Patroneo/qtgui/timeline.py

#! /usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Copyright 2020, Nils Hilbricht, Germany ( https://www.hilbricht.net )

This file is part of Patroneo ( https://www.laborejo.org )

Laborejo 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 3 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, see <http://www.gnu.org/licenses/>.
"""

import logging; logger = logging.getLogger(__name__); logger.info("import")


SIZE_UNIT = 25 #this is in manual sync with songeditor.py SIZE_UNIT

import engine.api as api #Session is already loaded and created, no duplication.
from PyQt5 import QtCore, QtGui, QtWidgets

class Timeline(QtWidgets.QGraphicsScene):
    def __init__(self, parentView):
        super().__init__()
        self.parentView = parentView
        self.addItem(TimelineRect(parentScene=self))

        #Set color, otherwise it will be transparent in window managers or wayland that want that.
        self.backColor = QtGui.QColor(55, 61, 69)
        self.setBackgroundBrush(self.backColor)



class TimelineRect(QtWidgets.QGraphicsRectItem):
    """Shows information about song progression.
    JACK transport only shares the current time.
    We cannot draw anything ahead of time other than what we know ourselves.
    We rely on external tempo information and cannot react to tempo changes.
    Our linear value is measures, so we display these."""
    def __init__(self, parentScene):
        self.height = 25
        super().__init__(0, 0, 1, self.height)
        self.parentScene = parentScene
        self._cachedExportDictScore = {}

        role = QtGui.QPalette.Light
        c = self.parentScene.parentView.parentMainWindow.fPalBlue.color(role)
        self.setBrush(c)

        role = QtGui.QPalette.BrightText
        self.brightText = self.parentScene.parentView.parentMainWindow.fPalBlue.color(role)

        self._cachedSubdivisions = 1
        self.measureNumbers = []
        #self._buffer_measuresPerGroup set in callback_setnumberOfMeasures, changed in wheelEvent. Utilized in hoverLeaveEvent

        self._pressed = False

        api.callbacks.numberOfMeasuresChanged.append(self.callback_setnumberOfMeasures)
        api.callbacks.scoreChanged.append(self.callback_setnumberOfMeasures) #sends information about measuresPerGroup
        api.callbacks.subdivisionsChanged.append(self.cache_subdivisions) #sends information about measuresPerGroup
        api.callbacks.timeSignatureChanged.append(self.cache_timesignature)

        self.setToolTip(QtCore.QCoreApplication.translate("Timeline", "Click to set playback position. Scroll with mousewheel to adjust measure grouping."))

    def cache_timesignature(self, howManyUnits, whatTypeOfUnit):
        self._cachedExportDictScore["howManyUnits"] = howManyUnits
        self._cachedExportDictScore["whatTypeOfUnit"] = whatTypeOfUnit

    def cache_subdivisions(self, subdivisions):
        self._cachedSubdivisions = subdivisions

    def callback_setnumberOfMeasures(self, exportDictScore):
        """We only draw one number and line for each group and not the barlines in between"""
        self._cachedExportDictScore = exportDictScore
        requestAmountOfMeasures = exportDictScore["numberOfMeasures"]
        self._buffer_measuresPerGroup = exportDictScore["measuresPerGroup"]

        self.setRect(0,0,requestAmountOfMeasures * SIZE_UNIT, SIZE_UNIT)

        #Delete old
        for l in self.measureNumbers:
            l.setParentItem(None)
            self.parentScene.removeItem(l)
        self.measureNumbers = []

        #Create new
        for i in range(requestAmountOfMeasures+1):
            if i > 0 and (i+1) % exportDictScore["measuresPerGroup"] == 1:
                measure = QtWidgets.QGraphicsSimpleTextItem(str(i)) #str(i).zfill(3)
                measure.setBrush(self.brightText)
                measure.setParentItem(self)
                measure.setPos((i-1)*SIZE_UNIT, 5) #some magic pixel values for finetuning.
                #measure.setEnabled(False) #Contrary to intuition this will not make this item ignore mouse clicks but just eat them. Enabling fowards mouse item to the timeline below.
                measure.setFlag(self.ItemIgnoresTransformations)
                self.measureNumbers.append(measure)

                barline = QtWidgets.QGraphicsLineItem(0,0,0,self.height)
                barline.setParentItem(self)
                barline.setPen(self.brightText)
                barline.setPos(i*SIZE_UNIT, 0)
                #barline.setEnabled(False)  #Contrary to intuition this will not make this item ignore mouse clicks but just eat them. Enabling fowards mouse item to the timeline below.
                barline.setFlag(self.ItemIgnoresTransformations)
                self.measureNumbers.append(barline)


    def _sendPlaybackPositionToEngine(self, posX):
        oneMeasureInTicks = ( self._cachedExportDictScore["howManyUnits"] * self._cachedExportDictScore["whatTypeOfUnit"] )  / self._cachedSubdivisions
        ratio =  oneMeasureInTicks / SIZE_UNIT
        value = posX * ratio
        api.seek(int(value))

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            event.accept()
            self._sendPlaybackPositionToEngine(event.scenePos().x())
            self._pressed = True

    def mouseMoveEvent(self, event):
        if self._pressed:
            self._sendPlaybackPositionToEngine(event.scenePos().x())
            event.accept()

    def mouseReleaseEvent(self, event):
        if event.button() == QtCore.Qt.LeftButton:
            event.accept()
            self._pressed = False


    def wheelEvent(self, event):
        """This buffers until hoverLeaveEvent and then the new value is sent in self.hoverLeaveEvent"""
        event.accept()
        if event.delta() > 0:
            self._buffer_measuresPerGroup += 1
        else:
            self._buffer_measuresPerGroup = max(1, self._buffer_measuresPerGroup-1)
        api.set_measuresPerGroup(self._buffer_measuresPerGroup)