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ScrollableList.py
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ScrollableList.py
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#Embedded file name: /Users/versonator/Jenkins/live/Projects/AppLive/Resources/MIDI Remote Scripts/Push/ScrollableList.py
from __future__ import with_statement
from functools import partial
from _Framework.CompoundComponent import CompoundComponent
from _Framework.Util import in_range, clamp, BooleanContext, index_if
from _Framework.SubjectSlot import subject_slot, Subject, subject_slot_group
from _Framework import Task, Defaults
from _Framework.ScrollComponent import ScrollComponent, Scrollable
import consts
class ScrollableListItem(object):
"""
Wrapper of an item of a scrollable list.
"""
def __init__(self, index = None, content = None, scrollable_list = None, *a, **k):
super(ScrollableListItem, self).__init__(*a, **k)
self._content = content
self._index = index
self._scrollable_list = scrollable_list
def __str__(self):
return unicode(self._content)
@property
def content(self):
return self._content
@property
def index(self):
return self._index
@property
def container(self):
return self._scrollable_list
@property
def is_selected(self):
return self._scrollable_list and self._scrollable_list.is_selected(self)
def select(self):
return self._scrollable_list and self._scrollable_list.select_item(self)
class ScrollableList(Subject, Scrollable):
"""
Class for managing a visual subset of a list of items.
The items will be wrapped in an item_type instance.
"""
__subject_events__ = ('selected_item', 'item_activated', 'scroll')
item_type = ScrollableListItem
def __init__(self, num_visible_items = 1, item_type = None, *a, **k):
super(ScrollableList, self).__init__(*a, **k)
if item_type != None:
self.item_type = item_type
self._items = []
self._num_visible_items = num_visible_items
self._selected_item_index = -1
self._last_activated_item_index = None
self._offset = 0
self._pager = Scrollable()
self._pager.scroll_up = self.prev_page
self._pager.scroll_down = self.next_page
self._pager.can_scroll_up = self.can_scroll_up
self._pager.can_scroll_down = self.can_scroll_down
@property
def pager(self):
return self._pager
def scroll_up(self):
if self.can_scroll_up():
self.select_item_index_with_border(self.selected_item_index - 1, 1)
self.notify_scroll()
def can_scroll_up(self):
return self._selected_item_index > 0
def scroll_down(self):
if self.can_scroll_down():
self.select_item_index_with_border(self.selected_item_index + 1, 1)
self.notify_scroll()
def can_scroll_down(self):
return self._selected_item_index < len(self._items) - 1
def _get_num_visible_items(self):
return self._num_visible_items
def _set_num_visible_items(self, num_items):
raise num_items >= 0 or AssertionError
self._num_visible_items = num_items
self._normalize_offset(self._selected_item_index)
num_visible_items = property(_get_num_visible_items, _set_num_visible_items)
@property
def visible_items(self):
return self.items[self._offset:self._offset + self._num_visible_items]
def select_item_index_with_offset(self, index, offset):
"""
Selects an item index but moves the view such that there are,
if possible, 'offset' number of elements visible before the
selected one. Does nothing if the item was already selected.
"""
if not (index != self.selected_item_index and index >= 0 and index < len(self._items) and self.selected_item_index != -1):
raise AssertionError
self._offset = clamp(index - offset, 0, len(self._items))
self._normalize_offset(index)
self._do_set_selected_item_index(index)
def select_item_index_with_border(self, index, border_size):
"""
Selects an item with an index. Moves the view if the selection would exceed the
border of the current view.
"""
if index >= 0 and index < len(self._items):
if not in_range(index, self._offset + border_size, self._offset + self._num_visible_items - border_size):
offset = index - (self._num_visible_items - 2 * border_size) if self.selected_item_index < index else index - border_size
self._offset = clamp(offset, 0, len(self._items))
self._normalize_offset(index)
self._do_set_selected_item_index(index)
def next_page(self):
if self.can_scroll_down():
current_page = self.selected_item_index / self.num_visible_items
last_page_index = len(self.items) - self.num_visible_items
if self.selected_item_index < last_page_index:
index = clamp((current_page + 1) * self.num_visible_items, 0, len(self.items) - self.num_visible_items)
else:
index = len(self.items) - 1
self.select_item_index_with_offset(index, 0)
def prev_page(self):
if self.can_scroll_up():
current_page = self.selected_item_index / self.num_visible_items
last_page_index = len(self.items) - self.num_visible_items
if self.selected_item_index <= last_page_index:
index = clamp((current_page - 1) * self.num_visible_items, 0, len(self.items) - self.num_visible_items)
else:
index = max(len(self.items) - self.num_visible_items, 0)
self.select_item_index_with_offset(index, 0)
def _set_selected_item_index(self, index):
if not (index >= 0 and index < len(self._items) and self.selected_item_index != -1):
raise AssertionError
self._normalize_offset(index)
self._do_set_selected_item_index(index)
def _get_selected_item_index(self):
return self._selected_item_index
selected_item_index = property(_get_selected_item_index, _set_selected_item_index)
def _normalize_offset(self, index):
if index >= 0:
if index >= self._offset + self._num_visible_items:
self._offset = index - (self._num_visible_items - 1)
elif index < self._offset:
self._offset = index
self._offset = clamp(self._offset, 0, len(self._items) - self._num_visible_items)
@property
def selected_item(self):
return self._items[self.selected_item_index] if in_range(self._selected_item_index, 0, len(self._items)) else None
@property
def items(self):
return self._items
def assign_items(self, items):
old_selection = unicode(self.selected_item)
for item in self._items:
item._scrollable_list = None
self._items = tuple([ self.item_type(index=index, content=item, scrollable_list=self) for index, item in enumerate(items) ])
if self._items:
new_selection = index_if(lambda item: unicode(item) == old_selection, self._items)
self._selected_item_index = new_selection if in_range(new_selection, 0, len(self._items)) else 0
self._normalize_offset(self._selected_item_index)
else:
self._offset = 0
self._selected_item_index = -1
self._last_activated_item_index = None
self.notify_selected_item()
self.request_notify_item_activated()
def select_item(self, item):
self.selected_item_index = item.index
def is_selected(self, item):
return item and item.index == self.selected_item_index
def request_notify_item_activated(self):
if self._selected_item_index != self._last_activated_item_index:
self._last_activated_item_index = self._selected_item_index
self.notify_item_activated()
def _do_set_selected_item_index(self, index):
if index != self._selected_item_index:
self._selected_item_index = index
self.notify_selected_item()
class ActionListItem(ScrollableListItem):
"""
Interface for an list element that can be actuated on.
"""
supports_action = False
def action(self):
pass
class ActionList(ScrollableList):
"""
A scrollable list of items that can be actuated on.
"""
item_type = ActionListItem
class DefaultItemFormatter(object):
"""
Item formatter that will indicate selection and show action_message if the item
is currently performing an action
"""
action_message = 'Loading...'
def __call__(self, index, item, action_in_progress):
display_string = ''
if item:
display_string += consts.CHAR_SELECT if item.is_selected else ' '
display_string += self.action_message if action_in_progress else unicode(item)
return display_string
class ListComponent(CompoundComponent):
"""
Component that handles a ScrollableList. If an action button is
passed, it can handle an ActionList.
"""
__subject_events__ = ('item_action',)
DIRECTION_ON_COLOR = 'List.ScrollerOn'
DIRECTION_OFF_COLOR = 'List.ScrollerOff'
SELECTION_DELAY = 0.5
ENCODER_FACTOR = 10.0
empty_list_message = ''
_current_action_item = None
_last_action_item = None
def __init__(self, scrollable_list = None, data_sources = tuple(), *a, **k):
super(ListComponent, self).__init__(*a, **k)
self._data_sources = data_sources
self._activation_task = Task.Task()
self._action_on_scroll_task = Task.Task()
self._scrollable_list = None
self._scroller = self.register_component(ScrollComponent())
self._pager = self.register_component(ScrollComponent())
self.last_action_item = lambda : self._last_action_item
self.item_formatter = DefaultItemFormatter()
if scrollable_list == None:
self.scrollable_list = ActionList(num_visible_items=len(data_sources))
else:
self.scrollable_list = scrollable_list
self._scrollable_list.num_visible_items = len(data_sources)
self._delay_activation = BooleanContext()
self._selected_index_float = 0.0
self._in_encoder_selection = BooleanContext(False)
self._execute_action_task = self._tasks.add(Task.sequence(Task.delay(1), Task.run(self._execute_action)))
self._execute_action_task.kill()
@property
def _trigger_action_on_scrolling(self):
button = self._on_action_button_value.subject
return button != None and button.is_pressed()
def _get_scrollable_list(self):
return self._scrollable_list
def _set_scrollable_list(self, new_list):
if new_list != self._scrollable_list:
self._scrollable_list = new_list
if new_list != None:
new_list.num_visible_items = len(self._data_sources)
self._scroller.scrollable = new_list
self._pager.scrollable = new_list.pager
self._on_scroll.subject = new_list
self._selected_index_float = new_list.selected_item_index
else:
self._scroller.scrollable = ScrollComponent.default_scrollable
self._scroller.scrollable = ScrollComponent.default_pager
self._on_selected_item_changed.subject = new_list
self.update_all()
scrollable_list = property(_get_scrollable_list, _set_scrollable_list)
def set_data_sources(self, sources):
self._data_sources = sources
if self._scrollable_list:
self._scrollable_list.num_visible_items = len(sources)
self._update_display()
def set_encoder_controls(self, encoder_controls):
self._on_encoder_value.replace_subjects(encoder_controls)
def set_selection_buttons(self, prev_button, next_button):
self.set_select_prev_button(prev_button)
self.set_select_next_button(next_button)
def set_select_prev_button(self, prev_button):
if prev_button:
prev_button.set_on_off_values(self.DIRECTION_ON_COLOR, self.DIRECTION_OFF_COLOR)
self._scroller.set_scroll_up_button(prev_button)
def set_select_next_button(self, next_button):
if next_button:
next_button.set_on_off_values(self.DIRECTION_ON_COLOR, self.DIRECTION_OFF_COLOR)
self._scroller.set_scroll_down_button(next_button)
def set_next_page_button(self, next_button):
if next_button:
next_button.set_on_off_values(self.DIRECTION_ON_COLOR, self.DIRECTION_OFF_COLOR)
self._pager.set_scroll_down_button(next_button)
def set_prev_page_button(self, prev_button):
if prev_button:
prev_button.set_on_off_values(self.DIRECTION_ON_COLOR, self.DIRECTION_OFF_COLOR)
self._pager.set_scroll_up_button(prev_button)
def set_action_button(self, button):
if button:
button.set_on_off_values('Browser.Load', 'Browser.LoadNotPossible')
self._on_action_button_value.subject = button
self._update_action_feedback()
def on_enabled_changed(self):
super(ListComponent, self).on_enabled_changed()
if not self.is_enabled():
self._execute_action_task.kill()
@subject_slot('scroll')
def _on_scroll(self):
if self._trigger_action_on_scrolling:
trigger_selected = partial(self._trigger_action, self.selected_item)
self._action_on_scroll_task.kill()
self._action_on_scroll_task = self._tasks.add(Task.sequence(Task.wait(Defaults.MOMENTARY_DELAY), Task.delay(1), Task.run(trigger_selected)))
@subject_slot('selected_item')
def _on_selected_item_changed(self):
self._scroller.update()
self._pager.update()
self._update_display()
self._update_action_feedback()
self._activation_task.kill()
self._action_on_scroll_task.kill()
if self.SELECTION_DELAY and self._delay_activation:
self._activation_task = self._tasks.add(Task.sequence(Task.wait(self.SELECTION_DELAY), Task.run(self._scrollable_list.request_notify_item_activated)))
else:
self._scrollable_list.request_notify_item_activated()
if not self._in_encoder_selection:
self._selected_index_float = float(self._scrollable_list.selected_item_index)
@subject_slot_group('normalized_value')
def _on_encoder_value(self, value, encoder):
self._add_offset_to_selected_index(value)
def _add_offset_to_selected_index(self, offset):
if self.is_enabled() and self._scrollable_list:
with self._delay_activation():
with self._in_encoder_selection():
self._selected_index_float = clamp(self._selected_index_float + offset * self.ENCODER_FACTOR, 0, len(self._scrollable_list.items))
self._scrollable_list.select_item_index_with_border(int(self._selected_index_float), 1)
@subject_slot('value')
def _on_action_button_value(self, value):
if value != 0 and self._current_action_item == None:
self._trigger_action(self.next_item if self._action_target_is_next_item() else self.selected_item)
@subject_slot('value')
def _on_next_page(self, value):
if value:
self._scrollable_list.next_page()
@subject_slot('value')
def _on_prev_page(self, value):
if value:
self._scrollable_list.prev_page()
def do_trigger_action(self, item):
item.action()
self.notify_item_action(item)
def _trigger_action(self, item):
if self.is_enabled() and self._can_be_used_for_action(item):
if self._scrollable_list != None:
self._scrollable_list.select_item(item)
self._current_action_item = item
self.update()
self._execute_action_task.restart()
def _execute_action(self):
""" Is called by the execute action task and should not be called directly
use _trigger_action instead """
if self._current_action_item != None:
self.do_trigger_action(self._current_action_item)
self._last_action_item = self._current_action_item
self._current_action_item = None
self.update()
@property
def selected_item(self):
return self._scrollable_list.selected_item if self._scrollable_list != None else None
@property
def next_item(self):
item = None
if self._scrollable_list != None:
all_items = self._scrollable_list.items
next_index = self._scrollable_list.selected_item_index + 1
item = all_items[next_index] if in_range(next_index, 0, len(all_items)) else None
return item
def _can_be_used_for_action(self, item):
return item != None and item.supports_action and item != self.last_action_item()
def _action_target_is_next_item(self):
return self.selected_item == self.last_action_item() and self._can_be_used_for_action(self.next_item)
def _update_action_feedback(self):
if self._on_action_button_value.subject != None:
action_light = 'Browser.Loading'
if self._current_action_item == None:
action_light = 'Browser.LoadNotPossible'
if self._action_target_is_next_item():
action_light = 'Browser.LoadNext'
elif self._can_be_used_for_action(self.selected_item):
action_light = 'Browser.Load'
self._on_action_button_value.subject.set_light(action_light)
def _update_display(self):
visible_items = self._scrollable_list.visible_items if self._scrollable_list else []
for index, data_source in enumerate(self._data_sources):
item = visible_items[index] if index < len(visible_items) else None
action_in_progress = item and item == self._current_action_item
display_string = self.item_formatter(index, item, action_in_progress)
data_source.set_display_string(display_string)
if not visible_items and self._data_sources and self.empty_list_message:
self._data_sources[0].set_display_string(self.empty_list_message)
def update(self):
if self.is_enabled():
self._update_action_feedback()
self._update_display()