dtedframecachelayer.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

    protected boolean firstProjectionWarningSent = false;

    /**
     * Prepares the graphics for the layer. This is where the
     * getRectangle() method call is made on the dted.
     * <p>
     * Occasionally it is necessary to abort a prepare call. When this
     * happens, the map will set the cancel bit in the LayerThread,
     * (the thread that is running the prepare). If this Layer needs
     * to do any cleanups during the abort, it should do so, but
     * return out of the prepare asap.
     *  
     */
    public synchronized OMGraphicList prepare() {

        if (isCancelled()) {
            Debug.message("dted", getName()
                    + "|DTEDFrameCacheLayer.prepare(): aborted.");
            return null;
        }

        if (cache == null) {
            Debug.message("dted",
                    getName()
                            + "|DTEDFrameCacheLayer can't add anything to map because the DTEDFrameCache has not been set.");
        }

        Projection projection = getProjection();

        if (projection == null) {
            Debug.output("DTED Layer needs to be added to the MapBean before it can draw images!");
            return new OMGraphicList();
        }

        // Check to make sure the projection is EqualArc
        if (!(projection instanceof EqualArc)) {
            if (!firstProjectionWarningSent) {
                fireRequestInfoLine("  DTED requires an Equal Arc projection (CADRG/LLXY) to view images.");
                Debug.output("DTEDFrameCacheLayer: DTED requires an Equal Arc projection (CADRG/LLXY) to view images.");
                firstProjectionWarningSent = true;
            }
            return new OMGraphicList();
        }

        Debug.message("basic", getName()
                + "|DTEDFrameCacheLayer.prepare(): doing it");

        // Setting the OMGraphicsList for this layer. Remember, the
        // OMGraphicList is made up of OMGraphics, which are generated
        // (projected) when the graphics are added to the list. So,
        // after this call, the list is ready for painting.

        // call getRectangle();
        if (Debug.debugging("dted")) {
            Debug.output(getName() + "|DTEDFrameCacheLayer.prepare(): "
                    + "calling getRectangle " + " with projection: "
                    + projection + " ul = " + projection.getUpperLeft()
                    + " lr = " + projection.getLowerRight());
        }

        OMGraphicList omGraphicList;

        if (projection.getScale() < maxScale) {
            omGraphicList = cache.getRectangle((EqualArc) projection);
        } else {
            fireRequestInfoLine("  The scale is too small for DTED viewing.");
            Debug.error("DTEDFrameCacheLayer: scale (1:" + projection.getScale()
                    + ") is smaller than minimum (1:" + maxScale + ") allowed.");
            omGraphicList = new OMGraphicList();
        }
        /////////////////////
        // safe quit
        int size = 0;
        if (omGraphicList != null) {
            size = omGraphicList.size();
            Debug.message("basic", getName()
                    + "|DTEDFrameCacheLayer.prepare(): finished with " + size
                    + " graphics");

            // Don't forget to project them. Since they are only
            // being recalled if the projection hase changed, then we
            // need to force a reprojection of all of them because the
            // screen position has changed.
            omGraphicList.project(projection, true);

        } else {
            Debug.message("basic",
                    getName()
                            + "|DTEDFrameCacheLayer.prepare(): finished with null graphics list");
        }

        return omGraphicList;
    }

    /**
     * Paints the layer.
     * 
     * @param g the Graphics context for painting
     */
    public void paint(java.awt.Graphics g) {
        super.paint(g);

        if (location != null)
            location.render(g);
        location = null;
    }

    /**
     * Get the value set for which DTED level is being used, 0-2.
     */
    public int getDtedLevel() {
        if (cache != null) {
            return cache.getDtedLevel();
        } else
            return LEVEL_0;
    }

    public void setDtedLevel(int level) {
        if (cache != null) {
            cache.setDtedLevel(level);
        }
    }

    /**
     * Get whether the cache will be killed when the layer is removed
     * from the map.
     */
    public boolean getKillCache() {
        return killCache;
    }

    public void setKillCache(boolean kc) {
        killCache = kc;
    }

    //----------------------------------------------------------------------
    // GUI
    //----------------------------------------------------------------------

    /** The user interface palette for the DTED layer. */
    protected Box palette = null;

    /** Creates the interface palette. */
    public Component getGUI() {

        if (palette == null) {
            if (Debug.debugging("dted"))
                Debug.output("DTEDFrameCacheLayer: creating DTED Palette.");

            palette = Box.createVerticalBox();
            Box subbox1 = Box.createHorizontalBox();
            Box subbox3 = Box.createHorizontalBox();

            // The DTED Level selector
            JPanel levelPanel = PaletteHelper.createPaletteJPanel("DTED Level");
            ButtonGroup levels = new ButtonGroup();

            ActionListener al = new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    if (cache != null) {
                        String ac = e.getActionCommand();
                        int newLevel;
                        if (ac.equalsIgnoreCase(level2Command))
                            newLevel = LEVEL_2;
                        else if (ac.equalsIgnoreCase(level1Command))
                            newLevel = LEVEL_1;
                        else
                            newLevel = LEVEL_0;
                        setDtedLevel(newLevel);
                    }
                }
            };

            JRadioButton level0 = new JRadioButton("Level 0");
            level0.addActionListener(al);
            level0.setActionCommand(level0Command);
            JRadioButton level1 = new JRadioButton("Level 1");
            level1.addActionListener(al);
            level1.setActionCommand(level1Command);
            JRadioButton level2 = new JRadioButton("Level 2");
            level2.addActionListener(al);
            level2.setActionCommand(level2Command);

            levels.add(level0);
            levels.add(level1);
            levels.add(level2);

            switch (getDtedLevel()) {
            case 2:
                level2.setSelected(true);
                break;
            case 1:
                level1.setSelected(true);
                break;
            case 0:
            default:
                level0.setSelected(true);
            }

            levelPanel.add(level0);
            levelPanel.add(level1);
            levelPanel.add(level2);

            // The DTED view selector from DTEDFrameCacheHandler
            JPanel viewPanel = PaletteHelper.createPaletteJPanel("View Type");
            viewPanel.add(cache.getGUI());

            JButton redraw = new JButton("Redraw DTED Layer");
            redraw.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent ae) {
                    doPrepare();
                }
            });

            subbox1.add(levelPanel);
            subbox1.add(viewPanel);
            palette.add(subbox1);
            subbox3.add(redraw);
            palette.add(subbox3);
        }

        return palette;
    }

    //----------------------------------------------------------------------
    // MapMouseListener interface implementation. This will be
    // replaced with a subclass of StandardMouseModeInterpreter that
    // only receives the map mouse click.
    //----------------------------------------------------------------------

    public synchronized MapMouseListener getMapMouseListener() {
        return this;
    }

    public String[] getMouseModeServiceList() {
        String[] services = { SelectMouseMode.modeID };
        return services;
    }

    public boolean mousePressed(MouseEvent e) {
        return false;
    }

    public boolean mouseReleased(MouseEvent e) {
        Projection projection = getProjection();
        LatLonPoint ll = projection.inverse(e.getX(), e.getY());
        location = new DTEDLocation(e.getX(), e.getY());
        location.setElevation(cache.getElevation(ll.getLatitude(),
                ll.getLongitude()));
        location.generate(projection);
        repaint();
        return true;
    }

    public boolean mouseClicked(MouseEvent e) {
        return false;
    }

    public void mouseEntered(MouseEvent e) {}

    public void mouseExited(MouseEvent e) {}

    public boolean mouseDragged(MouseEvent e) {
        return false;
    }

    public boolean mouseMoved(MouseEvent e) {
        return false;
    }

    public void mouseMoved() {}

}