fastplotlib · FlynnOConnell · Nov 23, 2025 · Nov 29, 2025 · Dec 4, 2025 · Dec 20, 2025
@@ -0,0 +1,110 @@
+"""
+ImGui File Dialog
+=================
+
+Example showing how to use imgui_bundle's portable file dialogs to load
+and display image files using ImageGraphic.
+
+Demonstrates:
+- Creating a custom EdgeWindow GUI panel
+- Using portable_file_dialogs for native file selection
+- Loading images with imageio and displaying them
+"""
+
+# test_example = false
+# sphinx_gallery_pygfx_docs = 'screenshot'
+
+import imageio.v3 as iio
+
+import fastplotlib as fpl
+from fastplotlib.ui import EdgeWindow
+from imgui_bundle import imgui, portable_file_dialogs as pfd
+
+
+# load an initial image from imageio's built-in images
+initial_image = iio.imread("imageio:astronaut.png")
+
+# create a figure with an ImageGraphic
+figure = fpl.Figure(size=(700, 560))
+image_graphic = figure[0, 0].add_image(initial_image)
+
+
+class FileDialogWidget(EdgeWindow):
+    """Widget with file dialog to load and display images."""
+
+    def __init__(self, figure, image_graphic):
+        super().__init__(
+            figure=figure,
+            size=200,
+            location="right",
+            title="File Dialog",
+        )
+        self._image_graphic = image_graphic
+        self._file_dialog = None
+        self._status_msg = "Click 'Open Image' to load a file"
+
+    def update(self):
+        """Render the ImGui interface."""
+        imgui.spacing()
+        imgui.text("Load an image file:")
+        imgui.spacing()
+
+        # open file button
+        if imgui.button("Open Image", imgui.ImVec2(-1, 0)):
+            self._file_dialog = pfd.open_file(
+                "Select Image File",
+                "",
+                ["Image Files", "*.png *.jpg *.jpeg *.tif *.tiff", "All Files", "*.*"],
+            )
+
+        # check for dialog result (non-blocking)
+        if self._file_dialog is not None and self._file_dialog.ready():
+            result = self._file_dialog.result()
+            if result:
+                self._load_image(result[0])
+            self._file_dialog = None
+
+        # status display
+        imgui.spacing()
+        imgui.separator()
+        imgui.spacing()
+        imgui.text_wrapped(self._status_msg)
+
+    def _load_image(self, filepath):
+        """Load an image file and update the graphic."""
+        try:
+            img_data = iio.imread(filepath)
+
+            # validate image format: must be 2D (grayscale) or 3D with 1-4 channels
+            if not (img_data.ndim == 2 or (img_data.ndim == 3 and img_data.shape[2] <= 4)):
+                self._status_msg = (
+                    f"Unsupported format: {img_data.shape}. "
+                    f"Expected (H, W) or (H, W, C) with C <= 4"
+                )
+                return
+
+            # check if the new image shape matches the current buffer
+            if img_data.shape == self._image_graphic.data.value.shape:
+                self._image_graphic.data = img_data
+            else:
+                # shape mismatch: remove old graphic and create a new one
+                subplot = self._image_graphic._plot_area
+                subplot.remove_graphic(self._image_graphic)
+                self._image_graphic = subplot.add_image(img_data)
+                subplot.auto_scale()
+
+            self._status_msg = f"Loaded: {filepath}"
+        except Exception as e:
+            self._status_msg = f"Error: {e}"
+
+
+figure.show()
+
+# add the file dialog widget
+widget = FileDialogWidget(figure, image_graphic)
+figure.add_gui(widget)
+
+
+if __name__ == "__main__":
+    print(__doc__)
+    fpl.loop.run()