The IDrawingCanvas class is a control class that provides support for drawing graphic objects. The drawing canvas contains an IGraphicGroup to which you can add graphic objects. By default, a paint handler is attached to the drawing canvas. When paint events occur, the paint handler sets the clip region to the drawing canvas' update region and iterates through the IGraphicGroup, redrawing the graphic objects necessary to update the window. If you do not add graphic objects to the IGraphicGroup, the drawing canvas simply paints the window using the current background color.
If you want to use your own paint handler instead of the drawing canvas' default paint handler, construct the IDrawingCanvas object without the useDefaultPaintHandler style. The default paint handler will not be attached to the drawing canvas.
You have the option of setting the graphic context that the drawing canvas will use when drawing the graphic objects contained in the IGraphicGroup object. By changing graphic contexts, you can change the appearance of the graphic objects or the device on which they are rendered.
To add graphic objects to a drawing canvas, create an IGraphicGroup object and call setGraphicList. The drawing canvas iterates through the drawing canvas for its IGraphicGroup. You can easily change the objects drawn in the drawing canvas by changing the IGraphicGroup object.
NOTE: The behavior of IDrawingCanvas has changed subtly in this release. In the past, the drawing canvas would repaint anytime it was resized. In this release, if the drawing canvas is resized smaller, it does not repaint. If your application requires the drawing canvas to repaint in this case call the refresh member function. In all other resize cases, the drawing canvas paints as it did in prior releases.
You can construct and destruct objects of this class. You cannot copy or assign IDrawingCanvas objects because both the copy constructor and assignment operators are private functions.
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public:
virtual ~IDrawingCanvas()
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public:
IDrawingCanvas( unsigned long windowIdentifier, IWindow* parent, IWindow* owner, const IRectangle& initial = IRectangle ( ), const Style& style = defaultStyle ( ) )
We recommend that you do the following:
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These members override the inherited canvas-protected functions to provide layout support.
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protected:
virtual ISize calcMinimumSize() const
Returns the minimum screen size this control can occupy, based on the size and positions of its child windows and graphic objects.
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Use these members to set and query the IGrafPort object, which is the drawing port that the drawing canvas uses when painting the window.
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virtual IGrafPort* grafPort() const
Returns a pointer to the drawing port that the drawing canvas uses for paint events. By default, the drawing canvas uses the drawing port that is provided from the paint event.
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virtual void setGrafPort(IGrafPort* grafPort)
Sets the drawing port that the drawing canvas uses when painting the window.
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Use these members to set and query the IGraphicGroup object, which the drawing canvas draws when paint events occur.
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public:
virtual IGraphicGroup* graphicGroup() const
Returns a pointer to the IGraphicGroup object set for the drawing canvas.
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virtual void setGraphicGroup(IGraphicGroup* group)
Sets the IGraphicGroup object that the drawing canvas draws when paint events occur.
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Use these style members to customize a window at the time you construct it. Most styles have equivalent member functions, which allow you to similarly modify a window after creating it. You can use these styles with the styles defined by the following nested classes:
Once you have constructed an IDrawingCanvas object, you can use IDrawingCanvas, ICanvas, and IWindow member functions to query and change individual styles.
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public:
virtual unsigned long convertToGUIStyle( const IBitFlag& style, bool extendedOnly = false ) const
Converts a style object into a value appropriate for the underlying system. The default action is to return the base GUI styles for the platform. Extended styles, those defined by the application and the Open Class Library, will be returned if you set extendedOnly to true.
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static Style defaultStyle()
Returns the current default style, which is the same as classDefaultStyle unless you have changed the style using setDefaultStyle.
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public:
static void setDefaultStyle(const Style& style)
Sets the default style for all subsequent drawing canvases.
This member function is not thread safe. In a multithreaded application, it should only be called when a conflict is not possible. A conflict can arise if you set the default style on one thread at the same time that it is being queried on another. In this situation, the query would take place while the style is in an unknown state.
When you create a window class and do not specifically specify window styles in the constructor, the Open Class Library queries the default style. Therefore, the only safe place to call this member function is when no other application threads that create windows are active.
Another way to avoid a conflict in a multithreaded application is to specifically specify window styles on window construction, rather than calling this member function.
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public:
static const Style classDefaultStyle
Specifies the original default style for this class, which is IDrawingCanvas::useDefaultPaintHandler | IWindow::visible | IWindow::clipSiblings.
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public:
static const Style useDefaultPaintHandler
If this style is set, a default paint handler attaches to the drawing canvas. If this style is not set, you must handle window painting.
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virtual ~ICanvas()
virtual ICanvas& addBorder()
virtual IColor backgroundColor() const
virtual IColor borderColor() const
IText borderText() const
IPoint bottomRightLayoutOffset() const
virtual IFont font() const
virtual bool hasBorder() const
virtual bool hasChildrenToLayout() const
ICanvas( unsigned long windowIdentifier, IWindow* parent, IWindow* owner, const IRectangle& initial = IRectangle ( ), const Style& style = defaultStyle ( ) )
virtual bool isTabStop() const
virtual IWindowHandle matchForMnemonic( unsigned short character ) const
virtual ICanvas& removeBorder()
virtual ICanvas& resetBorderColor()
virtual ICanvas& resetFont()
virtual ICanvas& setBorderColor(const IColor& borderColor)
virtual ICanvas& setBorderText( const IText& borderText, bool showBorder = true )
virtual ICanvas& setBorderText( const IResourceId& borderText, bool showBorder = true )
virtual ICanvas& setFont(const IFont& font)
virtual ICanvas& setLayoutDistorted( unsigned long layoutAttributesOn, unsigned long layoutAttributesOff )
IPoint topLeftLayoutOffset() const
virtual ~IControl()
virtual ~INotifier()
virtual INotifier& disableNotification() = 0
virtual INotifier& enableNotification( bool enable = true ) = 0
INotifier()
virtual bool isEnabledForNotification() const = 0
virtual INotifier& notifyObservers( const INotificationEvent& event ) = 0
virtual INotifier& notifyObserversAsync( const INotificationEvent& event )
const IThreadId& threadId() const
virtual ~IWindow()
IAccelTblHandle acceleratorHandle() const
IAcceleratorTable acceleratorTable() const
virtual IColor activeColor() const
IWindow& addOrReplaceAttribute( const IAttributeName& name, const IAttribute& attribute )
IWindow& adoptWindowData( const DataHandle& typeToken, IWindowData* windowData )
virtual IString asDebugInfo() const
virtual IString asString() const
IAttributeName attributeNameAt( const AttributeCursor& cursor ) const
const IAttribute* attributeWithName( const IAttributeName& name, ESearchType search = kWindowOnly ) const
virtual IWindow& capturePointer(bool capture = true)
ISize characterSize() const
IWindowHandle childAt(const ChildCursor& cursor) const
IWindow* childWindowAt(const ChildCursor& cursor) const
virtual IArgList convertToArgList( const IBitFlag& style ) const
static DataHandle dataHandleWithKey( const char* dataKeyName )
virtual IWindowHandle defaultEmphasisButton() const
static SiblingOrder defaultOrdering()
static IWindow* desktopWindow()
virtual IWindow& disable()
virtual IColor disabledBackgroundColor() const
virtual IColor disabledForegroundColor() const
virtual IWindow& disableGroup()
IWindow& disableMinimumSizeCaching()
virtual IWindow& disableNotification()
virtual IWindow& disableTabStop()
virtual IWindow& disableUpdate()
bool dispatchRemainingHandlers( IEvent& event, bool callDefProc = true )
virtual IWindow& enable(bool enableWindow = true)
virtual IWindow& enableGroup(bool enable = true)
IWindow& enableMinimumSizeCaching( bool enableCaching = true )
virtual IWindow& enableNotification(bool enable = true)
virtual IWindow& enableTabStop(bool enable = true)
virtual IWindow& enableUpdate(bool enableWindow = true)
static IWindow::ExceptionFn* exceptionFunction()
virtual IColor foregroundColor() const
virtual IWindowHandle handle() const
virtual bool handleException( IException& dispatcherException, IEvent& exceptionEvent )
virtual IWindowHandle handleForChildCreation() const
static IWindowHandle handleWithParent( unsigned long identifier, const IWindowHandle& parent )
static IWindowHandle handleWithPointerCaptured()
virtual bool hasFocus() const
virtual bool hasPointerCaptured() const
unsigned long helpId() const
virtual IWindow& hide()
virtual IWindow& hideSourceEmphasis()
virtual IColor hiliteBackgroundColor() const
virtual IColor hiliteForegroundColor() const
virtual unsigned long id() const
virtual IColor inactiveColor() const
virtual IRectangle invalidatedRect() const
virtual IRegionHandle invalidatedRegion() const
bool isAutoDeleteObject() const
bool isAutoDestroyWindow() const
bool isEnabled() const
virtual bool isEnabledForNotification() const
virtual bool isFrameWindow() const
virtual bool isGroup() const
bool isHandling(const EventMask& events) const
virtual bool isLayoutDistorted( unsigned long layoutAttribute ) const
bool isMinimumSizeCachingEnabled() const
bool isShowing() const
bool isUpdateEnabled() const
virtual bool isValid() const
bool isVisible() const
static bool isWindowValid(const IWindow* window)
IDMItemProvider* itemProvider() const
IWindow(const IWindowHandle& handle)
IWindow(unsigned long identifier, IWindow* parent)
virtual IRectangle layoutAdjustment() const
static IPoint mapPoint( const IPoint& point, const IWindowHandle& from, const IWindowHandle& to )
IMessageQueueHandle messageQueue() const
ISize minimumSize(bool windowCalculatedSize = false) const
virtual IPointerHandle mousePointer() const
static void movePointerTo(const IPoint& position)
virtual IWindow& moveSizeTo( const IRectangle& newSizeAndPosition )
virtual IWindow& moveTo(const IPoint& newPosition)
virtual IRectangle nativeRect() const
virtual INotifierAddress notifierAddress() const
virtual IWindow& notifyObservers( const INotificationEvent& event )
virtual IWindow& notifyObserversAsync( const INotificationEvent& event )
static IWindow* objectWindow()
virtual IWindow* owner() const
IWindow* parent() const
virtual ISize parentSize() const
static ISize parentSize(const IWindowHandle& windowHandle)
static IPoint pointerPosition()
virtual IPoint position() const
virtual IWindow& positionBehindSibling( const IWindowHandle& siblingWindow )
virtual IWindow& positionBehindSiblings()
virtual IWindow& positionOnSiblings()
virtual const IWindow& postEvent( EventType eventType, const IEventParameter1& parm1 = 0, const IEventParameter2& parm2 = 0 ) const
virtual const IWindow& postEvent(const IEvent& event) const
virtual const IWindow& postEvent( unsigned long eventId, const IEventParameter1& parm1 = 0, const IEventParameter2& parm2 = 0 ) const
virtual IPresSpaceHandle presSpace() const
virtual IRectangle rect() const
virtual IWindow& refresh( const IRectangle& invalidRectangle, bool immediate = false )
virtual IWindow& refresh(RefreshType type = paintAll)
virtual IWindow& releasePointer()
virtual void releasePresSpace( const IPresSpaceHandle& presentationSpaceHandle ) const
IWindow& removeAllAttributes()
IWindow& removeAttribute(const IAttributeName& name)
virtual IWindow& resetActiveColor()
virtual IWindow& resetBackgroundColor()
virtual IWindow& resetDisabledBackgroundColor()
virtual IWindow& resetDisabledForegroundColor()
virtual IWindow& resetFont()
virtual IWindow& resetForegroundColor()
virtual IWindow& resetHiliteBackgroundColor()
virtual IWindow& resetHiliteForegroundColor()
virtual IWindow& resetInactiveColor()
IWindow& resetMinimumSize()
virtual IWindow& resetShadowColor()
virtual IEventResult sendEvent(const IEvent& event) const
virtual IEventResult sendEvent( unsigned long eventId, const IEventParameter1& parm1 = 0, const IEventParameter2& parm2 = 0 ) const
virtual IEventResult sendEvent( EventType eventType, const IEventParameter1& parm1 = 0, const IEventParameter2& parm2 = 0 ) const
IWindow& setAcceleratorHandle( const IAccelTblHandle& handle )
IWindow& setAcceleratorTable( const IAcceleratorTable* acceleratorTable )
virtual IWindow& setActiveColor(const IColor& color)
IWindow& setAutoDeleteObject(bool autoDelete = true)
IWindow& setAutoDestroyWindow(bool autoDestroy = false)
virtual IWindow& setBackgroundColor(const IColor& color)
static void setDefaultOrdering(SiblingOrder order)
virtual IWindow& setDisabledBackgroundColor( const IColor& color )
virtual IWindow& setDisabledForegroundColor( const IColor& color )
static IWindow::ExceptionFn* setExceptionFunction( IWindow::ExceptionFn* exceptionFunction )
virtual IWindow& setFocus()
virtual IWindow& setFont(const IFont& font)
virtual IWindow& setForegroundColor(const IColor& color)
IWindow& setHelpId(unsigned long helpTopicId)
virtual IWindow& setHiliteBackgroundColor( const IColor& color )
virtual IWindow& setHiliteForegroundColor( const IColor& color )
virtual IWindow& setId(unsigned long newIdentifier)
virtual IWindow& setInactiveColor(const IColor& color)
IWindow& setItemProvider(IDMItemProvider* dragProvider)
virtual IWindow& setLayoutDistorted( unsigned long layoutAttributesOn, unsigned long layoutAttributesOff )
IWindow& setMinimumSize(const ISize& size)
virtual IWindow& setMousePointer( const IPointerHandle& mousePointer )
virtual IWindow& setOwner(const IWindow* newOwner)
virtual IWindow& setParent(const IWindow* newParent)
virtual IWindow& setShadowColor(const IColor& color)
virtual IColor shadowColor() const
virtual IWindow& show(bool showWindow = true)
virtual IWindow& showSourceEmphasis(bool show = true)
virtual ISize size() const
virtual IWindow& sizeTo(const ISize& newSize)
IWindow& startHandling(const EventMask& events)
IWindow& stopHandling(const EventMask& events)
virtual IWindow& validateRect( const IRectangle& validatedRectangle )
virtual IWindow& validateRegion( const IRegionHandle& validatedRegion )
virtual IRectangle visibleRectangle() const
IWindowData* windowData(const DataHandle& typeToken) const
static IWindow* windowWithHandle( const IWindowHandle& windowHandle, bool allThreads = true )
static IWindow* windowWithOwner( unsigned long identifier, const IWindow* owner, bool allThreads = true )
static IWindow* windowWithParent( unsigned long identifier, const IWindow* parent, bool allThreads = true )
static INotificationId const activeColorId
static const EventMask allMouseMoves
static INotificationId const attributeAddReplaceId
static INotificationId const attributeRemoveId
static INotificationId const backgroundColorId
static INotificationId const borderColorId
static const Style clipChildren
static const Style clipSiblings
static const Style clipToParent
static INotificationId const commandId
static const Style disabled
static INotificationId const disabledBackgroundColorId
static INotificationId const disabledForegroundColorId
static INotificationId const enableId
static INotificationId const focusId
static INotificationId const fontId
static INotificationId const foregroundColorId
static const Style group
static INotificationId const hiliteBackgroundColorId
static INotificationId const hiliteForegroundColorId
static INotificationId const inactiveColorId
static const Style leftToRight
static const EventMask mouseEntersLeaves
static const Style noStyle
static INotificationId const positionId
static const Style rightToLeft
static const Style saveBits
static INotificationId const shadowColorId
static INotificationId const sizeId
static const EventMask someMouseMoves
static const Style synchPaint
static INotificationId const systemCommandId
static const Style tabStop
static const Style visible
static INotificationId const visibleId
static INotificationId const allChangesId
static INotificationId const deleteId
static const Style border
static INotificationId const textId
IWindow& addHandler(IHandler* newHandler)
virtual IWindow& addObserver( IObserver& observer, const IInterest& interest )
static void addToWindowSet( IWindow* window, const IWindowHandle& windowHandle )
IWindow& bindMessageQueue(bool bindToMessageQueue = true)
IColor color(unsigned long colorArea) const
IColor color( unsigned long colorArea, const IColor& defaultColor ) const
virtual IWindowHandle create( unsigned long id, const char* text, unsigned long style, const char* windowClass, const IWindowHandle& parent, const IWindowHandle& owner, const IRectangle& initRect, const void* ctlData, const void* presParams, IWindow::SiblingOrder ordering = defaultOrdering ( ), unsigned long extendedStyle = 0 )
virtual IWindowHandle create( unsigned long id, const char* text, unsigned long style, IXmCreateFunction createFunction, const IWindowHandle& parent, const IWindowHandle& owner, const IRectangle& initRect, const void* callerArgList, unsigned int callerNumberArguments, IWindow::SiblingOrder ordering = defaultOrdering ( ), unsigned long extendedStyle = 0 )
virtual IWindowHandle create( unsigned long id, const char* text, const IBitFlag& style, const char* windowClass, const IWindow* parent, const IWindow* owner, const IRectangle& initRect, const void* ctlData, const void* presParams, IWindow::SiblingOrder ordering = defaultOrdering ( ) )
virtual IWindowHandle create( unsigned long id, const char* text, const IBitFlag& style, IXmCreateFunction createFunction, const IWindow* parent, const IWindow* owner, const IRectangle& initRect, IWindow::SiblingOrder ordering = defaultOrdering ( ) )
IWindow& defaultProcedure(IEvent& event)
bool deleteIsInProcess() const
bool dispatch(IEvent& event)
virtual unsigned long extendedStyle() const
bool isBoundToMessageQueue() const
virtual bool isDragStarting(IEvent& event)
bool isPrimaryWindow() const
bool isUserWindowWordReserved() const
IWindow()
IWindowNotifyHandler* notificationHandler() const
virtual IWindow& notifyObservers( const INotificationId& notification )
IObserverList& observerList( const IInterest* interest = 0 ) const
virtual IWindow& prepareForUse( const IWindowHandle& windowHandle )
virtual IWindow& removeAllObservers()
static void removeFromWindowSet(IWindow* window)
IWindow& removeHandler(IHandler* oldHandler)
virtual IWindow& removeObserver(IObserver& observer)
virtual IWindow& removeObserver( IObserver& observer, const IInterest& interest )
IWindow& reserveUserWindowWord(bool reserve = true)
virtual IWindow& resetColor(unsigned long colorArea)
ISize savedMinimumSize() const
IWindow& saveMinimumSize(const ISize& size)
virtual IWindow& setBidiSettings( const IBidiSettings& bidiSettings, bool childInherit, bool refresh )
virtual IWindow& setColor( unsigned long colorArea, const IColor& color )
virtual IWindow& setDefaultEmphasisButton( const IWindowHandle& defaultEmphasisButton, bool enable )
virtual IWindow& setDefaultPushButton( const IWindowHandle& defaultPushButton )
virtual IWindow& setExtendedStyle( unsigned long extendedStyle )
IWindow& setNotificationHandler( IWindowNotifyHandler* notifyHandler )
virtual IWindow& setStyle(unsigned long style)
IWindow& setWindowData(long index, unsigned long dataValue)
IWindow& setWindowData( long index, unsigned short dataValue )
IWindow& startHandlingEventsFor( unsigned long identifier, IWindow* parent )
IWindow& startHandlingEventsFor( const IWindowHandle& windowHandle )
virtual unsigned long style() const
IWindow& unbindMessageQueue()
unsigned long windowULong(long index) const
unsigned short windowUShort(long index) const
virtual INotifier& addObserver( IObserver& observer, const IInterest& interest )
virtual INotifier& notifyObservers( const INotificationId& id ) = 0
virtual IObserverList& observerList( const IInterest* anInterest = 0 ) const = 0
virtual INotifier& removeAllObservers() = 0
virtual INotifier& removeObserver( IObserver& observer, const IInterest& interest )
virtual INotifier& removeObserver(IObserver& observer) = 0
bool areChildrenReversed() const
virtual IWindowPosBuffer fixupChildren()
ICanvas()
ICanvas& initialize( unsigned long windowIdentifier, IWindow* parent, IWindow* owner, const IRectangle& initialRect, unsigned long style, unsigned long extendedStyle )
virtual ICanvas& layout()
ISize layoutSize() const
virtual bool passEventToOwner(IEvent& event)
IRectangle rectangleInsideBorder( const ISize& sizeWithBorder ) const
virtual ICanvas& setBidiSettings( const IBidiSettings& bidiSettings, bool childInherit, bool refresh )
ICanvas& setLayoutSize(const ISize& size)
ISize sizeWithBorder(const ISize& sizeWithoutBorder) const
IControl()