def _add_time_point(self, center_x, center_y, time_point):
"""Add a single time point item."""
x = center_x - (self.TIMEPOINT_DIAMETER / 2)
y = center_y - (self.TIMEPOINT_DIAMETER / 2)
# Create the acutal time point item
time_point_item = QGraphicsEllipseItem(0, 0, self.TIMEPOINT_DIAMETER,
self.TIMEPOINT_DIAMETER)
# The used color is the strongest one of the FRM II colors.
time_point_item.setBrush(QBrush(QColor(0x00, 0x71, 0xbb)))
time_point_item.setPen(QPen(0))
self.scene().addItem(time_point_item)
time_point_item.setPos(x, y)
# place the time point item above the timeline and the selection item
time_point_item.setZValue(2)
# Create the label of the time point showing the time in the
# defined strftime format on the right side of the time point item.
label = QGraphicsTextItem(time_point.strftime(self.STRFTIME_FMT))
label.setFont(QFont('Monospace'))
label_height = label.boundingRect().height()
# minor height adjustment
label_y = y - label_height / 6
self.scene().addItem(label)
label.setPos(x + self.SELECTION_DIAMETER + self.LABEL_SPACING, label_y)
# store references to the item and the timepoint in the same dict
# to be able to use it for forward and reverse lookup
self._time_point_items[time_point] = time_point_item
self._time_point_items[time_point_item] = time_point
class TimelineWidget(QGraphicsView):
"""General widget to display timeline with a list of ordered timepoints.
A timepoint is selectable via click and the timepointSelected signal
can be used to react to it."""
timepointSelected = pyqtSignal(object) # datetime.datetime object
# general layout and design parameters
TIMEPOINT_DIAMETER = 30
SELECTION_DIAMETER = 40
TIMEPOINT_SPACING = 50
TIMELINE_WIDTH = 5
LABEL_SPACING = 20
MARGIN_HORIZONTAL = 5
STRFTIME_FMT = '%H:%M:%S\n%Y-%m-%d'
def __init__(self, parent=None):
QGraphicsView.__init__(self, QGraphicsScene(), parent)
self.setAlignment(Qt.AlignLeft | Qt.AlignVCenter)
self.setRenderHints(QPainter.Antialiasing
| QPainter.SmoothPixmapTransform)
# margins set to 0 to simplify calculations
self.setContentsMargins(0, 0, 0, 0)
self.setViewportMargins(0, 0, 0, 0)
# full viewport updates required to avoid optical double selections
# caused by scrolling
self.setViewportUpdateMode(QGraphicsView.FullViewportUpdate)
self._time_points = []
self._time_point_items = {}
self._selection_item = None
# start with at least one time point (current time) to be able
# to reuse size calculation methods for the inital size
self.setTimePoints([datetime.now()])
@property
def time_points(self):
"""Sorted list of all timepoints (sorted new to old)"""
return self._time_points
@property
def selected_time_point(self):
"""Get the selected timeout as datetime object. None if there is no
selection."""
if self._selection_item is None:
return None
return self._time_point_items[self._selection_item]
@property
def previous_time_point(self):
"""Get the timepoint before (older than) the currently selected one as
datetime object. None if there is no selection"""
try:
index = self._time_points.index(self.selected_time_point)
return self._time_points[index + 1]
except (ValueError, IndexError):
return None
def resizeEvent(self, event):
"""Clear and readd all items on resize. Avoids complex scaling."""
self.scene().clear()
self.setTimePoints(self._time_points)
def setTimePoints(self, time_points):
"""Sets and list of datetime objects as timepoints, sets up all
necessary graphics items and adjusts sizes."""
self.scene().clear()
self._selection_item = None
# store the timepoints sorted from new to old
self._time_points = list(reversed(sorted(time_points)))
self._time_point_items = {}
# draw the timeline
self._timeline = self._add_timeline()
# draw the time points
self._add_time_points()
# update the scene size and a slightly larger widget size to avoid
# superfluous scrolling (and displaying of scroll bars)
size = self.scene().itemsBoundingRect().size()
self.setSceneRect(0, 0, size.width(), size.height() - 5)
if time_points:
self.setMinimumWidth(size.width() * 1.2)
self.setMaximumWidth(size.width() * 1.2)
def mousePressEvent(self, event):
"""Handle mouse press events to support item selection."""
item = self.itemAt(event.pos())
if item in self._time_point_items:
self._select_item(item)
return QGraphicsView.mousePressEvent(self, event)
def _select_item(self, item):
"""Select the given item by drawing a colored circle beneath the
selected item (so it looks like a ring around it.
Also emits the timepointSelected signal."""
# The selection_item used to signal the selection of a timepoint
# is always the same and is only moved.
if self._selection_item is None:
self._selection_item = QGraphicsEllipseItem(
0, 0, self.SELECTION_DIAMETER, self.SELECTION_DIAMETER)
# The used color is a cubical to the time point color
self._selection_item.setBrush(QBrush(QColor(0x70, 0xbb, 0x00)))
self._selection_item.setPen(QPen(0))
self.scene().addItem(self._selection_item)
# center position of the timepoint circle
center_x = item.pos().x() + self.TIMEPOINT_DIAMETER / 2
center_y = item.pos().y() + self.TIMEPOINT_DIAMETER / 2
# move selection item
self._selection_item.setPos(center_x - self.SELECTION_DIAMETER / 2,
center_y - self.SELECTION_DIAMETER / 2)
# store the selection_item like a timepoint item (using the timepoint
# of the selected item)
self._time_point_items[self._selection_item] = \
self._time_point_items[item]
# emit signal at the end to ensure a valid internal state before
# anything can react to it
self.timepointSelected.emit(self._time_point_items[item])
def _add_timeline(self):
"""Draw the timeline."""
# height is either the necessary space to display all items or the
# maximal available display size, so it's looks nicely in larger
# windows and enables scrolling in smaller ones.
height = self.TIMEPOINT_DIAMETER * len(self._time_points)
height += self.TIMEPOINT_SPACING * len(self._time_points)
height = max(height, self.viewport().height())
# draw the timeline left aligned with enough space to draw the items
# and the selection ring.
x = self.MARGIN_HORIZONTAL + (self.SELECTION_DIAMETER / 2)
# position the line on the left side of the item
item = QGraphicsLineItem(0, 0, 0, height)
# The used color for the timeline is the lightest one of the FRM II
# colors
item.setPen(QPen(QBrush(QColor(0xa3, 0xc1, 0xe7)),
self.TIMELINE_WIDTH))
self.scene().addItem(item)
# move the whole item to the desired timeline position
item.setPos(x, 0)
return item
def _add_time_points(self):
"""Add all time point items."""
if not self._time_points:
return
timeline_pos = self._timeline.pos()
timeline_size = self._timeline.boundingRect().size()
height = timeline_size.height()
# time points are always equally distributed on the timeline
spacing = height / float(len(self._time_points))
center_x = timeline_pos.x()
# add half of the items spacing on the top and bottom of the timeline
start = timeline_pos.y() - spacing / 2
for i, entry in enumerate(self._time_points):
self._add_time_point(center_x, start + spacing * (i + 1), entry)
def _add_time_point(self, center_x, center_y, time_point):
"""Add a single time point item."""
x = center_x - (self.TIMEPOINT_DIAMETER / 2)
y = center_y - (self.TIMEPOINT_DIAMETER / 2)
# Create the acutal time point item
time_point_item = QGraphicsEllipseItem(0, 0, self.TIMEPOINT_DIAMETER,
self.TIMEPOINT_DIAMETER)
# The used color is the strongest one of the FRM II colors.
time_point_item.setBrush(QBrush(QColor(0x00, 0x71, 0xbb)))
time_point_item.setPen(QPen(0))
self.scene().addItem(time_point_item)
time_point_item.setPos(x, y)
# place the time point item above the timeline and the selection item
time_point_item.setZValue(2)
# Create the label of the time point showing the time in the
# defined strftime format on the right side of the time point item.
label = QGraphicsTextItem(time_point.strftime(self.STRFTIME_FMT))
label.setFont(QFont('Monospace'))
label_height = label.boundingRect().height()
# minor height adjustment
label_y = y - label_height / 6
self.scene().addItem(label)
label.setPos(x + self.SELECTION_DIAMETER + self.LABEL_SPACING, label_y)
# store references to the item and the timepoint in the same dict
# to be able to use it for forward and reverse lookup
self._time_point_items[time_point] = time_point_item
self._time_point_items[time_point_item] = time_point