001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions.mapmode;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.awt.Rectangle;
007import java.awt.event.KeyEvent;
008import java.awt.event.MouseEvent;
009
010import org.openstreetmap.josm.Main;
011import org.openstreetmap.josm.gui.MapFrame;
012import org.openstreetmap.josm.gui.MapView;
013import org.openstreetmap.josm.gui.SelectionManager;
014import org.openstreetmap.josm.gui.SelectionManager.SelectionEnded;
015import org.openstreetmap.josm.tools.ImageProvider;
016import org.openstreetmap.josm.tools.Shortcut;
017
018/**
019 * Enable the zoom mode within the MapFrame.
020 *
021 * Holding down the left mouse button select a rectangle with the same aspect
022 * ratio than the current map view.
023 * Holding down left and right let the user move the former selected rectangle.
024 * Releasing the left button zoom to the selection.
025 *
026 * Rectangle selections with either height or width smaller than 3 pixels
027 * are ignored.
028 *
029 * @author imi
030 */
031public class ZoomAction extends MapMode implements SelectionEnded {
032
033    /**
034     * Manager that manages the selection rectangle with the aspect ratio of the MapView.
035     */
036    private final transient SelectionManager selectionManager;
037
038    /**
039     * Construct a ZoomAction without a label.
040     * @param mapFrame The MapFrame, whose zoom mode should be enabled.
041     */
042    public ZoomAction(MapFrame mapFrame) {
043        super(tr("Zoom"), "zoom", tr("Zoom and move map"),
044                Shortcut.registerShortcut("mapmode:zoom", tr("Mode: {0}", tr("Zoom")), KeyEvent.VK_Z, Shortcut.DIRECT),
045                mapFrame, ImageProvider.getCursor("normal", "zoom"));
046        selectionManager = new SelectionManager(this, true, mapFrame.mapView);
047    }
048
049    /**
050     * Zoom to the rectangle on the map.
051     */
052    @Override
053    public void selectionEnded(Rectangle r, MouseEvent e) {
054        if (r.width >= 3 && r.height >= 3 && Main.isDisplayingMapView()) {
055            MapView mv = Main.map.mapView;
056            mv.zoomToFactor(mv.getEastNorth(r.x+r.width/2, r.y+r.height/2), r.getWidth()/mv.getWidth());
057        }
058    }
059
060    @Override public void enterMode() {
061        super.enterMode();
062        selectionManager.register(Main.map.mapView, false);
063    }
064
065    @Override public void exitMode() {
066        super.exitMode();
067        selectionManager.unregister(Main.map.mapView);
068    }
069
070    @Override public String getModeHelpText() {
071        return tr("Zoom by dragging or Ctrl+. or Ctrl+,; move with Ctrl+up, left, down, right; move zoom with right button");
072    }
073}