class ScrollArea(Base, clutter.Group):
"""Wrapper of a clutter Group that allows for scrolling. ScrollArea
modifies the width of the content and it assumes that the content uses
percent modification (read: not default clutter objects)."""
__gsignals__ = {
'activated': (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, ()),
'moving': (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, ()),
}
MODE_SELECTION = 0
MODE_MOTION = 1
MODE_STOP = 2
STEP_SIZE_PERCENT = 0.04
def __init__(self, x, y, width, height, content):
Base.__init__(self)
clutter.Group.__init__(self)
self._motion_buffer = MotionBuffer()
self._offset = 0 # Drives the content motion.
self._offset_max = 0 # Maximum value of offset (equal on bottom).
self._old_offset = 0 # Stores the old value of offset on motions.
self._motion_handler = 0
self._active = None
self.step_size = self.get_abs_y(self.STEP_SIZE_PERCENT)
# Allowed area for the widget's scrolling content.
self.area_width = self.get_abs_x(width)
self.area_height = self.get_abs_y(height)
# Create content position indicator
self.indicator = ListIndicator(3 * width / 4, height, 0.2, 0.045,
ListIndicator.VERTICAL)
self.indicator.hide_position()
self.indicator.set_maximum(2)
self.add(self.indicator)
# A clipped Group to receive the content.
self._fixed_group = clutter.Group()
self._fixed_group.set_clip(0, 0, self.area_width, self.area_height)
self.add(self._fixed_group)
self.content = None
self._motion_timeline = clutter.Timeline(500)
self._motion_timeline.connect('completed',
self._motion_timeline_callback, None)
self._motion_alpha = clutter.Alpha(self._motion_timeline,
clutter.EASE_OUT_SINE)
self._motion_behaviour = LoopedPathBehaviour(self._motion_alpha)
self.set_content(content)
self.active = None
# Preparation to pointer events handling.
self.set_reactive(True)
self.connect('button-press-event', self._on_button_press_event)
self.connect('button-release-event', self._on_button_release_event)
self.connect('scroll-event', self._on_scroll_event)
self.set_position(self.get_abs_x(x), self.get_abs_y(y))
@property
def on_top(self):
"""True if we're on top."""
return self._offset == 0
@property
def on_bottom(self):
"""True if we're on bottom."""
return self._offset == self._offset_max
def _get_active(self):
"""Active property getter."""
return self._active
def _set_active(self, boolean):
"""Active property setter."""
if self._active == boolean:
return
self._active = boolean
if boolean:
# Show indicator if there is need for scrolling.
if self._offset_max >= 0:
self.indicator.show()
self.set_opacity(255)
self.emit('activated')
else:
self.indicator.hide()
self.set_opacity(128)
active = property(_get_active, _set_active)
def _get_offset(self):
"""Get current offset value."""
return self._offset
def _set_offset(self, integer):
"""Set current offset value."""
if self._offset == integer:
return
self._offset = integer
if self._offset < 0:
self._offset = 0
elif self._offset > self._offset_max:
self._offset = self._offset_max
self.content.set_position(0, -self._offset)
# Indicator updates.
if self.on_top:
self.indicator.set_current(1)
elif self.on_bottom:
self.indicator.set_current(2)
offset = property(_get_offset, _set_offset)
def set_content(self, content):
"""Set content into scroll area."""
if self.content is not None:
self._fixed_group.remove(self.content)
self._motion_behaviour.remove(self.content)
self.content = content
self._fixed_group.add(content)
self._offset_max = self.content.get_height() - self.area_height
self._motion_behaviour.apply(self.content)
def stop_animation(self):
"""Stops the timeline driving animation."""
self._motion_timeline.stop()
def scroll_to_top(self):
"""Scroll content back to top."""
self.offset = 0
def scroll_to_bottom(self):
"""Scroll content as much as possible."""
self.offset = self._offset_max
def scroll_up(self):
"""Scroll up by one step size."""
self.offset -= self.step_size
def scroll_down(self):
"""Scroll down by one step size."""
self.offset += self.step_size
def scroll_page_up(self):
"""Scroll up by one page. Page is a scroll area height."""
self.offset -= self.area_height
def scroll_page_down(self):
self.offset += self.area_height
def _update_motion_behaviour(self, target):
"""Preparation of looped behaviour applied to the content."""
self._motion_behaviour.start_knot = (0.0, -self.offset)
self._motion_behaviour.end_knot = (0.0, -target)
self._motion_behaviour.start_index = 0.0
# Need to set the end index to 0.9999. Indeed the LoopedPathBehaviour
# uses an index in [0, 1[. So index = 1 is equivalent to index = 0, the
# Actor will the be placed on the start_knot.
self._motion_behaviour.end_index = 0.9999
def _on_button_press_event(self, actor, event):
"""button-press-event handler."""
clutter.grab_pointer(self)
if not self.handler_is_connected(self._motion_handler):
self._motion_handler = self.connect('motion-event',
self._on_motion_event)
if self._motion_timeline.is_playing():
# A click with an animation pending should stop the animation.
self._motion_timeline.stop()
# Go to MODE_STOP to handle correctly next button-release event.
self._event_mode = self.MODE_STOP
self.offset = -self.content.get_y()
else:
# No animation pending so we're going to do nothing or to move
# all the content.
self._old_offset = self.offset
self._motion_buffer.start(event)
self._event_mode = self.MODE_SELECTION
return False
def _on_button_release_event(self, actor, event):
"""button-release-event handler."""
clutter.ungrab_pointer()
if self.handler_is_connected(self._motion_handler):
self.disconnect_by_func(self._on_motion_event)
self._motion_buffer.compute_from_last_motion_event(event)
if not self.active:
self.active = True
return
if self._event_mode == self.MODE_MOTION:
speed = self._motion_buffer.speed_y_from_last_motion_event
# Calculation of the new target according to vertical speed.
target = self.offset - speed * 200
if target < 0:
target = 0
elif target > self._offset_max:
target = self._offset_max
self._update_motion_behaviour(target)
self._motion_timeline.start()
return False
def _on_motion_event(self, actor, event):
"""motion-event handler."""
# Minimum distance we to move before we consider a motion has started.
motion_threshold = 10
self._motion_buffer.compute_from_start(event)
if self._motion_buffer.distance_from_start > motion_threshold:
self._motion_buffer.take_new_motion_event(event)
self._event_mode = self.MODE_MOTION
self.offset = self._old_offset - self._motion_buffer.dy_from_start
return False
def _on_scroll_event(self, actor, event):
"""scroll-event handler (mouse's wheel)."""
if not self.active:
self.active = True
return
# Do not scroll if there is no need.
if self._offset_max < 0:
return False
if event.direction == clutter.SCROLL_DOWN:
self.scroll_down()
else:
self.scroll_up()
self.emit('moving')
return False
def _motion_timeline_callback(self, timeline, screen):
"""Code executed when the animation is finished."""
self.offset = -self.content.get_y()
class ScrollArea(Base, clutter.Group):
"""Wrapper of a clutter Group that allows for scrolling. ScrollArea
modifies the width of the content and it assumes that the content uses
percent modification (read: not default clutter objects)."""
__gsignals__ = {
'activated' : ( gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, () ),
'moving' : ( gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, () ),
}
MODE_SELECTION = 0
MODE_MOTION = 1
MODE_STOP = 2
STEP_SIZE_PERCENT = 0.04
def __init__(self, x, y, width, height, content):
Base.__init__(self)
clutter.Group.__init__(self)
self._motion_buffer = MotionBuffer()
self._offset = 0 # Drives the content motion.
self._offset_max = 0 # Maximum value of offset (equal on bottom).
self._old_offset = 0 # Stores the old value of offset on motions.
self._motion_handler = 0
self._active = None
self.step_size = self.get_abs_y(self.STEP_SIZE_PERCENT)
# Allowed area for the widget's scrolling content.
self.area_width = self.get_abs_x(width)
self.area_height = self.get_abs_y(height)
# Create content position indicator
self.indicator = ListIndicator(3 * width / 4, height, 0.2, 0.045,
ListIndicator.VERTICAL)
self.indicator.hide_position()
self.indicator.set_maximum(2)
self.add(self.indicator)
# A clipped Group to receive the content.
self._fixed_group = clutter.Group()
self._fixed_group.set_clip(0, 0, self.area_width, self.area_height)
self.add(self._fixed_group)
self.content = None
self._motion_timeline = clutter.Timeline(500)
self._motion_timeline.connect('completed',
self._motion_timeline_callback, None)
self._motion_alpha = clutter.Alpha(self._motion_timeline,
clutter.EASE_OUT_SINE)
self._motion_behaviour = LoopedPathBehaviour(self._motion_alpha)
self.set_content(content)
self.active = None
# Preparation to pointer events handling.
self.set_reactive(True)
self.connect('button-press-event', self._on_button_press_event)
self.connect('button-release-event', self._on_button_release_event)
self.connect('scroll-event', self._on_scroll_event)
self.set_position(self.get_abs_x(x), self.get_abs_y(y))
@property
def on_top(self):
"""True if we're on top."""
return self._offset == 0
@property
def on_bottom(self):
"""True if we're on bottom."""
return self._offset == self._offset_max
def _get_active(self):
"""Active property getter."""
return self._active
def _set_active(self, boolean):
"""Active property setter."""
if self._active == boolean:
return
self._active = boolean
if boolean:
# Show indicator if there is need for scrolling.
if self._offset_max >= 0:
self.indicator.show()
self.set_opacity(255)
self.emit('activated')
else:
self.indicator.hide()
self.set_opacity(128)
active = property(_get_active, _set_active)
def _get_offset(self):
"""Get current offset value."""
return self._offset
def _set_offset(self, integer):
"""Set current offset value."""
if self._offset == integer:
return
self._offset = integer
if self._offset < 0:
self._offset = 0
elif self._offset > self._offset_max:
self._offset = self._offset_max
self.content.set_position(0, - self._offset)
# Indicator updates.
if self.on_top:
self.indicator.set_current(1)
elif self.on_bottom:
self.indicator.set_current(2)
offset = property(_get_offset, _set_offset)
def set_content(self, content):
"""Set content into scroll area."""
if self.content is not None:
self._fixed_group.remove(self.content)
self._motion_behaviour.remove(self.content)
self.content = content
self._fixed_group.add(content)
self._offset_max = self.content.get_height() - self.area_height
self._motion_behaviour.apply(self.content)
def stop_animation(self):
"""Stops the timeline driving animation."""
self._motion_timeline.stop()
def scroll_to_top(self):
"""Scroll content back to top."""
self.offset = 0
def scroll_to_bottom(self):
"""Scroll content as much as possible."""
self.offset = self._offset_max
def scroll_up(self):
"""Scroll up by one step size."""
self.offset -= self.step_size
def scroll_down(self):
"""Scroll down by one step size."""
self.offset += self.step_size
def scroll_page_up(self):
"""Scroll up by one page. Page is a scroll area height."""
self.offset -= self.area_height
def scroll_page_down(self):
self.offset += self.area_height
def _update_motion_behaviour(self, target):
"""Preparation of looped behaviour applied to the content."""
self._motion_behaviour.start_knot = (0.0, -self.offset)
self._motion_behaviour.end_knot = (0.0, -target)
self._motion_behaviour.start_index = 0.0
# Need to set the end index to 0.9999. Indeed the LoopedPathBehaviour
# uses an index in [0, 1[. So index = 1 is equivalent to index = 0, the
# Actor will the be placed on the start_knot.
self._motion_behaviour.end_index = 0.9999
def _on_button_press_event(self, actor, event):
"""button-press-event handler."""
clutter.grab_pointer(self)
if not self.handler_is_connected(self._motion_handler):
self._motion_handler = self.connect('motion-event',
self._on_motion_event)
if self._motion_timeline.is_playing():
# A click with an animation pending should stop the animation.
self._motion_timeline.stop()
# Go to MODE_STOP to handle correctly next button-release event.
self._event_mode = self.MODE_STOP
self.offset = -self.content.get_y()
else:
# No animation pending so we're going to do nothing or to move
# all the content.
self._old_offset = self.offset
self._motion_buffer.start(event)
self._event_mode = self.MODE_SELECTION
return False
def _on_button_release_event(self, actor, event):
"""button-release-event handler."""
clutter.ungrab_pointer()
if self.handler_is_connected(self._motion_handler):
self.disconnect_by_func(self._on_motion_event)
self._motion_buffer.compute_from_last_motion_event(event)
if not self.active:
self.active = True
return
if self._event_mode == self.MODE_MOTION:
speed = self._motion_buffer.speed_y_from_last_motion_event
# Calculation of the new target according to vertical speed.
target = self.offset - speed * 200
if target < 0:
target = 0
elif target > self._offset_max:
target = self._offset_max
self._update_motion_behaviour(target)
self._motion_timeline.start()
return False
def _on_motion_event(self, actor, event):
"""motion-event handler."""
# Minimum distance we to move before we consider a motion has started.
motion_threshold = 10
self._motion_buffer.compute_from_start(event)
if self._motion_buffer.distance_from_start > motion_threshold:
self._motion_buffer.take_new_motion_event(event)
self._event_mode = self.MODE_MOTION
self.offset = self._old_offset - self._motion_buffer.dy_from_start
return False
def _on_scroll_event(self, actor, event):
"""scroll-event handler (mouse's wheel)."""
if not self.active:
self.active = True
return
# Do not scroll if there is no need.
if self._offset_max < 0:
return False
if event.direction == clutter.SCROLL_DOWN:
self.scroll_down()
else:
self.scroll_up()
self.emit('moving')
return False
def _motion_timeline_callback(self, timeline, screen):
"""Code executed when the animation is finished."""
self.offset = -self.content.get_y()
