Add transform mode button for layers (napari#6794)

# References and relevant issues

Part of napari#3975

# Description

Add a button to activate the layers transform mode. Also, add a way to
reset the transform to the initial value set at layer creation (reset
trigger via Alt + Left mouse click over the transform mode button):

A preview:


![transform_mode_button](https://github.com/napari/napari/assets/16781833/6b19c949-4ce9-425b-bb89-a1b42b99bb8e)

# Notes/TODOs:

* [x] Icon selection/definition needs to be done (in progress)
* Possible icon design at
napari#3975 (comment)
* Selected icon at
napari#3975 (comment)
* [x] Implemented the Alt-click approach to trigger a reset with a
confirmation dialog but happy to check any other alternatives/ideas

---------

Co-authored-by: Isabela Presedo-Floyd <[email protected]>
Co-authored-by: Peter Sobolewski <[email protected]>
Co-authored-by: Draga Doncila Pop <[email protected]>

napari/_qt/layer_controls/_tests/test_qt_layer_controls.py

@@ -2,6 +2,7 @@
 import random
 import sys
 from typing import NamedTuple, Optional
+from unittest.mock import Mock
 
 import numpy as np
 import pytest
@@ -13,6 +14,7 @@
     QAbstractSpinBox,
     QCheckBox,
     QComboBox,
+    QMessageBox,
     QPushButton,
     QRadioButton,
 )
@@ -42,6 +44,7 @@
     Vectors,
 )
 from napari.utils.colormaps import DirectLabelColormap
+from napari.utils.events.event import Event
 
 
 class LayerTypeWithData(NamedTuple):
@@ -455,6 +458,130 @@ def test_create_layer_controls_qcolorswatchedit(
             assert not captured.err
 
 
+@pytest.mark.parametrize(
+    (
+        'layer_type_with_data',
+        'action_manager_trigger',
+    ),
+    [
+        (
+            _LABELS_WITH_DIRECT_COLORMAP,
+            'napari:activate_labels_transform_mode',
+        ),
+        (
+            _LABELS,
+            'napari:activate_labels_transform_mode',
+        ),
+        (
+            _IMAGE,
+            'napari:activate_image_transform_mode',
+        ),
+        (
+            _POINTS,
+            'napari:activate_points_transform_mode',
+        ),
+        (
+            _SHAPES,
+            'napari:activate_shapes_transform_mode',
+        ),
+        (
+            _SURFACE,
+            'napari:activate_surface_transform_mode',
+        ),
+        (
+            _TRACKS,
+            'napari:activate_tracks_transform_mode',
+        ),
+        (
+            _VECTORS,
+            'napari:activate_vectors_transform_mode',
+        ),
+    ],
+)
+def test_create_layer_controls_transform_mode_button(
+    qtbot,
+    create_layer_controls,
+    layer_type_with_data,
+    action_manager_trigger,
+    monkeypatch,
+):
+    action_manager_mock = Mock(trigger=Mock())
+
+    # Monkeypatch the action_manager instance to prevent `KeyError: 'layer'`
+    # over `napari.layers.utils.layer_utils.register_layer_attr_action._handle._wrapper`
+    monkeypatch.setattr(
+        'napari._qt.layer_controls.qt_layer_controls_base.action_manager',
+        action_manager_mock,
+    )
+
+    # create layer controls widget
+    ctrl = create_layer_controls(layer_type_with_data)
+
+    # check create widget corresponds to the expected class for each type of layer
+    assert isinstance(ctrl, layer_type_with_data.expected_isinstance)
+
+    # check transform mode button existence
+    assert ctrl.transform_button
+
+    # check layer mode change
+    assert ctrl.layer.mode == 'pan_zoom'
+    ctrl.transform_button.click()
+    assert ctrl.layer.mode == 'transform'
+
+    # check reset transform behavior
+    ctrl.layer.affine = None
+    assert ctrl.layer.affine != ctrl.layer._initial_affine
+
+    def reset_transform_warning_dialog(*args):
+        return QMessageBox.Yes
+
+    monkeypatch.setattr(
+        'qtpy.QtWidgets.QMessageBox.warning', reset_transform_warning_dialog
+    )
+    qtbot.mouseClick(
+        ctrl.transform_button,
+        Qt.LeftButton,
+        Qt.KeyboardModifier.AltModifier,
+    )
+    assert ctrl.layer.affine == ctrl.layer._initial_affine
+
+
+@pytest.mark.parametrize(
+    'layer_type_with_data',
+    [
+        _LABELS_WITH_DIRECT_COLORMAP,
+        _LABELS,
+        _IMAGE,
+        _POINTS,
+        _SHAPES,
+        _SURFACE,
+        _TRACKS,
+        _VECTORS,
+    ],
+)
+def test_layer_controls_invalid_mode(
+    qtbot,
+    create_layer_controls,
+    layer_type_with_data,
+):
+    # create layer controls widget
+    ctrl = create_layer_controls(layer_type_with_data)
+
+    # check create widget corresponds to the expected class for each type of layer
+    assert isinstance(ctrl, layer_type_with_data.expected_isinstance)
+
+    # check layer mode and corresponding mode button
+    assert ctrl.layer.mode == 'pan_zoom'
+    assert ctrl.panzoom_button.isChecked()
+
+    # check setting invalid mode
+    with pytest.raises(ValueError, match='not recognized'):
+        ctrl._on_mode_change(Event('mode', mode='invalid_mode'))
+
+    # check panzoom_button is still checked
+    assert ctrl.panzoom_button.isChecked()
+
+
 def test_unknown_raises(qtbot):
     class Test:
         """Unmatched class"""
@@ -550,17 +677,124 @@ def test_set_3d_display_with_shapes(qtbot):
     assert not layer.editable
 
 
+def test_set_3d_display_with_labels(qtbot):
+    """Some modes only work for labels layers rendered in 2D and not
+    in 3D. Verify that the related mode buttons are disabled upon switching to
+    3D rendering mode while the layer is still editable.
+    """
+    viewer = ViewerModel()
+    container = QtLayerControlsContainer(viewer)
+    qtbot.addWidget(container)
+    layer = viewer.add_labels(np.zeros((3, 4), dtype=int))
+    assert viewer.dims.ndisplay == 2
+    assert container.currentWidget().polygon_button.isEnabled()
+    assert container.currentWidget().transform_button.isEnabled()
+    assert layer.editable
+
+    viewer.dims.ndisplay = 3
+
+    assert not container.currentWidget().polygon_button.isEnabled()
+    assert not container.currentWidget().transform_button.isEnabled()
+    assert layer.editable
+
+
+@pytest.mark.parametrize(
+    'add_layer_with_data',
+    [
+        ('add_labels', np.zeros((3, 4), dtype=int)),
+        ('add_points', np.empty((0, 2))),
+        ('add_shapes', np.empty((0, 2, 4))),
+        ('add_image', np.random.rand(8, 8)),
+        (
+            'add_surface',
+            (
+                np.random.random((10, 2)),
+                np.random.randint(10, size=(6, 3)),
+                np.random.random(10),
+            ),
+        ),
+        ('add_tracks', np.zeros((2, 4))),
+        ('add_vectors', np.zeros((2, 2, 2))),
+    ],
+)
+def test_set_3d_display_and_layer_visibility(qtbot, add_layer_with_data):
+    """Some modes only work for layers rendered in 2D and not
+    in 3D. Verify that the related mode buttons are disabled upon switching to
+    3D rendering mode and the disable state is kept even when changing layer
+    visibility.
+
+    For the labels layer the specific polygon mode button should be disabled in
+    3D regardless of the layer being visible or not. For all the layers the same
+    applies for the transform mode button.
+    """
+    viewer = ViewerModel()
+    container = QtLayerControlsContainer(viewer)
+    qtbot.addWidget(container)
+    add_layer_method, data = add_layer_with_data
+    layer = getattr(viewer, add_layer_method)(data)
+
+    # 2D mode
+    assert viewer.dims.ndisplay == 2
+    if add_layer_method == 'add_labels':
+        assert container.currentWidget().polygon_button.isEnabled()
+    assert container.currentWidget().transform_button.isEnabled()
+
+    # 2D mode + layer not visible
+    layer.visible = False
+    if add_layer_method == 'add_labels':
+        assert not container.currentWidget().polygon_button.isEnabled()
+    assert not container.currentWidget().transform_button.isEnabled()
+
+    # 2D mode + layer visible
+    layer.visible = True
+    if add_layer_method == 'add_labels':
+        assert container.currentWidget().polygon_button.isEnabled()
+    assert container.currentWidget().transform_button.isEnabled()
+
+    # 3D mode
+    viewer.dims.ndisplay = 3
+    if add_layer_method == 'add_labels':
+        assert not container.currentWidget().polygon_button.isEnabled()
+    assert not container.currentWidget().transform_button.isEnabled()
+
+    # 3D mode + layer not visible
+    layer.visible = False
+    if add_layer_method == 'add_labels':
+        assert not container.currentWidget().polygon_button.isEnabled()
+    assert not container.currentWidget().transform_button.isEnabled()
+
+    # 3D mode + layer visible
+    layer.visible = True
+    if add_layer_method == 'add_labels':
+        assert not container.currentWidget().polygon_button.isEnabled()
+    assert not container.currentWidget().transform_button.isEnabled()
+
+
 # The following tests handle changes to the layer's visible and
 # editable state for layer control types that have controls to edit
 # the layer. For more context see:
 # https://github.com/napari/napari/issues/1346
+# Updated due to the addition of a transform mode button for all the layers,
+# For more context see:
+# https://github.com/napari/napari/pull/6794
 
 
 @pytest.fixture(
     params=(
         (Labels, np.zeros((3, 4), dtype=int)),
         (Points, np.empty((0, 2))),
         (Shapes, np.empty((0, 2, 4))),
+        (Image, np.random.rand(8, 8)),
+        (
+            Surface,
+            (
+                np.random.random((10, 2)),
+                np.random.randint(10, size=(6, 3)),
+                np.random.random(10),
+            ),
+        ),
+        (Tracks, np.zeros((2, 4))),
+        (Vectors, np.zeros((2, 2, 2))),
     )
 )
 def editable_layer(request):

napari/_qt/layer_controls/qt_image_controls.py

@@ -38,6 +38,22 @@ class QtImageControls(QtBaseImageControls):
 
     Attributes
     ----------
+    layer : napari.layers.Image
+        An instance of a napari Image layer.
+    MODE : Enum
+        Available modes in the associated layer.
+    PAN_ZOOM_ACTION_NAME : str
+        String id for the pan-zoom action to bind to the pan_zoom button.
+    TRANSFORM_ACTION_NAME : str
+        String id for the transform action to bind to the transform button.
+    button_group : qtpy.QtWidgets.QButtonGroup
+        Button group for image based layer modes (PAN_ZOOM TRANSFORM).
+    button_grid : qtpy.QtWidgets.QGridLayout
+        GridLayout for the layer mode buttons
+    panzoom_button : napari._qt.widgets.qt_mode_button.QtModeRadioButton
+        Button to pan/zoom shapes layer.
+    transform_button : napari._qt.widgets.qt_mode_button.QtModeRadioButton
+        Button to transform shapes layer.
     attenuationSlider : qtpy.QtWidgets.QSlider
         Slider controlling attenuation rate for `attenuated_mip` mode.
     attenuationLabel : qtpy.QtWidgets.QLabel
@@ -50,15 +66,15 @@ class QtImageControls(QtBaseImageControls):
         Slider controlling the isosurface threshold value for rendering.
     isoThresholdLabel : qtpy.QtWidgets.QLabel
         Label for the isosurface threshold slider widget.
-    layer : napari.layers.Image
-        An instance of a napari Image layer.
     renderComboBox : qtpy.QtWidgets.QComboBox
         Dropdown menu to select the rendering mode for image display.
     renderLabel : qtpy.QtWidgets.QLabel
         Label for the rendering mode dropdown menu.
     """
 
     layer: 'napari.layers.Image'
+    PAN_ZOOM_ACTION_NAME = 'activate_image_pan_zoom_mode'
+    TRANSFORM_ACTION_NAME = 'activate_image_transform_mode'
 
     def __init__(self, layer) -> None:
         super().__init__(layer)
@@ -168,6 +184,7 @@ def __init__(self, layer) -> None:
             colormap_layout.addWidget(self.colormapComboBox)
         colormap_layout.addStretch(1)
 
+        self.layout().addRow(self.button_grid)
         self.layout().addRow(self.opacityLabel, self.opacitySlider)
         self.layout().addRow(
             trans._('contrast limits:'), self.contrastLimitsSlider
@@ -366,6 +383,7 @@ def _on_ndisplay_changed(self):
             self._update_rendering_parameter_visibility()
             self.depictionComboBox.show()
             self.depictionLabel.show()
+        super()._on_ndisplay_changed()
 
 
 class PlaneNormalButtons(QWidget):

napari/_qt/layer_controls/qt_image_controls_base.py

@@ -5,7 +5,12 @@
 import numpy as np
 from qtpy.QtCore import Qt
 from qtpy.QtGui import QImage, QPixmap
-from qtpy.QtWidgets import QHBoxLayout, QLabel, QPushButton, QWidget
+from qtpy.QtWidgets import (
+    QHBoxLayout,
+    QLabel,
+    QPushButton,
+    QWidget,
+)
 from superqt import QDoubleRangeSlider
 
 from napari._qt.layer_controls.qt_colormap_combobox import QtColormapComboBox
@@ -53,6 +58,22 @@ class QtBaseImageControls(QtLayerControls):
 
     Attributes
     ----------
+    layer : napari.layers.Layer
+        An instance of a napari layer.
+    MODE : Enum
+        Available modes in the associated layer.
+    PAN_ZOOM_ACTION_NAME : str
+        String id for the pan-zoom action to bind to the pan_zoom button.
+    TRANSFORM_ACTION_NAME : str
+        String id for the transform action to bind to the transform button.
+    button_group : qtpy.QtWidgets.QButtonGroup
+        Button group for image based layer modes (PAN_ZOOM TRANSFORM).
+    button_grid : qtpy.QtWidgets.QGridLayout
+        GridLayout for the layer mode buttons
+    panzoom_button : napari._qt.widgets.qt_mode_button.QtModeRadioButton
+        Button to pan/zoom shapes layer.
+    transform_button : napari._qt.widgets.qt_mode_button.QtModeRadioButton
+        Button to transform shapes layer.
     clim_popup : napari._qt.qt_range_slider_popup.QRangeSliderPopup
         Popup widget launching the contrast range slider.
     colorbarLabel : qtpy.QtWidgets.QLabel
@@ -63,8 +84,6 @@ class QtBaseImageControls(QtLayerControls):
         Contrast range slider widget.
     gammaSlider : qtpy.QtWidgets.QSlider
         Gamma adjustment slider widget.
-    layer : napari.layers.Layer
-        An instance of a napari layer.
 
     """