com.agnie.gwt.common.client.mvp.AppController.java Source code

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Here is the source code for com.agnie.gwt.common.client.mvp.AppController.java

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/*******************************************************************************
 * Copyright (c) 2014 Agnie Technologies.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Agnie Technologies - initial API and implementation
 ******************************************************************************/
package com.agnie.gwt.common.client.mvp;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.user.client.History;
import com.google.gwt.user.client.ui.HTMLPanel;
import com.google.gwt.user.client.ui.Widget;

public abstract class AppController<PLACE extends Enum<PLACE>> implements ValueChangeHandler<String> {

    private Class<PLACE> placeType;
    private Place<PLACE> lastPlace;
    private PlaceManager<PLACE> placeMgr;

    public AppController(Class<PLACE> placeType) {
        this.placeType = placeType;
        History.addValueChangeHandler(this);
        placeMgr = new PlaceManager<PLACE>(this, placeType);
    }

    public PlaceManager<PLACE> getPlaceManager() {
        return placeMgr;
    }

    public void go() {
        if ("".equals(History.getToken())) {
            History.newItem(new Place<PLACE>(getDefaultPlace()).toString());
        } else {
            History.fireCurrentHistoryState();
        }
    }

    public void onValueChange(ValueChangeEvent<String> event) {
        if (checkIfWeCanProceed()) {
            String token = event.getValue();
            GWT.log("AppContorller on value change Stringtoken==" + token);
            if (token != null) {
                Presenter presenter = getPresenterForPlace(placeMgr.getTokenToPlace(placeType, token));
                if (presenter != null) {
                    presenter.go();
                    presenter.postRender();
                }
            }
        } else {
            // Just roll back the history token to the one from which page change action is initiated.
            History.newItem(lastPlace.toString(), false);
        }
    }

    protected boolean checkIfWeCanProceed() {
        HTMLPanel contentPanel = getMainContentRootPanel();
        if (contentPanel != null) {
            for (int index = 0; index < contentPanel.getWidgetCount(); index++) {
                Widget widget = contentPanel.getWidget(index);
                if (widget instanceof MainView) {
                    MainView priviousDisplay = (MainView) widget;
                    boolean resp = priviousDisplay.shouldWeProceed();
                    if (!resp)
                        return false;
                }
            }
        }
        return true;
    }

    public void setLastPlace(Place<PLACE> place) {
        this.lastPlace = place;
    }

    protected abstract HTMLPanel getMainContentRootPanel();

    protected abstract PLACE getDefaultPlace();

    protected abstract Presenter getPresenterForPlace(Place<PLACE> place);

}