gdk_pixbuf/pixbuf_animation_iter.rs
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// Take a look at the license at the top of the repository in the LICENSE file.
use std::time::{Duration, SystemTime};
use glib::translate::*;
use super::{ffi, Pixbuf};
glib::wrapper! {
/// An opaque object representing an iterator which points to a
/// certain position in an animation.
#[doc(alias = "GdkPixbufAnimationIter")]
pub struct PixbufAnimationIter(Object<ffi::GdkPixbufAnimationIter, ffi::GdkPixbufAnimationIterClass>);
match fn {
type_ => || ffi::gdk_pixbuf_animation_iter_get_type(),
}
}
impl PixbufAnimationIter {
/// Possibly advances an animation to a new frame.
///
/// Chooses the frame based on the start time passed to
/// gdk_pixbuf_animation_get_iter().
///
/// @current_time would normally come from g_get_current_time(), and
/// must be greater than or equal to the time passed to
/// gdk_pixbuf_animation_get_iter(), and must increase or remain
/// unchanged each time gdk_pixbuf_animation_iter_get_pixbuf() is
/// called. That is, you can't go backward in time; animations only
/// play forward.
///
/// As a shortcut, pass `NULL` for the current time and g_get_current_time()
/// will be invoked on your behalf. So you only need to explicitly pass
/// @current_time if you're doing something odd like playing the animation
/// at double speed.
///
/// If this function returns `FALSE`, there's no need to update the animation
/// display, assuming the display had been rendered prior to advancing;
/// if `TRUE`, you need to call gdk_pixbuf_animation_iter_get_pixbuf()
/// and update the display with the new pixbuf.
/// ## `current_time`
/// current time
///
/// # Returns
///
/// `TRUE` if the image may need updating
#[doc(alias = "gdk_pixbuf_animation_iter_advance")]
pub fn advance(&self, current_time: SystemTime) -> bool {
let diff = current_time
.duration_since(SystemTime::UNIX_EPOCH)
.expect("failed to convert time");
unsafe {
from_glib(ffi::gdk_pixbuf_animation_iter_advance(
self.to_glib_none().0,
&glib::ffi::GTimeVal {
tv_sec: diff.as_secs() as _,
tv_usec: diff.subsec_micros() as _,
},
))
}
}
/// Gets the current pixbuf which should be displayed.
///
/// The pixbuf might not be the same size as the animation itself
/// (gdk_pixbuf_animation_get_width(), gdk_pixbuf_animation_get_height()).
///
/// This pixbuf should be displayed for gdk_pixbuf_animation_iter_get_delay_time()
/// milliseconds.
///
/// The caller of this function does not own a reference to the returned
/// pixbuf; the returned pixbuf will become invalid when the iterator
/// advances to the next frame, which may happen anytime you call
/// gdk_pixbuf_animation_iter_advance().
///
/// Copy the pixbuf to keep it (don't just add a reference), as it may get
/// recycled as you advance the iterator.
///
/// # Returns
///
/// the pixbuf to be displayed
#[doc(alias = "gdk_pixbuf_animation_iter_get_pixbuf")]
#[doc(alias = "get_pixbuf")]
pub fn pixbuf(&self) -> Pixbuf {
unsafe {
from_glib_none(ffi::gdk_pixbuf_animation_iter_get_pixbuf(
self.to_glib_none().0,
))
}
}
/// Gets the number of milliseconds the current pixbuf should be displayed,
/// or -1 if the current pixbuf should be displayed forever.
///
/// The `g_timeout_add()` function conveniently takes a timeout in milliseconds,
/// so you can use a timeout to schedule the next update.
///
/// Note that some formats, like GIF, might clamp the timeout values in the
/// image file to avoid updates that are just too quick. The minimum timeout
/// for GIF images is currently 20 milliseconds.
///
/// # Returns
///
/// delay time in milliseconds (thousandths of a second)
#[doc(alias = "gdk_pixbuf_animation_iter_get_delay_time")]
#[doc(alias = "get_delay_time")]
pub fn delay_time(&self) -> Option<Duration> {
unsafe {
let res = ffi::gdk_pixbuf_animation_iter_get_delay_time(self.to_glib_none().0);
if res < 0 {
None
} else {
Some(Duration::from_millis(res as u64))
}
}
}
/// Used to determine how to respond to the area_updated signal on
/// #GdkPixbufLoader when loading an animation.
///
/// The `::area_updated` signal is emitted for an area of the frame currently
/// streaming in to the loader. So if you're on the currently loading frame,
/// you will need to redraw the screen for the updated area.
///
/// # Returns
///
/// `TRUE` if the frame we're on is partially loaded, or the last frame
#[doc(alias = "gdk_pixbuf_animation_iter_on_currently_loading_frame")]
pub fn on_currently_loading_frame(&self) -> bool {
unsafe {
from_glib(ffi::gdk_pixbuf_animation_iter_on_currently_loading_frame(
self.to_glib_none().0,
))
}
}
}