de.swm.commons.mobile.client.widgets.SlidePanel.java Source code

Introduction

Here is the source code for de.swm.commons.mobile.client.widgets.SlidePanel.java

Source

/*
 * Copyright 2011 SWM Services GmbH.
 * 
 * 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 de.swm.commons.mobile.client.widgets;

import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HasWidgets;
import com.google.gwt.user.client.ui.Widget;
import de.swm.commons.mobile.client.SWMMobile;
import de.swm.commons.mobile.client.event.DragController;
import de.swm.commons.mobile.client.event.SwipeEvent;
import de.swm.commons.mobile.client.event.SwipeEventsHandler;
import de.swm.commons.mobile.client.page.Transition;

import java.util.ArrayList;
import java.util.Iterator;

/**
 * * A slide panel reacts to finger slide gestures (sliding events).
 */
public class SlidePanel extends SWMMobileWidgetBase
        implements HasWidgets, SwipeEventsHandler, HasValueChangeHandlers<Boolean> {

    private final int firstSlideOnLoad;
    protected final FlowPanel contentPanel = new FlowPanel();
    protected int myCount = 0;
    protected int myCurrent = 0;
    protected SlideProvider mySlideProvider = null;
    protected final ArrayList<Widget> mySlides = new ArrayList<Widget>();
    protected boolean isRotate = false;

    /**
     * Default constructor.
     */
    public SlidePanel() {
        this(0);
    }

    /**
     * Slide constructor.
     *
     * @param firstSlideToLoad first slide which will be loaded.
     */
    public SlidePanel(int firstSlideToLoad) {
        this.firstSlideOnLoad = firstSlideToLoad;
        initWidget(contentPanel);
        setStyleName(SWMMobile.getTheme().getMGWTCssBundle().getSlidePanelCss().slidePanel());
    }

    public void setSlideCount(int count) {
        myCount = count;
    }

    public int getSlideCount() {
        return myCount > 0 ? myCount : mySlides.size();
    }

    public void setSlideProvider(SlideProvider provider) {
        mySlideProvider = provider;
    }

    public SlideProvider getSlideProvider() {
        return mySlideProvider;
    }

    @Override
    public void onInitialLoad() {
        super.onInitialLoad();
        myCurrent = firstSlideOnLoad;
        Slide slide = getSlide(myCurrent);
        if (slide != null) {
            contentPanel.add(slide);
        }
    }

    /**
     * Returns the {@link Slide} on the <code>index</code> position.
     *
     * @param index index.
     * @return the slide or null
     */
    public Slide getSlide(int index) {
        Slide slide = null;
        if (mySlideProvider != null) {
            slide = mySlideProvider.loadSlide(index);
        }
        if (slide == null && index < mySlides.size()) {
            slide = (Slide) mySlides.get(index);
        }
        return slide;
    }

    @Override
    public void onLoad() {
        super.onLoad();
        DragController.get().addSwipeEventsHandler(this);
    }

    @Override
    protected void onUnload() {
        DragController.get().removeSwipeEventHandler(this);
        super.onUnload();
    }

    @Override
    public void onSwipeHorizontal(SwipeEvent e) {
        if (e.getSpeed() < 0) { // swipe to next
            next();
        } else { // swipe to previous
            previous();
        }
    }

    @Override
    public void onSwipeVertical(SwipeEvent e) {
    }

    /**
     * Goes to the next slide.
     */
    public void next() {
        if (myCurrent >= getSlideCount() - 1) {
            if (!isRotate) {
                return;
            } else {
                myCurrent = -1;
            }
        }
        myCurrent++;
        moveNext();
    }

    /**
     * Moves to the next slide without boundary checks.
     */
    protected void moveNext() {
        Slide to = getSlide(myCurrent);
        Slide from = (Slide) contentPanel.getWidget(0);
        Transition transition = Transition.SLIDE;
        ValueChangeEvent.fire(this, true);
        transition.start(from, to, contentPanel, false);
    }

    /**
     * Goes to the previous slide.
     */
    public void previous() {
        if (myCurrent <= 0) {
            if (!isRotate) {
                return;
            } else {
                myCurrent = getSlideCount();
            }
        }
        myCurrent--;
        movePrevious();
    }

    /**
     * Moves to the previous slide without boundary checks.
     */
    protected void movePrevious() {
        Slide to = getSlide(myCurrent);
        Slide from = (Slide) contentPanel.getWidget(0);
        Transition transition = Transition.SLIDE;
        ValueChangeEvent.fire(this, false);
        transition.start(from, to, contentPanel, true);
    }

    @Override
    public void onTransitionEnd() {
        super.onTransitionEnd();
        contentPanel.remove(0);
    }

    public int getCurrentSlideIndex() {
        return myCurrent;
    }

    @Override
    public void add(Widget w) {
        assert (w instanceof Slide) : "Can only add Slide widgets to SlidePanel.";
        mySlides.add(w);
    }

    @Override
    public void clear() {
        mySlides.clear();
        contentPanel.clear();
    }

    @Override
    public Iterator<Widget> iterator() {
        return mySlides.iterator();
    }

    @Override
    public boolean remove(Widget w) {
        return mySlides.remove(w);
    }

    public void setRotate(boolean rotate) {
        isRotate = rotate;
    }

    public boolean isRotate() {
        return isRotate;
    }

    @Override
    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) {
        return this.addHandler(handler, ValueChangeEvent.getType());
    }

    /**
     * Slide Provider provides {@link Slide}s for the {@link SlidePanel}.
     */
    public interface SlideProvider {

        /**
         * Loads the slide on the index position
         *
         * @param index ths index
         * @return the slide
         */
        Slide loadSlide(int index);
    }
}