Java/SWT JFace Eclipse/Scroll

Create a ScrolledComposite with wrapping content

/*
 * Create a ScrolledComposite with wrapping content.
 *
 * For a list of all SWT example snippets see
 * http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.events.ControlAdapter;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.ruposite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
public class Snippet166 {
  public static void main(String[] args) {
    Display display = new Display();
    Image image1 = display.getSystemImage(SWT.ICON_WORKING);
    Image image2 = display.getSystemImage(SWT.ICON_QUESTION);
    Image image3 = display.getSystemImage(SWT.ICON_ERROR);
    Shell shell = new Shell(display);
    shell.setLayout(new FillLayout());
    final ScrolledComposite scrollComposite = new ScrolledComposite(shell,
        SWT.V_SCROLL | SWT.BORDER);
    final Composite parent = new Composite(scrollComposite, SWT.NONE);
    for (int i = 0; i <= 50; i++) {
      Label label = new Label(parent, SWT.NONE);
      if (i % 3 == 0)
        label.setImage(image1);
      if (i % 3 == 1)
        label.setImage(image2);
      if (i % 3 == 2)
        label.setImage(image3);
    }
    RowLayout layout = new RowLayout(SWT.HORIZONTAL);
    layout.wrap = true;
    parent.setLayout(layout);
    scrollComposite.setContent(parent);
    scrollComposite.setExpandVertical(true);
    scrollComposite.setExpandHorizontal(true);
    scrollComposite.addControlListener(new ControlAdapter() {
      public void controlResized(ControlEvent e) {
        Rectangle r = scrollComposite.getClientArea();
        scrollComposite.setMinSize(parent.ruputeSize(r.width,
            SWT.DEFAULT));
      }
    });
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    display.dispose();
  }
}

Create two ScrolledComposites that scroll in tandem

/*
 * Create two ScrolledComposites that scroll in tandem.
 *
 * For a list of all SWT example snippets see
 * http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Shell;
public class Snippet167 {
  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setLayout(new FillLayout());
    final ScrolledComposite sc1 = new ScrolledComposite(shell, SWT.BORDER
        | SWT.H_SCROLL | SWT.V_SCROLL);
    Button button1 = new Button(sc1, SWT.PUSH);
    button1.setText("Button 1");
    button1.setSize(400, 300);
    sc1.setContent(button1);
    final ScrolledComposite sc2 = new ScrolledComposite(shell, SWT.BORDER
        | SWT.H_SCROLL | SWT.V_SCROLL);
    Button button2 = new Button(sc2, SWT.PUSH);
    button2.setText("Button 2");
    button2.setSize(300, 400);
    sc2.setContent(button2);
    final ScrollBar vBar1 = sc1.getVerticalBar();
    final ScrollBar vBar2 = sc2.getVerticalBar();
    final ScrollBar hBar1 = sc1.getHorizontalBar();
    final ScrollBar hBar2 = sc2.getHorizontalBar();
    SelectionListener listener1 = new SelectionAdapter() {
      public void widgetSelected(SelectionEvent e) {
        int x = hBar1.getSelection()
            * (hBar2.getMaximum() - hBar2.getThumb())
            / Math.max(1, hBar1.getMaximum() - hBar1.getThumb());
        int y = vBar1.getSelection()
            * (vBar2.getMaximum() - vBar2.getThumb())
            / Math.max(1, vBar1.getMaximum() - vBar1.getThumb());
        sc2.setOrigin(x, y);
      }
    };
    SelectionListener listener2 = new SelectionAdapter() {
      public void widgetSelected(SelectionEvent e) {
        int x = hBar2.getSelection()
            * (hBar1.getMaximum() - hBar1.getThumb())
            / Math.max(1, hBar2.getMaximum() - hBar2.getThumb());
        int y = vBar2.getSelection()
            * (vBar1.getMaximum() - vBar1.getThumb())
            / Math.max(1, vBar2.getMaximum() - vBar2.getThumb());
        sc1.setOrigin(x, y);
      }
    };
    vBar1.addSelectionListener(listener1);
    hBar1.addSelectionListener(listener1);
    vBar2.addSelectionListener(listener2);
    hBar2.addSelectionListener(listener2);
    shell.setSize(400, 300);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}

Demonstrates ScrolledComposite

//Send questions, comments, bug reports, etc. to the authors:
//Rob Warner (rwarner@interspatial.ru)
//Robert Harris (rbrt_harris@yahoo.ru)
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
/**
 * This class demonstrates ScrolledComposite
 */
public class ScrolledCompositeTest {
  public void run() {
    Display display = new Display();
    Shell shell = new Shell(display);
    createContents(shell);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    display.dispose();
  }
  private void createContents(Composite parent) {
    parent.setLayout(new FillLayout());
    // Create the ScrolledComposite to scroll horizontally and vertically
    ScrolledComposite sc = new ScrolledComposite(parent, SWT.H_SCROLL
        | SWT.V_SCROLL);
    // Create a child composite to hold the controls
    Composite child = new Composite(sc, SWT.NONE);
    child.setLayout(new FillLayout());
    // Create the buttons
    new Button(child, SWT.PUSH).setText("One");
    new Button(child, SWT.PUSH).setText("Two");
    /*
     * // Set the absolute size of the child child.setSize(400, 400);
     */
    // Set the child as the scrolled content of the ScrolledComposite
    sc.setContent(child);
    // Set the minimum size
    sc.setMinSize(400, 400);
    // Expand both horizontally and vertically
    sc.setExpandHorizontal(true);
    sc.setExpandVertical(true);
  }
  public static void main(String[] args) {
    new ScrolledCompositeTest().run();
  }
}

Scroll a child control automatically

/*
 * Composite example snippet: scroll a child control automatically
 *
 * For a list of all SWT example snippets see
 * http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.ruposite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Shell;
public class Snippet9 {
  public static void main(String[] args) {
    Display display = new Display();
    final Shell shell = new Shell(display, SWT.SHELL_TRIM | SWT.H_SCROLL
        | SWT.V_SCROLL);
    final Composite composite = new Composite(shell, SWT.BORDER);
    composite.setSize(200, 400);
    final ScrollBar hBar = shell.getHorizontalBar();
    hBar.addListener(SWT.Selection, new Listener() {
      public void handleEvent(Event e) {
        Point location = composite.getLocation();
        location.x = -hBar.getSelection();
        composite.setLocation(location);
      }
    });
    final ScrollBar vBar = shell.getVerticalBar();
    vBar.addListener(SWT.Selection, new Listener() {
      public void handleEvent(Event e) {
        Point location = composite.getLocation();
        location.y = -vBar.getSelection();
        composite.setLocation(location);
      }
    });
    shell.addListener(SWT.Resize, new Listener() {
      public void handleEvent(Event e) {
        Point size = composite.getSize();
        Rectangle rect = shell.getClientArea();
        hBar.setMaximum(size.x);
        vBar.setMaximum(size.y);
        hBar.setThumb(Math.min(size.x, rect.width));
        vBar.setThumb(Math.min(size.y, rect.height));
        int hPage = size.x - rect.width;
        int vPage = size.y - rect.height;
        int hSelection = hBar.getSelection();
        int vSelection = vBar.getSelection();
        Point location = composite.getLocation();
        if (hSelection >= hPage) {
          if (hPage <= 0)
            hSelection = 0;
          location.x = -hSelection;
        }
        if (vSelection >= vPage) {
          if (vPage <= 0)
            vSelection = 0;
          location.y = -vSelection;
        }
        composite.setLocation(location);
      }
    });
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}

Scroll a control in a scrolled composite

/*
 * ScrolledComposite example snippet: scroll a control in a scrolled composite
 *
 * For a list of all SWT example snippets see
 * http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class Snippet5 {
  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setLayout(new FillLayout());
    // this button is always 400 x 400. Scrollbars appear if the window is
    // resized to be
    // too small to show part of the button
    ScrolledComposite c1 = new ScrolledComposite(shell, SWT.BORDER
        | SWT.H_SCROLL | SWT.V_SCROLL);
    Button b1 = new Button(c1, SWT.PUSH);
    b1.setText("fixed size button");
    b1.setSize(400, 400);
    c1.setContent(b1);
    // this button has a minimum size of 400 x 400. If the window is resized
    // to be big
    // enough to show more than 400 x 400, the button will grow in size. If
    // the window
    // is made too small to show 400 x 400, scrollbars will appear.
    ScrolledComposite c2 = new ScrolledComposite(shell, SWT.BORDER
        | SWT.H_SCROLL | SWT.V_SCROLL);
    Button b2 = new Button(c2, SWT.PUSH);
    b2.setText("expanding button");
    c2.setContent(b2);
    c2.setExpandHorizontal(true);
    c2.setExpandVertical(true);
    c2.setMinWidth(400);
    c2.setMinHeight(400);
    shell.setSize(600, 300);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}

scroll an image (flicker free, no double buffering)

/*
 * Canvas example snippet: scroll an image (flicker free, no double buffering)
 *
 * For a list of all SWT example snippets see
 * http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Shell;
public class Snippet48 {
  public static void main(String[] args) {
    Display display = new Display();
    final Shell shell = new Shell(display, SWT.SHELL_TRIM
        | SWT.NO_BACKGROUND | SWT.NO_REDRAW_RESIZE | SWT.V_SCROLL
        | SWT.H_SCROLL);
    Image originalImage = null;
    FileDialog dialog = new FileDialog(shell, SWT.OPEN);
    dialog.setText("Open an image file or cancel");
    String string = dialog.open();
    if (string != null) {
      originalImage = new Image(display, string);
    }
    if (originalImage == null) {
      int width = 150, height = 200;
      originalImage = new Image(display, width, height);
      GC gc = new GC(originalImage);
      gc.fillRectangle(0, 0, width, height);
      gc.drawLine(0, 0, width, height);
      gc.drawLine(0, height, width, 0);
      gc.drawText("Default Image", 10, 10);
      gc.dispose();
    }
    final Image image = originalImage;
    final Point origin = new Point(0, 0);
    final ScrollBar hBar = shell.getHorizontalBar();
    hBar.addListener(SWT.Selection, new Listener() {
      public void handleEvent(Event e) {
        int hSelection = hBar.getSelection();
        int destX = -hSelection - origin.x;
        Rectangle rect = image.getBounds();
        shell.scroll(destX, 0, 0, 0, rect.width, rect.height, false);
        origin.x = -hSelection;
      }
    });
    final ScrollBar vBar = shell.getVerticalBar();
    vBar.addListener(SWT.Selection, new Listener() {
      public void handleEvent(Event e) {
        int vSelection = vBar.getSelection();
        int destY = -vSelection - origin.y;
        Rectangle rect = image.getBounds();
        shell.scroll(0, destY, 0, 0, rect.width, rect.height, false);
        origin.y = -vSelection;
      }
    });
    shell.addListener(SWT.Resize, new Listener() {
      public void handleEvent(Event e) {
        Rectangle rect = image.getBounds();
        Rectangle client = shell.getClientArea();
        hBar.setMaximum(rect.width);
        vBar.setMaximum(rect.height);
        hBar.setThumb(Math.min(rect.width, client.width));
        vBar.setThumb(Math.min(rect.height, client.height));
        int hPage = rect.width - client.width;
        int vPage = rect.height - client.height;
        int hSelection = hBar.getSelection();
        int vSelection = vBar.getSelection();
        if (hSelection >= hPage) {
          if (hPage <= 0)
            hSelection = 0;
          origin.x = -hSelection;
        }
        if (vSelection >= vPage) {
          if (vPage <= 0)
            vSelection = 0;
          origin.y = -vSelection;
        }
        shell.redraw();
      }
    });
    shell.addListener(SWT.Paint, new Listener() {
      public void handleEvent(Event e) {
        GC gc = e.gc;
        gc.drawImage(image, origin.x, origin.y);
        Rectangle rect = image.getBounds();
        Rectangle client = shell.getClientArea();
        int marginWidth = client.width - rect.width;
        if (marginWidth > 0) {
          gc.fillRectangle(rect.width, 0, marginWidth, client.height);
        }
        int marginHeight = client.height - rect.height;
        if (marginHeight > 0) {
          gc
              .fillRectangle(0, rect.height, client.width,
                  marginHeight);
        }
      }
    });
    shell.setSize(200, 150);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}

Scroll SWT widgets into view when they get focus

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.ruposite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
/*
 * Scroll widgets into view when they get focus
 * 
 * For a list of all SWT example snippets see
 * http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
 */
public class Snippet188 {
  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setLayout(new GridLayout());
    Button b1 = new Button(shell, SWT.PUSH);
    b1.setText("top");
    b1
        .setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false,
            1, 1));
    final ScrolledComposite sc = new ScrolledComposite(shell, SWT.BORDER
        | SWT.H_SCROLL | SWT.V_SCROLL);
    sc.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));
    Composite c = new Composite(sc, SWT.NONE);
    c.setLayout(new GridLayout(10, true));
    for (int i = 0; i < 300; i++) {
      Button b = new Button(c, SWT.PUSH);
      b.setText("Button " + i);
    }
    Button b2 = new Button(shell, SWT.PUSH);
    b2.setText("bottom");
    b2
        .setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false,
            1, 1));
    sc.setContent(c);
    sc.setExpandHorizontal(true);
    sc.setExpandVertical(true);
    sc.setMinSize(c.ruputeSize(SWT.DEFAULT, SWT.DEFAULT));
    Listener listener = new Listener() {
      public void handleEvent(Event e) {
        Control child = (Control) e.widget;
        Rectangle bounds = child.getBounds();
        Rectangle area = sc.getClientArea();
        Point origin = sc.getOrigin();
        if (origin.x > bounds.x)
          origin.x = Math.max(0, bounds.x);
        if (origin.y > bounds.y)
          origin.y = Math.max(0, bounds.y);
        if (origin.x + area.width < bounds.x + bounds.width)
          origin.x = Math
              .max(0, bounds.x + bounds.width - area.width);
        if (origin.y + area.height < bounds.y + bounds.height)
          origin.y = Math.max(0, bounds.y + bounds.height
              - area.height);
        sc.setOrigin(origin);
      }
    };
    Control[] controls = c.getChildren();
    for (int i = 0; i < controls.length; i++) {
      controls[i].addListener(SWT.Activate, listener);
    }
    shell.setSize(300, 500);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}