Icon handling in plot items: use a dedicated icon name attribute

Author: PierreRaybaut

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog #
 
+## Version 2.7.2 ##
+
+🛠️ Bug fixes:
+
+* Fixed regression with respect to `guiqwt` regarding plot items instantiation:
+  * `guiqwt` was allowing to instantiate plot items without needing to create a `QApplication` instance (no GUI event loop was required)
+  * This was not the case with `plotpy`, so that it was not possible -for example- to serialize/deserialize plot items to JSON without creating a `QApplication` instance
+  * This is now fixed
+
 ## Version 2.7.1 ##
 
 🛠️ Bug fixes:

plotpy/interfaces/items.py

@@ -249,6 +249,23 @@ class IBasePlotItem:
     _can_move = True
     _can_resize = True
     _can_rotate = True
+    _icon_name = ""  # Icon name (e.g. "point.png")
+
+    def get_icon_name(self) -> str:
+        """Return the icon name
+
+        Returns:
+            Icon name
+        """
+        return self._icon_name
+
+    def set_icon_name(self, icon_name: str) -> None:
+        """Set the icon name
+
+        Args:
+            icon_name: Icon name
+        """
+        self._icon_name = icon_name
 
     def set_selectable(self, state: bool) -> None:
         """Set item selectable state

plotpy/items/annotation.py

@@ -60,6 +60,7 @@ class AnnotatedShape(AbstractShape):
     """
 
     __implements__ = (IBasePlotItem, ISerializableType)
+    _icon_name = "annotation.png"
     SHAPE_CLASS: type[AbstractShape] = RectangleShape  # to be overridden
     LABEL_ANCHOR: str = ""
 
@@ -88,7 +89,6 @@ def info_callback(annotation: AnnotatedShape) -> str:
         else:
             self.annotationparam = annotationparam
             self.annotationparam.update_item(self)
-        self.setIcon(get_icon("annotation.png"))
 
     def types(self) -> tuple[type[IItemType], ...]:
         """Returns a group or category for this item.
@@ -485,6 +485,7 @@ class AnnotatedPoint(AnnotatedShape):
     *annotationparam* (see :py:class:`.styles.AnnotationParam`)
     """
 
+    _icon_name = "point_shape.png"
     SHAPE_CLASS = PointShape
     LABEL_ANCHOR = "TL"
 
@@ -498,7 +499,6 @@ def __init__(
         super().__init__(annotationparam, info_callback)
         self.shape: PointShape
         self.set_pos(x, y)
-        self.setIcon(get_icon("point_shape.png"))
 
     # ----Public API-------------------------------------------------------------
     def set_pos(self, x, y):
@@ -547,6 +547,7 @@ class AnnotatedSegment(AnnotatedShape):
     (see :py:class:`.styles.AnnotationParam`)
     """
 
+    _icon_name = "segment.png"
     SHAPE_CLASS = SegmentShape
     LABEL_ANCHOR = "C"
 
@@ -562,7 +563,6 @@ def __init__(
         super().__init__(annotationparam, info_callback)
         self.shape: SegmentShape
         self.set_rect(x1, y1, x2, y2)
-        self.setIcon(get_icon("segment.png"))
 
     # ----Public API-------------------------------------------------------------
     def set_rect(self, x1, y1, x2, y2):
@@ -619,6 +619,7 @@ class AnnotatedPolygon(AnnotatedShape):
         annotationparam: Annotation parameters
     """
 
+    _icon_name = "polygon.png"
     SHAPE_CLASS = PolygonShape
     LABEL_ANCHOR = "C"
 
@@ -635,7 +636,6 @@ def __init__(
             self.set_points(points)
         if closed is not None:
             self.set_closed(closed)
-        self.setIcon(get_icon("polygon.png"))
 
     # ----Public API-------------------------------------------------------------
     def set_points(self, points: list[tuple[float, float]] | np.ndarray | None) -> None:
@@ -775,6 +775,7 @@ class AnnotatedRectangle(AnnotatedShape):
     (see :py:class:`.styles.AnnotationParam`)
     """
 
+    _icon_name = "rectangle.png"
     SHAPE_CLASS = RectangleShape
     LABEL_ANCHOR = "TL"
 
@@ -790,7 +791,6 @@ def __init__(
         super().__init__(annotationparam, info_callback)
         self.shape: RectangleShape
         self.set_rect(x1, y1, x2, y2)
-        self.setIcon(get_icon("rectangle.png"))
 
     # ----Public API-------------------------------------------------------------
     def set_rect(self, x1, y1, x2, y2):
@@ -842,6 +842,7 @@ class AnnotatedObliqueRectangle(AnnotatedRectangle):
     (see :py:class:`.styles.AnnotationParam`)
     """
 
+    _icon_name = "oblique_rectangle.png"
     SHAPE_CLASS = ObliqueRectangleShape
     LABEL_ANCHOR = "C"
 
@@ -851,7 +852,6 @@ def __init__(
         AnnotatedShape.__init__(self, annotationparam)
         self.shape: ObliqueRectangleShape
         self.set_rect(x0, y0, x1, y1, x2, y2, x3, y3)
-        self.setIcon(get_icon("oblique_rectangle.png"))
 
     # ----Public API-------------------------------------------------------------
     def get_tr_angle(self):
@@ -940,6 +940,7 @@ class AnnotatedEllipse(AnnotatedShape):
     (see :py:class:`.styles.AnnotationParam`)
     """
 
+    _icon_name = "ellipse_shape.png"
     SHAPE_CLASS = EllipseShape
     LABEL_ANCHOR = "C"
 
@@ -955,7 +956,6 @@ def __init__(
         super().__init__(annotationparam, info_callback)
         self.shape: EllipseShape
         self.set_xdiameter(x1, y1, x2, y2)
-        self.setIcon(get_icon("ellipse_shape.png"))
         self.switch_to_ellipse()
 
     # ----Public API-------------------------------------------------------------

plotpy/items/contour.py

@@ -110,10 +110,10 @@ class ContourItem(PolygonShape):
     _can_resize = False
     _can_rotate = False
     _can_move = False
+    _icon_name = "contour.png"
 
     def __init__(self, points=None, shapeparam=None):
         super().__init__(points, closed=True, shapeparam=shapeparam)
-        self.setIcon(get_icon("contour.png"))
 
 
 assert_interfaces_valid(ContourItem)

plotpy/items/curve/base.py

@@ -111,6 +111,7 @@ class CurveItem(QwtPlotCurve):
 
     _readonly = False
     _private = False
+    _icon_name = "curve.png"
 
     def __init__(self, curveparam: CurveParam | None = None) -> None:
         super().__init__()
@@ -123,7 +124,6 @@ def __init__(self, curveparam: CurveParam | None = None) -> None:
         self._x = None
         self._y = None
         self.update_params()
-        self.setIcon(get_icon("curve.png"))
 
     def _get_visible_axis_min(self, axis_id: int, axis_data: np.ndarray) -> float:
         """Return axis minimum excluding zero and negative values when
@@ -172,6 +172,22 @@ def types(self) -> tuple[type[IItemType], ...]:
         """
         return (ICurveItemType, ITrackableItemType, ISerializableType)
 
+    def get_icon_name(self) -> str:
+        """Return the icon name
+
+        Returns:
+            Icon name
+        """
+        return self._icon_name
+
+    def set_icon_name(self, icon_name: str) -> None:
+        """Set the icon name
+
+        Args:
+            icon_name: Icon name
+        """
+        self._icon_name = icon_name
+
     def set_selectable(self, state: bool) -> None:
         """Set item selectable state
 

plotpy/items/curve/errorbar.py

@@ -56,6 +56,8 @@ class ErrorBarCurveItem(CurveItem):
         errorbarparam: Error-bar parameters
     """
 
+    _icon_name = "errorbar.png"
+
     def __init__(
         self,
         curveparam: CurveParam | None = None,
@@ -73,7 +75,6 @@ def __init__(
         self._dx = None
         self._dy = None
         self.__minmaxarrays: dict[bool, tuple[float, float, float, float]] = {}
-        self.setIcon(get_icon("errorbar.png"))
 
     def serialize(
         self,

plotpy/items/grid.py

@@ -36,6 +36,7 @@ class GridItem(QwtPlotGrid):
 
     _readonly = True
     _private = False
+    _icon_name = "grid.png"
 
     def __init__(self, gridparam: GridParam | None = None) -> None:
         super().__init__()
@@ -47,7 +48,6 @@ def __init__(self, gridparam: GridParam | None = None) -> None:
         self.immutable = True  # set to false to allow moving points around
         self.update_params()  # won't work completely because it's not yet
         # attached to plot (actually, only canvas background won't be updated)
-        self.setIcon(get_icon("grid.png"))
 
     def types(self) -> tuple[type[IItemType], ...]:
         """Returns a group or category for this item.
@@ -95,6 +95,22 @@ def is_private(self) -> bool:
         """
         return self._private
 
+    def get_icon_name(self) -> str:
+        """Return the icon name
+
+        Returns:
+            Icon name
+        """
+        return self._icon_name
+
+    def set_icon_name(self, icon_name: str) -> None:
+        """Set the icon name
+
+        Args:
+            icon_name: Icon name
+        """
+        self._icon_name = icon_name
+
     def set_selectable(self, state: bool) -> None:
         """Set item selectable state
 

plotpy/items/histogram.py

@@ -67,6 +67,7 @@ class HistogramItem(CurveItem):
     """
 
     __implements__ = (IBasePlotItem,)
+    _icon_name = "histogram.png"
 
     def __init__(
         self,
@@ -92,7 +93,6 @@ def __init__(
             self.histparam = histparam
         CurveItem.__init__(self, curveparam)
         self.setCurveAttribute(QwtPlotCurve.Inverted)
-        self.setIcon(get_icon("histogram.png"))
 
     def set_hist_source(self, src: BaseImageItem) -> None:
         """Set histogram source

plotpy/items/image/base.py

@@ -82,6 +82,7 @@ class BaseImageItem(QwtPlotItem):
     _can_rotate = False
     _readonly = False
     _private = False
+    _icon_name = "image.png"
 
     def __init__(
         self, data: np.ndarray | None = None, param: Any | None = None
@@ -134,7 +135,6 @@ def __init__(
         if data is not None:
             self.set_data(data)
         self.param.update_item(self)
-        self.setIcon(get_icon("image.png"))
 
     # ---- Public API ----------------------------------------------------------
     def get_default_param(self) -> Any:
@@ -777,6 +777,22 @@ def is_empty(self) -> bool:
         """
         return self.data is None or self.data.size == 0
 
+    def get_icon_name(self) -> str:
+        """Return the icon name
+
+        Returns:
+            Icon name
+        """
+        return self._icon_name
+
+    def set_icon_name(self, icon_name: str) -> None:
+        """Set the icon name
+
+        Args:
+            icon_name: Icon name
+        """
+        self._icon_name = icon_name
+
     def set_selectable(self, state: bool) -> None:
         """Set item selectable state
 

plotpy/items/image/filter.py

@@ -75,6 +75,7 @@ class ImageFilterItem(BaseImageItem):
     _can_select = True
     _can_resize = True
     _can_move = True
+    _icon_name = "funct.png"
 
     def __init__(
         self, image: RawImageItem | None, filter: Callable, param: ImageFilterParam
@@ -92,7 +93,6 @@ def __init__(
 
         self.imagefilterparam = param
         self.imagefilterparam.update_imagefilter(self)
-        self.setIcon(get_icon("funct.png"))
 
     # ---- Public API -----------------------------------------------------------
     def set_image(self, image: RawImageItem | None) -> None: