org.semanticsoft.vaaclipse.presentation.renderers.AreaRenderer.java Source code

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/*******************************************************************************
 * Copyright (c) 2012 Rushan R. Gilmullin and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Rushan R. Gilmullin - initial API and implementation
 *******************************************************************************/

package org.semanticsoft.vaaclipse.presentation.renderers;

import java.util.List;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;

import org.eclipse.e4.core.services.events.IEventBroker;
import org.eclipse.e4.ui.model.application.ui.MElementContainer;
import org.eclipse.e4.ui.model.application.ui.MUIElement;
import org.eclipse.e4.ui.model.application.ui.advanced.MArea;
import org.eclipse.e4.ui.model.application.ui.advanced.MPlaceholder;
import org.eclipse.e4.ui.model.application.ui.basic.MPartSashContainer;
import org.eclipse.e4.ui.model.application.ui.basic.MPartSashContainerElement;
import org.eclipse.e4.ui.model.application.ui.basic.MPartStack;
import org.eclipse.e4.ui.workbench.IPresentationEngine;
import org.eclipse.e4.ui.workbench.UIEvents;
import org.eclipse.e4.ui.workbench.modeling.EModelService;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventHandler;
import org.semanticsoft.vaaclipse.api.VaadinExecutorService;
import org.semanticsoft.vaaclipse.presentation.utils.HierarchyUtils;
import org.semanticsoft.vaaclipse.widgets.ExtendedVerticalLayout;
import org.semanticsoft.vaaclipse.widgets.StackWidget;
import org.semanticsoft.vaaclipse.widgets.StackWidget.StateListener;

import com.vaadin.ui.AbstractOrderedLayout;
import com.vaadin.ui.Component;
import com.vaadin.ui.HorizontalLayout;

/**
 * @author rushan
 * 
 */
public class AreaRenderer extends VaadinRenderer {
    @Inject
    IEventBroker eventBroker;

    @Inject
    VaadinExecutorService executorService;

    private EventHandler childrenHandler = new EventHandler() {
        public void handleEvent(Event event) {
            Object changedObj = event.getProperty(UIEvents.EventTags.ELEMENT);

            //Stacks can not contains another stacks (yes, theoretically it can contains the stack in child placeholder, but
            //we search only top level stacks)
            if (changedObj instanceof MPartStack)
                return;

            @SuppressWarnings("unchecked")
            MElementContainer<? extends MUIElement> changedElement = (MElementContainer<MUIElement>) changedObj;

            if (!changedElement.isToBeRendered() || changedElement.getWidget() == null)
                return;

            String eventType = (String) event.getProperty(UIEvents.EventTags.TYPE);
            MUIElement child = null;
            if (UIEvents.EventTypes.ADD.equals(eventType))
                child = (MUIElement) event.getProperty(UIEvents.EventTags.NEW_VALUE);
            else if (UIEvents.EventTypes.REMOVE.equals(eventType))
                child = (MUIElement) event.getProperty(UIEvents.EventTags.OLD_VALUE);

            if (child == null || !child.isToBeRendered())
                return;

            if (!(child instanceof MPartStack || child instanceof MPartSashContainer))
                return;

            processChangedElement(changedElement);
        }
    };

    private EventHandler toBeRenderedHandler = new EventHandler() {
        public void handleEvent(Event event) {

            MUIElement changedElement = (MUIElement) event.getProperty(UIEvents.EventTags.ELEMENT);

            if (!(changedElement instanceof MPartStack || changedElement instanceof MPartSashContainer))
                return;

            processChangedElement(changedElement);
        }
    };

    private void processChangedElement(MUIElement changedElement) {
        MArea area = null;
        //if it is area we directly process it
        if (changedElement instanceof MArea)
            area = (MArea) changedElement;
        else {//otherwise we find parent area
            int loc = modelService.getElementLocation(changedElement);
            if (loc != EModelService.IN_SHARED_AREA)
                return;

            area = findArea(changedElement);
        }

        if (area != null) {
            final MArea closureArea = area;
            executorService.invokeLater(closureArea, new Runnable() {

                @Override
                public void run() {
                    refreshTopRightState(closureArea);
                }
            });
        }
    }

    private MArea findArea(MUIElement element) {
        MUIElement parent = element.getParent();
        while (parent != null) {
            if (parent instanceof MArea)
                return (MArea) parent;
            parent = parent.getParent();
        }
        return null;
    }

    @PostConstruct
    public void subscribe() {
        eventBroker.subscribe(UIEvents.ElementContainer.TOPIC_CHILDREN, childrenHandler);
        eventBroker.subscribe(UIEvents.UIElement.TOPIC_TOBERENDERED, toBeRenderedHandler);
    }

    @PreDestroy
    public void unsubscribe() {
        eventBroker.unsubscribe(childrenHandler);
        eventBroker.unsubscribe(toBeRenderedHandler);
    }

    @Override
    public void createWidget(MUIElement element, MElementContainer<MUIElement> parent) {
        if (!(element instanceof MArea))
            return;

        MArea area = (MArea) element;
        AbstractOrderedLayout areaComp;
        if (area.isHorizontal())
            areaComp = new HorizontalLayout();
        else {
            ExtendedVerticalLayout bi = new ExtendedVerticalLayout();
            bi.setVariableValue("e4ElementType", "area");
            areaComp = bi;
        }
        areaComp.addStyleName("area");
        areaComp.setSizeFull();
        element.setWidget(areaComp);
    }

    @Override
    public void processContents(MElementContainer<MUIElement> container) {
        MArea area = (MArea) (MElementContainer<?>) container;
        AbstractOrderedLayout parentPane = (AbstractOrderedLayout) area.getWidget();
        parentPane.removeAllComponents();
        for (MUIElement element : area.getChildren()) {
            if (element.isToBeRendered()) {
                if (element instanceof MPlaceholder)
                    element = ((MPlaceholder) element).getRef();
                parentPane.addComponent((Component) element.getWidget());
            }
        }

        refreshTopRightState(area);
    }

    /**
     * This method finds the top right part stack (located in top right corner)
     * and apply its maximize and minimize buttons to entire area. Then hide the
     * maximize and minimize buttons of other stacks in this area. So, there are
     * implemented the eclipse3-like approach to manage area (in e4 swt renderer
     * is used other way - if more than one stack is located in area, the top
     * container-tabfolder is created for entire area and buttons of this
     * container folder is used - i found this way is too heavy-weight).
     */
    @SuppressWarnings("restriction")
    private void refreshTopRightState(final MArea area) {
        MPartStack topLeftStak = HierarchyUtils.findTopLeftFolder(area);
        if (topLeftStak != null) {
            StackWidget topLeftStackWidget = (StackWidget) topLeftStak.getWidget();
            if (topLeftStackWidget != null) {
                topLeftStackWidget.setMaximizeEnabled(true);
                topLeftStackWidget.setMinimizeEnabled(true);
                topLeftStackWidget.removeAllStateListeners();

                topLeftStackWidget.addStateListener(new StateListener() {

                    @Override
                    public void stateChanged(int newState, int oldState) {
                        MPlaceholder ph = area.getCurSharedRef();
                        if (oldState == 0 && newState == 1)
                            setState(ph, IPresentationEngine.MAXIMIZED);
                        else if (oldState == 1 && newState == 0)
                            setState(ph, null);
                        else if (oldState == 1 && newState == -1) {
                            ph.getTags().remove(IPresentationEngine.MINIMIZED);
                            ph.getTags().remove(IPresentationEngine.MAXIMIZED);
                            ph.getTags().add(IPresentationEngine.MINIMIZED);
                        } else if (oldState == -1 && newState == 0) {
                            ph.getTags().remove(IPresentationEngine.MINIMIZED_BY_ZOOM);
                            ph.getTags().remove(IPresentationEngine.MINIMIZED);
                        } else if (oldState == 0 && newState == -1)
                            setState(ph, IPresentationEngine.MINIMIZED);
                    }

                    private void setState(MUIElement element, String state) {
                        element.getTags().remove(IPresentationEngine.MINIMIZED_BY_ZOOM);
                        if (IPresentationEngine.MINIMIZED.equals(state)) {
                            element.getTags().remove(IPresentationEngine.MAXIMIZED);
                            element.getTags().add(IPresentationEngine.MINIMIZED);
                        } else if (IPresentationEngine.MAXIMIZED.equals(state)) {
                            element.getTags().remove(IPresentationEngine.MINIMIZED);
                            element.getTags().add(IPresentationEngine.MAXIMIZED);
                        } else {
                            element.getTags().remove(IPresentationEngine.MINIMIZED);
                            element.getTags().remove(IPresentationEngine.MAXIMIZED);
                        }
                    }
                });
            }

            List<MPartStack> stacks = modelService.findElements(area, null, MPartStack.class, null);

            for (MPartStack stack : stacks) {
                if (stack.isToBeRendered() && stack != topLeftStak) {
                    StackWidget stackWidget = (StackWidget) stack.getWidget();
                    if (stackWidget != null) {
                        stackWidget.setMaximizeEnabled(false);
                        stackWidget.setMinimizeEnabled(false);
                        stackWidget.removeAllStateListeners();
                    }
                }
            }
        }
    }

    @Override
    public void addChildGui(MUIElement child, MElementContainer<MUIElement> element) {
        if (!(child instanceof MPartSashContainerElement))
            return;

        AbstractOrderedLayout areaWidget = (AbstractOrderedLayout) element.getWidget();
        int index = indexOf(child, element);
        areaWidget.addComponent((Component) child.getWidget(), index);
    }
}