René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: LA image mode not working anymore for custom toolbar buttons","articleBody":"### Bug summary\n\nPrior to `matplotlib 3.6`, I was able to use an icon for a custom tool in the toolbar of a figure which had a `LA` mode (see attached). Now I can't seem to be able to load it anymore as a custom icon.\r\n![icon](https://user-images.githubusercontent.com/12396317/217069351-d58fe762-3d97-4934-8ddb-d33bb7be4843.png)\r\n\n\n### Code for reproduction\n\n```python\nimport os\r\n\r\nimport matplotlib\r\nmatplotlib.rcParams[\"toolbar\"] = \"toolmanager\"\r\nimport matplotlib.pyplot as plt\r\nfrom matplotlib.backend_tools import ToolToggleBase\r\n\r\n\r\nclass CustomTool(ToolToggleBase):\r\n    image = os.path.join(os.path.dirname(__file__), \"icon.png\")\r\n\r\n\r\nif __name__ == \"__main__\":\r\n    fig = plt.figure()\r\n    toolmanager = fig.canvas.manager.toolmanager\r\n    toolbar = fig.canvas.manager.toolbar\r\n\r\n    toolmanager.add_tool(\"custom\", CustomTool)\r\n    toolbar.add_tool(\"custom\", \"group\")\n```\n\n\n### Actual outcome\n\n```\r\n/home/[...]/mwe.py:4: UserWarning: Treat the new Tool classes introduced in v1.5 as experimental for now; the API and rcParam may change in future versions.\r\n  matplotlib.rcParams[\"toolbar\"] = \"toolmanager\"\r\nTraceback (most recent call last):\r\n  File \"/home/[...]/mwe.py\", line 19, in \u003cmodule\u003e\r\n    toolbar.add_tool(\"custom\", \"group\")\r\n  File \"/home/[...]/lib/python3.10/site-packages/matplotlib/backend_bases.py\", line 3377, in add_tool\r\n    self.add_toolitem(tool.name, group, position,\r\n  File \"/home/[...]/lib/python3.10/site-packages/matplotlib/backends/_backend_tk.py\", line 957, in add_toolitem\r\n    button = NavigationToolbar2Tk._Button(frame, name, image_file, toggle,\r\n  File \"/home/[...]/lib/python3.10/site-packages/matplotlib/backends/_backend_tk.py\", line 792, in _Button\r\n    NavigationToolbar2Tk._set_image_for_button(self, b)\r\n  File \"/home/[...]/lib/python3.10/site-packages/matplotlib/backends/_backend_tk.py\", line 734, in _set_image_for_button\r\n    im_alt = _recolor_icon(im, foreground)\r\n  File \"/home/[...]/lib/python3.10/site-packages/matplotlib/backends/_backend_tk.py\", line 722, in _recolor_icon\r\n    image_data[black_mask, :3] = color\r\nValueError: shape mismatch: value array of shape (3,) could not be broadcast to indexing result of shape (0,2)\r\n```\r\n\n\n### Expected outcome\n\nNo errors should be raised and the icon should be displayed in the toolbar.\n\n### Additional information\n\nDowngrading to `matplotlib v 3.5.3` solves the issue. Don't know why this happens, but icons that have a `RGBA` mode (like the default icons) don't seem to have this problem. The attached icon has a `LA` mode.\n\n### Operating system\n\nUbuntu 22.04\n\n### Matplotlib Version\n\n3.6.3\n\n### Matplotlib Backend\n\nTkAgg\n\n### Python version\n\n3.10.6\n\n### Jupyter version\n\nN/A\n\n### Installation\n\npip","author":{"url":"https://github.com/fgoudreault","@type":"Person","name":"fgoudreault"},"datePublished":"2023-02-06T19:44:46.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/25164/matplotlib/issues/25164"}