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Graphics.UI.Gtk.Display.Image

Portability | portable (depends on GHC)
Stability | provisional
Maintainer | gtk2hs-users@lists.sourceforge.net

Contents

Detail
Class Hierarchy
Types
Constructors
Methods
Icon Sizes
Attributes

Description
A widget displaying an image
Synopsis

data Image
class MiscClass o => ImageClass o
castToImage :: GObjectClass obj => obj -> Image
toImage :: ImageClass o => o -> Image

data ImageType

= ImageEmpty
| ImagePixmap
| ImageImage
| ImagePixbuf
| ImageStock
| ImageIconSet
| ImageAnimation
| ImageIconName
| ImageGicon

imageNewFromFile :: FilePath -> IO Image
imageNewFromPixbuf :: Pixbuf -> IO Image
imageNewFromStock :: StockId -> IconSize -> IO Image
imageNew :: IO Image
imageNewFromIconName :: String -> IconSize -> IO Image
imageGetPixbuf :: Image -> IO Pixbuf
imageSetFromPixbuf :: Image -> Pixbuf -> IO ()
imageSetFromFile :: Image -> FilePath -> IO ()
imageSetFromStock :: Image -> StockId -> IconSize -> IO ()
imageSetFromIconName :: Image -> String -> IconSize -> IO ()
imageSetPixelSize :: Image -> Int -> IO ()
imageGetPixelSize :: Image -> IO Int
imageClear :: Image -> IO ()

data IconSize

= IconSizeInvalid
| IconSizeMenu
| IconSizeSmallToolbar
| IconSizeLargeToolbar
| IconSizeButton
| IconSizeDnd
| IconSizeDialog
| IconSizeUser Int

imagePixbuf :: PixbufClass pixbuf => ReadWriteAttr Image Pixbuf pixbuf
imagePixmap :: PixmapClass pixmap => ReadWriteAttr Image Pixmap pixmap
imageImage :: ImageClass image => ReadWriteAttr Image Image image
imageMask :: PixmapClass pixmap => ReadWriteAttr Image Pixmap pixmap
imageFile :: Attr Image String
imageStock :: Attr Image String
imageIconSize :: Attr Image Int
imagePixelSize :: Attr Image Int
imageIconName :: Attr Image String
imageStorageType :: ReadAttr Image ImageType

Detail

The `Image` widget displays an image. Various kinds of object can be displayed as an image; most typically, you would load a `Pixbuf` ("pixel buffer") from a file, and then display that. There's a convenience function to do this, `imageNewFromFile`, used as follows: If the file isn't loaded successfully, the image will contain a "broken image" icon similar to that used in many web browsers. If you want to handle errors in loading the file yourself, for example by displaying an error message, then load the image with Graphics.UI.Gtk.Gdk.Pixbuf.pixbufNewFromFile, then create the `Image` with `imageNewFromPixbuf`.

       image <- imageNewFromFile "myfile.png"

The image file may contain an animation, if so the `Image` will display an animation (PixbufAnimation) instead of a static image.

`Image` is a subclass of `Misc`, which implies that you can align it (center, left, right) and add padding to it, using `Misc` methods.

`Image` is a "no window" widget (has no `DrawWindow` of its own), so by default does not receive events. If you want to receive events on the image, such as button clicks, place the image inside a `EventBox`, then connect to the event signals on the event box.

When handling events on the event box, keep in mind that coordinates in the image may be different from event box coordinates due to the alignment and padding settings on the image (see `Misc`). The simplest way to solve this is to set the alignment to 0.0 (left/top), and set the padding to zero. Then the origin of the image will be the same as the origin of the event box.

Sometimes an application will want to avoid depending on external data files, such as image files. Gtk+ comes with a program to avoid this, called gdk-pixbuf-csource. This program allows you to convert an image into a C variable declaration, which can then be loaded into a `Pixbuf` using Graphics.UI.Gtk.Gdk.Pixbuf.pixbufNewFromInline.

Class Hierarchy

     |  GObject
     |   +----Object
     |         +----Widget
     |               +----Misc
     |                     +----Image

Types
data Image

Instances

GObjectClass Image
ImageClass Image
MiscClass Image
WidgetClass Image
ObjectClass Image

class MiscClass o => ImageClass o

Instances

ImageClass Image

castToImage :: GObjectClass obj => obj -> Image
toImage :: ImageClass o => o -> Image
data ImageType

Describes the image data representation used by a `Image`. If you want to get the image from the widget, you can only get the currently-stored representation. e.g. if the `imageStorageType` is `ImagePixbuf`, then you can call `imageGetPixbuf` but not imageGetStock. For empty images, you can request any storage type (call any of the get functions), but they will all return `Nothing`.
Constructors

ImageEmpty |
ImagePixmap |
ImageImage |
ImagePixbuf |
ImageStock |
ImageIconSet |
ImageAnimation |
ImageIconName |
ImageGicon |

Instances

Enum ImageType

Constructors
imageNewFromFile :: FilePath -> IO Image

Creates a new `Image` displaying the file `filename`. If the file isn't found or can't be loaded, the resulting `Image` will display a "broken image" icon.

If the file contains an animation, the image will contain an animation.

If you need to detect failures to load the file, use Graphics.UI.Gtk.Gdk.Pixbuf.pixbufNewFromFile to load the file yourself, then create the `Image` from the pixbuf. (Or for animations, use Graphics.UI.Gtk.Gdk.Pixbuf.pixbufAnimationNewFromFile).

The storage type (imageGetStorageType) of the returned image is not defined, it will be whatever is appropriate for displaying the file.

imageNewFromPixbuf :: Pixbuf -> IO Image
Creates a new `Image` displaying a `Pixbuf`. Note that this function just creates an `Image` from the pixbuf. The `Image` created will not react to state changes. Should you want that, you should use imageNewFromIconSet.
imageNewFromStock

:: StockId | `stockId` - a stock icon name
-> IconSize | `size` - a stock icon size
-> IO Image |
Creates a `Image` displaying a stock icon. If the stock icon name isn't known, the image will be empty.

imageNew :: IO Image
Creates a new empty `Image` widget.
imageNewFromIconName

:: String | `iconName` - an icon name
-> IconSize | `size` - a stock icon size
-> IO Image |

Creates a `Image` displaying an icon from the current icon theme. If the icon name isn't known, a "broken image" icon will be displayed instead. If the current icon theme is changed, the icon will be updated appropriately.

- Available since Gtk+ version 2.6

Methods
imageGetPixbuf :: Image -> IO Pixbuf
Gets the `Pixbuf` being displayed by the `Image`. The storage type of the image must be `ImageEmpty` or `ImagePixbuf` (see imageGetStorageType).
imageSetFromPixbuf :: Image -> Pixbuf -> IO ()
Overwrite the current content of the `Image` with a new `Pixbuf`.
imageSetFromFile :: Image -> FilePath -> IO ()
See `imageNewFromFile` for details.
imageSetFromStock

:: Image |
-> StockId | `stockId` - a stock icon name
-> IconSize | `size` - a stock icon size
-> IO () |
See `imageNewFromStock` for details.

imageSetFromIconName

:: Image |
-> String | `iconName` - an icon name
-> IconSize | `size` - an icon size
-> IO () |

See `imageNewFromIconName` for details.

- Available since Gtk+ version 2.6

imageSetPixelSize

:: Image |
-> Int | `pixelSize` - the new pixel size
-> IO () |

Sets the pixel size to use for named icons. If the pixel size is set to a `value /= -1`, it is used instead of the icon size set by `imageSetFromIconName`.

- Available since Gtk+ version 2.6

imageGetPixelSize :: Image -> IO Int

Gets the pixel size used for named icons.

- Available since Gtk+ version 2.6

imageClear :: Image -> IO ()

Resets the image to be empty.

- Available since Gtk+ version 2.8

Icon Sizes
data IconSize

The size of an icon in pixels.

- This enumeration contains one case that is not exported and which is used when new sizes are registered using Graphics.UI.Gtk.General.IconFactory.iconSizeRegister.
- Applying `show` to this type will reveal the name of the size that is registered with Gtk+.

Constructors

IconSizeInvalid | Don't scale but use any of the available sizes.
IconSizeMenu | Icon size to use in next to menu items in drop-down menus.
IconSizeSmallToolbar | Icon size for small toolbars.
IconSizeLargeToolbar | Icon size for larger toolbars.
IconSizeButton | Icon size for icons in buttons, next to the label.
IconSizeDnd | Icon size for icons in drag-and-drop.
IconSizeDialog | Icon size for icons next to dialog text.
IconSizeUser Int |

Instances

Enum IconSize
Eq IconSize
Show IconSize

Attributes
imagePixbuf :: PixbufClass pixbuf => ReadWriteAttr Image Pixbuf pixbuf
A `Pixbuf` to display.
imagePixmap :: PixmapClass pixmap => ReadWriteAttr Image Pixmap pixmap
A `Pixmap` to display.
imageImage :: ImageClass image => ReadWriteAttr Image Image image
A `Image` to display.
imageMask :: PixmapClass pixmap => ReadWriteAttr Image Pixmap pixmap
Mask bitmap to use with `Image` or `Pixmap`.
imageFile :: Attr Image String
Filename to load and display. Default value: ""
imageStock :: Attr Image String
Stock ID for a stock image to display. Default value: ""
imageIconSize :: Attr Image Int
Symbolic size to use for stock icon, icon set or named icon. Allowed values: >= 0 Default value: 4
imagePixelSize :: Attr Image Int
The pixel-size property can be used to specify a fixed size overriding the icon-size property for images of type `ImageIconName`. Allowed values: >= -1 Default value: -1
imageIconName :: Attr Image String
The name of the icon in the icon theme. If the icon theme is changed, the image will be updated automatically. Default value: ""
imageStorageType :: ReadAttr Image ImageType
The representation being used for image data. Default value: `ImageEmpty`
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