org.eclipse.swt.widgets
Class Canvas

java.lang.Object
  |
  +--org.eclipse.swt.widgets.Widget
        |
        +--org.eclipse.swt.widgets.Control
              |
              +--org.eclipse.swt.widgets.Scrollable
                    |
                    +--org.eclipse.swt.widgets.Composite
                          |
                          +--org.eclipse.swt.widgets.Canvas

All Implemented Interfaces:

Drawable, Runnable

Direct Known Subclasses:

Decorations

public class Canvas

extends Composite

Instances of this class provide a surface for drawing arbitrary graphics.

Styles:

(none)

Events:

(none)

This class may be subclassed by custom control implementors who are building controls that are not constructed from aggregates of other controls. That is, they are either painted using SWT graphics calls or are handled by native methods.

See Also:

Composite

Field Summary

Fields inherited from class org.eclipse.swt.widgets.Widget

h, INCMD_DISPOSE, INCMD_EXTKEY, INCMD_KEY, INCMD_LDOWN, INCMD_LUP, INCMD_MENU, INCMD_POS, UPDATEITEM_ENABLED, UPDATEITEM_NAME, w, x, y

Constructor Summary

Canvas(Composite parent, int style)
Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

Methods inherited from class org.eclipse.swt.widgets.Composite

getChildren, pack, setLayout

Methods inherited from class org.eclipse.swt.widgets.Scrollable

getClientArea

Methods inherited from class org.eclipse.swt.widgets.Control

computeSize, computeSize, getLayoutData, isFocusControl, pack, setBackground, setBounds, setFocus, setLayoutData, setSize, setSize, update

Methods inherited from class org.eclipse.swt.widgets.Widget

addListener, dispose, focusState, getBorderWidth, getDisplayArea, getSelection, getStyle, getText, isDisposed, removeListener, setBounds, setCursor, stop

Methods inherited from class java.lang.Object

equals, getClass, hashCode, toString

Methods inherited from interface org.eclipse.swt.graphics.Drawable

drawLine, drawRect, drawText, setColor

Methods inherited from interface java.lang.Runnable

run

Constructor Detail

Canvas

public Canvas(Composite parent,
              int style)

Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

Parameters:

parent - a composite control which will be the parent of the new instance (cannot be null)

style - the style of control to construct

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
• ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass

See Also:

SWT, Widget#checkSubclass, Widget.getStyle()