Image scroller for live view (#1917)

docs/release_notes/next/feature-1916-img_scroller_user_interface

@@ -0,0 +1 @@
+#1916 : Image scroller for live view

mantidimaging/gui/widgets/zslider/__init__.py

@@ -0,0 +1,3 @@
+# Copyright (C) 2023 ISIS Rutherford Appleton Laboratory UKRI
+# SPDX - License - Identifier: GPL-3.0-or-later
+from __future__ import annotations

mantidimaging/gui/widgets/zslider/zslider.py

@@ -0,0 +1,57 @@
+# Copyright (C) 2023 ISIS Rutherford Appleton Laboratory UKRI
+# SPDX - License - Identifier: GPL-3.0-or-later
+from __future__ import annotations
+
+from PyQt5.QtCore import pyqtSignal, Qt
+from PyQt5.QtWidgets import QGraphicsSceneMouseEvent
+from pyqtgraph import PlotItem, InfiniteLine
+
+
+class ZSlider(PlotItem):
+    """
+    A plot item to draw a z-axis slider mimicking the slider in PyQtGraph's ImageView
+
+    This gives us flexibility to choose what happens when the user move through the z-axis. It can be combined with
+    the one or more :py:class:`~mantidimaging.gui.widgets.mi_mini_image_view.view.MIMiniImageView`'s in a
+    GraphicsLayoutWidget. It is used in the Operations window to choose the slice to preview a filter with,
+    and in the Live Viewer scroll through images.
+
+    Emits a :code:`valueChanged` signal when the user moves the slider
+    """
+
+    z_line: InfiniteLine
+    valueChanged = pyqtSignal(int)
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.setFixedHeight(40)
+        self.hideAxis("left")
+        self.setXRange(0, 1)
+        self.setMouseEnabled(x=False, y=False)
+        self.hideButtons()
+
+        self.z_line = InfiniteLine(0, movable=True)
+        self.z_line.setPen((255, 255, 0, 200))
+        self.addItem(self.z_line)
+
+        self.z_line.sigPositionChanged.connect(self.value_changed)
+
+    def set_range(self, min: int, max: int) -> None:
+        self.z_line.setValue(min)
+        self.setXRange(min, max)
+        self.z_line.setBounds([min, max])
+
+    def set_value(self, value: int) -> None:
+        self.z_line.setValue(value)
+
+    def value_changed(self) -> None:
+        self.valueChanged.emit(int(self.z_line.value()))
+
+    def mousePressEvent(self, ev: 'QGraphicsSceneMouseEvent') -> None:
+        """
+        Adjusts built in behaviour to allow user to click anywhere on the line to jump there.
+        """
+        if ev.button() == Qt.MouseButton.LeftButton:
+            x = round(self.vb.mapSceneToView(ev.scenePos()).x())
+            self.set_value(x)
+        super().mousePressEvent(ev)

mantidimaging/gui/windows/live_viewer/live_view_widget.py

@@ -4,6 +4,7 @@
 from typing import TYPE_CHECKING
 from pyqtgraph import GraphicsLayoutWidget
 from mantidimaging.gui.widgets.mi_mini_image_view.view import MIMiniImageView
+from mantidimaging.gui.widgets.zslider.zslider import ZSlider
 
 if TYPE_CHECKING:
     import numpy as np
@@ -22,6 +23,10 @@ def __init__(self) -> None:
 
         self.image = MIMiniImageView(name="Projection")
         self.addItem(self.image, 0, 0)
+        self.nextRow()
+
+        self.z_slider = ZSlider()
+        self.addItem(self.z_slider)
 
     def show_image(self, image: np.ndarray) -> None:
         """

mantidimaging/gui/windows/live_viewer/model.py

@@ -72,6 +72,8 @@ class LiveViewerWindowModel:
         presenter for the spectrum viewer window
     path : Path
         path to dataset
+    images : list
+        list of images in directory
     """
 
     def __init__(self, presenter: 'LiveViewerWindowPresenter'):
@@ -87,6 +89,7 @@ def __init__(self, presenter: 'LiveViewerWindowPresenter'):
         self.presenter = presenter
         self._dataset_path: Path | None = None
         self.image_watcher: ImageWatcher | None = None
+        self.images: list[Image_Data] = []
 
     @property
     def path(self) -> Path | None:
@@ -98,7 +101,6 @@ def path(self, path: Path) -> None:
         self.image_watcher = ImageWatcher(path)
         self.image_watcher.image_changed.connect(self._handle_image_changed_in_list)
         self.image_watcher.find_images()
-        self.image_watcher.get_images()
 
     def _handle_image_changed_in_list(self, image_files: list[Image_Data]) -> None:
         """
@@ -108,11 +110,8 @@ def _handle_image_changed_in_list(self, image_files: list[Image_Data]) -> None:
 
         :param image_files: list of image files
         """
-        if not image_files:
-            self.presenter.handle_deleted()
-            self.presenter.update_image([])
-        else:
-            self.presenter.update_image(image_files)
+        self.images = image_files
+        self.presenter.update_image_list(image_files)
 
 
 class ImageWatcher(QObject):
@@ -127,21 +126,15 @@ class ImageWatcher(QObject):
         path to directory to watch
     watcher : QFileSystemWatcher
         file system watcher to watch directory
-    images : list
-        list of images in directory
     image_changed : pyqtSignal
         signal emitted when an image is added or removed
 
     Methods
     -------
     find_images()
-        Find all the images in the directory and emit the
-        image_changed signal for the last modified image.
+        Find all the images in the directory
     sort_images_by_modified_time(images)
         Sort the images by modified time.
-    find_last_modified_image()
-        Find the last modified image in the directory and
-        emit the image_changed signal.
     """
     image_changed = pyqtSignal(list)  # Signal emitted when an image is added or removed
 
@@ -160,16 +153,25 @@ def __init__(self, directory: Path):
         self.watcher = QFileSystemWatcher()
         self.watcher.directoryChanged.connect(self._handle_directory_change)
         self.watcher.addPath(str(self.directory))
-        self.images: list[Image_Data] = []
 
-    def find_images(self) -> None:
+    def find_images(self) -> list[Image_Data]:
         """
-        Find all the images in the directory and emit the
-        image_changed signal for the last modified image.
+        Find all the images in the directory.
         """
-        self.images = self._get_image_files()
+        image_files = []
+        for file_path in Path(self.directory).iterdir():
+            if self._is_image_file(file_path.name):
+                try:
+                    image_obj = Image_Data(file_path)
+                    if image_obj.image_size > 45:
+                        image_files.append(image_obj)
+                except FileNotFoundError:
+                    continue
+
+        return image_files
 
-    def sort_images_by_modified_time(self, images: list[Image_Data]) -> list[Image_Data]:
+    @staticmethod
+    def sort_images_by_modified_time(images: list[Image_Data]) -> list[Image_Data]:
         """
         Sort the images by modified time.
 
@@ -178,35 +180,18 @@ def sort_images_by_modified_time(self, images: list[Image_Data]) -> list[Image_D
         """
         return sorted(images, key=lambda x: x.image_modified_time)
 
-    def get_images(self) -> list[Image_Data]:
-        """Return the sorted images"""
-        return self.images
-
     def _handle_directory_change(self, directory: str) -> None:
         """
         Handle a directory change event. Update the list of images
         to reflect directory changes and emit the image_changed signal
-        for the last modified image.
+        with the sorted image list.
 
         :param directory: directory that has changed
         """
-        try:
-            self.find_images()
-            self.image_changed.emit(self.images)
-        except FileNotFoundError:
-            self.image_changed.emit([])
 
-    def _get_image_files(self) -> list[Image_Data]:
-        image_files = []
-        for file_path in Path(self.directory).iterdir():
-            if self._is_image_file(file_path.name):
-                try:
-                    image_obj = Image_Data(file_path)
-                    if image_obj.image_size > 45:
-                        image_files.append(image_obj)
-                except FileNotFoundError:
-                    continue
-        return self.sort_images_by_modified_time(image_files)
+        images = self.find_images()
+        images = self.sort_images_by_modified_time(images)
+        self.image_changed.emit(images)
 
     @staticmethod
     def _is_image_file(file_name: str) -> bool:

mantidimaging/gui/windows/live_viewer/presenter.py

@@ -48,19 +48,29 @@ def handle_deleted(self) -> None:
         """Handle the deletion of the image."""
         self.view.remove_image()
         self.clear_label()
+        self.view.live_viewer.z_slider.set_range(0, 1)
 
-    def update_image(self, images_list: list[Image_Data]) -> None:
+    def update_image_list(self, images_list: list[Image_Data]) -> None:
         """Update the image in the view."""
         if not images_list:
-            self.view.remove_image()
+            self.handle_deleted()
+            return
+
+        self.view.live_viewer.z_slider.set_range(0, len(images_list) - 1)
+        self.view.set_image_index(len(images_list) - 1)
+
+    def select_image(self, index: int) -> None:
+        if not self.model.images:
             return
-        latest_image = images_list[-1]
+        selected_image = self.model.images[index]
+        self.view.label_active_filename.setText(selected_image.image_name)
+
         try:
-            with tifffile.TiffFile(latest_image.image_path) as tif:
+            with tifffile.TiffFile(selected_image.image_path) as tif:
                 image_data = tif.asarray()
         except (IOError, KeyError, ValueError, DeflateError) as error:
-            logger.error("%s reading image: %s: %s", type(error).__name__, latest_image.image_path, error)
+            logger.error("%s reading image: %s: %s", type(error).__name__, selected_image.image_path, error)
+            self.view.remove_image()
             return
 
         self.view.show_most_recent_image(image_data)
-        self.view.label_active_filename.setText(latest_image.image_name)

mantidimaging/gui/windows/live_viewer/view.py

@@ -36,6 +36,8 @@ def __init__(self, main_window: 'MainWindowView', live_dir_path: Path) -> None:
         # reposition to the right of the main window to be visible when launched from cli
         self.move(self.main_window.x() + self.main_window.width(), self.main_window.y())
 
+        self.live_viewer.z_slider.valueChanged.connect(self.presenter.select_image)
+
     def show_most_recent_image(self, image: np.ndarray) -> None:
         """
         Show the most recently modified image in the image view.
@@ -50,3 +52,6 @@ def watch_directory(self) -> None:
     def remove_image(self) -> None:
         """Remove the image from the view."""
         self.live_viewer.handle_deleted()
+
+    def set_image_index(self, index: int) -> None:
+        self.live_viewer.z_slider.set_value(index)

mantidimaging/gui/windows/operations/filter_previews.py

@@ -3,19 +3,16 @@
 from __future__ import annotations
 
 from logging import getLogger
-from typing import TYPE_CHECKING
 
 import numpy as np
-from PyQt5.QtCore import Qt, QPoint, QRect, pyqtSignal
+from PyQt5.QtCore import QPoint, QRect
 from PyQt5.QtGui import QGuiApplication, QResizeEvent
-from pyqtgraph import ColorMap, GraphicsLayoutWidget, ImageItem, LegendItem, PlotItem, InfiniteLine
+from pyqtgraph import ColorMap, GraphicsLayoutWidget, ImageItem, LegendItem, PlotItem
 from pyqtgraph.graphicsItems.GraphicsLayout import GraphicsLayout
 
 from mantidimaging.core.utility.histogram import set_histogram_log_scale
 from mantidimaging.gui.widgets.mi_mini_image_view.view import MIMiniImageView
-
-if TYPE_CHECKING:
-    from PyQt5.QtWidgets import QGraphicsSceneMouseEvent
+from mantidimaging.gui.widgets.zslider.zslider import ZSlider
 
 LOG = getLogger(__name__)
 
@@ -32,42 +29,6 @@ def _data_valid_for_histogram(data) -> bool:
     return data is not None and any(d is not None for d in data)
 
 
-class ZSlider(PlotItem):
-    z_line: InfiniteLine
-    valueChanged = pyqtSignal(int)
-
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.setFixedHeight(40)
-        self.hideAxis("left")
-        self.setXRange(0, 1)
-        self.setMouseEnabled(x=False, y=False)
-        self.hideButtons()
-
-        self.z_line = InfiniteLine(0, movable=True)
-        self.z_line.setPen((255, 255, 0, 200))
-        self.addItem(self.z_line)
-
-        self.z_line.sigPositionChanged.connect(self.value_changed)
-
-    def set_range(self, min: int, max: int):
-        self.z_line.setValue(min)
-        self.setXRange(min, max)
-        self.z_line.setBounds([min, max])
-
-    def set_value(self, value: int):
-        self.z_line.setValue(value)
-
-    def value_changed(self):
-        self.valueChanged.emit(int(self.z_line.value()))
-
-    def mousePressEvent(self, ev: 'QGraphicsSceneMouseEvent'):
-        if ev.button() == Qt.MouseButton.LeftButton:
-            x = round(self.vb.mapSceneToView(ev.scenePos()).x())
-            self.set_value(x)
-        super().mousePressEvent(ev)
-
-
 class FilterPreviews(GraphicsLayoutWidget):
     histogram: PlotItem
     z_slider: ZSlider