pagespeed::image_compression::GifSquare Class Reference

Public Member Functions
	GifSquare (bool manual_gcb, net_instaweb::MessageHandler *handler)
bool	Open (const GoogleString &filename)
bool	PrepareScreen (bool gif89, size_px width, size_px height, const GifColorType *color_map, int num_colors, int bg_color_idx, size_t loop_count)
bool	PutImage (size_px left, size_px top, size_px width, size_px height, const GifColorType *colormap, int num_colors, int color_index, int transparent_idx, bool interlace, int delay_cs, int disposal_method)
bool	AnimateAllImages (int delay_cs, int transparent_idx, int disposal_method)
bool	Close ()
	Flushes and closes the GIF file.

Static Public Attributes
static const size_t	kNoLoopCountSpecified
static const GifColorType	kGifWhite
static const GifColorType	kGifBlack
static const GifColorType	kGifGray
static const GifColorType	kGifRed
static const GifColorType	kGifGreen
static const GifColorType	kGifBlue
static const GifColorType	kGifYellow

Member Function Documentation

bool pagespeed::image_compression::GifSquare::AnimateAllImages	(	int	delay_cs,
		int	transparent_idx,
		int	disposal_method
	)

Animates all GIF images by specifying that they should each be displayed for 'delay_cs' centiseconds, be disposed according to 'disposal_method', and have the 'transparent_idx' color of the previously-specified colormap be transparent

bool pagespeed::image_compression::GifSquare::Open

(

const GoogleString &

filename

)

Opens a GIF file under the given 'filename'. Returns true on success.

bool pagespeed::image_compression::GifSquare::PrepareScreen	(	bool	gif89,
		size_px	width,
		size_px	height,
		const GifColorType *	color_map,
		int	num_colors,
		int	bg_color_idx,
		size_t	loop_count
	)

Prepares the GIF screen to have dimensions 'width' by 'height', a background color 'bg_color_idx' into the 'colormap' of size 'num_colors' (a power of 2) that is used for the image. It marks this as a GIF89 image if 'gif89' is set. If loop_count is less than kNoLoopCountSpecified, it inserts an application extension block indicating to loop the animation forever (if zero) or the specified number of times. Returns true on success.

NOTE: Chrome (at least v35) interprets the loop_count as the number of times to repeat the animation, so the user will see the animation loop_count+1 times.

bool pagespeed::image_compression::GifSquare::PutImage	(	size_px	left,
		size_px	top,
		size_px	width,
		size_px	height,
		const GifColorType *	colormap,
		int	num_colors,
		int	color_index,
		int	transparent_idx,
		bool	interlace,
		int	delay_cs,
		int	disposal_method
	)

Puts a single GIF image. The image is a 'width' by 'height' rectangle whose color is given by the 'color_index'-th entry of the 'colormap', is positioned at position 'left', 'top' from the top left of the GIF screen, and will be discarded as per 'disposal_method'. The 'transparent_idx'-th color is marked as being fully transparent. The image is marked as being interlaced if 'interlace' is set, and is displayed for a duration of 'delay_cs' centiseconds.

Returns true on success.

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The documentation for this class was generated from the following file:

• pagespeed/kernel/image/gif_square.h