drawapplet.java

来自「开源（Open Source）项目JHotDraw的文档和源程序」· Java 代码 · 共 550 行 · 第 1/2 页

     * Creates the selection tool used in this editor. Override to use
     * a custom selection tool.
     */
    protected Tool createSelectionTool() {
        return new SelectionTool(view());
    }

    /**
     * Creates a tool button with the given image, tool, and text
     */
    protected ToolButton createToolButton(String iconName, String toolName, Tool tool) {
        return new ToolButton(this, iconName, toolName, tool);
    }

    /**
     * Creates the drawing used in this application.
     * You need to override this method to use a Drawing
     * subclass in your application. By default a standard
     * Drawing is returned.
     */
    protected Drawing createDrawing() {
        return new StandardDrawing();
    }

    /**
     * Creates the drawing view used in this application.
     * You need to override this method to use a DrawingView
     * subclass in your application. By default a standard
     * DrawingView is returned.
     */
    protected StandardDrawingView createDrawingView() {
        return new StandardDrawingView(this, 410, 370);
    }

    /**
     * Handles a user selection in the palette.
     * @see PaletteListener
     */
    public void paletteUserSelected(PaletteButton button) {
        ToolButton toolButton = (ToolButton) button;
        setTool(toolButton.tool(), toolButton.name());
        setSelected(toolButton);
    }

    /**
     * Handles when the mouse enters or leaves a palette button.
     * @see PaletteListener
     */
    public void paletteUserOver(PaletteButton button, boolean inside) {
        if (inside)
            showStatus(((ToolButton) button).name());
        else
            showStatus(fSelectedToolButton.name());
    }

    /**
     * Gets the current drawing.
     * @see DrawingEditor
     */
    public Drawing drawing() {
        return fDrawing;
    }

    /**
     * Gets the current tool.
     * @see DrawingEditor
     */
    public Tool tool() {
        return fTool;
    }

    /**
     * Gets the current drawing view.
     * @see DrawingEditor
     */
    public DrawingView view() {
        return fView;
    }

    /**
     * Sets the default tool of the editor.
     * @see DrawingEditor
     */
    public void toolDone() {
        setTool(fDefaultToolButton.tool(), fDefaultToolButton.name());
        setSelected(fDefaultToolButton);
    }

    /**
     * Handles a change of the current selection. Updates all
     * menu items that are selection sensitive.
     * @see DrawingEditor
     */
    public void selectionChanged(DrawingView view) {
        setupAttributes();
    }

    private void initDrawing() {
        fDrawing = createDrawing();
        fView.setDrawing(fDrawing);
        toolDone();
    }

    private void setTool(Tool t, String name) {
        if (fTool != null)
            fTool.deactivate();
        fTool = t;
        if (fTool != null) {
            showStatus(name);
            fTool.activate();
        }
    }

    private void setSelected(ToolButton button) {
        if (fSelectedToolButton != null)
            fSelectedToolButton.reset();
        fSelectedToolButton = button;
        if (fSelectedToolButton != null)
            fSelectedToolButton.select();
    }

    protected void loadDrawing(String param) {
        if (param == fgUntitled) {
            fDrawing.release();
            initDrawing();
            return;
        }

        String filename = getParameter(param);
        if (filename != null)
            readDrawing(filename);
    }

    private void readDrawing(String filename) {
        toolDone();
        String type = guessType(filename);
        if (type.equals("storable"))
            readFromStorableInput(filename);
        else if (type.equals("serialized"))
            readFromObjectInput(filename);
        else
            showStatus("Unknown file type");
    }

    private void readFromStorableInput(String filename) {
        try {
            URL url = new URL(getCodeBase(), filename);
            InputStream stream = url.openStream();
            StorableInput input = new StorableInput(stream);
            fDrawing.release();

            fDrawing = (Drawing)input.readStorable();
            fView.setDrawing(fDrawing);
        } catch (IOException e) {
            initDrawing();
            showStatus("Error:"+e);
        }
    }

    private void readFromObjectInput(String filename) {
        try {
            URL url = new URL(getCodeBase(), filename);
            InputStream stream = url.openStream();
            ObjectInput input = new ObjectInputStream(stream);
            fDrawing.release();
            fDrawing = (Drawing)input.readObject();
            fView.setDrawing(fDrawing);
        } catch (IOException e) {
            initDrawing();
            showStatus("Error: " + e);
        } catch (ClassNotFoundException e) {
            initDrawing();
            showStatus("Class not found: " + e);
        }
    }

    private String guessType(String file) {
        if (file.endsWith(".draw"))
            return "storable";
        if (file.endsWith(".ser"))
            return "serialized";
        return "unknown";
    }

    private void setupAttributes() {
        Color   frameColor = (Color)   AttributeFigure.getDefaultAttribute("FrameColor");
        Color   fillColor  = (Color)   AttributeFigure.getDefaultAttribute("FillColor");
        Color   textColor  = (Color)   AttributeFigure.getDefaultAttribute("TextColor");
        Integer arrowMode  = (Integer) AttributeFigure.getDefaultAttribute("ArrowMode");
        String  fontName   = (String)  AttributeFigure.getDefaultAttribute("FontName");

        FigureEnumeration k = fView.selectionElements();
        while (k.hasMoreElements()) {
            Figure f = k.nextFigure();
            frameColor = (Color) f.getAttribute("FrameColor");
            fillColor  = (Color) f.getAttribute("FillColor");
            textColor  = (Color) f.getAttribute("TextColor");
            arrowMode  = (Integer) f.getAttribute("ArrowMode");
            fontName   = (String) f.getAttribute("FontName");
        }

        fFrameColor.setSelectedIndex(ColorMap.colorIndex(frameColor));
        fFillColor.setSelectedIndex(ColorMap.colorIndex(fillColor));
        //fTextColor.select(ColorMap.colorIndex(textColor));
        if (arrowMode != null)
            fArrowChoice.setSelectedIndex(arrowMode.intValue());
        if (fontName != null)
            fFontChoice.setSelectedItem(fontName);
    }

    protected void setSimpleDisplayUpdate() {
        fView.setDisplayUpdate(new SimpleUpdateStrategy());
        fUpdateButton.setText("Simple Update");
        fSimpleUpdate = true;
    }

    protected void setBufferedDisplayUpdate() {
        fView.setDisplayUpdate(new BufferedUpdateStrategy());
        fUpdateButton.setText("Buffered Update");
        fSimpleUpdate = false;
    }

    /**
     * Shows a help page for the applet. The URL of the help
     * page is derived as follows: codeBase+appletClassname+Help.html"
     */
    protected void showHelp() {
        try {
            String appletPath = getClass().getName().replace('.', '/');
            URL url = new URL(getCodeBase(), appletPath+"Help.html");
            getAppletContext().showDocument(url, "Help");
        } catch (IOException e) {
            showStatus("Help file not found");
        }

    }

    /**
     * *** netscape browser work around ***
     */
    private void startSleeper() {
        if (fSleeper == null)
            fSleeper = new SleeperThread(this);
        fSleeper.start();
    }

    private void stopSleeper() {
        if (fSleeper != null)
            fSleeper.stop();
    }
}


class SleeperThread extends Thread {

    JApplet  fApplet;

    SleeperThread(JApplet applet) {
        fApplet = applet;
    }

    public void run() {
        try {
            for (;;) {
                fApplet.showStatus("loading icons...");
                sleep(50);
            }
        } catch (InterruptedException e) {
            return;
        }
    }

}