Graphics.UI.Gtk.ImageView.ImageView

Details

ImageView is a full-featured general purpose image viewer widget for GTK. It provides a scrollable, zoomable pane in which a pixbuf can be displayed.

Types

data ImageView

Instances

Eq ImageView

Ord ImageView

GObjectClass ImageView

ObjectClass ImageView

WidgetClass ImageView

ImageViewClass ImageView

class WidgetClass o => ImageViewClass o

Instances

ImageViewClass AnimView

ImageViewClass ImageView

Methods

imageViewNew :: IO ImageView

Creates a new image view with default values. The default values are:

• black bg : False * fitting : True * image tool : a ImageToolDragger instance * interpolation mode : InterpBilinear * offset : (0, 0) * pixbuf : Nothing * show cursor: True * show frame : True * transp : ImageTranspGrid * zoom : 1.0

imageViewGetViewport :: ImageViewClass view => view -> IO (Maybe Rectangle)

Fills in the rectangle with the current viewport. If pixbuf is Nothing, there is no viewport, rect is left untouched and False is returned. If the view is not allocated, the rectangles coordinates are set to the views offset and its width and height to zero.

The current viewport is defined as the rectangle, in zoomspace coordinates as the area of the loaded pixbuf the ImageView is currently showing.

imageViewGetDrawRect :: ImageViewClass view => view -> IO (Maybe Rectangle)

Get the rectangle in the widget where the pixbuf is painted.

For example, if the widgets allocated size is 100, 100 and the pixbufs size is 50, 50 and the zoom factor is 1.0, then the pixbuf will be drawn centered on the widget. rect will then be (25,25)-[50,50].

If the view is not allocated, then the rectangle will be set to (0,0)-[0,0] and True is returned.

This method is useful when converting from widget to image or zoom space coordinates.

imageViewGetCheckColors :: ImageViewClass view => view -> IO (Int, Int)

Reads the two colors used to draw transparent parts of images with an alpha channel. Note that if the transp setting of the view is ImageTranspBackground or ImageTranspColor, then both colors will be equal.

imageViewImageToWidgetRect

Arguments

:: ImageViewClass view

=> view

-> Rectangle

rectIn a Rectangle in image space coordinates to convert

-> Rectangle

rectOut a Rectangle to fill in with the widget space coordinates

-> IO Bool

returns True if the conversion was successful, False otherwise

Convert a rectangle in image space coordinates to widget space coordinates. If the view is not realized, or if it contains no pixbuf, then the conversion was unsuccessful, False is returned and rectOut is left unmodified.

The size of rectOut is rounded up. For example, if the zoom factor is 0.25 and the width of the input rectangle is 2, then its with in widget space coordinates is 0.5 which is rounded up to 1.

Note that this function may return a rectangle that is not visible on the widget.

imageViewSetOffset

Arguments

:: ImageViewClass view

=> view

-> Double

x X-component of the offset in zoom space coordinates.

-> Double

y Y-component of the offset in zoom space coordinates.

-> Bool

invalidate whether to invalidate the view or redraw immediately.

-> IO ()

Sets the offset of where in the image the ImageView should begin displaying image data.

The offset is clamped so that it will never cause the ImageView to display pixels outside the pixbuf. Setting this attribute causes the widget to repaint itself if it is realized.

If invalidate is True, the views entire area will be invalidated instead of redrawn immediately. The view is then queued for redraw, which means that additional operations can be performed on it before it is redrawn.

The difference can sometimes be important like when you are overlaying data and get flicker or artifacts when setting the offset. If that happens, setting invalidate to True could fix the problem. See the source code to ImageToolSelector for an example.

Normally, invalidate should always be False because it is much faster to repaint immedately than invalidating.

imageViewSetTransp

Arguments

:: ImageViewClass view

=> view

-> ImageTransp

transp The transparency type to use when drawing transparent images.

-> Int

transpColor Color to use when drawing transparent images.

-> IO ()

Sets how the view should draw transparent parts of images with an alpha channel. If transp is ImageTranspColor, the specified color will be used. Otherwise the transpColor argument is ignored. If it is ImageTranspBackground, the background color of the widget will be used. If it is ImageTranspGrid, then a grid with light and dark gray boxes will be drawn on the transparent parts.

Calling this method causes the widget to immediately repaint. It also causes the pixbufChanged signal to be emitted. This is done so that other widgets (such as ImageNav) will have a chance to render a view of the pixbuf with the new transparency settings.

The default values are:

• transp : ImageTranspGrid * transpColor : 0x000000

imageViewGetFitting

Arguments

:: ImageViewClass view

=> view

-> IO Bool

returns True if the view is fitting the image, False otherwise.

Returns the fitting setting of the view.

imageViewSetFitting

Arguments

:: ImageViewClass view

=> view

-> Bool

fitting whether to fit the image or not

-> IO ()

Sets whether to fit or not. If True, then the view will adapt the zoom so that the whole pixbuf is visible.

Setting the fitting causes the widget to immediately repaint itself.

Fitting is by default True.

imageViewGetPixbuf

Arguments

:: ImageViewClass view

=> view

-> IO Pixbuf

returns The pixbuf this view shows.

Returns the pixbuf this view shows.

imageViewSetPixbuf

Arguments

:: ImageViewClass view

=> view

-> Maybe Pixbuf

pixbuf The pixbuf to display or Nothing

-> Bool

resetFit Whether to reset fitting or not.

-> IO ()

Sets the pixbuf to display, or Nothing to not display any pixbuf. Normally, resetFit should be True which enables fitting. Which means that, initially, the whole pixbuf will be shown.

Sometimes, the fit mode should not be reset. For example, if ImageView is showing an animation, it would be bad to reset the fit mode for each new frame. The parameter should then be False which leaves the fit mode of the view untouched.

This method should not be used if merely the contents of the pixbuf has changed. See imageViewDamagePixels for that.

If resetFit is True, the zoomChanged signal is emitted, otherwise not. The pixbufChanged signal is also emitted.

The default pixbuf is Nothing.

imageViewGetZoom

Arguments

:: ImageViewClass view

=> view

-> IO Double

returns the current zoom factor

Get the current zoom factor of the view.

imageViewSetZoom

Arguments

:: ImageViewClass view

=> view

-> Double

zoom the new zoom factor

-> IO ()

Sets the zoom of the view.

Fitting is always disabled after this method has run. The zoomChanged signal is unconditionally emitted.

The default value is 1.0.

imageViewSetBlackBg

Arguments

:: ImageViewClass view

=> view

-> Bool

blackBg Whether to use a black background or not.

-> IO ()

If True, the view uses a black background. If False, the view uses the default (normally gray) background.

The default value is False.

imageViewGetBlackBg

Arguments

:: ImageViewClass view

=> view

-> IO Bool

returns True if a black background is used, otherwise False.

Returns whether the view renders the widget on a black background or not.

imageViewSetShowFrame

Arguments

:: ImageViewClass view

=> view

-> Bool

showFrame whether to show a frame around the pixbuf or not

-> IO ()

Sets whether to draw a frame around the image or not. When True, a one pixel wide frame is shown around the image. Setting this attribute causes the widget to immediately repaint itself.

The default value is True.

imageViewGetShowFrame :: ImageViewClass view => view -> IO Bool

Returns whether a one pixel frame is drawn around the pixbuf or not.

imageViewSetInterpolation

Arguments

:: ImageViewClass view

=> view

-> InterpType

interp The interpolation to use. One of InterpNearest, InterpBilinear and InterpHyper.

-> IO ()

Sets the interpolation mode of how the view. InterpHyper is the slowest, but produces the best results. InterpNearest is the fastest, but provides bad rendering quality. InterpBilinear is a good compromise.

Setting the interpolation mode causes the widget to immediately repaint itself.

The default interpolation mode is InterpBilinear.

imageViewGetInterpolation :: ImageViewClass view => view -> IO InterpType

Returns the current interpolation mode of the view.

imageViewSetShowCursor

Arguments

:: ImageViewClass view

=> view

-> Bool

showCursor whether to show the cursor or not

-> IO ()

Sets whether to show the mouse cursor when the mouse is over the widget or not. Hiding the cursor is useful when the widget is fullscreened.

The default value is True.

imageViewGetShowCursor

Arguments

:: ImageViewClass view

=> view

-> IO Bool

returns True if the cursor is shown, otherwise False.

Returns whether to show the mouse cursor when the mouse is over the widget or not.

imageViewSetTool

Arguments

:: ImageViewClass view

=> view

-> IImageTool

tool The image tool to usek (must not be Nothing)

-> IO ()

Set the image tool to use. If the new tool is the same as the current tool, then nothing will be done. Otherwise iimageToolPixbufChanged is called so that the tool has a chance to generate initial data for the pixbuf.

Setting the tool causes the widget to immediately repaint itself.

The default image tool is a ImageToolDragger instance. See also IImageTool.

imageViewGetTool :: ImageViewClass view => view -> IO IImageTool

Gets the image tool ImageView uses for rendering and handling input events.

imageViewZoomIn :: ImageViewClass view => view -> IO ()

Zoom in the view one step. Calling this method causes the widget to immediately repaint itself.

imageViewZoomOut :: ImageViewClass view => view -> IO ()

Zoom out the view one step. Calling this method causes the widget to immediately repaint itself.

imageViewDamagePixels

Arguments

:: ImageViewClass view

=> view

-> Maybe Rectangle

rect rectangle in image space coordinates to mark as damaged or Nothing, to mark the whole pixbuf as damaged.

-> IO ()

Mark the pixels in the rectangle as damaged. That the pixels are damaged, means that they have been modified and that the view must redraw them to ensure that the visible part of the image corresponds to the pixels in that image. Calling this method emits the pixbufChanged signal.

This method must be used when modifying the image data:

'imageViewDamagePixels (View, &(Gdkrectangle){20, 20, 60, 60})';

If the whole pixbuf has been modified then rect should be Nothing to indicate that a total update is needed. | See also imageViewSetPixbuf.

imageViewLibraryVersion :: IO String

Returns a string with the format major.minor.micro which denotes the runtime version of ImageView being used.

Signals

mouseWheelScroll :: ImageViewClass view => Signal view (ScrollDirection -> IO ())

The mouseWheelScroll signal is emitted when the mouse wheel is scrolled on the view and ControlMask is not held down.

pixbufChanged :: ImageViewClass view => Signal view (IO ())

The pixbufChanged signal is emitted when the pixbuf the image view shows is changed and when its image data is changed. Listening to this signal is useful if you, for example, have a label that displays the width and height of the pixbuf in the view.

scroll :: ImageViewClass view => Signal view (ScrollType -> ScrollType -> IO ())

The scroll signal is a keybinding signal emitted when a key is used to scroll the view. The signal should not be used by clients of this library.

setFitting :: ImageViewClass view => Signal view (Int -> IO ())

setScrollAdjustments :: ImageViewClass view => Signal view (Adjustment -> Adjustment -> IO ())

setZoom :: ImageViewClass view => Signal view (Double -> IO ())

The setZoom signal is a keybinding signal emitted when GDK_1, GDK_2 or GDK_3 is pressed on the widget which causes the zoom to be set to 100%, 200% or 300%. The signal should not be used by clients of this library.

zoomChanged :: ImageViewClass view => Signal view (IO ())

The zoomChanged signal is emitted when the zoom factor of the view changes. Listening to this signal is useful if, for example, you have a label that displays the zoom factor of the view. Use imageViewGetZoom to retrieve the value.

zoomIn :: ImageViewClass view => Signal view (IO ())

zoomOut :: ImageViewClass view => Signal view (IO ())