net.sf.mmm.client.ui.gwt.widgets.richtext.AbstractSelectionFeatureBehavior.java Source code

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Here is the source code for net.sf.mmm.client.ui.gwt.widgets.richtext.AbstractSelectionFeatureBehavior.java

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/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
 * http://www.apache.org/licenses/LICENSE-2.0 */
package net.sf.mmm.client.ui.gwt.widgets.richtext;

import java.util.List;

import net.sf.mmm.client.ui.gwt.widgets.ComboBox;
import net.sf.mmm.client.ui.gwt.widgets.DataList;
import net.sf.mmm.client.ui.gwt.widgets.LabelWidget;

import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * A variant of {@link AbstractClickFeatureBehavior} for a selection {@link #getFeature() feature} that is
 * offered as a combobox.
 * 
 * @author Joerg Hohwiller (hohwille at users.sourceforge.net)
 * @since 1.0.0
 */
abstract class AbstractSelectionFeatureBehavior extends AbstractClickFeatureBehavior {

    /** @see #getFontSettingsLabel() */
    private LabelWidget fontSettingsLabel;

    /** @see #getFontSettingsWidget() */
    private FlowPanel fontSettingsWidget;

    /** @see #getFontSettingsWidget() */
    private ComboBox combobox;

    /** The {@link DataList} with the options. */
    private DataList dataList;

    /**
     * The constructor.
     * 
     * @param richTextToolbar is the {@link RichTextToolbar} owning this {@link FeatureBehavior}.
     */
    public AbstractSelectionFeatureBehavior(RichTextToolbar richTextToolbar) {

        super(richTextToolbar);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public abstract void applyFontSettings();

    /**
     * @return the {@link List} of available options for the {@link #getDataList() datalist}.
     */
    protected abstract List<String> createOptions();

    /**
     * {@inheritDoc}
     */
    @Override
    public Widget getFontSettingsWidget() {

        if (this.fontSettingsWidget == null) {
            this.fontSettingsWidget = new FlowPanel();
            this.fontSettingsWidget.add(getCombobox());
            this.fontSettingsWidget.add(getDataList());
            if (!isVisible()) {
                this.fontSettingsWidget.setVisible(false);
            }
        }
        return this.fontSettingsWidget;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected boolean hasFontSettingsWidget() {

        return (this.fontSettingsWidget != null);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public LabelWidget getFontSettingsLabel() {

        if (this.fontSettingsLabel == null) {
            this.fontSettingsLabel = createFontSettingsLabel();
        }
        return this.fontSettingsLabel;
    }

    /**
     * @return the {@link DataList} for the {@link #getFontSettingsWidget() popup widget} combo.
     */
    protected DataList getDataList() {

        if (this.dataList == null) {
            this.dataList = new DataList();
            this.dataList.setId(createId("_LIST"));
            this.dataList.setOptions(createOptions());
        }
        return this.dataList;
    }

    /**
     * @return the {@link ComboBox} with the selection of the feature value from the {@link #createOptions()
     *         options}.
     */
    protected ComboBox getCombobox() {

        if (this.combobox == null) {
            this.combobox = new ComboBox();
            this.combobox.setId(createId("_COMBO"));
            this.combobox.setDataList(getDataList());
        }
        return this.combobox;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setFontSettingsPreviewElement(final Element element) {

        super.setFontSettingsPreviewElement(element);
        ValueChangeHandler<String> handler = new ValueChangeHandler<String>() {

            /**
             * {@inheritDoc}
             */
            @Override
            public void onValueChange(ValueChangeEvent<String> event) {

                String value = event.getValue();
                if (value != null) {
                    Style style = element.getStyle();
                    applyFontSettings(value, style);
                }
            }
        };
        getCombobox().addValueChangeHandler(handler);
    }

    /**
     * @param style the {@link Style} to modify.
     */
    public void applyFontSettings(Style style) {

        applyFontSettings(getCombobox().getValue(), style);
    }

    /**
     * @param value the value to set (e.g. font family).
     * @param style the {@link Style} to modify.
     */
    protected abstract void applyFontSettings(String value, Style style);

    /**
     * {@inheritDoc}
     */
    @Override
    public void updateFontSettings() {

        super.updateFontSettings();
        String value = getValue();
        getCombobox().setValue(value, true);
    }

    /**
     * @return the current value of the font setting in the rich text area.
     */
    protected abstract String getValue();

}