source: josm/trunk/src/org/openstreetmap/josm/gui/download/AbstractDownloadSourcePanel.java@ 12654

// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.gui.download;

import java.util.Objects;

import javax.swing.Icon;
import javax.swing.JPanel;

import org.openstreetmap.josm.data.Bounds;

/**
 * GUI representation of {@link DownloadSource} that is shown to the user in
 * {@link DownloadDialog}.
 * @param <T> The type of the data that a download source uses.
 */
public abstract class AbstractDownloadSourcePanel<T> extends JPanel {

    public AbstractDownloadSourcePanel(final DownloadSource<T> downloadSource) {
        Objects.requireNonNull(downloadSource);
        this.downloadSource = downloadSource;
    }

    /**
     * The download source of this panel.
     */
    protected transient DownloadSource<T> downloadSource;

    /**
     * Gets the data.
     * @return Returns the data.
     */
    public abstract T getData();

    /**
     * Gets the download source of this panel.
     * @return Returns the download source of this panel.
     */
    public DownloadSource<T> getDownloadSource() {
        return this.downloadSource;
    }

    /**
     * Saves the current user preferences devoted to the data source.
     */
    public abstract void rememberSettings();

    /**
     * Restores the latest user preferences devoted to the data source.
     */
    public abstract void restoreSettings();

    /**
     * Performs the logic needed in case if the user triggered the download
     * action in {@link DownloadDialog}.
     * @return Returns {@code true} if the required procedure of handling the
     * download action succeeded and {@link DownloadDialog} can be closed, e.g. validation,
     * otherwise {@code false}.
     */
    public abstract boolean checkDownload(Bounds bbox, DownloadSettings settings);

    /**
     * Performs the logic needed in case if the user triggered the cancel
     * action in {@link DownloadDialog}.
     */
    public void checkCancel() {
        // nothing, let download dialog to close
        // override if necessary
    }

    /**
     * Gets the icon of the download source panel.
     * @return The icon. Can be {@code null} if there is no icon associated with
     * this download source.
     */
    public Icon getIcon() {
        return null;
    }

    /**
     * Updates GUI components of the panel according to the bbox changes.
     * @param bbox The new value for the bounding box.
     */
    public void boudingBoxChanged(Bounds bbox) {
        // override this if the panel must react on bbox changes
    }

    /**
     * Tells the {@link DownloadSource} to start downloading
     * @param currentBounds The bounds to download for
     * @param downloadSettings The remaining download settings
     */
    public void triggerDownload(Bounds currentBounds, DownloadSettings downloadSettings) {
        getDownloadSource().doDownload(currentBounds, getData(), downloadSettings);
    }
}