Added support for colormap inversion

Author: PierreRaybaut

.coveragerc

@@ -9,6 +9,10 @@ omit =
     */qwt/*
     */guidata/*
 
-exclude_lines =
+[report]
+exclude_also =
+    def __repr__
+    raise AssertionError
+    raise NotImplementedError
     if __name__ == .__main__.:
-    if TYPE_CHECKING:
+    if TYPE_CHECKING:

CHANGELOG.md

@@ -1,8 +1,21 @@
 # Changelog #
 
-## Version 2.2.1 ##
+## Version 2.3.0 ##
 
-Changes:
+In this release, test coverage is 75%.
+
+New features:
+
+* Added support for colormap inversion:
+  * The user can now invert the colormap of an image item:
+    * From the image parameters dialog ("Invert colormap" checkbox)
+    * From the plot context menu (right-click on the image item)
+  * `BaseImageItem.set_color_map` method takes a new `invert` parameter (which
+    defaults to `None`, meaning that the behavior is unchanged)
+  * New `ReverseColormapTool`: registered by default in the plot widget, like the
+    `ColormapTool` (add the "Invert colormap" entry in the context menu of the image)
+
+Other changes:
 
 * Image plot items deserialization:
   * When an image plot item is deserialized, and needs to be reloaded from a file,

doc/features/tools/overview.rst

@@ -60,6 +60,7 @@ The `tools` module provides the following tools:
 * :py:class:`.tools.ItemListPanelTool`
 * :py:class:`.tools.ContrastPanelTool`
 * :py:class:`.tools.ColormapTool`
+* :py:class:`.tools.ReverseColormapTool`
 * :py:class:`.tools.XCSPanelTool`
 * :py:class:`.tools.YCSPanelTool`
 * :py:class:`.tools.CrossSectionTool`

doc/features/tools/reference.rst

@@ -106,6 +106,8 @@ Image tools
    :members:
 .. autoclass:: plotpy.tools.ColormapTool
    :members:
+.. autoclass:: plotpy.tools.ReverseColormapTool
+   :members:
 .. autoclass:: plotpy.tools.XCSPanelTool
    :members:
 .. autoclass:: plotpy.tools.YCSPanelTool

plotpy/__init__.py

@@ -20,7 +20,7 @@
 .. _GitHub: https://github.com/PierreRaybaut/plotpy
 """
 
-__version__ = "2.2.1"
+__version__ = "2.3.0"
 __VERSION__ = tuple([int(number) for number in __version__.split(".")])
 
 # --- Important note: DATAPATH and LOCALEPATH are used by guidata.configtools

plotpy/items/image/base.py

@@ -416,11 +416,15 @@ def set_background_color(self, qcolor: QColor | str) -> None:
         else:
             self.lut = (a, b, np.uint32(QG.QColor(qcolor).rgb() & 0xFFFFFF), cmap)
 
-    def set_color_map(self, name_or_table: str | EditableColormap) -> None:
+    def set_color_map(
+        self, name_or_table: str | EditableColormap, invert: bool | None = None
+    ) -> None:
         """Set colormap
 
         Args:
             name_or_table: Colormap name or colormap
+            invert: True to invert colormap, False otherwise (Default value = None,
+             i.e. do not change the default behavior)
         """
         if name_or_table is self.cmap_table:
             # This avoids rebuilding the LUT all the time
@@ -429,6 +433,8 @@ def set_color_map(self, name_or_table: str | EditableColormap) -> None:
             table = get_cmap(name_or_table)
         else:
             table = name_or_table
+        if invert is not None:
+            table.invert = invert
         self.cmap_table = table
         self.cmap = table.colorTable(FULLRANGE)
         cmap_a = self.lut[3]

plotpy/items/image/filter.py

@@ -45,6 +45,7 @@
     from plotpy.interfaces import IItemType
     from plotpy.items import RawImageItem, XYImageItem
     from plotpy.styles import ImageFilterParam, ItemParameters
+    from plotpy.widgets.colormap.widget import EditableColormap
 
 
 # ==============================================================================
@@ -188,18 +189,20 @@ def move_with_selection(self, delta_x: float, delta_y: float) -> None:
         self.border_rect.move_with_selection(delta_x, delta_y)
 
     def set_color_map(
-        self, name_or_table: str | qwt.color_map.QwtLinearColorMap
+        self, name_or_table: str | EditableColormap, invert: bool | None = None
     ) -> None:
         """Set colormap
 
         Args:
             name_or_table: Colormap name or colormap
+            invert: True to invert colormap, False otherwise (Default value = None,
+             i.e. do not change the default behavior)
         """
         if self.use_source_cmap:
             if self.image is not None:
-                self.image.set_color_map(name_or_table)
+                self.image.set_color_map(name_or_table, invert)
         else:
-            BaseImageItem.set_color_map(self, name_or_table)
+            BaseImageItem.set_color_map(self, name_or_table, invert)
 
     def get_color_map(self) -> qwt.color_map.QwtLinearColorMap:
         """Get colormap"""

plotpy/items/image/image_items.py

@@ -38,6 +38,7 @@
     from qtpy.QtGui import QColor, QPainter
 
     from plotpy.interfaces import IItemType
+    from plotpy.widgets.colormap.widget import EditableColormap
 
 try:
     from plotpy._scaler import INTERP_NEAREST, _scale_rect, _scale_xy
@@ -806,16 +807,14 @@ def set_background_color(self, qcolor: QColor | str) -> None:
         self.lut = None
 
     def set_color_map(
-        self, name_or_table: str | qwt.color_map.QwtLinearColorMap
+        self, name_or_table: str | EditableColormap, invert: bool | None = None
     ) -> None:
         """Set colormap
 
         Args:
             name_or_table: Colormap name or colormap
-
-        .. warning::
-
-            This method is not implemented for this item type.
+            invert: True to invert colormap, False otherwise (Default value = None,
+             i.e. do not change the default behavior)
         """
         self.lut = None