Struct gtk::Image

source · []
#[repr(transparent)]
pub struct Image { /* private fields */ }
Expand description

The Image widget displays an image. Various kinds of object can be displayed as an image; most typically, you would load a gdk_pixbuf::Pixbuf (“pixel buffer”) from a file, and then display that. There’s a convenience function to do this, from_file(), used as follows:

⚠️ The following code is in C ⚠️

  GtkWidget *image;
  image = gtk_image_new_from_file ("myfile.png");

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 gdk_pixbuf::Pixbuf::from_file(), then create the Image with from_pixbuf().

The image file may contain an animation, if so the Image will display an animation (gdk_pixbuf::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 gdk::Window 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.

Handling button press events on a Image.

⚠️ The following code is in C ⚠️

  static gboolean
  button_press_callback (GtkWidget      *event_box,
                         GdkEventButton *event,
                         gpointer        data)
  {
    g_print ("Event box clicked at coordinates %f,%f\n",
             event->x, event->y);

    // Returning TRUE means we handled the event, so the signal
    // emission should be stopped (don’t call any further callbacks
    // that may be connected). Return FALSE to continue invoking callbacks.
    return TRUE;
  }

  static GtkWidget*
  create_image (void)
  {
    GtkWidget *image;
    GtkWidget *event_box;

    image = gtk_image_new_from_file ("myfile.png");

    event_box = gtk_event_box_new ();

    gtk_container_add (GTK_CONTAINER (event_box), image);

    g_signal_connect (G_OBJECT (event_box),
                      "button_press_event",
                      G_CALLBACK (button_press_callback),
                      image);

    return image;
  }

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 library allows you to convert an image into a C variable declaration, which can then be loaded into a gdk_pixbuf::Pixbuf using gdk_pixbuf_new_from_inline().

CSS nodes

GtkImage has a single CSS node with the name image. The style classes may appear on image CSS nodes: .icon-dropshadow, .lowres-icon.

Implements

ImageExt, [MiscExt][trait@crate::prelude::MiscExt], WidgetExt, glib::ObjectExt, BuildableExt, ImageExtManual, WidgetExtManual, BuildableExtManual

Implementations

Creates a new empty Image widget.

Returns

a newly created Image widget.

Creates a Image displaying the given animation. The Image does not assume a reference to the animation; you still need to unref it if you own references. Image will add its own reference rather than adopting yours.

Note that the animation frames are shown using a timeout with G_PRIORITY_DEFAULT. When using animations to indicate busyness, keep in mind that the animation will only be shown if the main loop is not busy with something that has a higher priority.

animation

an animation

Returns

a new Image widget

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. This function never returns None, it always returns a valid Image widget.

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

If you need to detect failures to load the file, use gdk_pixbuf::Pixbuf::from_file() to load the file yourself, then create the Image from the pixbuf. (Or for animations, use gdk_pixbuf::PixbufAnimation::from_file()).

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

filename

a filename

Returns

a new 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.

icon

an icon

size

a stock icon size (IconSize)

Returns

a new Image displaying the themed icon

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.

icon_name

an icon name or None

size

a stock icon size (IconSize)

Returns

a new Image displaying the themed icon

Creates a new Image displaying pixbuf. The Image does not assume a reference to the pixbuf; you still need to unref it if you own references. Image will add its own reference rather than adopting yours.

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 from_icon_name().

pixbuf

a gdk_pixbuf::Pixbuf, or None

Returns

a new Image

Creates a new Image displaying the resource file resource_path. If the file isn’t found or can’t be loaded, the resulting Image will display a “broken image” icon. This function never returns None, it always returns a valid Image widget.

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

If you need to detect failures to load the file, use gdk_pixbuf::Pixbuf::from_file() to load the file yourself, then create the Image from the pixbuf. (Or for animations, use gdk_pixbuf::PixbufAnimation::from_file()).

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

resource_path

a resource path

Returns

a new Image

Creates a new Image displaying surface. The Image does not assume a reference to the surface; you still need to unref it if you own references. Image will add its own reference rather than adopting yours.

surface

a cairo::Surface, or None

Returns

a new Image

Creates a new builder-style object to construct a Image.

This method returns an instance of ImageBuilder which can be used to create a Image.

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Returns the type identifier of Self.

Auto Trait Implementations

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Similar to Self::set_property but fails instead of panicking.

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Sets multiple properties of the object at once. Read more

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Block a given signal handler. Read more

Unblock a given signal handler.

Stop emission of the currently emitted signal.

Stop emission of the currently emitted signal by the (possibly detailed) signal name.

Similar to Self::connect but fails instead of panicking.

Connect to the signal signal_name on this object. Read more

Similar to Self::connect_id but fails instead of panicking.

Connect to the signal signal_id on this object. Read more

Similar to Self::connect_local but fails instead of panicking.

Connect to the signal signal_name on this object. Read more

Similar to Self::connect_local_id but fails instead of panicking.

Connect to the signal signal_id on this object. Read more

Similar to Self::connect_unsafe but fails instead of panicking.

Connect to the signal signal_name on this object. Read more

Similar to Self::connect_unsafe_id but fails instead of panicking.

Similar to Self::connect_closure but fails instead of panicking.

Connect a closure to the signal signal_name on this object. Read more

Similar to Self::connect_closure_id but fails instead of panicking.

Connect a closure to the signal signal_id on this object. Read more

Limits the lifetime of closure to the lifetime of the object. When the object’s reference count drops to zero, the closure will be invalidated. An invalidated closure will ignore any calls to Closure::invoke. Read more

Connect to the signal signal_id on this object. Read more

Similar to Self::emit but fails instead of panicking.

Emit signal by signal id. Read more

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🔬 This is a nightly-only experimental API. (toowned_clone_into)

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The type returned in the event of a conversion error.

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