198 lines
6.5 KiB
Python
198 lines
6.5 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
""" pygame.examples.scroll
|
||
|
|
|
||
|
|
An zoomed image viewer that demonstrates Surface.scroll
|
||
|
|
|
||
|
|
This example shows a scrollable image that has a zoom factor of eight.
|
||
|
|
It uses the Surface.scroll function to shift the image on the display
|
||
|
|
surface. A clip rectangle protects a margin area. If called as a function,
|
||
|
|
the example accepts an optional image file path. If run as a program
|
||
|
|
it takes an optional file path command line argument. If no file
|
||
|
|
is provided a default image file is used.
|
||
|
|
|
||
|
|
When running click on a black triangle to move one pixel in the direction
|
||
|
|
the triangle points. Or use the arrow keys. Close the window or press ESC
|
||
|
|
to quit.
|
||
|
|
"""
|
||
|
|
import sys
|
||
|
|
import os
|
||
|
|
|
||
|
|
import pygame as pg
|
||
|
|
from pygame.transform import scale
|
||
|
|
|
||
|
|
main_dir = os.path.dirname(os.path.abspath(__file__))
|
||
|
|
|
||
|
|
# game constants
|
||
|
|
DIR_UP = 1
|
||
|
|
DIR_DOWN = 2
|
||
|
|
DIR_LEFT = 3
|
||
|
|
DIR_RIGHT = 4
|
||
|
|
|
||
|
|
zoom_factor = 8
|
||
|
|
|
||
|
|
|
||
|
|
def draw_arrow(surf, color, posn, direction):
|
||
|
|
x, y = posn
|
||
|
|
if direction == DIR_UP:
|
||
|
|
pointlist = ((x - 29, y + 30), (x + 30, y + 30), (x + 1, y - 29), (x, y - 29))
|
||
|
|
elif direction == DIR_DOWN:
|
||
|
|
pointlist = ((x - 29, y - 29), (x + 30, y - 29), (x + 1, y + 30), (x, y + 30))
|
||
|
|
elif direction == DIR_LEFT:
|
||
|
|
pointlist = ((x + 30, y - 29), (x + 30, y + 30), (x - 29, y + 1), (x - 29, y))
|
||
|
|
else:
|
||
|
|
pointlist = ((x - 29, y - 29), (x - 29, y + 30), (x + 30, y + 1), (x + 30, y))
|
||
|
|
pg.draw.polygon(surf, color, pointlist)
|
||
|
|
|
||
|
|
|
||
|
|
def add_arrow_button(screen, regions, posn, direction):
|
||
|
|
draw_arrow(screen, "black", posn, direction)
|
||
|
|
draw_arrow(regions, (direction, 0, 0), posn, direction)
|
||
|
|
|
||
|
|
|
||
|
|
def scroll_view(screen, image, direction, view_rect):
|
||
|
|
src_rect = None
|
||
|
|
zoom_view_rect = screen.get_clip()
|
||
|
|
image_w, image_h = image.get_size()
|
||
|
|
if direction == DIR_UP:
|
||
|
|
if view_rect.top > 0:
|
||
|
|
screen.scroll(dy=zoom_factor)
|
||
|
|
view_rect.move_ip(0, -1)
|
||
|
|
src_rect = view_rect.copy()
|
||
|
|
src_rect.h = 1
|
||
|
|
dst_rect = zoom_view_rect.copy()
|
||
|
|
dst_rect.h = zoom_factor
|
||
|
|
elif direction == DIR_DOWN:
|
||
|
|
if view_rect.bottom < image_h:
|
||
|
|
screen.scroll(dy=-zoom_factor)
|
||
|
|
view_rect.move_ip(0, 1)
|
||
|
|
src_rect = view_rect.copy()
|
||
|
|
src_rect.h = 1
|
||
|
|
src_rect.bottom = view_rect.bottom
|
||
|
|
dst_rect = zoom_view_rect.copy()
|
||
|
|
dst_rect.h = zoom_factor
|
||
|
|
dst_rect.bottom = zoom_view_rect.bottom
|
||
|
|
elif direction == DIR_LEFT:
|
||
|
|
if view_rect.left > 0:
|
||
|
|
screen.scroll(dx=zoom_factor)
|
||
|
|
view_rect.move_ip(-1, 0)
|
||
|
|
src_rect = view_rect.copy()
|
||
|
|
src_rect.w = 1
|
||
|
|
dst_rect = zoom_view_rect.copy()
|
||
|
|
dst_rect.w = zoom_factor
|
||
|
|
elif direction == DIR_RIGHT:
|
||
|
|
if view_rect.right < image_w:
|
||
|
|
screen.scroll(dx=-zoom_factor)
|
||
|
|
view_rect.move_ip(1, 0)
|
||
|
|
src_rect = view_rect.copy()
|
||
|
|
src_rect.w = 1
|
||
|
|
src_rect.right = view_rect.right
|
||
|
|
dst_rect = zoom_view_rect.copy()
|
||
|
|
dst_rect.w = zoom_factor
|
||
|
|
dst_rect.right = zoom_view_rect.right
|
||
|
|
if src_rect is not None:
|
||
|
|
scale(image.subsurface(src_rect), dst_rect.size, screen.subsurface(dst_rect))
|
||
|
|
pg.display.update(zoom_view_rect)
|
||
|
|
|
||
|
|
|
||
|
|
def main(image_file=None):
|
||
|
|
if image_file is None:
|
||
|
|
image_file = os.path.join(main_dir, "data", "arraydemo.bmp")
|
||
|
|
margin = 80
|
||
|
|
view_size = (30, 20)
|
||
|
|
zoom_view_size = (view_size[0] * zoom_factor, view_size[1] * zoom_factor)
|
||
|
|
win_size = (zoom_view_size[0] + 2 * margin, zoom_view_size[1] + 2 * margin)
|
||
|
|
background_color = pg.Color("beige")
|
||
|
|
|
||
|
|
pg.init()
|
||
|
|
pg.display.set_caption("Scroll Example")
|
||
|
|
|
||
|
|
# set up key repeating so we can hold down the key to scroll.
|
||
|
|
old_k_delay, old_k_interval = pg.key.get_repeat()
|
||
|
|
pg.key.set_repeat(500, 30)
|
||
|
|
|
||
|
|
try:
|
||
|
|
screen = pg.display.set_mode(win_size)
|
||
|
|
screen.fill(background_color)
|
||
|
|
pg.display.flip()
|
||
|
|
|
||
|
|
image = pg.image.load(image_file).convert()
|
||
|
|
image_w, image_h = image.get_size()
|
||
|
|
|
||
|
|
if image_w < view_size[0] or image_h < view_size[1]:
|
||
|
|
print("The source image is too small for this example.")
|
||
|
|
print("A %i by %i or larger image is required." % zoom_view_size)
|
||
|
|
return
|
||
|
|
|
||
|
|
regions = pg.Surface(win_size, 0, 24)
|
||
|
|
add_arrow_button(screen, regions, (40, win_size[1] // 2), DIR_LEFT)
|
||
|
|
add_arrow_button(
|
||
|
|
screen, regions, (win_size[0] - 40, win_size[1] // 2), DIR_RIGHT
|
||
|
|
)
|
||
|
|
add_arrow_button(screen, regions, (win_size[0] // 2, 40), DIR_UP)
|
||
|
|
add_arrow_button(
|
||
|
|
screen, regions, (win_size[0] // 2, win_size[1] - 40), DIR_DOWN
|
||
|
|
)
|
||
|
|
pg.display.flip()
|
||
|
|
|
||
|
|
screen.set_clip((margin, margin, zoom_view_size[0], zoom_view_size[1]))
|
||
|
|
|
||
|
|
view_rect = pg.Rect(0, 0, view_size[0], view_size[1])
|
||
|
|
|
||
|
|
scale(
|
||
|
|
image.subsurface(view_rect),
|
||
|
|
zoom_view_size,
|
||
|
|
screen.subsurface(screen.get_clip()),
|
||
|
|
)
|
||
|
|
pg.display.flip()
|
||
|
|
|
||
|
|
# the direction we will scroll in.
|
||
|
|
direction = None
|
||
|
|
|
||
|
|
clock = pg.time.Clock()
|
||
|
|
clock.tick()
|
||
|
|
|
||
|
|
going = True
|
||
|
|
|
||
|
|
while going:
|
||
|
|
# wait for events before doing anything.
|
||
|
|
# events = [pg.event.wait()] + pg.event.get()
|
||
|
|
events = pg.event.get()
|
||
|
|
|
||
|
|
# During the loop, if a key is held, scroll the view.
|
||
|
|
keys = pg.key.get_pressed()
|
||
|
|
if keys[pg.K_UP]:
|
||
|
|
scroll_view(screen, image, DIR_UP, view_rect)
|
||
|
|
if keys[pg.K_DOWN]:
|
||
|
|
scroll_view(screen, image, DIR_DOWN, view_rect)
|
||
|
|
if keys[pg.K_LEFT]:
|
||
|
|
scroll_view(screen, image, DIR_LEFT, view_rect)
|
||
|
|
if keys[pg.K_RIGHT]:
|
||
|
|
scroll_view(screen, image, DIR_RIGHT, view_rect)
|
||
|
|
|
||
|
|
for e in events:
|
||
|
|
# quit if the event is quit.
|
||
|
|
if e.type == pg.QUIT:
|
||
|
|
going = False
|
||
|
|
|
||
|
|
# handle mouse button presses on arrows.
|
||
|
|
elif e.type == pg.MOUSEBUTTONDOWN:
|
||
|
|
direction = regions.get_at(e.pos)[0]
|
||
|
|
elif e.type == pg.MOUSEBUTTONUP:
|
||
|
|
direction = None
|
||
|
|
|
||
|
|
if direction:
|
||
|
|
scroll_view(screen, image, direction, view_rect)
|
||
|
|
clock.tick(30)
|
||
|
|
|
||
|
|
finally:
|
||
|
|
pg.key.set_repeat(old_k_delay, old_k_interval)
|
||
|
|
pg.quit()
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
if len(sys.argv) > 1:
|
||
|
|
image_file = sys.argv[1]
|
||
|
|
else:
|
||
|
|
image_file = None
|
||
|
|
main(image_file)
|