Programming Reference: ODAIXCanvas

# Programming Reference

## ODAIXCanvas

Class definition file | AIXPCanv.idl
Class C++ Binding | AIXPCanv.xh

Class hierarchy

    SOMObject
       ODObject
          ODPlatformCanvas
             ODAIXCanvas

Description | The ODAIXCanvas class is an AIX X-Windows specific SOM class that serves as a platform parent class for other classes used to encapsulate AIX drawing contexts. The ODAIXCanvas class is derived from ODPlatformCanvas and wraps an X-Windows graphics context (GC). It can be instantiated directly to access the CreateConcreteCanvas factory method for creating instances of ODAIXStandardCanvas and ODAIXWindowCanvas. These two classes override nearly all of the methods of ODAIXCanvas. ODAIXStandardCanvas is used to initialize offscreen static, offscreen dynamic, and onscreen static canvases. ODAIXWindowCanvas is used to initialize onscreen dynamic canvases. Because ODAIXStandardCanvas and ODAIXWindowCanvas do not introduce any new methods, objects of both classes can be referred to using a pointer to an ODAIXCanvas.

Methods

The methods defined for the ODAIXCanvas class include:

- GetDisplay (AIX)
- GetGC (AIX)
- GetPixmap (AIX)
- GetWidget (AIX)
- GetWindow (AIX)
- InitPlatformCanvas (AIX)
- InitPlatformWindowCanvas (AIX)

Overridden methods

The methods overridden by the ODAIXCanvas class include:

- ODPlatformCanvas::CreateConcreteCanvas
- ODPlatformCanvas::GetPlatformCanvasType
- ODPlatformCanvas::GetSystemType
- ODPlatformCanvas::HasWindow
- ODPlatformCanvas::IsInitialized

### GetDisplay (AIX)

This method returns the X-Windows display pointer associated with this platform canvas.

Signature

    Display *GetDisplay ()

Parameters

None.

Returns

rv (Display *) - returns

  An X-Windows display pointer.

Remarks

This method must be overridden by a subclass. This method returns a kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

### GetGC (AIX)

This method returns a handle to the graphics context of this platform canvas.

Signature

    GC GetGC ()

Parameters

None.

Returns

rv (GC) - returns

  A handle to the graphics context of the platform canvas.

Remarks

This method must be overridden by a subclass. This method returns a kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

If this platform canvas is a subclass, and it has been initialized, then the handle to the device context will be returned.

The user is responsible for freeing the graphics context when it is no longer used by the canvas.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

### GetPixmap (AIX)

This method returns a reference to the pixmap associated with this platform canvas.

Signature

    Pixmap GetPixmap ()

Parameters

None.

Returns

rv (Pixmap) - returns

  An X-Windows pixmap handle.

Remarks

This method must be overridden by a subclass. This method returns a kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

If this platform canvas is an ODAIXWindowCanvas, and it has been initialized, then this method returns a pixmap associated with this platform canvas.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

### GetWidget (AIX)

This method returns a reference to the widget associated with this platform canvas.

Signature

    Widget GetWidget ()

Parameters

None.

Returns

rv (Widget) - returns

  An X-Windows Toolkit widget handle.

Remarks

This method must be overridden by a subclass. This method returns a kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

If this platform canvas is an ODAIXWindowCanvas, and it has been initialized, then this method returns the widget associated with this platform canvas.

This widget may be NULL.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

### GetWindow (AIX)

This method returns a reference to the window associated with this platform canvas.

Signature

    Window GetWindow ()

Parameters

None.

Returns

rv (Window) - returns

  An X-Windows window handle.

Remarks

This method must be overridden by a subclass. This method returns a kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

If this platform canvas is an ODAIXWindowCanvas, and it has been initialized, then this method returns a window associated with this platform canvas.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

### InitPlatformCanvas (AIX)

This method initializes the platform canvas using a handle to a pixmap and a graphics context.

Signature

    void InitPlatformCanvas (Display *display,
                             Pixmap pixmap,
                             GC gc)

Parameters

display (Display *) - input

  A pointer to a valid X-Windows display structure.

pixmap (Pixmap) - input

  An X-Windows pixmap handle.

gc (GC) - input

  An X-Windows graphics context.

Returns

None.

Remarks

This method must be overridden by a subclass. This method returns kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

### InitPlatformWindowCanvas (AIX)

This method initializes the platform canvas using a handle to a window and a graphics context.

Signature

    void InitPlatformWindowCanvas (Display *display,
                                   Window window,
                                   Widget widget,
                                   GC gc)

Parameters

display (Display *) - input

  A pointer to a valid X-Windows display structure.

window (Window) - input

  An X-Windows window handle.

widget (Widget) - input

  An X-Windows Tookit Widget, may be NULL if a widget is not associated with this canvas.

gc (GC) - input

  An X-Windows graphics context.

Returns

None.

Remarks

This method must be overridden by a subclass. This method returns kODErrInvalidObjectType if this platform canvas is an ODAIXCanvas.

Exception Handling

kODErrInvalidObjectType | This method is not valid on this object.

[ Top | Previous | Next | Contents | Index | Documentation Homepage ]