PyGobject（八十四）GdkPixbuf.Pixbuf

GdkPixbuf.Pixbuf

这是gdk-pixbuf库的主要结构。它被用于表示图像。它包含关于图像的像素数据、宽度和高度等信息。

Methods

方法修饰词	方法名及参数
static	from_pixdata (pixdata, copy_pixels)
static	get_file_info (filename)
static	get_file_info_async (filename, cancellable, callback, *user_data)
static	get_file_info_finish (async_result)
static	get_formats ()
static	new (colorspace, has_alpha, bits_per_sample, width, height)
static	new_from_bytes (data, colorspace, has_alpha, bits_per_sample, width, height, rowstride)
static	new_from_data (data, colorspace, has_alpha, bits_per_sample, width, height, rowstride, destroy_fn, *destroy_fn_data)
static	new_from_file (filename)
static	new_from_file_at_scale (filename, width, height, preserve_aspect_ratio)
static	new_from_file_at_size (filename, width, height)
static	new_from_inline (data, copy_pixels)
static	new_from_resource (resource_path)
static	new_from_resource_at_scale (resource_path, width, height, preserve_aspect_ratio)
static	new_from_stream (stream, cancellable)
static	new_from_stream_async (stream, cancellable, callback, *user_data)
static	new_from_stream_at_scale (stream, width, height, preserve_aspect_ratio, cancellable)
static	new_from_stream_at_scale_async (stream, width, height, preserve_aspect_ratio, cancellable, callback, *user_data)
static	new_from_stream_finish (async_result)
static	new_from_xpm_data (data)
static	save_to_stream_finish (async_result)
	add_alpha (substitute_color, r, g, b)
	apply_embedded_orientation ()
	composite (dest, dest_x, dest_y, dest_width, dest_height, offset_x, offset_y, scale_x, scale_y, interp_type, overall_alpha)
	composite_color (dest, dest_x, dest_y, dest_width, dest_height, offset_x, offset_y, scale_x, scale_y, interp_type, overall_alpha, check_x, check_y, check_size, color1, color2)
	composite_color_simple (dest_width, dest_height, interp_type, overall_alpha, check_size, color1, color2)
	copy ()
	copy_area (src_x, src_y, width, height, dest_pixbuf, dest_x, dest_y)
	fill (pixel)
	flip (horizontal)
	get_bits_per_sample ()
	get_byte_length ()
	get_colorspace ()
	get_has_alpha ()
	get_height ()
	get_n_channels ()
	get_option (key)
	get_options ()
	get_pixels ()
	get_rowstride ()
	get_width ()
	new_subpixbuf (src_x, src_y, width, height)
	read_pixel_bytes ()
	read_pixels ()
	rotate_simple (angle)
	saturate_and_pixelate (dest, saturation, pixelate)
	save_to_bufferv (type, option_keys, option_values)
	save_to_callbackv (save_func, user_data, type, option_keys, option_values)
	savev (filename, type, option_keys, option_values)
	scale (dest, dest_x, dest_y, dest_width, dest_height, offset_x, offset_y, scale_x, scale_y, interp_type)
	scale_simple (dest_width, dest_height, interp_type)

Virtual Methods

Properties

Name	Type	Flags	Short Description
bits-per-sample	int	r/w/co	The number of bits per sample
colorspace	GdkPixbuf.Colorspace	r/w/co	The colorspace in which the samples are interpreted
has-alpha	bool	r/w/co	Whether the pixbuf has an alpha channel
height	int	r/w/co	The number of rows of the pixbuf
n-channels	int	r/w/co	The number of samples per pixel
pixel-bytes	GLib.Bytes	r/w/co	Readonly pixel data
pixels	int	r/w/co	A pointer to the pixel data of the pixbuf
rowstride	int	r/w/co	The number of bytes between the start of a row and the start of the next row
width	int	r/w/co	The number of columns of the pixbuf

Signals

Name	Short Description

例子

代码：

#!/usr/bin/env python3
# Created by xiaosanyu at 16/7/19
# section 132
# 
# author: xiaosanyu
# website: yuxiaosan.tk \
#          http://blog.youkuaiyun.com/a87b01c14
# created: 16/7/19

TITLE = "Pixbuf"
DESCRIPTION = """
A GdkPixbuf represents an image, normally in RGB or RGBA format.
Pixbufs are normally used to load files from disk and perform
image scaling.

This demo is not all that educational, but looks cool. It was written
by Extreme Pixbuf Hacker Federico Mena Quintero. It also shows
off how to use GtkDrawingArea to do a simple animation.

Look at the Image demo for additional pixbuf usage examples.
"""

import gi

gi.require_version("Gtk", "3.0")
from gi.repository import Gtk, Gdk, GdkPixbuf, GLib
import os
from math import *

background_name = "background.jpg"
image_names = ("apple-red.png",
               "gnome-applets.png",
               "gnome-calendar.png",
               "gnome-foot.png",
               "gnome-gmush.png",
               "gnome-gimp.png",
               "gnome-gsame.png",
               "gnu-keys.png")
images = []
prefix = os.path.realpath(os.path.join(os.path.dirname(__file__), "Data"))
start_time = 0
CYCLE_TIME = 3000000


class PixbufsWindow(Gtk.Window):
    def __init__(self):
        Gtk.Window.__init__(self, title="Pixbuf demo")
        self.set_resizable(False)
        self.background = None
        self.back_width = 10
        self.back_height = 10
        rlt = self.load_pixbufs()
        if not rlt[0]:
            dialog = Gtk.MessageDialog(self,
                                       Gtk.DialogFlags.DESTROY_WITH_PARENT,
                                       Gtk.MessageType.ERROR,
                                       Gtk.ButtonsType.CLOSE,
                                       "Failed to load an image: %s" % rlt[1])

            dialog.run()
            dialog.destroy()

        else:
            self.set_size_request(self.back_width, self.back_height)

            self.pixbuf = GdkPixbuf.Pixbuf.new(GdkPixbuf.Colorspace.RGB, False, 8, self.back_width, self.back_height);

            da = Gtk.DrawingArea.new()

            da.connect("draw", self.draw_cb)

            self.add(da)

            da.add_tick_callback(self.on_tick, da)

    def load_pixbufs(self):
        if self.background:
            return True, ""  # already loaded earlier
        try:
            self.background = GdkPixbuf.Pixbuf.new_from_file(os.path.join(prefix, background_name))
            self.back_width = self.background.get_width()
            self.back_height = self.background.get_height()

            for image in image_names:
                images.append(GdkPixbuf.Pixbuf.new_from_file(os.path.join(prefix, image)))
        except GLib.Error as e:
            return False, e.message

        return True, ""

    def draw_cb(self, drawingarea, cr):
        Gdk.cairo_set_source_pixbuf(cr, self.pixbuf, 0, 0)
        cr.paint()

        return True

    def on_tick(self, da, frame_clock, *data):
        global start_time
        self.background.copy_area(0, 0, self.back_width, self.back_height,
                                  self.pixbuf, 0, 0)

        if start_time == 0:
            start_time = frame_clock.get_frame_time()

        current_time = frame_clock.get_frame_time()
        f = ((current_time - start_time) % CYCLE_TIME) / CYCLE_TIME

        xmid = self.back_width / 2.0
        ymid = self.back_height / 2.0

        radius = min(xmid, ymid) / 2.0

        for i, image in enumerate(images):
            r1 = Gdk.Rectangle()
            r2 = Gdk.Rectangle()
            dest = Gdk.Rectangle()

            ang = 2.0 * GLib.PI * i / len(images) - f * 2.0 * GLib.PI

            iw = image.get_width()
            ih = image.get_height()

            r = radius + (radius / 3.0) * sin(f * 2.0 * GLib.PI)

            xpos = floor(xmid + r * cos(ang) - iw / 2.0 + 0.5)
            ypos = floor(ymid + r * sin(ang) - ih / 2.0 + 0.5)

            k = sin(f * 2.0 * GLib.PI) if i & 1 else cos(f * 2.0 * GLib.PI)
            k = 2.0 * pow(k, 2)
            k = max(0.25, k)

            r1.x = xpos
            r1.y = ypos
            r1.width = iw * k
            r1.height = ih * k

            r2.x = 0
            r2.y = 0
            r2.width = self.back_width
            r2.height = self.back_height
            rlt = Gdk.rectangle_intersect(r1, r2)
            if rlt[0]:
                dest = rlt[1]
                image.composite(self.pixbuf,
                                dest.x, dest.y,
                                dest.width, dest.height,
                                xpos, ypos,
                                k, k,
                                GdkPixbuf.InterpType.NEAREST,
                                max(127, fabs(255 * sin(f * 2.0 * GLib.PI))) if (i & 1) else \
                                    max(127, fabs(255 * cos(f * 2.0 * GLib.PI))))

        da.queue_draw()

        return GLib.SOURCE_CONTINUE


def main():
    win = PixbufsWindow()
    win.connect("delete-event", Gtk.main_quit)
    win.show_all()
    Gtk.main()


if __name__ == "__main__":
    main()

代码下载地址：http://download.youkuaiyun.com/detail/a87b01c14/9594728