cc.alcina.framework.gwt.client.cell.PropertyDomainSuggestCell.java Source code

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Here is the source code for cc.alcina.framework.gwt.client.cell.PropertyDomainSuggestCell.java

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/*
 * Copyright 2010 Google Inc.
 *
 * 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 cc.alcina.framework.gwt.client.cell;

import static com.google.gwt.dom.client.BrowserEvents.*;

import java.util.function.Function;

import com.google.gwt.cell.client.AbstractEditableCell;
import com.google.gwt.cell.client.ValueUpdater;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.text.shared.SafeHtmlRenderer;
import com.google.gwt.text.shared.SimpleSafeHtmlRenderer;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.Event.NativePreviewEvent;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.PopupPanel.PositionCallback;

import cc.alcina.framework.gwt.client.gwittir.widget.BoundSuggestBox;

/**
 *
 */
public class PropertyDomainSuggestCell<T> extends AbstractEditableCell<T, T> {
    private static final int ESCAPE = 27;

    private int offsetX = 0;

    private int offsetY = -4;

    private Object lastKey;

    private Element lastParent;

    private int lastIndex;

    private int lastColumn;

    private T lastValue;

    private PopupPanel panel;

    private final SafeHtmlRenderer<String> renderer;

    private ValueUpdater<T> valueUpdater;

    private BoundSuggestBox suggestor;

    private Function<T, String> toStringMapper;

    String lastFilter = "";

    private String lastFilterText;

    public PropertyDomainSuggestCell(Function<T, String> toStringMapper, BoundSuggestBox suggestor) {
        super(CLICK, KEYDOWN);
        this.toStringMapper = toStringMapper;
        this.suggestor = suggestor;
        this.renderer = SimpleSafeHtmlRenderer.getInstance();
        this.panel = new PopupPanel(true, true) {
            @Override
            protected void onPreviewNativeEvent(NativePreviewEvent event) {
                if (Event.ONKEYUP == event.getTypeInt()) {
                    if (event.getNativeEvent().getKeyCode() == ESCAPE) {
                        // Dismiss when escape is pressed
                        panel.hide();
                    }
                }
            }
        };
        panel.addStyleName("property-selector");
        panel.addCloseHandler(new CloseHandler<PopupPanel>() {
            public void onClose(CloseEvent<PopupPanel> event) {
                lastKey = null;
                lastValue = null;
                lastIndex = -1;
                lastColumn = -1;
                if (lastParent != null && !event.isAutoClosed()) {
                    // Refocus on the containing cell after the user selects a
                    // value, but
                    // not if the popup is auto closed.
                    lastParent.focus();
                }
                lastParent = null;
            }
        });
        panel.add(suggestor);
        // Hide the panel and call valueUpdater.update when a value is selected
        suggestor.addPropertyChangeListener("value", event -> {
            // Remember the values before hiding the popup.
            Element cellParent = lastParent;
            T oldValue = lastValue;
            Object key = lastKey;
            int index = lastIndex;
            int column = lastColumn;
            panel.hide();
            // Update the cell and value updater.
            T value = (T) event.getNewValue();
            setViewData(key, value);
            setValue(new Context(index, column, key), cellParent, oldValue);
            if (valueUpdater != null) {
                valueUpdater.update(value);
            }
            lastFilterText = suggestor.getLastFilterText();
        });
    }

    @Override
    public boolean isEditing(Context context, Element parent, T value) {
        return lastKey != null && lastKey.equals(context.getKey());
    }

    @Override
    public void onBrowserEvent(Context context, Element parent, T value, NativeEvent event,
            ValueUpdater<T> valueUpdater) {
        super.onBrowserEvent(context, parent, value, event, valueUpdater);
        if (CLICK.equals(event.getType())) {
            onEnterKeyDown(context, parent, value, event, valueUpdater);
        }
    }

    @Override
    public void render(Context context, T value, SafeHtmlBuilder sb) {
        // Get the view data.
        Object key = context.getKey();
        T viewData = getViewData(key);
        if (viewData != null && viewData.equals(value)) {
            clearViewData(key);
            viewData = null;
        }
        String s = null;
        if (viewData != null) {
            s = toStringMapper.apply(viewData);
        } else if (value != null) {
            s = toStringMapper.apply(value);
        }
        if (s != null) {
            sb.append(renderer.render(s));
        }
    }

    @Override
    protected void onEnterKeyDown(Context context, Element parent, T value, NativeEvent event,
            ValueUpdater<T> valueUpdater) {
        this.lastKey = context.getKey();
        this.lastParent = parent;
        this.lastValue = value;
        this.lastIndex = context.getIndex();
        this.lastColumn = context.getColumn();
        this.valueUpdater = valueUpdater;
        T viewData = getViewData(lastKey);
        suggestor.setValue(value);
        int tdWidth = parent.getParentElement().getOffsetWidth();
        panel.setPopupPositionAndShow(new PositionCallback() {
            public void setPosition(int offsetWidth, int offsetHeight) {
                panel.setWidth(tdWidth + "px");
                panel.setPopupPosition(lastParent.getAbsoluteLeft() + offsetX,
                        lastParent.getAbsoluteTop() + offsetY);
                suggestor.setFilterText(lastFilterText);
            }
        });
    }
}