Java Tutorial/SWT/Widget
Содержание
- 1 Add ControlListener to control
- 2 Compute Widget Size
- 3 Control: set a background image (a dynamic gradient)
- 4 Control Size and location
- 5 Get Preferred size
- 6 Get Widget Style
- 7 Inherit a background color or image
- 8 Relative position to Control
- 9 Relative position to Display
- 10 Set Bounds
- 11 Set Control Size
- 12 Set Location and Size
- 13 Setting Widget bounds
- 14 The Widget Class
- 15 Widget can be disposed: addDisposeListener(DisposeListener listener)
Add ControlListener to control
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.events.ControlEvent; import org.eclipse.swt.events.ControlListener; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.layout.RowLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.ruposite; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class ControlListenerAdd {
static int count = 0;
public static void main(String[] args) {
Display display = new Display();
final Shell shell = new Shell(display);
shell.setLayout(new RowLayout());
final Composite composite = new Composite(shell, SWT.BORDER);
composite.setLayout(new RowLayout());
composite.setBackground(display.getSystemColor(SWT.COLOR_YELLOW));
composite.addControlListener(new ControlListener() {
public void controlMoved(ControlEvent e) {
}
public void controlResized(ControlEvent e) {
System.out.println("Composite resize.");
}
});
Button buttonAdd = new Button(shell, SWT.PUSH);
buttonAdd.setText("Add new button");
buttonAdd.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
Button button = new Button(composite, SWT.PUSH);
button.setText("Button #" + (count++));
composite.layout(true);
composite.pack();
}
});
shell.setSize(450, 100);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}</source>
Compute Widget Size
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class WidgetSizeCompute {
public static void main(String[] args) {
final Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new GridLayout());
Button button = new Button(shell, SWT.PUSH | SWT.LEFT);
button.setText("Button");
System.out.println("Bounds: " + button.getBounds());
System.out.println("computeSize: " + button.ruputeSize(100, SWT.DEFAULT));
System.out.println("computeSize: " + button.ruputeSize(40, SWT.DEFAULT));
System.out.println("computeSize: " + button.ruputeSize(SWT.DEFAULT, 100));
System.out.println("computeSize: " + button.ruputeSize(SWT.DEFAULT, 20));
System.out.println("computeSize: " + button.ruputeSize(SWT.DEFAULT, 15));
System.out.println("computeSize: " + button.ruputeSize(100, 200));
System.out.println("computeSize: " + button.ruputeSize(SWT.DEFAULT, SWT.DEFAULT));
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Control: set a background image (a dynamic gradient)
<source lang="java">
/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/
/*
* Control example snippet: set a background image (a dynamic gradient) * * For a list of all SWT example snippets see * http://www.eclipse.org/swt/snippets/ * * @since 3.2 */
import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.GC; 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.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; public class BackgroundImageControl {
static Image oldImage;
public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setBackgroundMode(SWT.INHERIT_DEFAULT);
FillLayout layout1 = new FillLayout(SWT.VERTICAL);
layout1.marginWidth = layout1.marginHeight = 10;
shell.setLayout(layout1);
Group group = new Group(shell, SWT.NONE);
group.setText("Group ");
RowLayout layout2 = new RowLayout(SWT.VERTICAL);
layout2.marginWidth = layout2.marginHeight = layout2.spacing = 10;
group.setLayout(layout2);
for (int i = 0; i < 8; i++) {
Button button = new Button(group, SWT.RADIO);
button.setText("Button " + i);
}
shell.addListener(SWT.Resize, new Listener() {
public void handleEvent(Event event) {
Rectangle rect = shell.getClientArea();
Image newImage = new Image(display, Math.max(1, rect.width), 1);
GC gc = new GC(newImage);
gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
gc.setBackground(display.getSystemColor(SWT.COLOR_BLUE));
gc.fillGradientRectangle(rect.x, rect.y, rect.width, 1, false);
gc.dispose();
shell.setBackgroundImage(newImage);
if (oldImage != null)
oldImage.dispose();
oldImage = newImage;
}
});
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
if (oldImage != null)
oldImage.dispose();
display.dispose();
}
}</source>
Control Size and location
Control is the abstract superclass of all windowed user interface classes.
<source lang="java">
import org.eclipse.swt.SWT; 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 ControlSizeLocation {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
Button button = new Button(shell, SWT.PUSH);
shell.setSize(260, 120);
shell.open();
System.out.println("------------------------------");
System.out.println("getBounds: " + button.getBounds());
System.out.println("getLocation: " + button.getLocation());
System.out.println("getSize: " + button.getSize());
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Get Preferred size
(From SWT API) The preferred size of a control is the size that it would best be displayed at. The width hint and height hint arguments allow the caller to ask a control questions such as "Given a particular width, how high does the control need to be to show all of the contents?" To indicate that the caller does not wish to constrain a particular dimension, the constant SWT.DEFAULT is passed for the hint.
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class GetPreferredSize {
public static void main(String[] args) {
final Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new GridLayout());
Button button = new Button(shell, SWT.PUSH | SWT.LEFT);
button.setText("Button");
System.out.println("toControl: " + button.toControl(100, 200));
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Get Widget Style
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Shell; public class WidgetStyle {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
Label label = new Label(shell, SWT.SHADOW_IN | SWT.CENTER);
shell.setLayout(new GridLayout());
if ((label.getStyle() & SWT.CENTER) != 1) {
System.out.println("center");
} else {
System.out.println("not center");
}
shell.setSize(260, 120);
shell.open();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Inherit a background color or image
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.layout.RowLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Shell; public class BackgroundColorImageInherit {
public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setLayout(new RowLayout(SWT.VERTICAL));
Color color = display.getSystemColor(SWT.COLOR_CYAN);
Group group = new Group(shell, SWT.NONE);
group.setText("SWT.INHERIT_NONE");
group.setBackground(color);
group.setBackgroundMode(SWT.INHERIT_NONE);
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
}</source>
Relative position to Control
(From ST API) Returns a point which is the result of converting the argument, which is specified in display relative coordinates, to coordinates relative to the receiver.
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class ControlRelativePosition {
public static void main(String[] args) {
final Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new GridLayout());
Button button = new Button(shell, SWT.PUSH | SWT.LEFT);
button.setText("Button");
System.out.println("toControl: " + button.toControl(100, 200));
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Relative position to Display
Returns a point which is the result of converting the argument, which is specified in coordinates relative to the receiver, to display relative coordinates.
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class DisplayPositionRelative {
public static void main(String[] args) {
final Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new GridLayout());
Button button = new Button(shell, SWT.PUSH | SWT.LEFT);
button.setText("Button");
System.out.println("toDisplay: " + button.toDisplay(100, 200));
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Set Bounds
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class ControlBounds {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
Button button = new Button(shell, SWT.PUSH);
button.setBounds(20,20,200,20);
shell.setSize(260, 120);
shell.open();
System.out.println("------------------------------");
System.out.println("getBounds: " + button.getBounds());
System.out.println("getLocation: " + button.getLocation());
System.out.println("getSize: " + button.getSize());
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Set Control Size
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Cursor; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class ControlSizeSetting {
public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setSize(150, 150);
final Cursor[] cursor = new Cursor[1];
Button button = new Button(shell, SWT.PUSH);
button.setText("Change cursor");
Point size = button.ruputeSize(SWT.DEFAULT, SWT.DEFAULT);
button.setSize(size);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
if (cursor[0] != null)
cursor[0].dispose();
display.dispose();
}
}</source>
Set Location and Size
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class ControlLocationSize {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
Button button = new Button(shell, SWT.PUSH);
button.setLocation(new Point(20,20));
button.setSize(new Point(200,20));
shell.setSize(260, 120);
shell.open();
System.out.println("------------------------------");
System.out.println("getBounds: " + button.getBounds());
System.out.println("getLocation: " + button.getLocation());
System.out.println("getSize: " + button.getSize());
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
Setting Widget bounds
<source lang="java">
import org.eclipse.swt.SWT; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class WidgetBoundsSetting {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setBounds(10, 10, 200, 200);
Button button1 = new Button(shell, SWT.PUSH);
button1.setText("&Typical button");
button1.setBounds(10, 10, 180, 30);
Button button2 = new Button(shell, SWT.PUSH);
button2.setText("&Overidden button");
button2.setBounds(10, 50, 180, 30);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
}</source>
The Widget Class
- org.eclipse.widgets.Widget class is the top-level class of all the UI components in SWT/JFace.
- A Widget can be created and disposed of, and it is capable of issuing notifications to listeners when events occur.
- The Constructor: public Widget(Widget parent, int style)
- Almost all kinds of UI components in SWT/JFace have similar constructors as this one.
Widget can be disposed: addDisposeListener(DisposeListener listener)
<source lang="java">
import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class WidgetDisposeListener {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent e) {
System.out.println(e.widget + " disposed");
}
});
shell.setSize(260, 120);
shell.open();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}</source>
