drag_button.py

"""@package docstring
Drag button class.
This class creates a dragbutton which can be clicked, dragged and dropped.
"""

import os.path

from PyQt5.QtWidgets import QPushButton
from PyQt5.QtCore import Qt, QSize
from PyQt5.QtGui import QIcon

from utils import decorate_class, handle_error


@decorate_class(handle_error)
class DragButton(QPushButton):
    def __init__(self, name, operation, operation_path_name, window, parent = None):
        self.name = name
        self._window = window
        self.operation = operation
        self.operation_path_name = operation_path_name
        self.clicked = 0
        self.pressed = False
        super(DragButton, self).__init__(self._window)

    def mousePressEvent(self, event):
        self._mouse_press_pos = None
        self._mouse_move_pos = None

        if event.button() == Qt.LeftButton:
            self._mouse_press_pos = event.globalPos()
            self._mouse_move_pos = event.globalPos()

            for signal in self._window.signalList:
                signal.update()

            self.clicked += 1
            if self.clicked == 1:
                self.pressed = True
                self.setStyleSheet("background-color: grey; border-style: solid;\
                border-color: black; border-width: 2px; border-radius: 10px")
                path_to_image = os.path.join('operation_icons', self.operation_path_name + '_grey.png')
                self.setIcon(QIcon(path_to_image))
                self.setIconSize(QSize(50, 50))
                self._window.pressed_button.append(self)

            elif self.clicked == 2:
                self.clicked = 0
                self.pressed = False
                self.setStyleSheet("background-color: white; border-style: solid;\
                border-color: black; border-width: 2px; border-radius: 10px")
                path_to_image = os.path.join('operation_icons', self.operation_path_name + '.png')
                self.setIcon(QIcon(path_to_image))
                self.setIconSize(QSize(50, 50))
                self._window.pressed_button.remove(self)

        super(DragButton, self).mousePressEvent(event)

    def mouseMoveEvent(self, event):
        if event.buttons() == Qt.LeftButton:
            cur_pos = self.mapToGlobal(self.pos())
            global_pos = event.globalPos()
            diff = global_pos - self._mouse_move_pos
            new_pos = self.mapFromGlobal(cur_pos + diff)
            self.move(new_pos)

            self._mouse_move_pos = global_pos

        self._window.update()
        super(DragButton, self).mouseMoveEvent(event)

    def mouseReleaseEvent(self, event):
        if self._mouse_press_pos is not None:
            moved = event.globalPos() - self._mouse_press_pos
            if moved.manhattanLength() > 3:
                event.ignore()
                return

        super(DragButton, self).mouseReleaseEvent(event)

    def remove(self):
        self.deleteLater()