/usr/share/sugar/activities/ImageViewer.activity/ImageView.py is in sugar-imageviewer-activity 62-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 | # Copyright (C) 2008, One Laptop per Child
# Author: Sayamindu Dasgupta <sayamindu@laptop.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
import cairo
import math
from gi.repository import Gtk
from gi.repository import Gdk
from gi.repository import GdkPixbuf
from gi.repository import GObject
ZOOM_STEP = 0.05
ZOOM_MAX = 10
ZOOM_MIN = 0.05
def _surface_from_file(file_location, ctx):
pixbuf = GdkPixbuf.Pixbuf.new_from_file(file_location)
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32,
pixbuf.get_width(), pixbuf.get_height())
ctx_surface = cairo.Context(surface)
Gdk.cairo_set_source_pixbuf(ctx_surface, pixbuf, 0, 0)
ctx_surface.paint()
return surface
def _rotate_surface(surface, direction):
ctx = cairo.Context(surface)
new_surface = ctx.get_target().create_similar(
cairo.CONTENT_COLOR_ALPHA, surface.get_height(),
surface.get_width())
ctx_surface = cairo.Context(new_surface)
if direction == 1:
ctx_surface.translate(surface.get_height(), 0)
else:
ctx_surface.translate(0, surface.get_width())
ctx_surface.rotate(math.pi / 2 * direction)
ctx_surface.set_source_surface(surface, 0, 0)
ctx_surface.paint()
return new_surface
class ImageViewer(Gtk.DrawingArea, Gtk.Scrollable):
__gtype_name__ = 'ImageViewer'
__gproperties__ = {
"hscroll-policy": (Gtk.ScrollablePolicy, "hscroll-policy",
"hscroll-policy", Gtk.ScrollablePolicy.MINIMUM,
GObject.PARAM_READWRITE),
"hadjustment": (Gtk.Adjustment, "hadjustment", "hadjustment",
GObject.PARAM_READWRITE),
"vscroll-policy": (Gtk.ScrollablePolicy, "hscroll-policy",
"hscroll-policy", Gtk.ScrollablePolicy.MINIMUM,
GObject.PARAM_READWRITE),
"vadjustment": (Gtk.Adjustment, "hadjustment", "hadjustment",
GObject.PARAM_READWRITE),
}
def __init__(self):
Gtk.DrawingArea.__init__(self)
self._file_location = None
self._surface = None
self._zoom = None
self._target_point = None
self._anchor_point = None
self._in_dragtouch = False
self._in_zoomtouch = False
self._zoomtouch_scale = 1
self._in_scrolling = False
self._scrolling_hid = None
self._hadj = None
self._vadj = None
self._hadj_value_changed_hid = None
self._vadj_value_changed_hid = None
self.connect('draw', self.__draw_cb)
def set_file_location(self, file_location):
self._surface = None
self._zoom = None
self._file_location = file_location
self.queue_draw()
def do_get_property(self, prop):
# We don't use the getter but GTK wants it defined as we are
# implementing Gtk.Scrollable interface.
pass
def do_set_property(self, prop, value):
# The scrolled window will give us the adjustments. Make a
# reference to them and also connect to their value-changed
# signal.
if prop.name == 'hadjustment':
if value is not None:
hadj = value
self._hadj_value_changed_hid = \
hadj.connect('value-changed', self.__hadj_value_changed_cb)
self._hadj = hadj
elif prop.name == 'vadjustment':
if value is not None:
vadj = value
self._vadj_value_changed_hid = \
vadj.connect('value-changed', self.__vadj_value_changed_cb)
self._vadj = vadj
def _update_adjustments(self):
alloc = self.get_allocation()
scaled_width = self._surface.get_width() * self._zoom
scaled_height = self._surface.get_height() * self._zoom
page_size_x = alloc.width * 1.0 / scaled_width
self._hadj.set_lower(0)
self._hadj.set_page_size(page_size_x)
self._hadj.set_upper(1.0)
self._hadj.set_step_increment(0.1)
self._hadj.set_page_increment(0.5)
page_size_y = alloc.height * 1.0 / scaled_height
self._vadj.set_lower(0)
self._vadj.set_page_size(page_size_y)
self._vadj.set_upper(1.0)
self._vadj.set_step_increment(0.1)
self._vadj.set_page_increment(0.5)
anchor_scaled = (self._anchor_point[0] * self._zoom,
self._anchor_point[1] * self._zoom)
# This vector is the top left coordinate of the scaled image.
scaled_image_topleft = (self._target_point[0] - anchor_scaled[0],
self._target_point[1] - anchor_scaled[1])
max_topleft = (scaled_width - alloc.width,
scaled_height - alloc.height)
max_value = (1.0 - page_size_x,
1.0 - page_size_y)
# This two linear functions map the topleft corner of the
# image to the value each adjustment.
if max_topleft[0] != 0:
self._hadj.disconnect(self._hadj_value_changed_hid)
self._hadj.set_value(-1 * max_value[0] *
scaled_image_topleft[0] / max_topleft[0])
self._hadj_value_changed_hid = \
self._hadj.connect('value-changed',
self.__hadj_value_changed_cb)
if max_topleft[1] != 0:
self._vadj.disconnect(self._vadj_value_changed_hid)
self._vadj.set_value(-1 * max_value[1] *
scaled_image_topleft[1] / max_topleft[1])
self._vadj_value_changed_hid = \
self._vadj.connect('value-changed',
self.__vadj_value_changed_cb)
def _stop_scrolling(self):
self._in_scrolling = False
self.queue_draw()
return False
def _start_scrolling(self):
if not self._in_scrolling:
self._in_scrolling = True
# Add or update a timer after which the in_scrolling flag will
# be set to False. This is to perform a faster drawing while
# scrolling.
if self._scrolling_hid is not None:
GObject.source_remove(self._scrolling_hid)
self._scrolling_hid = GObject.timeout_add(200,
self._stop_scrolling)
def __hadj_value_changed_cb(self, adj):
alloc = self.get_allocation()
scaled_width = self._surface.get_width() * self._zoom
anchor_scaled_x = self._anchor_point[0] * self._zoom
scaled_image_left = self._target_point[0] - anchor_scaled_x
max_left = scaled_width - alloc.width
max_value = 1.0 - adj.get_page_size()
new_left = -1 * max_left * adj.get_value() / max_value
delta_x = scaled_image_left - new_left
self._anchor_point = (self._anchor_point[0] + delta_x,
self._anchor_point[1])
self._start_scrolling()
self.queue_draw()
def __vadj_value_changed_cb(self, adj):
alloc = self.get_allocation()
scaled_height = self._surface.get_height() * self._zoom
anchor_scaled_y = self._anchor_point[1] * self._zoom
scaled_image_top = self._target_point[1] - anchor_scaled_y
max_top = scaled_height - alloc.height
max_value = 1.0 - adj.get_page_size()
new_top = -1 * max_top * adj.get_value() / max_value
delta_y = scaled_image_top - new_top
self._anchor_point = (self._anchor_point[0],
self._anchor_point[1] + delta_y)
self._start_scrolling()
self.queue_draw()
def _center_target_point(self):
alloc = self.get_allocation()
self._target_point = (alloc.width / 2, alloc.height / 2)
def _center_anchor_point(self):
self._anchor_point = (self._surface.get_width() / 2,
self._surface.get_height() / 2)
def _center_if_small(self):
# If at the current size the image surface is smaller than the
# available space, center it on the canvas.
alloc = self.get_allocation()
scaled_width = self._surface.get_width() * self._zoom
scaled_height = self._surface.get_height() * self._zoom
if alloc.width >= scaled_width and alloc.height >= scaled_height:
self._center_target_point()
self._center_anchor_point()
self.queue_draw()
def set_zoom(self, zoom):
if zoom < ZOOM_MIN or zoom > ZOOM_MAX:
return
self._zoom = zoom
self.queue_draw()
def get_zoom(self):
return self._zoom
def can_zoom_in(self):
return self._zoom + ZOOM_STEP < ZOOM_MAX
self._update_adjustments()
def can_zoom_out(self):
return self._zoom - ZOOM_STEP > ZOOM_MIN
self._update_adjustments()
def zoom_in(self):
if not self.can_zoom_in():
return
self._zoom += ZOOM_STEP
self._update_adjustments()
self.queue_draw()
def zoom_out(self):
if not self.can_zoom_out():
return
self._zoom -= ZOOM_MIN
self._center_if_small()
self._update_adjustments()
self.queue_draw()
def zoom_to_fit(self):
# This tries to figure out a best fit model
# If the image can fit in, we show it in 1:1,
# in any other case we show it in a fit to screen way
alloc = self.get_allocation()
surface_width = self._surface.get_width()
surface_height = self._surface.get_height()
if alloc.width < surface_width or alloc.height < surface_height:
# Image is larger than allocated size
self._zoom = min(alloc.width * 1.0 / surface_width,
alloc.height * 1.0 / surface_height)
else:
self._zoom = 1.0
self._center_target_point()
self._center_anchor_point()
self._update_adjustments()
self.queue_draw()
def zoom_original(self):
self._zoom = 1
self._center_if_small()
self._update_adjustments()
self.queue_draw()
def _move_anchor_to_target(self, prev_target_point):
# Calculate the new anchor point, move it from the previous
# target to the new one.
prev_anchor_scaled = (self._anchor_point[0] * self._zoom,
self._anchor_point[1] * self._zoom)
# This vector is the top left coordinate of the scaled image.
scaled_image_topleft = (prev_target_point[0] - prev_anchor_scaled[0],
prev_target_point[1] - prev_anchor_scaled[1])
anchor_scaled = (self._target_point[0] - scaled_image_topleft[0],
self._target_point[1] - scaled_image_topleft[1])
self._anchor_point = (int(anchor_scaled[0] * 1.0 / self._zoom),
int(anchor_scaled[1] * 1.0 / self._zoom))
def start_dragtouch(self, coords):
self._in_dragtouch = True
prev_target_point = self._target_point
# Set target point to the relative coordinates of this view.
self._target_point = (coords[1], coords[2])
self._move_anchor_to_target(prev_target_point)
self.queue_draw()
def update_dragtouch(self, coords):
# Drag touch will be replaced by zoom touch if another finger
# is placed over the display. When the user finishes zoom
# touch, it will probably remove one finger after the other,
# and this method will be called. In that probable case, we
# need to start drag touch again.
if not self._in_dragtouch:
self.start_dragtouch(coords)
return
self._target_point = (coords[1], coords[2])
self._update_adjustments()
self.queue_draw()
def finish_dragtouch(self, coords):
self._in_dragtouch = False
self._center_if_small()
self._update_adjustments()
def start_zoomtouch(self, center):
self._in_zoomtouch = True
self._zoomtouch_scale = 1
# Zoom touch replaces drag touch.
self._in_dragtouch = False
prev_target_point = self._target_point
# Set target point to the relative coordinates of this view.
alloc = self.get_allocation()
self._target_point = (center[1] - alloc.x, center[2] - alloc.y)
self._move_anchor_to_target(prev_target_point)
self.queue_draw()
def update_zoomtouch(self, center, scale):
self._zoomtouch_scale = scale
# Set target point to the relative coordinates of this view.
alloc = self.get_allocation()
self._target_point = (center[1] - alloc.x, center[2] - alloc.y)
self.queue_draw()
def finish_zoomtouch(self):
self._in_zoomtouch = False
# Apply zoom
self._zoom = self._zoom * self._zoomtouch_scale
self._zoomtouch_scale = 1
# Restrict zoom values
if self._zoom < ZOOM_MIN:
self._zoom = ZOOM_MIN
elif self._zoom > ZOOM_MAX:
self._zoom = ZOOM_MAX
self._center_if_small()
self._update_adjustments()
self.queue_draw()
def rotate_anticlockwise(self):
self._surface = _rotate_surface(self._surface, -1)
# Recalculate the anchor point to make it relative to the new
# top left corner.
self._anchor_point = (
self._anchor_point[1],
self._surface.get_height() - self._anchor_point[0])
self._update_adjustments()
self.queue_draw()
def rotate_clockwise(self):
self._surface = _rotate_surface(self._surface, 1)
# Recalculate the anchor point to make it relative to the new
# top left corner.
self._anchor_point = (
self._surface.get_width() - self._anchor_point[1],
self._anchor_point[0])
self._update_adjustments()
self.queue_draw()
def __draw_cb(self, widget, ctx):
# If the image surface is not set, it reads it from the file
# location. If the file location is not set yet, it just
# returns.
if self._surface is None:
if self._file_location is None:
return
self._surface = _surface_from_file(self._file_location, ctx)
if self._zoom is None:
self.zoom_to_fit()
# If no target point was set via pinch-to-zoom, default to the
# center of the screen.
if self._target_point is None:
self._center_target_point()
# If no anchor point was set via pinch-to-zoom, default to the
# center of the surface.
if self._anchor_point is None:
self._center_anchor_point()
self._update_adjustments()
ctx.translate(*self._target_point)
zoom_absolute = self._zoom * self._zoomtouch_scale
ctx.scale(zoom_absolute, zoom_absolute)
ctx.translate(self._anchor_point[0] * -1, self._anchor_point[1] * -1)
ctx.set_source_surface(self._surface, 0, 0)
# Perform faster draw if the view is zooming or scrolling via
# mouse or touch.
if self._in_zoomtouch or self._in_dragtouch or self._in_scrolling:
ctx.get_source().set_filter(cairo.FILTER_NEAREST)
ctx.paint()
|