com.bearsoft.gwt.ui.widgets.grid.cells.TreeExpandableCell.java Source code

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Here is the source code for com.bearsoft.gwt.ui.widgets.grid.cells.TreeExpandableCell.java

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package com.bearsoft.gwt.ui.widgets.grid.cells;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

import com.bearsoft.gwt.ui.widgets.grid.processing.TreeDataProvider;
import com.google.gwt.cell.client.Cell;
import com.google.gwt.cell.client.ValueUpdater;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.BrowserEvents;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.dom.client.Style;
import com.google.gwt.safecss.shared.SafeStyles;
import com.google.gwt.safecss.shared.SafeStylesBuilder;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;

/**
 * 
 * @author mg
 * @param <T>
 * @param <C>
 */
public class TreeExpandableCell<T, C> extends DivDecoratorCell<C> {

    public interface Template extends SafeHtmlTemplates {

        @SafeHtmlTemplates.Template("<div class='{0}' style='{1}'><div style='height:100%'>{2}</div></div>")
        SafeHtml outerDiv(String aClasses, SafeStyles aStyle, SafeHtml cellContents);
    }

    public static int DEAFAULT_INDENT = 24;
    private static final Template template = GWT.create(Template.class);
    protected int indent;
    protected TreeDataProvider<T> treeProvider;
    protected boolean visible = true;

    public TreeExpandableCell(Cell<C> aCell) {
        this(aCell, null, DEAFAULT_INDENT);
    }

    public TreeExpandableCell(Cell<C> aCell, int aIndent) {
        this(aCell, null, aIndent);
    }

    public TreeExpandableCell(Cell<C> aCell, TreeDataProvider<T> aTreeProvider, int aIndent) {
        super(aCell);
        indent = aIndent;
        treeProvider = aTreeProvider;
    }

    public TreeDataProvider<T> getDataProvider() {
        return treeProvider;
    }

    public void setDataProvider(TreeDataProvider<T> aValue) {
        treeProvider = aValue;
    }

    public boolean isVisible() {
        return visible;
    }

    public void setVisible(boolean aValue) {
        visible = aValue;
    }

    @Override
    public void render(Context context, C value, SafeHtmlBuilder sb) {
        if (treeProvider != null) {
            SafeHtmlBuilder cellBuilder = new SafeHtmlBuilder();
            cell.render(context, value, cellBuilder);
            int deepness = getDeepness(context);
            int outerDivPadding = indent * (deepness + 1);
            SafeStyles styles = new SafeStylesBuilder()
                    .trustedNameAndValue("background-position", indent * deepness, Style.Unit.PX)
                    .paddingLeft(outerDivPadding, Style.Unit.PX).position(Style.Position.RELATIVE)
                    .height(100, Style.Unit.PCT).toSafeStyles();
            sb.append(template.outerDiv(outerDivClasses(context), styles, cellBuilder.toSafeHtml()));
        } else {
            cell.render(context, value, sb);
        }
    }

    @Override
    public Set<String> getConsumedEvents() {
        if (visible) {
            if (treeProvider != null) {
                Set<String> consumed = new HashSet<>();
                consumed.addAll(cell.getConsumedEvents());
                consumed.add(BrowserEvents.MOUSEDOWN);
                return consumed;
            } else {
                return cell.getConsumedEvents();
            }
        } else {
            return null;
        }
    }

    @Override
    public void onBrowserEvent(Context context, Element parent, C value, NativeEvent event,
            ValueUpdater<C> valueUpdater) {
        if (treeProvider != null) {
            super.onBrowserEvent(context, parent, value, event, valueUpdater);
        } else {
            cell.onBrowserEvent(context, parent, value, event, valueUpdater);
        }
    }

    @Override
    protected Element getCellParent(Element parent) {
        if (treeProvider != null) {
            return super.getCellParent(parent);
        } else {
            return parent;
        }
    }

    @Override
    protected int outerDivPadding(Cell.Context aContext) {
        return indent * (getDeepness(aContext) + 1);
    }

    @Override
    protected String outerDivClasses(Cell.Context aContext) {
        return isExpandable(aContext)
                ? (isExpanded(aContext) ? "treegrid-expanded-cell" : "treegrid-collapased-cell")
                : "";
    }

    protected boolean isExpanded(Cell.Context aContext) {
        T element = treeProvider.getList().get(aContext.getIndex());
        return treeProvider.isExpanded(element);
    }

    protected boolean isExpandable(Cell.Context aContext) {
        T element = treeProvider.getList().get(aContext.getIndex());
        return !treeProvider.getTree().isLeaf(element);
    }

    /**
     * 
     * @param aContext
     * @return Deepness value, 0 based. 0 means that an element is on the top
     *         level (e.g. element is root of a forest).
     */
    protected int getDeepness(Cell.Context aContext) {
        T element = treeProvider.getList().get(aContext.getIndex());
        List<T> path = treeProvider.buildPathTo(element);
        return path != null && !path.isEmpty() ? path.size() - 1 : 0;
    }

    @Override
    protected void onNonCellBrowserEvent(Cell.Context context, Element parent, C value, NativeEvent event,
            ValueUpdater<C> valueUpdater) {
        if (treeProvider != null) {
            if (BrowserEvents.MOUSEDOWN.equals(event.getType())) {
                T toBeToggled = treeProvider.getList().get(context.getIndex());
                treeProvider.getList().set(context.getIndex(), toBeToggled);
                if (isExpanded(context)) {
                    treeProvider.collapse(toBeToggled);
                } else {
                    treeProvider.expand(toBeToggled);
                }
            } else if (cell.getConsumedEvents().contains(event.getType())) {
                cell.onBrowserEvent(context, getCellParent(parent), value, event, valueUpdater);
            }
        }
    }
}