#include <gdi.h>
| class CBitmapDevice : public CGraphicsDevice |
| Public Member Functions | |
|---|---|
| pure virtual TInt | AddFile(const TDesC &, TInt &) |
| TInt | CreateBitmapContext(CBitmapContext *&) |
| pure virtual TInt | FontHeightInPixels(TInt, TInt) |
| pure virtual TInt | GetNearestFontInPixels(CFont *&, const TFontSpec &) |
| virtual TInt | GetNearestFontToDesignHeightInPixels(CFont *&, const TFontSpec &) |
| virtual TInt | GetNearestFontToMaxHeightInPixels(CFont *&, const TFontSpec &, TInt) |
| pure virtual void | GetPixel(TRgb &, const TPoint &) |
| pure virtual void | GetScanLine(TDes8 &, const TPoint &, TInt, TDisplayMode) |
| pure virtual void | RemoveFile(TInt) |
Defines an abstract interface for the capabilities and attributes of a bitmapped graphics device.
The class specialises the graphics device interface CGraphicsDevice for bitmaps graphics. The Window Server Client-Side API provides one implementation of the interface, CWsScreenDevice, for screen drawing. Another implementation, CFbsBitmapDevice, is used for drawing to in-memory bitmaps. A third, CFbsScreenDevice, is used (rarely) to access the screen directly, without the mediation of the window server.
Adds a font file to the device's typeface store. The specified font file must be accessible to any process, i.e. not located inside an application's private directory.
This pure virtual function is implemented in derived classes.
| Parameters | |
|---|---|
| aName | The name of the font file. |
| aId | On return, contains an ID for the font file. |
| TInt | CreateBitmapContext | ( | CBitmapContext *& | aGC | ) | [inline] |
Creates a bitmap context for this bitmap device.
| Parameters | |
|---|---|
| aGC | On return, holds a pointer to the created bitmap context. |
Gets the height, in pixels, of the specified typeface at one of its defined heights.
The typeface is identified by by an index. For a given typeface, there are a discrete number of heights; the specific height is also identified by an index.
The value returned is rounded up or down to the nearest font height in pixels.
This pure virtual function is implemented in derived classes.
See also: TTypefaceSupport CGraphicsDevice::NumTypefaces() CGraphicsDevice::TypefaceSupport()
| Parameters | |
|---|---|
| aTypefaceIndex | A typeface index number, in the range: 0 to (NumTypefaces() - 1). |
| aHeightIndex | A font height index number, in the range: 0 to (iNumHeights - 1) where iNumHeights is a public data member of the TTypefaceSupport object returned by TypefaceSupport(). |
Gets the font which is the nearest to the given font specification.
When the font is no longer needed, call ReleaseFont().
Note that this deprecated function is replaced by the new GetNearestFontToDesignHeightInPixels() yielding (virtually) the same result. However clients are strongly encouraged to use the new GetNearestFontToMaxHeightInPixels() function instead. This will guarantee that every character within any given text string will fit within the given amount of pixels, whereas the design height is an aesthetic unit decided by the font designer without strict physical meaning, which may result in cropped characters.
DeprecatedUse GetNearestFontToDesignHeightInPixels
| Parameters | |
|---|---|
| aFont | On return, contains a pointer to the nearest font. |
| aFontSpec | The specification of the font to be matched. |
Gets the font which is the nearest to the given font specification.
When the font is no longer needed, call ReleaseFont().
This new function replaces the deprecated GetNearestFontInPixels() yielding (virtually) the same result. However clients are strongly encouraged to use the new GetNearestFontToMaxHeightInPixels() function instead. This will guarantee that every character within any given text string will fit within the given amount of pixels, whereas the design height is an aesthetic unit decided by the font designer without strict physical meaning, which may result in cropped characters.
Gets the font which is the nearest to the given font specification.
When the font is no longer needed, call ReleaseFont().
The font and bitmap server returns a pointer to the nearest matching font from those available. Matches to max height of font - this does its best to return a font that will fit within the maximum height specified (but note that variations due to hinting algorithms may rarely result in this height being exceeded by up to one pixel). Problems can also be encountered with bitmap fonts where the typeface exists but doesn't have a font small enough.
Gets the RGB colour of an individual pixel on a bitmapped graphics device.
This pure virtual function is implemented in derived classes.
| Parameters | |
|---|---|
| aColor | On return, should contain the RGB colour of the pixel. |
| aPixel | The (x,y) co-ordinates of the pixel. The top left pixel is (0,0). |
| void | GetScanLine | ( | TDes8 & | aBuf, |
| const TPoint & | aStartPixel, | |||
| TInt | aLength, | |||
| TDisplayMode | aDispMode | |||
| ) | const [pure virtual] | |||
Copies a scanline into a buffer.
The pixels are converted from the display mode format on the bitmapped graphics device to the format of the specified device display mode.
By specifying the start pixel and the number of pixels, either the whole or a portion of a bitmapped graphics device pixel row may be copied.
This pure virtual function is implemented in derived classes.
| Parameters | |
|---|---|
| aBuf | An 8 bit modifiable descriptor buffer into which pixels are copied; it must be sufficiently large to store all the scanline pixels. |
| aStartPixel | The (x,y) co-ordinates of the first pixel of the bitmap scanline to be put into the buffer. |
| aLength | The number of pixels to put into the buffer. |
| aDispMode | The display mode into which to convert the pixels. |
| void | RemoveFile | ( | TInt | aId = 0 | ) | [pure virtual] |
Removes a font file from the font store.
This pure virtual function is implemented in derived classes.
| Parameters | |
|---|---|
| aId | The ID of the font file to be removed. The default is 0. |