[wxWidgets.git] / contrib / src / gizmos / statpict.txt

wxStaticPicture class
by Wade Brainerd (wadeb@wadeb.com)

Description:

This class is an improved version of wxStaticBitmap.  

Rather than using a native bitmap control, it uses DC operations to draw the
control.  This makes its appearance more consistent across platforms, and
allows for additional features.

Features include:

  wxStaticBitmap compatible API - drop-in replacement.  Image alignment - top,
  left, bottom, right, center vertical and/or horizontal.
  Image scaling - scale horizontally and/or vertically, justified scaling
  (maintains image aspect ratio).

Platforms tested:  

  wxMSW
  wxGTK
  wxMac
  
Implementation notes:

Under MSW wxWindows uses the operating system to do an optimized (potentially
hardware accelerated) blit in wxDC::DrawBitmap.  This is usually fast enough to
do image scaling without affecting the program's interactivity.  

On wxMac and wxGTK however, wxDC::DrawBitmap implicitly calls wxImage::Scale 
which is a much slower operation.  Therefore, on these platforms wxStaticPicture 
caches the scaled image to make updates that don't change the image (overlapping 
windows, etc.) faster.
Commit	Line	Data
fca36d9a JS	1	wxStaticPicture class
	2	by Wade Brainerd (wadeb@wadeb.com)
	3
	4	Description:
	5
	6	This class is an improved version of wxStaticBitmap.
	7
	8	Rather than using a native bitmap control, it uses DC operations to draw the
	9	control. This makes its appearance more consistent across platforms, and
	10	allows for additional features.
	11
	12	Features include:
	13
	14	wxStaticBitmap compatible API - drop-in replacement. Image alignment - top,
	15	left, bottom, right, center vertical and/or horizontal.
	16	Image scaling - scale horizontally and/or vertically, justified scaling
	17	(maintains image aspect ratio).
	18
	19	Platforms tested:
	20
	21	wxMSW
	22	wxGTK
	23	wxMac
	24
	25	Implementation notes:
	26
	27	Under MSW wxWindows uses the operating system to do an optimized (potentially
	28	hardware accelerated) blit in wxDC::DrawBitmap. This is usually fast enough to
	29	do image scaling without affecting the program's interactivity.
	30
	31	On wxMac and wxGTK however, wxDC::DrawBitmap implicitly calls wxImage::Scale
	32	which is a much slower operation. Therefore, on these platforms wxStaticPicture
	33	caches the scaled image to make updates that don't change the image (overlapping
	34	windows, etc.) faster.