class GraphWindow(QMainWindow):
""" Qt application window showing a single vector graph.
Save graph using right click menu.
Attributes:
_graph_display Widget that shows the graph image
_svg_bytes SVG bytes representing currently displayed image
"""
window_width = 600 # type: float # Height is computed from aspect ratio
def __init__(self,
graph_svg: bytes = None,
aspect_ratio: float = 1.0) -> None:
super().__init__()
self._svg_bytes = bytes()
# Add image widget:
self._graph_display = QSvgWidget()
self.setCentralWidget(self._graph_display)
if graph_svg is not None:
self.set_graph(graph_svg)
self._graph_display.setContextMenuPolicy(Qt.CustomContextMenu)
self._graph_display.customContextMenuRequested.connect(
self._show_context_menu)
self._graph_display.setToolTip("Right-click to save image")
self._graph_display.setToolTipDuration(2000)
# Set correct aspect ratio:
self.setFixedSize(self.window_width, self.window_width * aspect_ratio)
def _show_context_menu(self, point: QPoint) -> None:
""" Show a context menu for the graph display. """
menu = QMenu(self)
save_action = QAction("Save current image...", menu)
save_action.triggered.connect(
lambda checked: self._save_current_image())
menu.addAction(save_action)
menu.exec(self._graph_display.mapToGlobal(point))
def _save_current_image(self):
""" Copy current image and save it to a file. """
current_svg = deepcopy(self._svg_bytes) # type: bytes
file_path = QFileDialog.getSaveFileUrl()[0].path() # type: str
with open(file_path, "w") as outfile:
outfile.write(current_svg.decode())
@pyqtSlot(bytes)
def set_graph(self, graph_svg: bytes) -> None:
"""Renders SVG bytes in the graph display."""
self._graph_display.load(graph_svg)
self._svg_bytes = graph_svg
