qt: add initial wizard classes for desktop client

electrum/gui/qt/wizard/wizard.py

@@ -0,0 +1,174 @@
+from abc import abstractmethod
+
+from PyQt5.QtCore import Qt, QVariant, QTimer, pyqtSignal, pyqtSlot
+from PyQt5.QtGui import QPixmap
+from PyQt5.QtWidgets import (QDialog, QApplication, QPushButton, QWidget, QLabel, QVBoxLayout, QScrollArea,
+                             QHBoxLayout, QLayout, QStackedWidget)
+
+from electrum.i18n import _
+from ..util import Buttons, icon_path
+from electrum.logging import get_logger
+
+
+class QEAbstractWizard(QDialog):
+    _logger = get_logger(__name__)
+
+    # def __init__(self, config: 'SimpleConfig', app: QApplication, plugins: 'Plugins', *, gui_object: 'ElectrumGui'):
+    def __init__(self, config: 'SimpleConfig', app: QApplication, daemon):
+        QDialog.__init__(self, None)
+        self.app = app
+        self.config = config
+        # self.gui_thread = gui_object.gui_thread
+        self.setMinimumSize(600, 400)
+        self.title = QLabel()
+        self.main_widget = QStackedWidget(self)
+        self.back_button = QPushButton(_("Back"), self)
+        self.back_button.clicked.connect(self.on_back_button_clicked)
+        self.next_button = QPushButton(_("Next"), self)
+        self.next_button.clicked.connect(self.on_next_button_clicked)
+        self.next_button.setDefault(True)
+        self.logo = QLabel()
+        self.please_wait = QLabel(_("Please wait..."))
+        self.please_wait.setAlignment(Qt.AlignCenter)
+        self.please_wait.setVisible(False)
+        self.icon_filename = None
+
+        outer_vbox = QVBoxLayout(self)
+        inner_vbox = QVBoxLayout()
+        inner_vbox.addWidget(self.title)
+        inner_vbox.addWidget(self.main_widget)
+        inner_vbox.addStretch(1)
+        inner_vbox.addWidget(self.please_wait)
+        inner_vbox.addStretch(1)
+        scroll_widget = QWidget()
+        scroll_widget.setLayout(inner_vbox)
+        scroll = QScrollArea()
+        scroll.setFocusPolicy(Qt.NoFocus)
+        scroll.setWidget(scroll_widget)
+        scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
+        scroll.setWidgetResizable(True)
+        icon_vbox = QVBoxLayout()
+        icon_vbox.addWidget(self.logo)
+        icon_vbox.addStretch(1)
+        hbox = QHBoxLayout()
+        hbox.addLayout(icon_vbox)
+        hbox.addSpacing(5)
+        hbox.addWidget(scroll)
+        hbox.setStretchFactor(scroll, 1)
+        outer_vbox.addLayout(hbox)
+        outer_vbox.addLayout(Buttons(self.back_button, self.next_button))
+        self.set_icon('electrum.png')
+        self.show()
+        self.raise_()
+
+        QTimer.singleShot(40, self.strt)
+
+        # TODO: re-test if needed on macOS
+        # self.refresh_gui()  # Need for QT on MacOSX.  Lame.
+
+    # def refresh_gui(self):
+    #     # For some reason, to refresh the GUI this needs to be called twice
+    #     self.app.processEvents()
+    #     self.app.processEvents()
+
+    def strt(self):
+        view = self.start_wizard()
+        self.load_next_component(view)
+
+    def load_next_component(self, view, wdata={}):
+        comp = self.view_to_component(view)
+        page = comp(self.main_widget)
+        page.wizard_data = wdata
+        page.updated.connect(self.on_page_updated)
+        self._logger.debug(f'{page!r}')
+        self.main_widget.setCurrentIndex(self.main_widget.addWidget(page))
+        page.apply()
+        self.update(page.wizard_data)
+
+    @pyqtSlot(object)
+    def on_page_updated(self, page):
+        page.apply()
+        self.update(page.wizard_data)
+
+    def set_icon(self, filename):
+        prior_filename, self.icon_filename = self.icon_filename, filename
+        self.logo.setPixmap(QPixmap(icon_path(filename))
+                            .scaledToWidth(60, mode=Qt.SmoothTransformation))
+        return prior_filename
+
+    def can_go_back(self):
+        return len(self._stack) > 0
+
+    def update(self, wdata: dict):
+        self.back_button.setText(_('Back') if self.can_go_back() else _('Cancel'))
+        self.next_button.setText(_('Next') if not self.is_last(wdata) else _('Finish'))
+
+    def on_back_button_clicked(self):
+        if self.can_go_back():
+            wdata = self.prev()
+            self.main_widget.removeWidget(self.main_widget.currentWidget())
+            self.update(wdata)
+        else:
+            self.close()
+
+    def on_next_button_clicked(self):
+        wc = self.main_widget.currentWidget()
+        wc.apply()
+        wd = wc.wizard_data.copy()
+        if self.is_last(wd):
+            self.finished(wd)
+            self.close()
+        else:
+            next = self.submit(wd)
+            self.load_next_component(next['view'], wd)
+
+    def start_wizard(self) -> str:
+        self.start()
+        return self._current.view
+
+    def view_to_component(self, view) -> QWidget:
+        return self.navmap[view]['gui']
+
+    def submit(self, wizard_data) -> dict:
+        wdata = wizard_data.copy()
+        self.log_state(wdata)
+        view = self.resolve_next(self._current.view, wdata)
+        return {
+            'view': view.view,
+            'wizard_data': view.wizard_data
+        }
+
+    def prev(self) -> dict:
+        viewstate = self.resolve_prev()
+        return viewstate.wizard_data
+
+    def is_last(self, wizard_data: dict) -> bool:
+        wdata = wizard_data.copy()
+        return self.is_last_view(self._current.view, wdata)
+
+
+### support classes
+
+
+class WizardComponent(QWidget):
+    updated = pyqtSignal(object)
+
+    def __init__(self, parent: QWidget = None, *, title: str = None, layout: QLayout = None):
+        super().__init__(parent)
+        self.setLayout(layout if layout else QVBoxLayout(self))
+        self.wizard_data = {}
+        self.title = title if title is not None else 'No title'
+        self._valid = False
+
+    @property
+    def valid(self):
+        return self._valid
+
+    @abstractmethod
+    def apply(self):
+        pass
+
+    @pyqtSlot()
+    def on_updated(self, *args):
+        self.updated.emit(self)
+