Example usage for java.awt Canvas getGraphics

Introduction

In this page you can find the example usage for java.awt Canvas getGraphics.

Prototype

public Graphics getGraphics() 

Source Link

Document

Creates a graphics context for this component.

Usage

From source file:SWT2D.java

private void run() {
    // Create top level shell
    final Display display = new Display();
    final Shell shell = new Shell(display);
    shell.setText("Java 2D Example");
    // GridLayout for canvas and button
    shell.setLayout(new GridLayout());
    // Create container for AWT canvas
    final Composite canvasComp = new Composite(shell, SWT.EMBEDDED);
    // Set preferred size
    GridData data = new GridData();
    data.widthHint = 600;/*w w  w .  j  a  v  a2s. c o m*/
    data.heightHint = 500;
    canvasComp.setLayoutData(data);
    // Create AWT Frame for Canvas
    java.awt.Frame canvasFrame = SWT_AWT.new_Frame(canvasComp);
    // Create Canvas and add it to the Frame
    final java.awt.Canvas canvas = new java.awt.Canvas();
    canvasFrame.add(canvas);
    // Get graphical context and cast to Java2D
    final java.awt.Graphics2D g2d = (java.awt.Graphics2D) canvas.getGraphics();
    // Enable antialiasing
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    // Remember initial transform
    final java.awt.geom.AffineTransform origTransform = g2d.getTransform();
    // Create Clear button and position it
    Button clearButton = new Button(shell, SWT.PUSH);
    clearButton.setText("Clear");
    data = new GridData();
    data.horizontalAlignment = GridData.CENTER;
    clearButton.setLayoutData(data);
    // Event processing for Clear button
    clearButton.addSelectionListener(new SelectionAdapter() {
        public void widgetSelected(SelectionEvent e) {
            // Delete word list and redraw canvas
            wordList.clear();
            canvasComp.redraw();
        }
    });
    // Process canvas mouse clicks
    canvas.addMouseListener(new java.awt.event.MouseListener() {
        public void mouseClicked(java.awt.event.MouseEvent e) {
        }

        public void mouseEntered(java.awt.event.MouseEvent e) {
        }

        public void mouseExited(java.awt.event.MouseEvent e) {
        }

        public void mousePressed(java.awt.event.MouseEvent e) {
            // Manage pop-up editor
            display.syncExec(new Runnable() {
                public void run() {
                    if (eShell == null) {
                        // Create new Shell: non-modal!
                        eShell = new Shell(shell, SWT.NO_TRIM | SWT.MODELESS);
                        eShell.setLayout(new FillLayout());
                        // Text input field
                        eText = new Text(eShell, SWT.BORDER);
                        eText.setText("Text rotation in the SWT?");
                        eShell.pack();
                        // Set position (Display coordinates)
                        java.awt.Rectangle bounds = canvas.getBounds();
                        org.eclipse.swt.graphics.Point pos = canvasComp.toDisplay(bounds.width / 2,
                                bounds.height / 2);
                        Point size = eShell.getSize();
                        eShell.setBounds(pos.x, pos.y, size.x, size.y);
                        // Open Shell
                        eShell.open();
                    } else if (!eShell.isVisible()) {
                        // Editor versteckt, sichtbar machen
                        eShell.setVisible(true);
                    } else {
                        // Editor is visible - get text
                        String t = eText.getText();
                        // set editor invisible
                        eShell.setVisible(false);
                        // Add text to list and redraw canvas
                        wordList.add(t);
                        canvasComp.redraw();
                    }
                }
            });
        }

        public void mouseReleased(java.awt.event.MouseEvent e) {
        }
    });
    // Redraw the canvas
    canvasComp.addPaintListener(new PaintListener() {
        public void paintControl(PaintEvent e) {
            // Pass the redraw task to AWT event queue
            java.awt.EventQueue.invokeLater(new Runnable() {
                public void run() {
                    // Compute canvas center
                    java.awt.Rectangle bounds = canvas.getBounds();
                    int originX = bounds.width / 2;
                    int originY = bounds.height / 2;
                    // Reset canvas
                    g2d.setTransform(origTransform);
                    g2d.setColor(java.awt.Color.WHITE);
                    g2d.fillRect(0, 0, bounds.width, bounds.height);
                    // Set font
                    g2d.setFont(new java.awt.Font("Myriad", java.awt.Font.PLAIN, 32));
                    double angle = 0d;
                    // Prepare star shape
                    double increment = Math.toRadians(30);
                    Iterator iter = wordList.iterator();
                    while (iter.hasNext()) {
                        // Determine text colors in RGB color cycle
                        float red = (float) (0.5 + 0.5 * Math.sin(angle));
                        float green = (float) (0.5 + 0.5 * Math.sin(angle + Math.toRadians(120)));
                        float blue = (float) (0.5 + 0.5 * Math.sin(angle + Math.toRadians(240)));
                        g2d.setColor(new java.awt.Color(red, green, blue));
                        // Redraw text
                        String text = (String) iter.next();
                        g2d.drawString(text, originX + 50, originY);
                        // Rotate for next text output
                        g2d.rotate(increment, originX, originY);
                        angle += increment;
                    }
                }
            });
        }
    });
    // Finish shell and open it
    shell.pack();
    shell.open();
    // SWT event processing
    while (!shell.isDisposed()) {
        if (!display.readAndDispatch())
            display.sleep();
    }
    display.dispose();
}

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