TWidgetSet class

In unit InterfaceBase

Provides an application helper class (platform and drawing interface).

Declaration

pascal

TWidgetSet = class(TObject)

Inheritance

TWidgetSet
TObject

Description

TWidgetSet is a TObject descendant which implements an application helper class that provides access to platform-specific operating system and drawing interfaces. A number of methods are declared as abstract virtual, and must be implemented in descendent classes. Other methods are declared as virtual to allow them to be overridden for a specific platform.

TWidgetSet is used as the ancestor for platform-specific implementations like TWin32WidgetSet, TGTKWidgetSet, TQtWidgetSet, TCarbonWidgetSet, TCocoaWidgetSet, et. al.

The WidgetSet variable provides access to the TWidgetSet singleton for the current widgetset implementation.

Properties

`AppHandle`	public	Native handle for a TApplication instance.
`ThemeServices`	public	Theme services class instance for the widgetset.

Methods

`PassCmdLineOptions`	protected	Passes command line arguments needed for the platform.
`CreateThemeServices`	protected	Theme services class instance for the widgetset.
`GetAppHandle`	protected	Gets the value for the AppHandle property.
`SetAppHandle`	protected	Sets the value for the AppHandle property.
`Create`	public	Constructor for the class instance.
`BeforeDestruction`	public	Performs actions needed before freeing the class instance.
`AppInit`	public	Initializes the application for the platform, and returns Screen information.
`AppRun`	public	Enters a state in which the application waits for system messages.
`AppWaitMessage`	public	Waits for arrival of a message.
`AppProcessMessages`	public	Handles all pending messages.
`AppTerminate`	public	Terminates the application.
`AppMinimize`	public	Minimizes the whole application to the taskbar.
`AppRestore`	public	Restore application previously minimized to the taskbar.
`AppBringToFront`	public	Brings the entire application on top of all other non-topmost programs.
`AppSetIcon`	public	Sets the icon in the taskbar.
`AppSetTitle`	public	Sets the title for an application.
`AppSetVisible`	public	Changes the visibility of the application window.
`AppRemoveStayOnTopFlags`	public	Resets all StayOnTop windows to NoTopmost.
`AppRestoreStayOnTopFlags`	public	Sets all windows in the StayOnTop list to TopMost.
`AppSetMainFormOnTaskBar`	public	Shows or hides the taskbar icon for the MainForm.
`AppSetupMainForm`	public	Sets the window state for the specified main form to match the CmdShow parameter passed when startted from a shortcut.
`BeginMessageProcess`	public
`EndMessageProcess`	public
`LCLPlatform`	public	Returns the name for the widgetset used for the platform.
`GetLCLCapability`	public	Checks whether the widgetset supports the specified LCL capability.
`DCGetPixel`	public	Gets the color for a pixel on the specified device context.
`DCSetPixel`	public	Sets the color for a pixel on the specified device context.
`DCRedraw`	public	Redraws the device context for the specified canvas handle.
`DCSetAntialiasing`	public	Enables or disables anti-aliasing for the specified device context.
`SetDesigning`	public	Sets the flag which indicates a designer is active for the specified component.
`InitStockFont`	public	Initializes a font object to a (predefined) stock font.
`IsHelpKey`	public	Checks whether the widgetset uses the key to show help.
`CreateTimer`	public	Creates a timer with the given callback method.
`DestroyTimer`	public	Destroys the timer with the specified handle.
`Arc`	public	Use Arc to draw an elliptically curved line with the current Pen.
`AngleChord`	public	Use AngleChord to draw a filled Chord shape on a canvas.
`BeginPaint`	public	Start painting in a window.
`BitBlt`	public	Copies part of a source DC into a destination DC, using the specified raster operation.
`CallNextHookEx`	public	Calls the next procedure in the hook chain.
`CallWindowProc`	public	Calls another Window procedure, to handle a message.
`ClientToScreen`	public	Converts (relative) Client coordinates into absolute Screen coordinates.
`CombineRgn`	public	Combines two regions.
`CreateBitmap`	public	Creates a bitmap for the widgetset.
`CreateBrushIndirect`	public	Creates a logical brush that has the specified style, color, and pattern.
`CreateBrushWithRadialGradient`	public
`CreateCaret`	public	Creates a new shape for the system caret and assigns ownership of the caret to the specified window.
`CreateCompatibleBitmap`	public	Creates a bitmap that is compatible with the given DC.
`CreateCompatibleDC`	public	Creates a memory Device Context, compatible with the device for the given DC.
`CreateDIBitmap`	public	Creates a Device Dependent Bitmap (DDB) from a Device Independent Bitmap (DIB).
`CreateDIBSection`	public	Creates a bitmap into which the application can write.
`CreateEllipticRgn`	public	Creates an elliptic region, bounded by the given rectangle.
`CreateFontIndirect`	public	Creates a logical font, selectable into any DC.
`CreateFontIndirectEx`	public	Creates a logical font, selectable into any DC. Allows for a long font name.
`CreateIconIndirect`	public	Creates an icon or cursor.
`CreatePalette`	public	Creates a logical palette, selectable into any DC.
`CreatePatternBrush`	public	Creates a logical brush, selectable into any DC.
`CreatePenIndirect`	public	Creates a logical Pen, selectable into any DC.
`CreatePolygonRgn`	public	Creates a polygonal region.
`CreateRectRgn`	public	Creates a rectangular region.
`CreateRoundRectRgn`	public	Creates a rectangular region with rounded corners.
`DeleteCriticalSection`	public	Deletes an un-owned critical section.
`DeleteDC`	public	Deletes a Device Context created using CreateDC.
`DeleteObject`	public	Deletes a graphic object, freeing all system resources associated with the object.
`DestroyCaret`	public	Destroys the caret but doesn't free the bitmap.
`DestroyCursor`	public	Destroys a mouse cursor.
`DestroyIcon`	public	Destroys an icon.
`DPtoLP`	public	Converts an array of Device Points (coordinates) into Logical Points.
`DrawFrameControl`	public	Draws a window frame control, of the specified type and style.
`DrawFocusRect`	public	Shows or hides a focus rectangle.
`DrawEdge`	public	Draws one or more edges of a rectangle.
`DrawText`	public	Draws formatted text within a rectangle.
`EnableScrollBar`	public	Enables or disables the arrows in a scrollbar control, or the scrollbars in a window.
`EnableWindow`	public	Enables or disables mouse and keyboard input to the specified window or control.
`EndPaint`	public	Ends a paint operation in a window, started with BeginPaint.
`EnterCriticalSection`	public	Enters a critical section.
`EnumDisplayMonitors`	public	Calls a callback function for every available display monitor.
`EnumFontFamilies`	public	Invokes a callback function for every font available on a specified device.
`EnumFontFamiliesEx`	public	Invokes a callback function for every available font that matches certain criteria.
`Ellipse`	public	Draws a filled circle or ellipse, bounded by a rectangle.
`EqualRgn`	public
`ExcludeClipRect`	public	Excludes a rectangle from the clipping region, i.e. prevents painting within the rectangle.
`ExtCreatePen`	public	Creates a logical pen, selectable into any DC.
`ExtTextOut`	public	Draws a string without formatting (single line).
`ExtSelectClipRGN`	public	Combines the passed Region with the current clipping region.
`FillRect`	public	Fills a rectangle using the specified brush.
`FillRgn`	public	Fills a region using the specified brush.
`FloodFill`	public	Fills an area of the display surface with the current brush.
`FrameRect`	public	Draws a border around a rectangle.
`GetActiveWindow`	public	Returns the Handle of the active window of the calling thread.
`GetBitmapBits`	public	Fills a buffer with the bitmap bits.
`GetBkColor`	public	Returns the background color of a device context.
`GetCapture`	public	Returns the window that captures mouse messages.
`GetCaretPos`	public	Returns the caret position, in client coordinates.
`GetClientRect`	public	Returns the client rectangle of a window.
`GetClipBox`	public	Returns the smallest rectangle which includes the entire clipping region of a device context.
`GetClipRGN`	public	Returns the clipping region of a device context.
`GetCompositorExtendedBorder`	public
`GetCurrentObject`	public	Returns the currently selected object in a device context.
`GetCursorPos`	public	Gets the mouse cursor position, in screen coordinates.
`GetCharABCWidths`	public	Returns the ABC widths of a range of character codes.
`GetDC`	public	Returns the handle for the Device Context (DC) in the client area of a window.
`GetDeviceCaps`	public	Returns various device specific information.
`GetDIBits`	public	Fills a buffer with bitmap color bits.
`GetDoubleClickTime`	public	Returns the double-click time, in milliseconds.
`GetFocus`	public	Returns the handle of the window that has the focus in the current thread.
`GetFontLanguageInfo`	public	Returns language information about the currently selected font.
`GetForegroundWindow`	public	Returns the window that the user is currently working with, session wide.
`GetIconInfo`	public	Returns information about an Icon or Cursor.
`GetKeyState`	public	The status of a virtual key.
`GetMapMode`	public	Returns the mapping mode of a device context.
`GetMonitorInfo`	public	Returns information about a display monitor.
`GetDpiForMonitor`	public
`GetObject`	public	Returns information about a graphics object.
`GetPaletteEntries`	public	Retrieves a range of color entries from a logical palette.
`GetParent`	public	Returns the parent window of a window.
`GetProp`	public	Retrieves a property value for a window.
`GetRgnBox`	public	Returns the bounding rectangle of a region, containing the entire region.
`GetROP2`	public	The current Foreground Mixing Mode in a device context.
`GetScrollInfo`	public	Returns all or selected information about a ScrollBar.
`GetStockObject`	public	Retrieves a handle to one of the predefined graphic objects.
`GetSysColor`	public	Retrieves the system color for standard display elements.
`GetSysColorBrush`	public	Retrieves a system brush for standard display elements.
`GetSystemPaletteEntries`	public	Retrieves a range of color entries from the system palette for a device.
`GetSystemMetrics`	public	Retrieves various system metrics.
`GetTextColor`	public	The current text color in a device context.
`GetTextExtentExPoint`	public	Calculates the number of characters, that fit into some horizontal space.
`GetTextExtentPoint`	public	Computes the display width and height of a string.
`GetTextExtentPoint32`	public	Computes the display width and height for a string.
`GetTextMetrics`	public	Retrieves the metrics for the currently selected font.
`GetViewPortExtEx`	public	Returns the size of the viewport for a device context.
`GetViewPortOrgEx`	public	Returns the origin of the viewport for a device context.
`GetWindowExtEx`	public	Returns the extent of a window, in logical units.
`GetWindowLong`	public	Returns the attributes of a window.
`GetWindowRect`	public	Retrieves the bounding rectangle of a window, in screen coordinates.
`GetWindowSize`	public	Returns the Width and Height of the window.
`GetWindowOrgEx`	public	Retrieves the window origin for a device context in logical units.
`GradientFill`	public	Fills rectangle or triangle areas with gradient colors.
`HideCaret`	public	Removes the caret from the screen.
`InitializeCriticalSection`	public	Initializes a Critical Section object.
`IntersectClipRect`	public	Shrinks the clipping region of an Device Context to a rectangular boundary, e.g. a text area.
`InvalidateRect`	public	Marks a display area for repaint.
`InvalidateRgn`	public	Marks a display area for repaint.
`IsDBCSLeadByte`	public
`IsIconic`	public	True when the window is minimized.
`IsWindow`	public	Checks whether a handle refers to a window.
`IsWindowEnabled`	public	Determines whether a window can receive mouse and keyboard input.
`IsWindowVisible`	public	The definite Visible state of a window.
`IsZoomed`	public	True when the window is maximized.
`LeaveCriticalSection`	public	Releases a critical section, and allows use by other threads.
`LineTo`	public	Draws a line from the current position up to, but not including, the specified point.
`LoadBitmap`	public
`LoadCursor`	public
`LoadIcon`	public
`LPtoDP`	public	Converts logical coordinates into device coordinates.
`MaskBlt`	public	Copies part of a source DC into an destination DC, using the specified foreground and background raster operations.
`MessageBox`	public	Displays a modal dialog message box.
`MonitorFromPoint`	public	Finds a monitor from the screen coordinates.
`MonitorFromRect`	public	Finds the monitor covering most of a rectangle.
`MonitorFromWindow`	public	Finds the monitor covering most of a window.
`MoveToEx`	public	Moves the current position to the specified point.
`OffsetRgn`	public	Moves a region relative.
`PaintRgn`	public
`PeekMessage`	public	Checks the thread's message queue for a message.
`Pie`	public	Draws a filled pie-shaped wedge, from an ellipse and two radials.
`PolyBezier`	public	Draws Bezier curves.
`Polygon`	public	Draws a filled Polygon.
`Polyline`	public	Draws a sequence of lines between the specified points.
`PostMessage`	public	Sends a message to a window, without waiting for the message result.
`PtInRegion`	public	Tests whether a point lies in a region.
`RealizePalette`	public	Maps palette entries from the current logical palette to the system palette.
`Rectangle`	public	Draws a filled rectangle.
`RectInRegion`	public
`RectVisible`	public	Checks whether the clipping region contains (part of) a rectangle.
`RedrawWindow`	public	Redraws (part of) a window.
`ReleaseCapture`	public	Restores normal mouse input processing, after SetCapture.
`ReleaseDC`	public	Releases an Device Context obtained by GetDC.
`RemoveProp`	public	Removes a named property from a window.
`RestoreDC`	public	Restores an Device Context (DC) to an previously saved state.
`RoundRect`	public	Draws a filled rectangle with rounded corners.
`SaveDC`	public	Saves the state of an Device Context in the context stack.
`ScreenToClient`	public	Converts absolute Screen coordinates into Client relative coordinates.
`ScrollWindowEx`	public	Scrolls the content of a window, by a number of pixels.
`SelectClipRGN`	public	Sets the ClipRegion of an DeviceContext.
`SelectObject`	public	Selects an object into an device context.
`SelectPalette`	public	Selects a logical palette into an device context.
`SendMessage`	public	Sends a message to a window.
`SetActiveWindow`	public	Sets focus to the specified window, if the application is on top.
`SetBkColor`	public	Sets the current background color of an device context.
`SetBkMode`	public	Sets the background mix mode (transparency) of an device context.
`SetCapture`	public	Sets the mouse capture to the specified window.
`SetCaretPos`	public	Moves the Caret to the specified coordinates.
`SetCaretPosEx`	public	Moves the Caret into a window.
`SetCursor`	public	Changes the shape of the mouse cursor.
`SetCursorPos`	public	Changes the position of the mouse cursor.
`SetFocus`	public	Sets the keyboard input focus to the specified window.
`SetForegroundWindow`	public	Moves a window in front of all other windows, and activates it.
`SetMapMode`	public	Sets the mapping mode of an device context.
`SetMenu`	public	Assigns a menu to a window.
`SetParent`	public	Changes the parent of a window.
`SetProp`	public	Adds a property to a window.
`SetRectRgn`	public
`SetROP2`	public	Sets the Foreground Mixing Mode in a device context.
`SetScrollInfo`	public	Sets (selected) parameters of a scroll bar.
`SetStretchBltMode`	public	Sets the StrechBlt mode for an device context.
`SetSysColors`	public	Sets the colors for one or more display elements of window borders and desktop.
`SetTextCharacterExtra`	public	Sets extra inter-character spacing in text output.
`SetTextColor`	public	Sets the text color in a device context.
`SetWindowLong`	public	Sets an attribute of a window.
`SetViewPortExtEx`	public	Sets the extent of the viewport for a device context.
`SetViewPortOrgEx`	public	Sets the device origin corresponding to the window origin (0,0) in a device context.
`SetWindowExtEx`	public	Sets the extent of the window for an device context.
`SetWindowOrgEx`	public	Specifies which window point maps to the viewport origin (0,0).
`SetWindowPos`	public	Changes the size, position, and Z order of a window.
`SetWindowRgn`	public	Restricts the visible part of the entire window.
`ShowCaret`	public	Shows the Caret (text cursor).
`ShowScrollBar`	public	Shows or hides a ScrollBar.
`ShowWindow`	public	Shows a window in an specific state.
`StretchBlt`	public	Copies a rectangular region to a device context, shrinking or stretching it as needed.
`StretchDIBits`	public	Copies a rectangular region from a DIB into an device context, shrinking or stretching it as required.
`SystemParametersInfo`	public	Retrieves or sets one of the system-wide parameters.
`TextOut`	public	Draws an string without formatting (single line).
`UpdateWindow`	public	Forces an immediate repaint of a window, if required.
`WindowFromPoint`	public	Finds the window containing the specified point.
`AddEventHandler`	public	Adds an event handler routine for the specified handle.
`AddProcessEventHandler`	public	Adds a process handler routine for the specified handle.
`AddPipeEventHandler`	public	Adds a pipe handler routine for the specified handle.
`AllocateHWnd`	public	Allocates an invisible window that can be used to receive messages.
`AskUser`	public	Displays a dialog box with the specified values, and returns the modal result.
`CallDefaultWndHandler`	public	Calls the default window handler to process a message from a control.
`ClipboardFormatToMimeType`	public	Gets the MIME type for the specified clipboard format.
`ClipboardGetData`	public	Gets clipboard data for a given format and saves it to the specified stream.
`ClipboardGetFormats`	public	Gets a list of available registered clipboard formats.
`ClipboardGetOwnerShip`	public	Sets the requested formats and requests ownership of the clipboard.
`ClipboardRegisterFormat`	public	Registers a clipboard format for the specified MIME type.
`ClipboardFormatNeedsNullByte`	public
`CreateEmptyRegion`	public
`CreatePixmapIndirect`	public
`CreateRegionCopy`	public
`CreateRubberBand`	public
`CreateStandardCursor`	public	Creates one of the standard cursors.
`DCClipRegionValid`	public
`DeallocateHWnd`	public	Deletes a window created with AllocateHWnd.
`DestroyRubberBand`	public
`DrawDefaultDockImage`	public	Draws the DockRect during drag-dock operations.
`DrawGrid`	public	Draws a grid lines inside a rectangle with the specified spacing.
`ExtUTF8Out`	public	Draws an UTF-8 string without formatting (single line).
`FontIsMonoSpace`	public	Determines if the typeface in the specified font handle is a mono-spaced font.
`Frame3d`	public	Draws a 3D frame for a rectangle on a device context using the specified style.
`GetAcceleratorString`	public	Gets a string representing the specified key and shift modifier.
`GetAvailableNativeCanvasTypes`	public
`GetAvailableNativeHandleTypes`	public
`GetCaretRespondToFocus`	public
`GetClientBounds`	public	Gets the coordinates for the client area in the specified window handle.
`GetCmdLineParamDescForInterface`	public
`GetControlConstraints`	public	Updates the constraints object (e.g. TSizeConstraints) with interface specific bounds.
`GetDCOpacity`	public
`GetDCOriginRelativeToWindow`	public
`GetDesignerDC`	public
`GetDeviceSize`	public
`GetLCLOwnerObject`	public
`GetNativeCanvas`	public
`GetNativeHandle`	public
`GetScrollBarSize`	public
`GetScrollbarVisible`	public
`GetWindowRelativePosition`	public
`InvalidateFrame`	public
`IsDesignerDC`	public
`IsMobilePlatform`	public
`IsCDIntfControl`	public
`MoveWindowOrgEx`	public
`PromptUser`	public
`PromptUserAtXY`	public
`RadialArc`	public
`RadialChord`	public
`RadialPie`	public
`RawImage_CreateBitmaps`	public
`RawImage_DescriptionFromBitmap`	public
`RawImage_DescriptionFromDevice`	public
`RawImage_FromBitmap`	public
`RawImage_FromDevice`	public
`RawImage_QueryDescription`	public
`RegroupMenuItem`	public
`ReleaseDesignerDC`	public
`RemoveEventHandler`	public
`RemoveProcessEventHandler`	public
`RemovePipeEventHandler`	public
`RequestInput`	public
`SendCachedLCLMessages`	public
`SetCanvasScaleFactor`	public
`SetCaretRespondToFocus`	public
`SetComboMinDropDownSize`	public
`SetDCOpacity`	public
`SetEventHandlerFlags`	public
`SetRubberBandRect`	public
`ShowSelectItemDialog`	public
`StretchMaskBlt`	public
`TextUTF8Out`	public	Writes UTF-8-encoded text to the specified device context.

Fields

FThemeServices protected Theme services class instance for the widgetset.

Inherited

From TObject (40)

AfterConstruction CheckDisposed ClassInfo ClassName ClassNameIs ClassParent ClassType CleanupInstance DefaultHandler DefaultHandlerStr Destroy Dispatch DispatchStr Disposed DisposeOf Equals FieldAddress Free FreeInstance GetDisposed GetHashCode GetInterface GetInterfaceByStr GetInterfaceEntry GetInterfaceEntryByStr GetInterfaceTable GetInterfaceWeak GetLastCastErrorInfo InheritsFrom InitInstance InstanceSize MethodAddress MethodName newinstance QualifiedClassName SafeCallException StringMessageTable SystemHasExtendedRTTI ToString UnitName

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.