def _get_widgets(self, idx):
        prior_idx = self._get_prior_idx(self.params[idx])
        ptype = self.rundata.get("PSP_byname%i_type" % prior_idx, "N")
        image = self.rundata.get("PSP_byname%i_image" % prior_idx, "")
        mean = self.rundata.get("PSP_byname%i_mean" % prior_idx, "")
        prec = self.rundata.get("PSP_byname%i_prec" % prior_idx, "")
        trans = self.rundata.get("PSP_byname%i_transform" % prior_idx, "")

        type_combo = QtGui.QComboBox()
        type_combo.addItem("Normal", "N")
        type_combo.addItem("Image Prior", "I")
        type_combo.addItem("Spatial prior, type M", "M")
        type_combo.addItem("Spatial prior , type P", "P")
        type_combo.addItem("Spatial prior, type m", "m")
        type_combo.addItem("Spatial prior , type p", "p")
        type_combo.addItem("ARD prior", "A")
        type_combo.setSizeAdjustPolicy(QtGui.QComboBox.AdjustToContents)
        type_combo.setCurrentIndex(type_combo.findData(ptype))
        type_combo.currentIndexChanged.connect(self._changed)

        image_combo = OverlayCombo(self.ivm, static_only=True)
        image_combo.setSizeAdjustPolicy(QtGui.QComboBox.AdjustToContents)
        if image != "":
            image_combo.setCurrentIndex(image_combo.findText(image))
        image_combo.currentIndexChanged.connect(self._changed)

        mean_cb = QtGui.QCheckBox()
        mean_cb.setChecked(ptype != "I" and mean != "")
        mean_cb.stateChanged.connect(self._changed)

        mean_edit = QtGui.QLineEdit(mean)
        mean_edit.editingFinished.connect(self._changed)

        prec_cb = QtGui.QCheckBox()
        prec_cb.setChecked(prec != "")
        prec_cb.stateChanged.connect(self._changed)

        prec_edit = QtGui.QLineEdit(prec)
        prec_edit.editingFinished.connect(self._changed)

        trans_combo = QtGui.QComboBox()
        trans_combo.addItem("Default transformation", "")
        trans_combo.addItem("No transformation", "I")
        trans_combo.addItem("Log transformation", "L")
        trans_combo.addItem("Soft-plus transformation", "S")
        trans_combo.addItem("Fractional transformation", "F")
        trans_combo.setSizeAdjustPolicy(QtGui.QComboBox.AdjustToContents)
        trans_combo.setCurrentIndex(trans_combo.findData(trans))
        trans_combo.currentIndexChanged.connect(self._changed)

        return (type_combo, QtGui.QLabel("Image: "), image_combo, mean_cb,
                QtGui.QLabel("Custom mean: "), mean_edit, prec_cb,
                QtGui.QLabel("Custom precision: "), prec_edit, trans_combo)
class ImageOptionWidget(OptionWidget):
    """
    OptionWidget subclass which allows image options to be chosen
    from the current list of overlays
    """
    def __init__(self, opt, **kwargs):
        OptionWidget.__init__(self, opt, **kwargs)
        self.combo = OverlayCombo(self.ivm, static_only=True)
        self.widgets.append(self.combo)

    def get_value(self):
        return self.combo.currentText()

    def set_value(self, value):
        idx = self.combo.findText(value)
        self.combo.setCurrentIndex(idx)

    def add(self, grid, row):
        OptionWidget.add(self, grid, row)
        grid.addWidget(self.combo, row, 1)
Exemple #3
0
class AslImageWidget(QtGui.QWidget, LogSource):
    """
    QWidget which allows an ASL data set to be described

    This is intended to be embedded into a QpWidget which supports processing of ASL data
    """

    # Signal emitted when the data or metadata is changed
    sig_changed = QtCore.Signal()

    def __init__(self, ivm, parent=None, **kwargs):
        LogSource.__init__(self)
        QtGui.QWidget.__init__(self, parent)
        self.ivm = ivm
        self.data = None
        self.default_md = kwargs.get("default_metadata", DEFAULT_METADATA)
        self.md = dict(self.default_md)
        self.aslimage = None
        self.valid = True

        vbox = QtGui.QVBoxLayout()
        self.setLayout(vbox)

        grid = QtGui.QGridLayout()

        grid.addWidget(QtGui.QLabel("ASL data"), 0, 0)
        self.data_combo = OverlayCombo(self.ivm)
        self.data_combo.currentIndexChanged.connect(self._data_changed)
        grid.addWidget(self.data_combo, 0, 1)

        view_classes = [
            LabelType, RepeatsChoice, NumPhases, NumEncodings, BlockFormat,
            DataStructure, SignalView, Labelling, Readout, SliceTime,
            Multiband, Times, BolusDurations, VariableRepeats
        ]

        self.views = []
        for idx, view_class in enumerate(view_classes):
            if view_class in kwargs.get("ignore_views", ()):
                continue
            view = view_class(grid, ypos=idx + 2)
            view.ivm = self.ivm
            view.sig_md_changed.connect(self._metadata_changed)
            self.views.append(view)

        #grid.addWidget(QtGui.QLabel("Data order preview"), 5, 0)

        # Code below is for specific multiple phases
        #self.phases_lbl = QtGui.QLabel("Phases (\N{DEGREE SIGN})")
        #grid.addWidget(self.phases_lbl, 3, 0)
        #self.phases_lbl.setVisible(False)
        #self.phases = NumberList([float(x)*360/8 for x in range(8)])
        #grid.addWidget(self.phases, 3, 1)
        #self.phases.setVisible(False)

        grid.setColumnStretch(0, 0)
        grid.setColumnStretch(1, 1)
        grid.setColumnStretch(2, 0)
        grid.setRowStretch(len(view_classes) + 2, 1)

        self.grid = grid
        vbox.addLayout(grid)

        self.warn_label = WarningBox()
        vbox.addWidget(self.warn_label)

        self._update_ui()
        self._data_changed()

    def set_data_name(self, name):
        """ Set the name of the data item being displayed """
        if name not in self.ivm.data:
            raise QpException("Data not found: %s" % name)
        else:
            idx = self.data_combo.findText(name)
            self.data_combo.setCurrentIndex(idx)

    def _data_changed(self):
        """
        New data selected - load any previously defined metadata, and validate it 
        """
        self.data = self.ivm.data.get(self.data_combo.currentText(), None)
        for idx in range(self.grid.count()):
            if idx > 1:
                w = self.grid.itemAt(idx).widget()
                if w is not None:
                    w.setEnabled(self.data is not None)

        if self.data is not None:
            self.md = self.data.metadata.get("AslData", None)
            if self.md is None:
                self.md = dict(self.default_md)
                if self.data.nvols % 2 == 0:
                    # Even number of volumes - guess TC pairs
                    # FIXME don't need block format for single TI
                    self.md["iaf"] = "tc"
                    self.md["ibf"] = "tis"
            for view in self.views:
                view.set_data(self.data, self.md)
            self._validate_metadata()
            self.sig_changed.emit()

    def _metadata_changed(self, sender):
        """
        Called when a view has changed the metadata
        """
        self.debug("Metadata changed %s", sender)
        if self.data is not None:
            self.debug("Current metadata: %s", self.md)
        self.debug("New metadata: %s", sender.md)
        self.md = sender.md
        self._validate_metadata()
        self._save_metadata()
        self.sig_changed.emit()

    def _save_metadata(self):
        """
        Set the metadata on the dataset
        """
        if self.data is not None:
            current_md = self.data.metadata.get("AslData", {})
            self.debug("Save: Current metadata: %s", current_md)
            if self.md != current_md:
                self.debug("Different!")
                self.data.metadata["AslData"] = dict(self.md)
                self.debug("Saved: %s ", self.md)
                self._update_ui()

    def _update_ui(self, ignore=()):
        """ 
        Update user interface from the current metadata 
        """
        try:
            for view in self.views:
                if view not in ignore:
                    view.set_data(self.data, self.md)
        finally:
            self.updating_ui = False

    def _validate_metadata(self):
        """
        Validate data against specified TIs, etc
        """
        try:
            if self.md and self.data is not None:
                self.debug("Validating metadata: %s", str(self.md))
                self.aslimage, _ = qpdata_to_aslimage(self.data,
                                                      metadata=self.md)
            self.warn_label.clear()
            self.valid = True
        except ValueError as e:
            self.debug("Failed: %s", str(e))
            self.aslimage = None
            self.warn_label.warn(str(e))
            self.valid = False

    def get_options(self):
        """ Get batch options """
        options = {}
        if self.data is not None:
            options["data"] = self.data.name
            options.update(self.md)
        return options
Exemple #4
0
class ClusteringWidget(QpWidget):
    """
    Widget for doing K-means clustering on 3D or 4D data
    """
    def __init__(self, **kwargs):
        super(ClusteringWidget,
              self).__init__(name="KMeans Clustering",
                             icon="clustering",
                             desc="Generate clusters from 3D or 4D data",
                             group="Clustering",
                             position=2,
                             **kwargs)
        self.curves = {}

    def init_ui(self):
        self.process = KMeansProcess(self.ivm)
        layout = QtGui.QVBoxLayout()
        self.setLayout(layout)

        title = TitleWidget(self, help="cluster")
        layout.addWidget(title)

        DESC = """
<i>Performs clustering of 3D or 4D data using the K-means algorithm.
PCA reduction is used on 4D data to extract representative curves
"""
        desc = QtGui.QLabel(DESC)
        desc.setWordWrap(True)
        layout.addWidget(desc)

        gbox = QtGui.QGroupBox()
        gbox.setTitle('Clustering options')

        grid = QtGui.QGridLayout()
        gbox.setLayout(grid)

        # Data to cluster
        grid.addWidget(QtGui.QLabel("Data"), 0, 0)
        self.data_combo = OverlayCombo(self.ivm)
        self.data_combo.currentIndexChanged.connect(self._data_changed)
        grid.addWidget(self.data_combo, 0, 1)

        grid.addWidget(QtGui.QLabel("ROI"), 1, 0)
        self.roi_combo = RoiCombo(self.ivm, none_option=True)
        grid.addWidget(self.roi_combo, 1, 1)

        # Number of clusters inside the ROI
        self.n_clusters = NumericOption("Number of clusters",
                                        grid,
                                        xpos=2,
                                        ypos=0,
                                        minval=2,
                                        maxval=20,
                                        default=4,
                                        intonly=True)
        self.n_clusters.spin.setToolTip("")

        # Number of PCA modes
        self.n_pca = NumericOption("Number of PCA modes",
                                   grid,
                                   xpos=2,
                                   ypos=1,
                                   minval=1,
                                   maxval=10,
                                   default=3,
                                   intonly=True)
        self.n_pca.spin.setToolTip("")

        # Output ROI name
        grid.addWidget(QtGui.QLabel("Output name"), 2, 0)
        self.output_name = QtGui.QLineEdit("clusters")
        grid.addWidget(self.output_name, 2, 1)
        layout.addWidget(gbox)

        # Run clustering button
        hbox = QtGui.QHBoxLayout()
        self.run_btn = QtGui.QPushButton('Run', self)
        self.run_btn.clicked.connect(self.run_clustering)
        hbox.addWidget(self.run_btn)
        hbox.addStretch(1)
        layout.addLayout(hbox)

        # Plot window, showing representative curves for 4D data
        self.show_curves_btn = QtGui.QPushButton('Show representative curves',
                                                 self)
        self.show_curves_btn.clicked.connect(self._show_curves)
        layout.addWidget(self.show_curves_btn)
        self.plotwin = pg.GraphicsLayoutWidget()
        self.plotwin.setBackground(background=None)
        self.plot = self.plotwin.addPlot(title="Cluster representative curves")
        self.plot.setLabel('left', "Signal Enhancement")
        self.plotwin.setVisible(False)
        layout.addWidget(self.plotwin)

        # Statistics
        self.show_count_btn = QtGui.QPushButton('Show voxel counts', self)
        self.show_count_btn.clicked.connect(self._show_counts)
        layout.addWidget(self.show_count_btn)
        self.stats_gbox = QtGui.QGroupBox()
        self.stats_gbox.setTitle('Voxel count')

        self.count_table = QtGui.QStandardItemModel()
        self.count_view = QtGui.QTableView()
        self.count_view.resizeColumnsToContents()
        self.count_view.setModel(self.count_table)

        hbox = QtGui.QHBoxLayout()
        hbox.addWidget(self.count_view)
        self.stats_gbox.setLayout(hbox)
        self.stats_gbox.setVisible(False)
        layout.addWidget(self.stats_gbox)

        # Merge regions
        self.show_merge_btn = QtGui.QPushButton('Show merge options', self)
        self.show_merge_btn.clicked.connect(self._show_merge)
        layout.addWidget(self.show_merge_btn)

        self.merge_gbox = QtGui.QGroupBox()
        self.merge_gbox.setTitle('Merge regions')
        vbox = QtGui.QVBoxLayout()
        self.merge_gbox.setLayout(vbox)

        hbox = QtGui.QHBoxLayout()
        self.merge_btn = QtGui.QPushButton('Merge', self)
        self.merge_btn.clicked.connect(self._run_merge)
        hbox.addWidget(self.merge_btn)
        hbox.addWidget(QtGui.QLabel('Merge region '))
        self.merge_region1 = QtGui.QLineEdit('1', self)
        hbox.addWidget(self.merge_region1)
        hbox.addWidget(QtGui.QLabel(' with '))
        self.merge_region2 = QtGui.QLineEdit('2', self)
        hbox.addWidget(self.merge_region2)
        vbox.addLayout(hbox)

        hbox = QtGui.QHBoxLayout()
        self.auto_merge_btn = QtGui.QPushButton('AutoMerge', self)
        self.auto_merge_btn.clicked.connect(self._run_automerge)
        hbox.addWidget(self.auto_merge_btn)
        hbox.addStretch(1)
        vbox.addLayout(hbox)

        self.merge_gbox.setVisible(False)
        layout.addWidget(self.merge_gbox)

        layout.addStretch(1)

    def activate(self):
        self.ivl.sig_focus_changed.connect(self._focus_changed)
        self.ivm.sig_current_roi.connect(self._current_roi_changed)
        self.ivm.sig_main_data.connect(self._main_data_changed)
        self._data_changed()

    def deactivate(self):
        self.ivl.sig_focus_changed.disconnect(self._focus_changed)
        self.ivm.sig_current_roi.disconnect(self._current_roi_changed)
        self.ivm.sig_main_data.disconnect(self._main_data_changed)

    def _current_roi_changed(self, roi):
        if roi is not None and roi.name != self.output_name.text():
            self.roi_combo.setCurrentIndex(self.roi_combo.findText(roi.name))

    def _main_data_changed(self, data):
        if data is not None:
            idx = self.data_combo.findText(data.name)
        else:
            idx = 0
        self.data_combo.setCurrentIndex(idx)

    def _data_changed(self):
        data = self.ivm.data.get(self.data_combo.currentText(), None)
        if data is not None:
            is4d = data.nvols > 1
            self.debug("Number of vols: %i, 4d=%s", data.nvols, is4d)
            self.n_pca.label.setVisible(is4d)
            self.n_pca.spin.setVisible(is4d)
            self.show_curves_btn.setVisible(is4d)
            self.plotwin.setVisible(is4d and self.plotwin.isVisible())
            self.auto_merge_btn.setEnabled(is4d)
        self.run_btn.setEnabled(data is not None)

    def _focus_changed(self):
        self._update_voxel_count()

    def _show_curves(self):
        if self.plotwin.isVisible():
            self.plotwin.setVisible(False)
            self.show_curves_btn.setText("Show representative curves")
        else:
            self.plotwin.setVisible(True)
            self.show_curves_btn.setText("Hide representative curves")

    def _show_counts(self):
        if self.stats_gbox.isVisible():
            self.stats_gbox.setVisible(False)
            self.show_count_btn.setText("Show voxel counts")
        else:
            self.stats_gbox.setVisible(True)
            self.show_count_btn.setText("Hide voxel counts")

    def _show_merge(self):
        if self.merge_gbox.isVisible():
            self.merge_gbox.setVisible(False)
            self.show_merge_btn.setText("Show merge_options")
        else:
            self.merge_gbox.setVisible(True)
            self.show_merge_btn.setText("Hide merge options")

    def batch_options(self):
        options = {
            "data": self.data_combo.currentText(),
            "roi": self.roi_combo.currentText(),
            "n-clusters": self.n_clusters.spin.value(),
            "output-name": self.output_name.text(),
            "invert-roi": False,
        }

        if options["roi"] == "<none>":
            del options["roi"]

        if self.n_pca.label.isVisible():
            # 4D PCA options
            options["n-pca"] = self.n_pca.spin.value()
            options["reduction"] = "pca"
            options["norm-data"] = True

        return "KMeans", options

    def run_clustering(self):
        """
        Run kmeans clustering using normalised PCA modes
        """
        options = self.batch_options()[1]

        self.process.run(options)
        self._update_voxel_count()
        if self.n_pca.label.isVisible():
            self.update_plot()

    def _update_voxel_count(self):
        self.count_table.clear()
        self.count_table.setVerticalHeaderItem(
            0, QtGui.QStandardItem("Voxel count"))

        roi = self.ivm.rois.get(self.output_name.text(), None)
        if roi is not None:
            col_idx = 0
            for region, name in roi.regions.items():
                self.count_table.setHorizontalHeaderItem(
                    col_idx, QtGui.QStandardItem(name))

                # Volume count
                voxel_count = np.sum(roi.raw() == region)
                self.count_table.setItem(
                    0, col_idx,
                    QtGui.QStandardItem(str(np.around(voxel_count))))
                col_idx += 1

    def update_plot(self):
        """
        Plot the cluster curves
        :return:
        """
        # Clear graph
        self.plot.clear()
        self.plot.setLabel('bottom', "Volume", "")
        if self.plot.legend is not None:
            # Work around pyqtgraph legend bug - the legend is recreated multiple times!
            # https://stackoverflow.com/questions/42792858/pyqtgraph-delete-persisting-legend-in-pyqt4-gui
            self.plot.legend.scene().removeItem(self.plot.legend)
        data = self.ivm.data.get(self.data_combo.currentText(), None)
        roi = self.ivm.rois.get(self.output_name.text(), None)
        if roi is not None and data is not None and data.nvols > 1:
            # Generate mean curve for each cluster
            self._generate_cluster_means(roi, data)

            self.plot.addLegend()

            # Plotting using single or multiple plots
            for region, name in roi.regions.items():
                if np.sum(self.curves[region]) == 0:
                    continue

                pencol = get_pencol(roi, region)
                curve = self.plot.plot(pen=pencol, width=8.0, name=name)
                xx = np.arange(len(self.curves[region]))
                curve.setData(xx, self.curves[region])

    def _run_merge(self):
        m1 = int(self.merge_region1.text())
        m2 = int(self.merge_region2.text())
        self._merge(m1, m2)

    def _run_automerge(self):
        # Use PCA features or true curves?
        # Mean features from each cluster
        # Distance matrix between features
        if len(self.curves) < 2: return

        curvemat = np.zeros((len(self.curves), self.ivm.main.nvols))
        row_region = {}
        idx = 0
        for region, curve in self.curves.items():
            row_region[idx] = region
            curvemat[idx, :] = curve
            idx += 1
        distmat = pairwise.euclidean_distances(curvemat)
        distmat[distmat == 0] = np.inf
        loc1 = np.where(distmat == distmat.min())[0]
        self._merge(row_region[loc1[0]], row_region[loc1[1]])

    def _generate_cluster_means(self, roi, data):
        """
        Generate the mean curves for each cluster
        Returns:
        """
        self.curves = {}
        for region in roi.regions:
            roi_data = data.mask(roi, region=region, output_flat=True)
            mean = np.median(roi_data, axis=0)
            self.curves[region] = mean

    def _merge(self, m1, m2):
        roi = self.ivm.rois.get(self.output_name.text(), None)
        if roi is not None:
            roi_data = roi.raw()
            roi_data[roi_data == m1] = m2

            # signal the change
            self.ivm.add(NumpyData(roi_data,
                                   grid=roi.grid,
                                   name=self.output_name.text(),
                                   roi=True),
                         make_current=True)

            # replot
            self.update_plot()
            self._update_voxel_count()
Exemple #5
0
class OverlayViewWidget(QtGui.QGroupBox):
    """ Change view options for ROI """
    def __init__(self, ivl, view):
        QtGui.QGroupBox.__init__(self)
        self.ivl = ivl
        self.ivm = ivl.ivm
        self.view = view

        grid = QtGui.QGridLayout()
        grid.setVerticalSpacing(2)
        grid.setContentsMargins(5, 5, 5, 5)
        self.setLayout(grid)

        grid.addWidget(QtGui.QLabel("Overlay"), 0, 0)
        self.overlay_combo = OverlayCombo(self.ivm,
                                          none_option=True,
                                          set_first=False)
        grid.addWidget(self.overlay_combo, 0, 1)
        grid.addWidget(QtGui.QLabel("View"), 1, 0)
        self.ov_view_combo = QtGui.QComboBox()
        self.ov_view_combo.addItem("All")
        self.ov_view_combo.addItem("Only in ROI")
        self.ov_view_combo.addItem("None")
        grid.addWidget(self.ov_view_combo, 1, 1)
        grid.addWidget(QtGui.QLabel("Color map"), 2, 0)
        hbox = QtGui.QHBoxLayout()
        self.ov_cmap_combo = QtGui.QComboBox()
        self.ov_cmap_combo.addItem("jet")
        self.ov_cmap_combo.addItem("hot")
        self.ov_cmap_combo.addItem("gist_heat")
        self.ov_cmap_combo.addItem("flame")
        self.ov_cmap_combo.addItem("bipolar")
        self.ov_cmap_combo.addItem("spectrum")
        hbox.addWidget(self.ov_cmap_combo)
        self.ov_levels_btn = QtGui.QPushButton()
        self.ov_levels_btn.setIcon(QtGui.QIcon(get_icon("levels.png")))
        self.ov_levels_btn.setFixedSize(16, 16)
        self.ov_levels_btn.setToolTip("Adjust colour map levels")
        self.ov_levels_btn.clicked.connect(self._show_ov_levels)
        self.ov_levels_btn.setEnabled(False)
        hbox.addWidget(self.ov_levels_btn)
        grid.addLayout(hbox, 2, 1)
        grid.addWidget(QtGui.QLabel("Alpha"), 3, 0)
        self.ov_alpha_sld = QtGui.QSlider(QtCore.Qt.Horizontal, self)
        self.ov_alpha_sld.setFocusPolicy(QtCore.Qt.NoFocus)
        self.ov_alpha_sld.setRange(0, 255)
        self.ov_alpha_sld.setValue(255)
        grid.addWidget(self.ov_alpha_sld, 3, 1)
        grid.setRowStretch(4, 1)

        self.overlay_combo.currentIndexChanged.connect(self._combo_changed)
        self.ov_view_combo.currentIndexChanged.connect(self._view_changed)
        self.ov_cmap_combo.currentIndexChanged.connect(self._cmap_changed)
        self.ov_alpha_sld.valueChanged.connect(self._alpha_changed)
        self.view.sig_view_changed.connect(self._update)

    def _update(self, view):
        widgets = [
            self.ov_view_combo, self.ov_cmap_combo, self.ov_alpha_sld,
            self.overlay_combo
        ]
        try:
            for widget in widgets:
                widget.blockSignals(True)

            if not view.get("visible"):
                self.ov_view_combo.setCurrentIndex(2)
            elif view.get("roi_only"):
                self.ov_view_combo.setCurrentIndex(1)
            else:
                self.ov_view_combo.setCurrentIndex(0)

            # 'Custom' only appears as a flag to indicate the user has messed with the
            # LUT using the histogram widget. Otherwise is is hidden
            cmap = view.get("cmap")
            if cmap == "custom":
                idx = self.ov_cmap_combo.findText("custom")
                if idx >= 0:
                    self.ov_cmap_combo.setCurrentIndex(idx)
                else:
                    self.ov_cmap_combo.addItem("custom")
                    idx = self.ov_cmap_combo.findText("custom")
                    self.ov_cmap_combo.setCurrentIndex(idx)
            else:
                idx = self.ov_cmap_combo.findText("custom")
                if idx >= 0:
                    self.ov_cmap_combo.removeItem(idx)
                idx = self.ov_cmap_combo.findText(view.get("cmap"))
                self.ov_cmap_combo.setCurrentIndex(idx)

            self.ov_alpha_sld.setValue(view.get("alpha"))

            self.ov_levels_btn.setEnabled(view.data is not None)
            if view.data is not None:
                idx = self.overlay_combo.findText(view.data.name)
                self.overlay_combo.setCurrentIndex(idx)
            else:
                self.overlay_combo.setCurrentIndex(-1)
        except:
            import traceback
            traceback.print_exc()
        finally:
            for widget in widgets:
                widget.blockSignals(False)

    def _combo_changed(self, idx):
        if idx > 0:
            data_name = self.overlay_combo.itemText(idx)
            self.ivm.set_current_data(data_name)
        else:
            self.ivl.ivm.set_current_data(None)

    def _cmap_changed(self, idx):
        cmap = self.ov_cmap_combo.itemText(idx)
        self.view.set("cmap", cmap)

    def _view_changed(self, idx):
        """ Viewing style (all or within ROI only) changed """
        self.view.set("visible", idx in (0, 1))
        self.view.set("roi_only", (idx == 1))

    def _alpha_changed(self, alpha):
        """ Set the data transparency """
        self.view.set("alpha", alpha)

    def _show_ov_levels(self):
        dlg = LevelsDialog(self, self.ivl, self.ivm, self.view)
        dlg.exec_()