[help] add help dialg stub

fixtracks/dialogs/help.py

@@ -0,0 +1,79 @@
+from PySide6.QtGui import QIcon
+from PySide6.QtWidgets import QDialog, QDialogButtonBox, QFrame, QHBoxLayout
+from PySide6.QtWidgets import QPushButton, QSizePolicy, QTextBrowser, QVBoxLayout, QWidget
+from PySide6.QtCore import QSettings, QUrl, Qt
+
+from fixtracks.info import DOCS_ROOT_FILE
+
+class HelpDialog(QDialog):
+
+    def __init__(self, parent=None) -> None:
+        super().__init__(parent=parent)
+        self._settings = QSettings()
+        width = int(self._settings.value("help/width", 640))
+        height = int(self._settings.value("help/height", 480))
+        x = int(self._settings.value("help/pos_x", 100))
+        y = int(self._settings.value("help/pos_y", 100))
+
+        self.setModal(True)
+        self.setMinimumSize(640, 480)
+        self.resize(width, height)
+        self.move(x, y)
+        self.finished.connect(self.on_finished)
+        self.help = HelpBrowser()
+
+        self.help._edit.historyChanged.connect(self._on_history_changed)
+
+        self.back_btn = QPushButton(QIcon(":/icons/docs_back"), "back")
+        self.back_btn.setEnabled(False)
+        self.back_btn.clicked.connect(self.help._edit.backward)
+        self.home_btn = QPushButton(QIcon(":/icons/docs_home"), "home")
+        self.home_btn.clicked.connect(self.help._edit.home)
+        self.fwd_btn = QPushButton(QIcon(":/icons/docs_forward"), "forward")
+        self.fwd_btn.setLayoutDirection(Qt.RightToLeft)
+        self.fwd_btn.setEnabled(False)
+        self.fwd_btn.clicked.connect(self.help._edit.forward)
+
+        empty = QWidget()
+        empty.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Preferred)
+
+        hbox = QHBoxLayout()
+        hbox.addWidget(self.back_btn)
+        hbox.addWidget(self.home_btn)
+        hbox.addWidget(self.fwd_btn)
+        hbox.addWidget(empty)
+
+        bbox = QDialogButtonBox(QDialogButtonBox.StandardButton.Ok)
+        bbox.accepted.connect(self.accept)
+        layout = QVBoxLayout()
+
+        layout.addLayout(hbox)
+        layout.addWidget(self.help)
+        layout.addWidget(bbox)
+        self.setLayout(layout)
+
+    def _on_history_changed(self):
+        self.back_btn.setEnabled(self.help._edit.isBackwardAvailable())
+        self.fwd_btn.setEnabled(self.help._edit.isForwardAvailable())
+
+    def on_finished(self):
+        self._settings.setValue("help/width", self.width())
+        self._settings.setValue("help/height", self.height())
+        self._settings.setValue("help/pos_x", self.x())
+        self._settings.setValue("help/pos_y", self.y())
+
+
+class HelpBrowser(QWidget):
+
+    def __init__(self, parent=None) -> None:
+        super().__init__(parent=parent)
+        self.setLayout(QVBoxLayout())
+        doc_url = QUrl.fromLocalFile(DOCS_ROOT_FILE)
+        self._edit = QTextBrowser()
+        self._edit.setOpenLinks(True)
+        self._edit.setOpenExternalLinks(True)
+        self._edit.setSource(doc_url)
+        self._edit.setEnabled(True)
+        self._edit.setFrameShape(QFrame.NoFrame)
+
+        self.layout().addWidget(self._edit)