Source code for openlp.core.ui.lib.listwidgetwithdnd

# -*- coding: utf-8 -*-
# vim: autoindent shiftwidth=4 expandtab textwidth=120 tabstop=4 softtabstop=4

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# OpenLP - Open Source Lyrics Projection                                      #
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# Copyright (c) 2008-2017 OpenLP Developers                                   #
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"""
Extend QListWidget to handle drag and drop functionality
"""
import os

from PyQt5 import QtCore, QtGui, QtWidgets

from openlp.core.common import Registry, UiStrings


[docs]class ListWidgetWithDnD(QtWidgets.QListWidget):
    """
    Provide a list widget to store objects and handle drag and drop events
    """
    def __init__(self, parent=None, name=''):
        """
        Initialise the list widget
        """
        super().__init__(parent)
        self.mime_data_text = name
        self.no_results_text = UiStrings().NoResults
        self.setSpacing(1)
        self.setSelectionMode(QtWidgets.QAbstractItemView.ExtendedSelection)
        self.setAlternatingRowColors(True)
        self.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
        self.locked = False

[docs]    def activateDnD(self):
        """
        Activate DnD of widget
        """
        self.setAcceptDrops(True)
        self.setDragDropMode(QtWidgets.QAbstractItemView.DragDrop)
        Registry().register_function(('%s_dnd' % self.mime_data_text), self.parent().load_file)

[docs]    def clear(self, search_while_typing=False, override_lock=False):
        """
        Re-implement clear, so that we can customise feedback when using 'Search as you type'

        :param search_while_typing: True if we want to display the customised message
        :return: None
        """
        if self.locked and not override_lock:
            return
        if search_while_typing:
            self.no_results_text = UiStrings().ShortResults
        else:
            self.no_results_text = UiStrings().NoResults
        super().clear()

[docs]    def mouseMoveEvent(self, event):
        """
        Drag and drop event does not care what data is selected as the recipient will use events to request the data
        move just tell it what plugin to call
        """
        if event.buttons() != QtCore.Qt.LeftButton:
            event.ignore()
            return
        if not self.selectedItems():
            event.ignore()
            return
        drag = QtGui.QDrag(self)
        mime_data = QtCore.QMimeData()
        drag.setMimeData(mime_data)
        mime_data.setText(self.mime_data_text)
        drag.exec(QtCore.Qt.CopyAction)

[docs]    def dragEnterEvent(self, event):
        """
        When something is dragged into this object, check if you should be able to drop it in here.
        """
        if event.mimeData().hasUrls():
            event.accept()
        else:
            event.ignore()

[docs]    def dragMoveEvent(self, event):
        """
        Make an object droppable, and set it to copy the contents of the object, not move it.
        """
        if event.mimeData().hasUrls():
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()
        else:
            event.ignore()

[docs]    def dropEvent(self, event):
        """
        Receive drop event check if it is a file and process it if it is.

        :param event:  Handle of the event pint passed
        """
        if event.mimeData().hasUrls():
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()
            files = []
            for url in event.mimeData().urls():
                local_file = os.path.normpath(url.toLocalFile())
                if os.path.isfile(local_file):
                    files.append(local_file)
                elif os.path.isdir(local_file):
                    listing = os.listdir(local_file)
                    for file in listing:
                        files.append(os.path.join(local_file, file))
            Registry().execute('{mime_data}_dnd'.format(mime_data=self.mime_data_text),
                               {'files': files, 'target': self.itemAt(event.pos())})
        else:
            event.ignore()

[docs]    def paintEvent(self, event):
        """
        Re-implement paintEvent so that we can add 'No Results' text when the listWidget is empty.

        :param event: A QPaintEvent
        :return: None
        """
        super().paintEvent(event)
        if not self.count():
            viewport = self.viewport()
            painter = QtGui.QPainter(viewport)
            font = QtGui.QFont()
            font.setItalic(True)
            painter.setFont(font)
            painter.drawText(QtCore.QRect(0, 0, viewport.width(), viewport.height()),
                             (QtCore.Qt.AlignHCenter | QtCore.Qt.TextWordWrap), self.no_results_text)