.getViewerCenterCoord().x - this.model.getZoom().getViewerBound().getWidth() / 2;
			}
			if (param == "goright") {
				newX = this.model.getViewerCenterCoord().x + this.model.getZoom().getViewerBound().getWidth() / 2;
			}
			var newCoord = new Coordinate(newX, newY);
			if (!newCoord.same(this.model.getViewerCenterCoord())) {
				this.model.setViewerCenterCoord(newCoord);
			}
		}
	}
}