Fl_Image Class Reference

Base class for image caching and drawing. More...

#include <Fl_Image.H>

Inheritance diagram for Fl_Image:

Public Member Functions
int	w () const
int	h () const
int	d () const
int	ld () const
int	count () const
const char *const *	data () const
int	fail ()
	Fl_Image (int W, int H, int D)
virtual	~Fl_Image ()
virtual Fl_Image *	copy (int W, int H)
Fl_Image *	copy ()
virtual void	color_average (Fl_Color c, float i)
void	inactive ()
virtual void	desaturate ()
virtual void	label (Fl_Widget *w)
virtual void	label (Fl_Menu_Item *m)
virtual void	draw (int X, int Y, int W, int H, int cx=0, int cy=0)
void	draw (int X, int Y)
virtual void	uncache ()

Static Public Member Functions
static void	RGB_scaling (Fl_RGB_Scaling)
static Fl_RGB_Scaling	RGB_scaling ()

Static Public Attributes
static const int	ERR_NO_IMAGE = -1
static const int	ERR_FILE_ACCESS = -2
static const int	ERR_FORMAT = -3

Protected Member Functions
void	w (int W)
void	h (int H)
void	d (int D)
void	ld (int LD)
void	data (const char *const *p, int c)
void	draw_empty (int X, int Y)

Static Protected Member Functions
static void	labeltype (const Fl_Label *lo, int lx, int ly, int lw, int lh, Fl_Align la)
static void	measure (const Fl_Label *lo, int &lw, int &lh)

Private Member Functions
Fl_Image &	operator= (const Fl_Image &)
	Fl_Image (const Fl_Image &)

Private Attributes
int	w_
int	h_
int	d_
int	ld_
int	count_
const char *const *	data_

Static Private Attributes
static Fl_RGB_Scaling	RGB_scaling_ = FL_RGB_SCALING_NEAREST

Detailed Description

Base class for image caching and drawing.

Fl_Image is the base class used for caching and drawing all kinds of images in FLTK. This class keeps track of common image data such as the pixels, colormap, width, height, and depth. Virtual methods are used to provide type-specific image handling.

Since the Fl_Image class does not support image drawing by itself, calling the draw() method results in a box with an X in it being drawn instead.

Definition at line 55 of file Fl_Image.H.

Constructor & Destructor Documentation

Fl_Image() [1/2]

Fl_Image::Fl_Image ( const Fl_Image &  )

private

Referenced by copy().

Fl_Image() [2/2]

Fl_Image::Fl_Image	(	int	W,
		int	H,
		int	D
	)

The constructor creates an empty image with the specified width, height, and depth. The width and height are in pixels. The depth is 0 for bitmaps, 1 for pixmap (colormap) images, and 1 to 4 for color images.

Definition at line 47 of file Fl_Image.cxx.

~Fl_Image()

Fl_Image::~Fl_Image ( )

virtual

The destructor is a virtual method that frees all memory used by the image.

Definition at line 55 of file Fl_Image.cxx.

Member Function Documentation

color_average()

void Fl_Image::color_average ( Fl_Color  c, float  i  )

virtual

The color_average() method averages the colors in the image with the FLTK color value c. The i argument specifies the amount of the original image to combine with the color, so a value of 1.0 results in no color blend, and a value of 0.0 results in a constant image of the specified color.

An internal copy is made of the original image before changes are applied, to avoid modifying the original image.

Reimplemented in Fl_RGB_Image, Fl_Shared_Image, Fl_Pixmap, and Fl_Tiled_Image.

Definition at line 106 of file Fl_Image.cxx.

Referenced by Fl_Tiled_Image::color_average(), and Fl_Shared_Image::color_average().

copy() [1/2]

Fl_Image* Fl_Image::copy ( )

inline

The copy() method creates a copy of the specified image. If the width and height are provided, the image is resized to the specified size. The image should be deleted (or in the case of Fl_Shared_Image, released) when you are done with it.

Definition at line 150 of file Fl_Image.H.

References copy().

Referenced by copy().

copy() [2/2]

Fl_Image * Fl_Image::copy ( int  W, int  H  )

virtual

The copy() method creates a copy of the specified image. If the width and height are provided, the image is resized to the specified size. The image should be deleted (or in the case of Fl_Shared_Image, released) when you are done with it.

Reimplemented in Fl_RGB_Image, Fl_Shared_Image, Fl_Pixmap, Fl_Bitmap, and Fl_Tiled_Image.

Definition at line 91 of file Fl_Image.cxx.

References d(), Fl_Image(), and H.

Referenced by Fl_Tree_Prefs::closeicon(), Fl_Tiled_Image::color_average(), Fl_Window::combine_mask(), Fl_Shared_Image::copy(), Fl_Tiled_Image::desaturate(), Fl_Shared_Image::draw(), Fl_Window::draw(), Fl_Tree_Prefs::Fl_Tree_Prefs(), Fl_Tree_Prefs::openicon(), Fl_Shared_Image::reload(), and Fl_Tree_Prefs::usericon().

count()

int Fl_Image::count ( ) const

inline

The count() method returns the number of data values associated with the image. The value will be 0 for images with no associated data, 1 for bitmap and color images, and greater than 2 for pixmap images.

Definition at line 133 of file Fl_Image.H.

Referenced by Fl_Pixmap::delete_data(), Fl_Shared_Image::draw(), Fl_File_Icon::load_image(), Fl_Window::shape(), Fl_Shared_Image::update(), Fl_File_Chooser::update_preview(), and Fluid_Image::write_static().

d() [1/2]

int Fl_Image::d ( ) const

inline

Returns the current image depth. The return value will be 0 for bitmaps, 1 for pixmaps, and 1 to 4 for color images.

Definition at line 121 of file Fl_Image.H.

Referenced by Fl_RGB_Image::color_average(), copy(), Fl_RGB_Image::copy(), Fl_RGB_Image::desaturate(), Fl_Shared_Image::draw(), Fl_BMP_Image::Fl_BMP_Image(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), fl_mult_matrix(), Fl_PNM_Image::Fl_PNM_Image(), Fl_RGB_Image::Fl_RGB_Image(), fl_rotate(), Fl_Graphics_Driver::font_descriptor(), Fl_PNG_Image::load_png_(), and Fl_Shared_Image::update().

d() [2/2]

void Fl_Image::d ( int  D )

inlineprotected

Sets the current image depth.

Definition at line 84 of file Fl_Image.H.

Referenced by alpha_blend(), Fl_PostScript_Graphics_Driver::draw(), Fl_Xlib_Graphics_Driver::draw(), fl_handle(), icons_to_property(), image_to_icon(), Fl_File_Icon::load_image(), Fl_Gl_Device_Plugin::print(), Fl_Window::shape(), Fl_Window::shape_alpha_(), Fl_Shared_Image::update(), Fl_File_Chooser::update_preview(), write_image_inside(), and Fluid_Image::write_static().

data() [1/2]

const char* const * Fl_Image::data ( ) const

inline

Returns a pointer to the current image data array. Use the count() method to find the size of the data array.

Definition at line 138 of file Fl_Image.H.

Referenced by Fl_Pixmap::color_average(), Fl_Pixmap::copy(), Fl_Pixmap::copy_data(), Fl_Pixmap::delete_data(), Fl_Pixmap::desaturate(), Fl_Bitmap::Fl_Bitmap(), fl_draw_image(), fl_draw_image_mono(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), Fl_RGB_Image::Fl_RGB_Image(), Fl_XPM_Image::Fl_XPM_Image(), Fl_Pixmap::measure(), Fl_Pixmap::prepare(), Fl_Pixmap::set_data(), and Fl_Shared_Image::update().

data() [2/2]

void Fl_Image::data ( const char *const *  p, int  c  )

inlineprotected

Sets the current array pointer and count of pointers in the array.

Definition at line 100 of file Fl_Image.H.

References p.

Referenced by Fl_Window::combine_mask(), Fl_PostScript_Graphics_Driver::draw(), fl_handle(), Fl_RGB_Image::Fl_RGB_Image(), icons_to_property(), image_to_icon(), Fl_File_Icon::load_image(), Fl_Window::shape_alpha_(), start(), Fl_Shared_Image::update(), and Fluid_Image::write_static().

desaturate()

void Fl_Image::desaturate ( )

virtual

The desaturate() method converts an image to grayscale. If the image contains an alpha channel (depth = 4), the alpha channel is preserved.

An internal copy is made of the original image before changes are applied, to avoid modifying the original image.

Reimplemented in Fl_RGB_Image, Fl_Shared_Image, Fl_Pixmap, and Fl_Tiled_Image.

Definition at line 117 of file Fl_Image.cxx.

Referenced by Fl_Tiled_Image::desaturate(), and Fl_Shared_Image::desaturate().

draw() [1/2]

void Fl_Image::draw ( int  X, int  Y  )

inline

Draws the image. This form specifies the upper-lefthand corner of the image.

Definition at line 180 of file Fl_Image.H.

References draw(), and Y.

Referenced by draw().

draw() [2/2]

void Fl_Image::draw ( int  X, int  Y, int  W, int  H, int  cx = 0, int  cy = 0  )

virtual

Draws the image with a bounding box. Arguments X,Y,W,H specify a bounding box for the image, with the origin
(upper-left corner) of the image offset by the cx and cy arguments.

In other words: fl_push_clip(X,Y,W,H) is applied, the image is drawn with its upper-left corner at X-cx,Y-cy and its own width and height, fl_pop_clip() is applied.

Reimplemented in Fl_RGB_Image, Fl_Pixmap, Fl_Bitmap, Fl_Shared_Image, and Fl_Tiled_Image.

Definition at line 66 of file Fl_Image.cxx.

References draw_empty().

Referenced by Fl_Tiled_Image::draw(), Fl_Shared_Image::draw(), Fl_Tree_Item::draw(), Fl_Scroll::draw_clip(), Fl_PostScript_Graphics_Driver::draw_scaled(), fl_draw(), Fl_Browser::item_draw(), and labeltype().

draw_empty()

void Fl_Image::draw_empty ( int  X, int  Y  )

protected

The protected method draw_empty() draws a box with an X in it. It can be used to draw any image that lacks image data.

Definition at line 75 of file Fl_Image.cxx.

References fl_color(), FL_FOREGROUND_COLOR, fl_line(), fl_rect(), h(), w(), and Y.

Referenced by draw(), Fl_Xlib_Graphics_Driver::draw(), Fl_Pixmap::prepare(), and Fl_Bitmap::start().

fail()

int Fl_Image::fail

(

)

Returns a value that is not 0 if there is currently no image available.

Example use:

[..]
Fl_Box box(X,Y,W,H);
Fl_JPEG_Image jpg("/tmp/foo.jpg");
switch ( jpg.fail() ) {
    case Fl_Image::ERR_NO_IMAGE:
    case Fl_Image::ERR_FILE_ACCESS:
        fl_alert("/tmp/foo.jpg: %s", strerror(errno));    // shows actual os error to user
        exit(1);
    case Fl_Image::ERR_FORMAT:
        fl_alert("/tmp/foo.jpg: couldn't decode image");
        exit(1);
}
box.image(jpg);
[..]

Returns

ERR_NO_IMAGE if no image was found

ERR_FILE_ACCESS if there was a file access related error (errno should be set)

ERR_FORMAT if image decoding failed.

Definition at line 169 of file Fl_Image.cxx.

References d_, ERR_NO_IMAGE, h_, ld_, and w_.

h() [1/2]

int Fl_Image::h ( ) const

inline

Returns the current image height in pixels.

Definition at line 115 of file Fl_Image.H.

Referenced by Fl_RGB_Image::color_average(), Fl_Tiled_Image::copy(), Fl_Bitmap::copy(), Fl_Pixmap::copy(), Fl_Shared_Image::copy(), Fl_RGB_Image::copy(), Fl_Pixmap::copy_data(), Fl_RGB_Image::desaturate(), Fl_Tiled_Image::draw(), Fl_Bitmap::draw(), Fl_Pixmap::draw(), Fl_Shared_Image::draw(), Fl_RGB_Image::draw(), draw_empty(), fl_arc(), Fl_BMP_Image::Fl_BMP_Image(), fl_clip_box(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), fl_not_clipped(), fl_pie(), Fl_PNM_Image::Fl_PNM_Image(), fl_push_clip(), fl_rect(), fl_rectf(), Fl_RGB_Image::Fl_RGB_Image(), fl_text_extents(), Fl_XBM_Image::Fl_XBM_Image(), Fl_PNG_Image::load_png_(), Fl_Pixmap::measure(), Fl_Pixmap::prepare(), Fl_Shared_Image::reload(), Fl_Shared_Image::scale(), Fl_Bitmap::start(), and Fl_Shared_Image::update().

h() [2/2]

void Fl_Image::h ( int  H )

inlineprotected

Sets the current image height in pixels.

Definition at line 80 of file Fl_Image.H.

References H.

Referenced by Fl_Tree_Item::calc_item_height(), Fl_Window::combine_mask(), Fl_Tiled_Image::draw(), Fl_Shared_Image::draw(), Fl_Tree_Item::draw(), Fl_PostScript_Graphics_Driver::draw(), Fl_Help_View::draw(), Fl_Xlib_Graphics_Driver::draw(), Fl_Widget::draw_backdrop(), Fl_PostScript_Graphics_Driver::draw_scaled(), Fluid_Image::find(), fl_draw(), fl_handle(), fl_normal_measure(), Fl_RGB_Image::Fl_RGB_Image(), Fl_Help_View::format(), Fl_Help_View::format_table(), Fl_Shared_Image::get(), Fl_Browser::icon(), icons_to_property(), image_to_icon(), Fl_Browser::item_height(), labeltype(), Fl_File_Icon::load_image(), measure(), Fl_Gl_Device_Plugin::print(), Fl_Shared_Image::reload(), Fl_Shared_Image::scale(), Fl_Window::shape_alpha_(), traverse_to_gl_subwindows(), Fl_Shared_Image::update(), Fl_File_Chooser::update_preview(), write_image_inside(), and Fluid_Image::write_static().

inactive()

void Fl_Image::inactive ( )

inline

The inactive() method calls color_average(FL_BACKGROUND_COLOR, 0.33f) to produce an image that appears grayed out.

An internal copy is made of the original image before changes are applied, to avoid modifying the original image.

Definition at line 160 of file Fl_Image.H.

References f, and FL_GRAY.

Referenced by Fl_Tree_Prefs::closeicon(), Fl_Tree_Prefs::Fl_Tree_Prefs(), Fl_Tree_Prefs::openicon(), and Fl_Tree_Prefs::usericon().

label() [1/2]

void Fl_Image::label ( Fl_Menu_Item *  m )

virtual

The label() methods are an obsolete way to set the image attribute of a widget or menu item. Use the image() or deimage() methods of the Fl_Widget and Fl_Menu_Item classes instead.

Reimplemented in Fl_RGB_Image, Fl_Pixmap, and Fl_Bitmap.

Definition at line 138 of file Fl_Image.cxx.

References _FL_IMAGE_LABEL, Fl_Menu_Item::label(), labeltype(), measure(), and Fl::set_labeltype().

label() [2/2]

void Fl_Image::label ( Fl_Widget *  widget )

virtual

The label() methods are an obsolete way to set the image attribute of a widget or menu item. Use the image() or deimage() methods of the Fl_Widget and Fl_Menu_Item classes instead.

Reimplemented in Fl_RGB_Image, Fl_Pixmap, and Fl_Bitmap.

Definition at line 127 of file Fl_Image.cxx.

References Fl_Widget::image().

Referenced by Fl_Menu_Type::build_menu(), Fl_Input_Choice_Type::build_menu(), and Fl_Menu_Item::image().

labeltype()

void Fl_Image::labeltype ( const Fl_Label *  lo, int  lx, int  ly, int  lw, int  lh, Fl_Align  la  )

staticprotected

Definition at line 182 of file Fl_Image.cxx.

References Fl_Label::color, draw(), FL_ALIGN_BOTTOM, FL_ALIGN_LEFT, FL_ALIGN_RIGHT, FL_ALIGN_TOP, fl_color(), h(), Fl_Label::value, and w().

Referenced by Fl_Bitmap::label(), Fl_Pixmap::label(), label(), and Fl_RGB_Image::label().

ld() [1/2]

int Fl_Image::ld ( ) const

inline

Returns the current line data size in bytes.

See also

ld(int)

Definition at line 126 of file Fl_Image.H.

Referenced by Fl_RGB_Image::color_average(), Fl_RGB_Image::copy(), Fl_RGB_Image::desaturate(), Fl_BMP_Image::Fl_BMP_Image(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), Fl_PNM_Image::Fl_PNM_Image(), Fl_RGB_Image::Fl_RGB_Image(), and Fl_PNG_Image::load_png_().

ld() [2/2]

void Fl_Image::ld ( int  LD )

inlineprotected

Sets the current line data size in bytes.

Color images may contain extra data that is included after every line of color image data and is normally not present.

If LD is zero, then line data size is assumed to be w() * d() bytes.

If LD is non-zero, then it must be positive and larger than w() * d() to account for the extra data per line.

Definition at line 96 of file Fl_Image.H.

Referenced by alpha_blend(), Fl_PostScript_Graphics_Driver::draw(), Fl_Xlib_Graphics_Driver::draw(), icons_to_property(), image_to_icon(), Fl_File_Icon::load_image(), Fl_Gl_Device_Plugin::print(), write_image_inside(), and Fluid_Image::write_static().

measure()

void Fl_Image::measure ( const Fl_Label *  lo, int &  lw, int &  lh  )

staticprotected

Definition at line 207 of file Fl_Image.cxx.

References h(), Fl_Label::value, and w().

Referenced by Fl_Pixmap::Fl_Pixmap(), Fl_Bitmap::label(), Fl_Pixmap::label(), label(), and Fl_RGB_Image::label().

operator=()

Fl_Image& Fl_Image::operator= ( const Fl_Image &  )

private

RGB_scaling() [1/2]

Fl_RGB_Scaling Fl_Image::RGB_scaling ( )

static

Returns the currently used RGB image scaling method.

Definition at line 226 of file Fl_Image.cxx.

References RGB_scaling_.

Referenced by Fl_RGB_Image::copy(), Fl_Shared_Image::draw(), and Fl_Paged_Device::draw_decorated_window().

RGB_scaling() [2/2]

void Fl_Image::RGB_scaling ( Fl_RGB_Scaling  method )

static

Sets the RGB image scaling method used for copy(int, int). Applies to all RGB images, defaults to FL_RGB_SCALING_NEAREST.

Definition at line 221 of file Fl_Image.cxx.

References RGB_scaling_.

uncache()

void Fl_Image::uncache ( )

virtual

If the image has been cached for display, delete the cache data. This allows you to change the data used for the image and then redraw it without recreating an image object.

Reimplemented in Fl_RGB_Image, Fl_Shared_Image, Fl_Pixmap, and Fl_Bitmap.

Definition at line 63 of file Fl_Image.cxx.

Referenced by Fl_Shared_Image::uncache().

w() [1/2]

int Fl_Image::w ( ) const

inline

Returns the current image width in pixels.

Definition at line 111 of file Fl_Image.H.

Referenced by Fl_RGB_Image::color_average(), Fl_Tiled_Image::copy(), Fl_Bitmap::copy(), Fl_Pixmap::copy(), Fl_Shared_Image::copy(), Fl_RGB_Image::copy(), Fl_Pixmap::copy_data(), Fl_RGB_Image::desaturate(), Fl_Tiled_Image::draw(), Fl_Bitmap::draw(), Fl_Pixmap::draw(), Fl_Shared_Image::draw(), Fl_RGB_Image::draw(), draw_empty(), fl_arc(), Fl_BMP_Image::Fl_BMP_Image(), fl_clip_box(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), fl_not_clipped(), fl_pie(), Fl_PNM_Image::Fl_PNM_Image(), fl_push_clip(), fl_rect(), fl_rectf(), Fl_RGB_Image::Fl_RGB_Image(), fl_text_extents(), Fl_XBM_Image::Fl_XBM_Image(), Fl_PNG_Image::load_png_(), Fl_Pixmap::measure(), Fl_Pixmap::prepare(), Fl_Shared_Image::reload(), Fl_Shared_Image::scale(), Fl_Bitmap::start(), and Fl_Shared_Image::update().

w() [2/2]

void Fl_Image::w ( int  W )

inlineprotected

Sets the current image width in pixels.

Definition at line 76 of file Fl_Image.H.

Referenced by alpha_blend(), Fl_Window::combine_mask(), Fl_Tiled_Image::draw(), Fl_Shared_Image::draw(), Fl_Tree_Item::draw(), Fl_PostScript_Graphics_Driver::draw(), Fl_Help_View::draw(), Fl_Xlib_Graphics_Driver::draw(), Fl_Widget::draw_backdrop(), Fl_PostScript_Graphics_Driver::draw_scaled(), Fl_Tree::draw_tree(), Fluid_Image::find(), find_best_icon(), fl_draw(), fl_handle(), fl_normal_measure(), Fl_RGB_Image::Fl_RGB_Image(), Fl_Help_View::format(), Fl_Help_View::format_table(), Fl_Shared_Image::get(), icons_to_property(), image_to_icon(), Fl_Browser::item_draw(), Fl_Browser::item_width(), labeltype(), Fl_File_Icon::load_image(), measure(), Fl_Gl_Device_Plugin::print(), Fl_Shared_Image::reload(), Fl_Shared_Image::scale(), Fl_Window::shape_alpha_(), traverse_to_gl_subwindows(), Fl_Shared_Image::update(), Fl_File_Chooser::update_preview(), write_image_inside(), and Fluid_Image::write_static().

Member Data Documentation

count_

int Fl_Image::count_

private

Definition at line 63 of file Fl_Image.H.

d_

int Fl_Image::d_

private

Definition at line 63 of file Fl_Image.H.

Referenced by fail().

data_

const char* const * Fl_Image::data_

private

Definition at line 64 of file Fl_Image.H.

ERR_FILE_ACCESS

const int Fl_Image::ERR_FILE_ACCESS = -2

static

Definition at line 59 of file Fl_Image.H.

Referenced by Fl_BMP_Image::Fl_BMP_Image(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), Fl_PNM_Image::Fl_PNM_Image(), and Fl_PNG_Image::load_png_().

ERR_FORMAT

const int Fl_Image::ERR_FORMAT = -3

static

Definition at line 60 of file Fl_Image.H.

Referenced by Fl_BMP_Image::Fl_BMP_Image(), Fl_GIF_Image::Fl_GIF_Image(), Fl_JPEG_Image::Fl_JPEG_Image(), Fl_PNM_Image::Fl_PNM_Image(), and Fl_PNG_Image::load_png_().

ERR_NO_IMAGE

const int Fl_Image::ERR_NO_IMAGE = -1

static

Definition at line 58 of file Fl_Image.H.

Referenced by fail().

h_

int Fl_Image::h_

private

Definition at line 63 of file Fl_Image.H.

Referenced by fail().

ld_

int Fl_Image::ld_

private

Definition at line 63 of file Fl_Image.H.

Referenced by fail().

RGB_scaling_

Fl_RGB_Scaling Fl_Image::RGB_scaling_ = FL_RGB_SCALING_NEAREST

staticprivate

Definition at line 65 of file Fl_Image.H.

Referenced by RGB_scaling().

w_

int Fl_Image::w_

private

Definition at line 63 of file Fl_Image.H.

Referenced by fail().

---

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

• FL/Fl_Image.H
• src/Fl_Image.cxx